diff --git a/hbase-client/src/main/java/org/apache/hadoop/hbase/CacheEvictionStats.java b/hbase-client/src/main/java/org/apache/hadoop/hbase/CacheEvictionStats.java index 615b3a467e6e..3012efffcd2b 100644 --- a/hbase-client/src/main/java/org/apache/hadoop/hbase/CacheEvictionStats.java +++ b/hbase-client/src/main/java/org/apache/hadoop/hbase/CacheEvictionStats.java @@ -18,6 +18,7 @@ package org.apache.hadoop.hbase; import java.util.Collections; +import java.util.IdentityHashMap; import java.util.Map; import java.util.stream.Collectors; import org.apache.hadoop.hbase.client.RegionInfo; @@ -28,7 +29,7 @@ public final class CacheEvictionStats { private final long evictedBlocks; private final long maxCacheSize; - private final Map exceptions; + private final IdentityHashMap exceptions; CacheEvictionStats(CacheEvictionStatsBuilder builder) { this.evictedBlocks = builder.evictedBlocks; @@ -44,6 +45,7 @@ public long getMaxCacheSize() { return maxCacheSize; } + @SuppressWarnings("IdentityHashMapUsage") public Map getExceptions() { return Collections.unmodifiableMap(exceptions); } diff --git a/hbase-client/src/main/java/org/apache/hadoop/hbase/CacheEvictionStatsBuilder.java b/hbase-client/src/main/java/org/apache/hadoop/hbase/CacheEvictionStatsBuilder.java index 4b31d98611bc..025a0ff68329 100644 --- a/hbase-client/src/main/java/org/apache/hadoop/hbase/CacheEvictionStatsBuilder.java +++ b/hbase-client/src/main/java/org/apache/hadoop/hbase/CacheEvictionStatsBuilder.java @@ -17,15 +17,15 @@ */ package org.apache.hadoop.hbase; -import java.util.HashMap; -import java.util.Map; +import java.util.IdentityHashMap; import org.apache.yetus.audience.InterfaceAudience; @InterfaceAudience.Private public final class CacheEvictionStatsBuilder { + long evictedBlocks = 0; long maxCacheSize = 0; - Map exceptions = new HashMap<>(); + IdentityHashMap exceptions = new IdentityHashMap<>(); CacheEvictionStatsBuilder() { } @@ -44,6 +44,7 @@ public void addException(byte[] regionName, Throwable ie) { exceptions.put(regionName, ie); } + @SuppressWarnings("IdentityHashMapUsage") public CacheEvictionStatsBuilder append(CacheEvictionStats stats) { this.evictedBlocks += stats.getEvictedBlocks(); this.maxCacheSize += stats.getMaxCacheSize(); @@ -54,4 +55,5 @@ public CacheEvictionStatsBuilder append(CacheEvictionStats stats) { public CacheEvictionStats build() { return new CacheEvictionStats(this); } + } diff --git a/hbase-client/src/main/java/org/apache/hadoop/hbase/CatalogFamilyFormat.java b/hbase-client/src/main/java/org/apache/hadoop/hbase/CatalogFamilyFormat.java index 6ad1a18e83da..e2708b9fc42c 100644 --- a/hbase-client/src/main/java/org/apache/hadoop/hbase/CatalogFamilyFormat.java +++ b/hbase-client/src/main/java/org/apache/hadoop/hbase/CatalogFamilyFormat.java @@ -349,8 +349,8 @@ public static TableState getTableState(Result r) throws IOException { } /** - * @return Deserialized values of <qualifier,regioninfo> pairs taken from column values that - * match the regex 'info:merge.*' in array of cells. + * Return deserialized values of <qualifier,regioninfo> pairs taken from column values that + * match the regex 'info:merge.*' in array of cells. */ @Nullable public static Map getMergeRegionsWithName(Cell[] cells) { @@ -376,8 +376,8 @@ public static Map getMergeRegionsWithName(Cell[] cells) { } /** - * @return Deserialized regioninfo values taken from column values that match the regex - * 'info:merge.*' in array of cells. + * Return deserialized regioninfo values taken from column values that match the regex + * 'info:merge.*' in array of cells. */ @Nullable public static List getMergeRegions(Cell[] cells) { @@ -386,8 +386,8 @@ public static List getMergeRegions(Cell[] cells) { } /** - * @return True if any merge regions present in cells; i.e. the column in - * cell matches the regex 'info:merge.*'. + * Return true if any merge regions present in cells; i.e. the column in + * cell matches the regex 'info:merge.*'. */ public static boolean hasMergeRegions(Cell[] cells) { for (Cell cell : cells) { @@ -399,7 +399,7 @@ public static boolean hasMergeRegions(Cell[] cells) { } /** - * @return True if the column in cell matches the regex 'info:merge.*'. + * Return true if the column in cell matches the regex 'info:merge.*'. */ public static boolean isMergeQualifierPrefix(Cell cell) { // Check to see if has family and that qualifier starts with the merge qualifier 'merge' diff --git a/hbase-client/src/main/java/org/apache/hadoop/hbase/ClientMetaTableAccessor.java b/hbase-client/src/main/java/org/apache/hadoop/hbase/ClientMetaTableAccessor.java index e948048325fe..d02273dac066 100644 --- a/hbase-client/src/main/java/org/apache/hadoop/hbase/ClientMetaTableAccessor.java +++ b/hbase-client/src/main/java/org/apache/hadoop/hbase/ClientMetaTableAccessor.java @@ -59,6 +59,7 @@ private ClientMetaTableAccessor() { } @InterfaceAudience.Private + @SuppressWarnings("ImmutableEnumChecker") public enum QueryType { ALL(HConstants.TABLE_FAMILY, HConstants.CATALOG_FAMILY), REGION(HConstants.CATALOG_FAMILY), @@ -101,8 +102,7 @@ public static CompletableFuture> getTableState(AsyncTable> @@ -127,8 +127,7 @@ public static CompletableFuture> getTableState(AsyncTable> @@ -167,8 +166,8 @@ private static Optional getTableState(Result r) throws IOException { } /** - * Used to get all region locations for the specific table. n * @param tableName table we're - * looking for, can be null for getting all regions + * Used to get all region locations for the specific table we're looking for. Can be null for + * getting all regions. * @return the list of region locations. The return value will be wrapped by a * {@link CompletableFuture}. */ @@ -191,9 +190,8 @@ public static CompletableFuture> getTableHRegionLocations( } /** - * Used to get table regions' info and server. n * @param tableName table we're looking for, can - * be null for getting all regions - * @param excludeOfflinedSplitParents don't return split parents + * Used to get table regions' info and server for the table we're looking for. Can be null for + * getting all regions. * @return the list of regioninfos and server. The return value will be wrapped by a * {@link CompletableFuture}. */ @@ -220,24 +218,12 @@ private static CompletableFuture>> getTableReg return future; } - /** - * Performs a scan of META table for given table. n * @param tableName table withing we scan - * @param type scanned part of meta - * @param visitor Visitor invoked against each row - */ private static CompletableFuture scanMeta(AsyncTable metaTable, TableName tableName, QueryType type, final Visitor visitor) { return scanMeta(metaTable, getTableStartRowForMeta(tableName, type), getTableStopRowForMeta(tableName, type), type, Integer.MAX_VALUE, visitor); } - /** - * Performs a scan of META table for given table. n * @param startRow Where to start the scan - * @param stopRow Where to stop the scan - * @param type scanned part of meta - * @param maxRows maximum rows to return - * @param visitor Visitor invoked against each row - */ private static CompletableFuture scanMeta(AsyncTable metaTable, byte[] startRow, byte[] stopRow, QueryType type, int maxRows, final Visitor visitor) { int rowUpperLimit = maxRows > 0 ? maxRows : Integer.MAX_VALUE; @@ -383,7 +369,7 @@ public boolean visit(Result r) throws IOException { abstract void add(Result r); /** - * @return Collected results; wait till visits complete to collect all possible results + * Return collected results; wait till visits complete to collect all possible results */ List getResults() { return this.results; @@ -468,6 +454,7 @@ private static Optional getRegionLocations(Result r) { } /** + * Determine the start row for scanning META according to query type * @param tableName table we're working with * @return start row for scanning META according to query type */ @@ -493,6 +480,7 @@ public static byte[] getTableStartRowForMeta(TableName tableName, QueryType type } /** + * Determine the stop row for scanning META according to query type * @param tableName table we're working with * @return stop row for scanning META according to query type */ diff --git a/hbase-client/src/main/java/org/apache/hadoop/hbase/ClusterId.java b/hbase-client/src/main/java/org/apache/hadoop/hbase/ClusterId.java index e769e80847f9..e730c044181e 100644 --- a/hbase-client/src/main/java/org/apache/hadoop/hbase/ClusterId.java +++ b/hbase-client/src/main/java/org/apache/hadoop/hbase/ClusterId.java @@ -34,9 +34,7 @@ public class ClusterId { private final String id; - /** - * New ClusterID. Generates a uniqueid. - */ + /** New ClusterID. Generates a unique UUID. */ public ClusterId() { this(UUID.randomUUID().toString()); } @@ -45,16 +43,16 @@ public ClusterId(final String uuid) { this.id = uuid; } - /** - * @return The clusterid serialized using pb w/ pb magic prefix - */ + /** Return the cluster id serialized using pb with the pb magic prefix */ public byte[] toByteArray() { return ProtobufUtil.prependPBMagic(convert().toByteArray()); } /** + * Parse a serialized representation of the cluster id. * @param bytes A pb serialized {@link ClusterId} instance with pb magic prefix - * @return An instance of {@link ClusterId} made from bytes n * @see #toByteArray() + * @return An instance of {@link ClusterId} made from bytes + * @see #toByteArray() */ public static ClusterId parseFrom(final byte[] bytes) throws DeserializationException { if (ProtobufUtil.isPBMagicPrefix(bytes)) { @@ -74,24 +72,17 @@ public static ClusterId parseFrom(final byte[] bytes) throws DeserializationExce } } - /** - * @return A pb instance to represent this instance. - */ + /** Return a pb instance to represent this instance. */ public ClusterIdProtos.ClusterId convert() { ClusterIdProtos.ClusterId.Builder builder = ClusterIdProtos.ClusterId.newBuilder(); return builder.setClusterId(this.id).build(); } - /** - * n * @return A {@link ClusterId} made from the passed in cid - */ + /** Return a {@link ClusterId} made from the passed in cid */ public static ClusterId convert(final ClusterIdProtos.ClusterId cid) { return new ClusterId(cid.getClusterId()); } - /** - * @see java.lang.Object#toString() - */ @Override public String toString() { return this.id; diff --git a/hbase-client/src/main/java/org/apache/hadoop/hbase/ClusterMetrics.java b/hbase-client/src/main/java/org/apache/hadoop/hbase/ClusterMetrics.java index e36010c424ce..82ce0f7d0076 100644 --- a/hbase-client/src/main/java/org/apache/hadoop/hbase/ClusterMetrics.java +++ b/hbase-client/src/main/java/org/apache/hadoop/hbase/ClusterMetrics.java @@ -70,28 +70,28 @@ public interface ClusterMetrics { /** - * @return the HBase version string as reported by the HMaster + * Return the HBase version string as reported by the master. */ @Nullable String getHBaseVersion(); /** - * @return the names of region servers on the dead list + * Return the names of region servers on the dead list. */ List getDeadServerNames(); /** - * @return the names of region servers on the decommissioned list + * Return the names of region servers on the decommissioned list. */ List getDecommissionedServerNames(); /** - * @return the names of region servers on the live list + * Return the names of region servers on the live list. */ Map getLiveServerMetrics(); /** - * @return the number of regions deployed on the cluster + * Return the number of regions deployed on the cluster. */ default int getRegionCount() { return getLiveServerMetrics().entrySet().stream() @@ -99,7 +99,7 @@ default int getRegionCount() { } /** - * @return the number of requests since last report + * Return the number of requests since the last report. */ default long getRequestCount() { return getLiveServerMetrics().entrySet().stream() @@ -115,7 +115,7 @@ default long getRequestCount() { ServerName getMasterName(); /** - * @return the names of backup masters + * Return the names of the backup masters. */ List getBackupMasterNames(); @@ -148,7 +148,7 @@ default long getLastMajorCompactionTimestamp(byte[] regionName) { List getServersName(); /** - * @return the average cluster load + * Return the average cluster load. */ default double getAverageLoad() { int serverSize = getLiveServerMetrics().size(); @@ -159,7 +159,7 @@ default double getAverageLoad() { } /** - * Provide region states count for given table. e.g howmany regions of give table are + * Provide region states count for given table. e.g how many regions of give table are * opened/closed/rit etc * @return map of table to region states count */ diff --git a/hbase-client/src/main/java/org/apache/hadoop/hbase/ClusterMetricsBuilder.java b/hbase-client/src/main/java/org/apache/hadoop/hbase/ClusterMetricsBuilder.java index 5695f5b65ade..7254209487b2 100644 --- a/hbase-client/src/main/java/org/apache/hadoop/hbase/ClusterMetricsBuilder.java +++ b/hbase-client/src/main/java/org/apache/hadoop/hbase/ClusterMetricsBuilder.java @@ -67,13 +67,13 @@ public static ClusterStatusProtos.ClusterStatus toClusterStatus(ClusterMetrics m .collect(Collectors.toList())) .addAllTableRegionStatesCount(metrics.getTableRegionStatesCount().entrySet().stream() .map(status -> ClusterStatusProtos.TableRegionStatesCount.newBuilder() - .setTableName(ProtobufUtil.toProtoTableName((status.getKey()))) + .setTableName(ProtobufUtil.toProtoTableName(status.getKey())) .setRegionStatesCount(ProtobufUtil.toTableRegionStatesCount(status.getValue())).build()) .collect(Collectors.toList())) .addAllDecommissionedServers(metrics.getDecommissionedServerNames().stream() .map(ProtobufUtil::toServerName).collect(Collectors.toList())); if (metrics.getMasterName() != null) { - builder.setMaster(ProtobufUtil.toServerName((metrics.getMasterName()))); + builder.setMaster(ProtobufUtil.toServerName(metrics.getMasterName())); } if (metrics.getMasterTasks() != null) { builder.addAllMasterTasks(metrics.getMasterTasks().stream() diff --git a/hbase-client/src/main/java/org/apache/hadoop/hbase/CoprocessorEnvironment.java b/hbase-client/src/main/java/org/apache/hadoop/hbase/CoprocessorEnvironment.java index edbc5f479d6e..64b40e3caf5d 100644 --- a/hbase-client/src/main/java/org/apache/hadoop/hbase/CoprocessorEnvironment.java +++ b/hbase-client/src/main/java/org/apache/hadoop/hbase/CoprocessorEnvironment.java @@ -28,29 +28,25 @@ @InterfaceStability.Evolving public interface CoprocessorEnvironment { - /** @return the Coprocessor interface version */ + /** Return the coprocessor interface version */ int getVersion(); - /** @return the HBase version as a string (e.g. "0.21.0") */ + /** Return the HBase version as a string (e.g. "0.21.0") */ String getHBaseVersion(); - /** @return the loaded coprocessor instance */ + /** Return the loaded coprocessor instance */ C getInstance(); - /** @return the priority assigned to the loaded coprocessor */ + /** Return the priority assigned to the loaded coprocessor */ int getPriority(); - /** @return the load sequence number */ + /** Return the load sequence number */ int getLoadSequence(); - /** - * @return a Read-only Configuration; throws {@link UnsupportedOperationException} if you try to - * set a configuration. - */ + /** Return a read-only Configuration. */ Configuration getConfiguration(); - /** - * @return the classloader for the loaded coprocessor instance - */ + /** Return the classloader for the loaded coprocessor instance */ ClassLoader getClassLoader(); + } diff --git a/hbase-client/src/main/java/org/apache/hadoop/hbase/HBaseServerException.java b/hbase-client/src/main/java/org/apache/hadoop/hbase/HBaseServerException.java index 2e4ebbd0baa6..f7c463aecaf1 100644 --- a/hbase-client/src/main/java/org/apache/hadoop/hbase/HBaseServerException.java +++ b/hbase-client/src/main/java/org/apache/hadoop/hbase/HBaseServerException.java @@ -45,8 +45,8 @@ public HBaseServerException(boolean serverOverloaded, String message) { } /** + * Return true if the server was considered overloaded when the exception was thrown * @param t throwable to check for server overloaded state - * @return True if the server was considered overloaded when the exception was thrown */ public static boolean isServerOverloaded(Throwable t) { if (t instanceof HBaseServerException) { @@ -56,6 +56,8 @@ public static boolean isServerOverloaded(Throwable t) { } /** + * Set or clear the server overloaded status. + *

* Necessary for parsing RemoteException on client side * @param serverOverloaded True if server was overloaded when exception was thrown */ @@ -63,9 +65,7 @@ public void setServerOverloaded(boolean serverOverloaded) { this.serverOverloaded = serverOverloaded; } - /** - * @return True if server was considered overloaded when exception was thrown - */ + /** Return true if server was considered overloaded when exception was thrown */ public boolean isServerOverloaded() { return serverOverloaded; } diff --git a/hbase-client/src/main/java/org/apache/hadoop/hbase/HRegionLocation.java b/hbase-client/src/main/java/org/apache/hadoop/hbase/HRegionLocation.java index 0decb58bc20b..34395e2f0243 100644 --- a/hbase-client/src/main/java/org/apache/hadoop/hbase/HRegionLocation.java +++ b/hbase-client/src/main/java/org/apache/hadoop/hbase/HRegionLocation.java @@ -100,8 +100,8 @@ public long getSeqNum() { } /** - * @return String made of hostname and port formatted as per - * {@link Addressing#createHostAndPortStr(String, int)} + * Return a string made of hostname and port formatted as per + * {@link Addressing#createHostAndPortStr(String, int)} */ public String getHostnamePort() { return Addressing.createHostAndPortStr(this.getHostname(), this.getPort()); diff --git a/hbase-client/src/main/java/org/apache/hadoop/hbase/RegionLocations.java b/hbase-client/src/main/java/org/apache/hadoop/hbase/RegionLocations.java index 4d6dd6d43fa3..4c0390c6c3be 100644 --- a/hbase-client/src/main/java/org/apache/hadoop/hbase/RegionLocations.java +++ b/hbase-client/src/main/java/org/apache/hadoop/hbase/RegionLocations.java @@ -208,6 +208,7 @@ public RegionLocations removeElementsWithNullLocation() { * @param other the locations to merge with * @return an RegionLocations object with merged locations or the same object if nothing is merged */ + @SuppressWarnings("ReferenceEquality") public RegionLocations mergeLocations(RegionLocations other) { assert other != null; @@ -280,6 +281,7 @@ private HRegionLocation selectRegionLocation(HRegionLocation oldLocation, * @return an RegionLocations object with updated locations or the same object if nothing is * updated */ + @SuppressWarnings("ReferenceEquality") public RegionLocations updateLocation(HRegionLocation location, boolean checkForEquals, boolean force) { assert location != null; diff --git a/hbase-client/src/main/java/org/apache/hadoop/hbase/RegionMetrics.java b/hbase-client/src/main/java/org/apache/hadoop/hbase/RegionMetrics.java index d873c4bc1cb4..b5e4ad44a3db 100644 --- a/hbase-client/src/main/java/org/apache/hadoop/hbase/RegionMetrics.java +++ b/hbase-client/src/main/java/org/apache/hadoop/hbase/RegionMetrics.java @@ -28,160 +28,118 @@ @InterfaceAudience.Public public interface RegionMetrics { - /** - * @return the region name - */ + /** Return the region name */ byte[] getRegionName(); - /** - * @return the number of stores - */ + /** Return the number of stores */ int getStoreCount(); - /** - * @return the number of storefiles - */ + /** Return the number of storefiles */ int getStoreFileCount(); - /** - * @return the total size of the storefiles - */ + /** Return the total size of the storefiles */ Size getStoreFileSize(); - /** - * @return the memstore size - */ + /** Return the memstore size */ Size getMemStoreSize(); - /** - * @return the number of read requests made to region - */ + /** Return the number of read requests made to region */ long getReadRequestCount(); - /** - * @return the number of write requests made to region - */ + /** Return the number of write requests made to region */ long getWriteRequestCount(); - /** - * @return the number of coprocessor service requests made to region - */ + /** Return the number of coprocessor service requests made to region */ public long getCpRequestCount(); /** - * @return the number of write requests and read requests and coprocessor service requests made to - * region + * Return the number of write requests and read requests and coprocessor service requests made to + * region */ default long getRequestCount() { return getReadRequestCount() + getWriteRequestCount() + getCpRequestCount(); } - /** - * @return the region name as a string - */ + /** Return the region name as a string */ default String getNameAsString() { return Bytes.toStringBinary(getRegionName()); } - /** - * @return the number of filtered read requests made to region - */ + /** Return the number of filtered read requests made to region */ long getFilteredReadRequestCount(); /** + * Return the current total size of root-level indexes for the region. + *

* TODO: why we pass the same value to different counters? Currently, the value from * getStoreFileIndexSize() is same with getStoreFileRootLevelIndexSize() see * HRegionServer#createRegionLoad. - * @return The current total size of root-level indexes for the region */ Size getStoreFileIndexSize(); - /** - * @return The current total size of root-level indexes for the region - */ + /** Return the current total size of root-level indexes for the region */ Size getStoreFileRootLevelIndexSize(); - /** - * @return The total size of all index blocks, not just the root level - */ + /** Return the total size of all index blocks, not just the root level */ Size getStoreFileUncompressedDataIndexSize(); - /** - * @return The total size of all Bloom filter blocks, not just loaded into the block cache - */ + /** Return the total size of all Bloom filter blocks, not just loaded into the block cache */ Size getBloomFilterSize(); - /** - * @return the total number of cells in current compaction - */ + /** Return the total number of cells in current compaction */ long getCompactingCellCount(); - /** - * @return the number of already compacted kvs in current compaction - */ + /** Return the number of already compacted kvs in current compaction */ long getCompactedCellCount(); /** + * Return the completed sequence Id for the region. + *

* This does not really belong inside RegionLoad but its being done in the name of expediency. - * @return the completed sequence Id for the region */ long getCompletedSequenceId(); - /** - * @return completed sequence id per store. - */ + /** Return the completed sequence id per store. */ Map getStoreSequenceId(); - /** - * @return the uncompressed size of the storefiles - */ + /** Return the uncompressed size of the storefiles */ Size getUncompressedStoreFileSize(); - /** - * @return the data locality of region in the regionserver. - */ + /** Return the data locality of region in the regionserver. */ float getDataLocality(); - /** - * @return the timestamp of the oldest hfile for any store of this region. - */ + /** Return the timestamp of the oldest hfile for any store of this region. */ long getLastMajorCompactionTimestamp(); - /** - * @return the reference count for the stores of this region - */ + /** Return the reference count for the stores of this region */ int getStoreRefCount(); /** - * @return the max reference count for any store file among all compacted stores files of this - * region + * Return the max reference count for any store file among all compacted stores files of this + * region */ int getMaxCompactedStoreFileRefCount(); /** + * Return the data locality for ssd of region in the regionserver. + *

* Different from dataLocality,this metric's numerator only include the data stored on ssd - * @return the data locality for ssd of region in the regionserver */ float getDataLocalityForSsd(); - /** - * @return the data at local weight of this region in the regionserver - */ + /** Return the data at local weight of this region in the regionserver */ long getBlocksLocalWeight(); /** + * Return the data at local with ssd weight of this region in the regionserver + *

* Different from blocksLocalWeight,this metric's numerator only include the data stored on ssd - * @return the data at local with ssd weight of this region in the regionserver */ long getBlocksLocalWithSsdWeight(); - /** - * @return the block total weight of this region - */ + /** Return the block total weight of this region */ long getBlocksTotalWeight(); - /** - * @return the compaction state of this region - */ + /** Return the compaction state of this region */ CompactionState getCompactionState(); } diff --git a/hbase-client/src/main/java/org/apache/hadoop/hbase/ServerMetrics.java b/hbase-client/src/main/java/org/apache/hadoop/hbase/ServerMetrics.java index 38286afa2d15..7f1e60da90fd 100644 --- a/hbase-client/src/main/java/org/apache/hadoop/hbase/ServerMetrics.java +++ b/hbase-client/src/main/java/org/apache/hadoop/hbase/ServerMetrics.java @@ -31,103 +31,84 @@ @InterfaceAudience.Public public interface ServerMetrics { + /** Return the server name **/ ServerName getServerName(); - /** - * @return the version number of a regionserver. - */ + /** Return the version number of the regionserver. */ default int getVersionNumber() { return 0; } - /** - * @return the string type version of a regionserver. - */ + /** Return the string formatted version of the regionserver. */ default String getVersion() { return "0.0.0"; } - /** - * @return the number of requests per second. - */ + /** Return the number of requests per second. */ long getRequestCountPerSecond(); - /** - * @return total Number of requests from the start of the region server. - */ + /** Return the total number of requests over the lifetime of the region server. */ long getRequestCount(); - /** - * @return total Number of read requests from the start of the region server. - */ + /** Return the total number of read requests over the lifetime of the region server. */ long getReadRequestsCount(); - /** - * @return total Number of write requests from the start of the region server. - */ + /** Return the total number of write requests over the lifetime of the region server. */ long getWriteRequestsCount(); - /** - * @return the amount of used heap - */ + /** Return the amount of used heap */ Size getUsedHeapSize(); - /** - * @return the maximum allowable size of the heap - */ + /** Return the maximum allowable size of the heap */ Size getMaxHeapSize(); + /** Return the info server port. */ int getInfoServerPort(); /** - * Call directly from client such as hbase shell - * @return the list of ReplicationLoadSource + * Return the list of replication load sources. + *

+ * Used by clients such as the hbase shell */ List getReplicationLoadSourceList(); /** - * Call directly from client such as hbase shell - * @return a map of ReplicationLoadSource list per peer id + * Return the map of replication load sources as a list list per peer id. + *

+ * Used by clients such as the hbase shell */ Map> getReplicationLoadSourceMap(); /** - * Call directly from client such as hbase shell n + * return the replication load sink. + *

+ * Used by clients such as the hbase shell */ @Nullable ReplicationLoadSink getReplicationLoadSink(); - /** - * @return region load metrics - */ + /** Return the region load metrics */ Map getRegionMetrics(); /** - * @return metrics per user + * Return the region metrics per user */ Map getUserMetrics(); - /** - * Return the RegionServer-level and Region-level coprocessors - * @return string set of loaded RegionServer-level and Region-level coprocessors - */ + /** Return the combined list of RegionServer-level and Region-level coprocessors. */ Set getCoprocessorNames(); - /** - * @return the timestamp (server side) of generating this metrics - */ + /** Return the timestamp (server side) when metrics were last collected. */ long getReportTimestamp(); - /** - * @return the last timestamp (server side) of generating this metrics - */ + /** Return the last timestamp (server side) when metrics were last collected. */ long getLastReportTimestamp(); /** - * Called directly from clients such as the hbase shell - * @return the active monitored tasks + * Return the list of active monitored tasks. + *

+ * Used by clients such as the hbase shell */ @Nullable List getTasks(); - } diff --git a/hbase-client/src/main/java/org/apache/hadoop/hbase/ServerMetricsBuilder.java b/hbase-client/src/main/java/org/apache/hadoop/hbase/ServerMetricsBuilder.java index 99f8520aa362..7ca833453c30 100644 --- a/hbase-client/src/main/java/org/apache/hadoop/hbase/ServerMetricsBuilder.java +++ b/hbase-client/src/main/java/org/apache/hadoop/hbase/ServerMetricsBuilder.java @@ -44,10 +44,6 @@ @InterfaceAudience.Private public final class ServerMetricsBuilder { - /** - * @param sn the server name - * @return a empty metrics - */ public static ServerMetrics of(ServerName sn) { return newBuilder(sn).build(); } @@ -300,6 +296,7 @@ public int getVersionNumber() { return versionNumber; } + @Override public String getVersion() { return version; } @@ -414,16 +411,20 @@ public String toString() { int currentMaxCompactedStoreFileRefCount = r.getMaxCompactedStoreFileRefCount(); maxCompactedStoreFileRefCount = Math.max(maxCompactedStoreFileRefCount, currentMaxCompactedStoreFileRefCount); - uncompressedStoreFileSizeMB += r.getUncompressedStoreFileSize().get(Size.Unit.MEGABYTE); - storeFileSizeMB += r.getStoreFileSize().get(Size.Unit.MEGABYTE); - memStoreSizeMB += r.getMemStoreSize().get(Size.Unit.MEGABYTE); - storefileIndexSizeKB += r.getStoreFileUncompressedDataIndexSize().get(Size.Unit.KILOBYTE); + uncompressedStoreFileSizeMB = (long) (uncompressedStoreFileSizeMB + + r.getUncompressedStoreFileSize().get(Size.Unit.MEGABYTE)); + storeFileSizeMB = (long) (storeFileSizeMB + r.getStoreFileSize().get(Size.Unit.MEGABYTE)); + memStoreSizeMB = (long) (memStoreSizeMB + r.getMemStoreSize().get(Size.Unit.MEGABYTE)); + storefileIndexSizeKB = (long) (storefileIndexSizeKB + + r.getStoreFileUncompressedDataIndexSize().get(Size.Unit.KILOBYTE)); readRequestsCount += r.getReadRequestCount(); cpRequestsCount += r.getCpRequestCount(); writeRequestsCount += r.getWriteRequestCount(); filteredReadRequestsCount += r.getFilteredReadRequestCount(); - rootLevelIndexSizeKB += r.getStoreFileRootLevelIndexSize().get(Size.Unit.KILOBYTE); - bloomFilterSizeMB += r.getBloomFilterSize().get(Size.Unit.MEGABYTE); + rootLevelIndexSizeKB = (long) (rootLevelIndexSizeKB + + r.getStoreFileRootLevelIndexSize().get(Size.Unit.KILOBYTE)); + bloomFilterSizeMB = + (long) (bloomFilterSizeMB + r.getBloomFilterSize().get(Size.Unit.MEGABYTE)); compactedCellCount += r.getCompactedCellCount(); compactingCellCount += r.getCompactingCellCount(); } diff --git a/hbase-client/src/main/java/org/apache/hadoop/hbase/Size.java b/hbase-client/src/main/java/org/apache/hadoop/hbase/Size.java index c248849e3630..692df9681427 100644 --- a/hbase-client/src/main/java/org/apache/hadoop/hbase/Size.java +++ b/hbase-client/src/main/java/org/apache/hadoop/hbase/Size.java @@ -70,28 +70,28 @@ public Size(double value, Unit unit) { } /** - * @return size unit + * Return the size unit */ public Unit getUnit() { return unit; } /** - * get the value + * Return the value */ public long getLongValue() { return (long) value; } /** - * get the value + * Return the value */ public double get() { return value; } /** - * get the value which is converted to specified unit. + * Return the value which is converted to specified unit. * @param unit size unit * @return the converted value */ diff --git a/hbase-client/src/main/java/org/apache/hadoop/hbase/UserMetrics.java b/hbase-client/src/main/java/org/apache/hadoop/hbase/UserMetrics.java index 2710aa9be273..a67d893e8b01 100644 --- a/hbase-client/src/main/java/org/apache/hadoop/hbase/UserMetrics.java +++ b/hbase-client/src/main/java/org/apache/hadoop/hbase/UserMetrics.java @@ -40,43 +40,31 @@ interface ClientMetrics { long getFilteredReadRequestsCount(); } - /** - * @return the user name - */ + /** Return the user name */ byte[] getUserName(); - /** - * @return the number of read requests made by user - */ + /** Return the number of read requests made by user */ long getReadRequestCount(); - /** - * @return the number of write requests made by user - */ + /** Return the number of write requests made by user */ long getWriteRequestCount(); /** - * @return the number of write requests and read requests and coprocessor service requests made by - * the user + * Return the number of write requests and read requests and coprocessor service requests made by + * the user */ default long getRequestCount() { return getReadRequestCount() + getWriteRequestCount(); } - /** - * @return the user name as a string - */ + /** Return the user name as a string */ default String getNameAsString() { return Bytes.toStringBinary(getUserName()); } - /** - * @return metrics per client(hostname) - */ + /** Return user metrics per client(hostname) */ Map getClientMetrics(); - /** - * @return count of filtered read requests for a user - */ + /** Return the number of filtered read requests for a user */ long getFilteredReadRequests(); } diff --git a/hbase-client/src/main/java/org/apache/hadoop/hbase/UserMetricsBuilder.java b/hbase-client/src/main/java/org/apache/hadoop/hbase/UserMetricsBuilder.java index ab63f19fec85..4a66283146d9 100644 --- a/hbase-client/src/main/java/org/apache/hadoop/hbase/UserMetricsBuilder.java +++ b/hbase-client/src/main/java/org/apache/hadoop/hbase/UserMetricsBuilder.java @@ -17,6 +17,7 @@ */ package org.apache.hadoop.hbase; +import java.nio.charset.StandardCharsets; import java.util.HashMap; import java.util.Map; import org.apache.hadoop.hbase.util.Strings; @@ -30,7 +31,8 @@ public final class UserMetricsBuilder { public static UserMetrics toUserMetrics(ClusterStatusProtos.UserLoad userLoad) { - UserMetricsBuilder builder = UserMetricsBuilder.newBuilder(userLoad.getUserName().getBytes()); + UserMetricsBuilder builder = + UserMetricsBuilder.newBuilder(userLoad.getUserName().getBytes(StandardCharsets.UTF_8)); userLoad.getClientMetricsList().stream() .map(clientMetrics -> new ClientMetricsImpl(clientMetrics.getHostName(), clientMetrics.getReadRequestsCount(), clientMetrics.getWriteRequestsCount(), diff --git a/hbase-client/src/main/java/org/apache/hadoop/hbase/client/AbstractResponse.java b/hbase-client/src/main/java/org/apache/hadoop/hbase/client/AbstractResponse.java index bb44defbac6a..ede1ff31c2b0 100644 --- a/hbase-client/src/main/java/org/apache/hadoop/hbase/client/AbstractResponse.java +++ b/hbase-client/src/main/java/org/apache/hadoop/hbase/client/AbstractResponse.java @@ -26,12 +26,8 @@ abstract class AbstractResponse { public enum ResponseType { - - SINGLE(0), - MULTI(1); - - ResponseType(int value) { - } + SINGLE, + MULTI; } public abstract ResponseType type(); diff --git a/hbase-client/src/main/java/org/apache/hadoop/hbase/client/AbstractRpcBasedConnectionRegistry.java b/hbase-client/src/main/java/org/apache/hadoop/hbase/client/AbstractRpcBasedConnectionRegistry.java index 2380335e56b0..df14421e5444 100644 --- a/hbase-client/src/main/java/org/apache/hadoop/hbase/client/AbstractRpcBasedConnectionRegistry.java +++ b/hbase-client/src/main/java/org/apache/hadoop/hbase/client/AbstractRpcBasedConnectionRegistry.java @@ -133,10 +133,8 @@ private void populateStubs(Set addrs) throws IOException { * For describing the actual asynchronous rpc call. *

* Typically, you can use lambda expression to implement this interface as - * - * 

-   * (c, s, d) -> s.xxx(c, your request here, d)
-   *
+ *

+ * {@code (c, s, d) -> s.xxx(c, your request here, d) } */ @FunctionalInterface protected interface Callable { diff --git a/hbase-client/src/main/java/org/apache/hadoop/hbase/client/Admin.java b/hbase-client/src/main/java/org/apache/hadoop/hbase/client/Admin.java index d2b57476128c..a296651dfaf6 100644 --- a/hbase-client/src/main/java/org/apache/hadoop/hbase/client/Admin.java +++ b/hbase-client/src/main/java/org/apache/hadoop/hbase/client/Admin.java @@ -111,12 +111,11 @@ public interface Admin extends Abortable, Closeable { @Override boolean isAborted(); - /** - * @return Connection used by this object. - */ + /** Return the connection used by this object. */ Connection getConnection(); /** + * Return true if the table already exists. * @param tableName Table to check. * @return true if table exists already. * @throws IOException if a remote or network exception occurs @@ -189,7 +188,7 @@ default TableName[] listTableNames(Pattern pattern) throws IOException { * Get a table descriptor. * @param tableName as a {@link TableName} * @return the tableDescriptor - * @throws org.apache.hadoop.hbase.TableNotFoundException + * @throws org.apache.hadoop.hbase.TableNotFoundException if the table is not found * @throws IOException if a remote or network exception occurs */ TableDescriptor getDescriptor(TableName tableName) throws TableNotFoundException, IOException; @@ -383,20 +382,23 @@ default void disableTable(TableName tableName) throws IOException { } /** + * Return true if the table is online * @param tableName name of table to check - * @return true if table is on-line + * @return true if table is online * @throws IOException if a remote or network exception occurs */ boolean isTableEnabled(TableName tableName) throws IOException; /** + * Return true if the table is offline * @param tableName name of table to check - * @return true if table is off-line + * @return true if table is offline * @throws IOException if a remote or network exception occurs */ boolean isTableDisabled(TableName tableName) throws IOException; /** + * Return true if all regions of the table are available * @param tableName name of table to check * @return true if all regions of the table are available * @throws IOException if a remote or network exception occurs @@ -1102,7 +1104,7 @@ default ClusterMetrics getClusterMetrics() throws IOException { ClusterMetrics getClusterMetrics(EnumSet

* The {@code stubMaker} is just a delegation to the {@code newStub} call. Usually it is only a * one line lambda expression, like: - * - * 

-   * 
-   * channel -> xxxService.newStub(channel)
-   * 
-   *
- * + *

+ * {@code channel -> xxxService.newStub(channel) } * @param stubMaker a delegation to the actual {@code newStub} call. * @param callable a delegation to the actual protobuf rpc call. See the comment of * {@link ServiceCaller} for more details. @@ -1434,13 +1442,8 @@ CompletableFuture coprocessorService(Function stubMaker *

* The {@code stubMaker} is just a delegation to the {@code newStub} call. Usually it is only a * one line lambda expression, like: - * - * 

-   * 
-   * channel -> xxxService.newStub(channel)
-   * 
-   *
- * + *

+ * {@code channel -> xxxService.newStub(channel) } * @param stubMaker a delegation to the actual {@code newStub} call. * @param callable a delegation to the actual protobuf rpc call. See the comment of * {@link ServiceCaller} for more details. @@ -1647,7 +1650,6 @@ default CompletableFuture> hasUserPermissions(List per /** * Creates a new RegionServer group with the given name * @param groupName the name of the group - * @throws IOException if a remote or network exception occurs */ CompletableFuture addRSGroup(String groupName); @@ -1655,34 +1657,29 @@ default CompletableFuture> hasUserPermissions(List per * Get group info for the given group name * @param groupName the group name * @return group info - * @throws IOException if a remote or network exception occurs */ CompletableFuture getRSGroup(String groupName); /** * Get group info for the given hostPort * @param hostPort HostPort to get RSGroupInfo for - * @throws IOException if a remote or network exception occurs */ CompletableFuture getRSGroup(Address hostPort); /** * Get group info for the given table * @param tableName table name to get RSGroupInfo for - * @throws IOException if a remote or network exception occurs */ CompletableFuture getRSGroup(TableName tableName); /** * Lists current set of RegionServer groups - * @throws IOException if a remote or network exception occurs */ CompletableFuture> listRSGroups(); /** * Get all tables in this RegionServer group. * @param groupName the group name - * @throws IOException if a remote or network exception occurs * @see #getConfiguredNamespacesAndTablesInRSGroup(String) */ CompletableFuture> listTablesInRSGroup(String groupName); @@ -1697,7 +1694,6 @@ default CompletableFuture> hasUserPermissions(List per * in the group 'A', but this method will not return these tables but only the namespace 'nsA', * while the {@link #listTablesInRSGroup(String)} will return all these tables. * @param groupName the group name - * @throws IOException if a remote or network exception occurs * @see #listTablesInRSGroup(String) */ CompletableFuture, List>> @@ -1706,7 +1702,6 @@ default CompletableFuture> hasUserPermissions(List per /** * Remove RegionServer group associated with the given name * @param groupName the group name - * @throws IOException if a remote or network exception occurs */ CompletableFuture removeRSGroup(String groupName); @@ -1716,7 +1711,6 @@ default CompletableFuture> hasUserPermissions(List per * servers to join other clusters. So we need to remove these servers from the group. 2. * Dead/recovering/live servers will be disallowed. * @param servers set of servers to remove - * @throws IOException if a remote or network exception occurs */ CompletableFuture removeServersFromRSGroup(Set

servers); @@ -1724,7 +1718,6 @@ default CompletableFuture> hasUserPermissions(List per * Move given set of servers to the specified target RegionServer group * @param servers set of servers to move * @param groupName the group to move servers to - * @throws IOException if a remote or network exception occurs */ CompletableFuture moveServersToRSGroup(Set
servers, String groupName); @@ -1732,7 +1725,6 @@ default CompletableFuture> hasUserPermissions(List per * Set the RegionServer group for tables * @param tables tables to set group for * @param groupName group name for tables - * @throws IOException if a remote or network exception occurs */ CompletableFuture setRSGroup(Set tables, String groupName); @@ -1740,7 +1732,6 @@ default CompletableFuture> hasUserPermissions(List per * Balance regions in the given RegionServer group * @param groupName the group name * @return BalanceResponse details about the balancer run - * @throws IOException if a remote or network exception occurs */ default CompletableFuture balanceRSGroup(String groupName) { return balanceRSGroup(groupName, BalanceRequest.defaultInstance()); @@ -1751,7 +1742,6 @@ default CompletableFuture balanceRSGroup(String groupName) { * @param groupName the group name * @param request options to define how the balancer should run * @return BalanceResponse details about the balancer run - * @throws IOException if a remote or network exception occurs */ CompletableFuture balanceRSGroup(String groupName, BalanceRequest request); @@ -1759,7 +1749,6 @@ default CompletableFuture balanceRSGroup(String groupName) { * Rename rsgroup * @param oldName old rsgroup name * @param newName new rsgroup name - * @throws IOException if a remote or network exception occurs */ CompletableFuture renameRSGroup(String oldName, String newName); @@ -1767,7 +1756,6 @@ default CompletableFuture balanceRSGroup(String groupName) { * Update RSGroup configuration * @param groupName the group name * @param configuration new configuration of the group name to be set - * @throws IOException if a remote or network exception occurs */ CompletableFuture updateRSGroupConfig(String groupName, Map configuration); diff --git a/hbase-client/src/main/java/org/apache/hadoop/hbase/client/AsyncAdminRequestRetryingCaller.java b/hbase-client/src/main/java/org/apache/hadoop/hbase/client/AsyncAdminRequestRetryingCaller.java index de6e967f21c4..d3bec8b3cfbf 100644 --- a/hbase-client/src/main/java/org/apache/hadoop/hbase/client/AsyncAdminRequestRetryingCaller.java +++ b/hbase-client/src/main/java/org/apache/hadoop/hbase/client/AsyncAdminRequestRetryingCaller.java @@ -29,9 +29,6 @@ import org.apache.hadoop.hbase.shaded.protobuf.generated.AdminProtos.AdminService; -/** - * @since 2.0.0 - */ @InterfaceAudience.Private public class AsyncAdminRequestRetryingCaller extends AsyncRpcRetryingCaller { diff --git a/hbase-client/src/main/java/org/apache/hadoop/hbase/client/AsyncTable.java b/hbase-client/src/main/java/org/apache/hadoop/hbase/client/AsyncTable.java index 5497b4a0b723..129ef418d8b4 100644 --- a/hbase-client/src/main/java/org/apache/hadoop/hbase/client/AsyncTable.java +++ b/hbase-client/src/main/java/org/apache/hadoop/hbase/client/AsyncTable.java @@ -223,16 +223,14 @@ default CompletableFuture incrementColumnValue(byte[] row, byte[] family, * This is a fluent style API, the code is like: * * 
-   * 
    * table.checkAndMutate(row, family).qualifier(qualifier).ifNotExists().thenPut(put)
-   *     .thenAccept(succ -> {
-   *       if (succ) {
-   *         System.out.println("Check and put succeeded");
-   *       } else {
-   *         System.out.println("Check and put failed");
-   *       }
-   *     });
-   * 
+   *   .thenAccept(succ -> {
+   *     if (succ) {
+   *       System.out.println("Check and put succeeded");
+   *     } else {
+   *       System.out.println("Check and put failed");
+   *     }
+   *   });
    *
* * @deprecated Since 3.0.0, will be removed in 4.0.0. For internal test use only, do not use it @@ -250,11 +248,13 @@ default CompletableFuture incrementColumnValue(byte[] row, byte[] family, interface CheckAndMutateBuilder { /** + * Supply a specific column qualifier to check. * @param qualifier column qualifier to check. */ CheckAndMutateBuilder qualifier(byte[] qualifier); /** + * Supply a time range to check. * @param timeRange time range to check. */ CheckAndMutateBuilder timeRange(TimeRange timeRange); @@ -273,12 +273,14 @@ default CheckAndMutateBuilder ifEquals(byte[] value) { } /** + * Check for a match against a sequence of bytes. * @param compareOp comparison operator to use * @param value the expected value */ CheckAndMutateBuilder ifMatches(CompareOperator compareOp, byte[] value); /** + * Provide a Put to commit if the check passes. * @param put data to put if check succeeds * @return {@code true} if the new put was executed, {@code false} otherwise. The return value * will be wrapped by a {@link CompletableFuture}. @@ -286,6 +288,7 @@ default CheckAndMutateBuilder ifEquals(byte[] value) { CompletableFuture thenPut(Put put); /** + * Provide a Delete to commit if the check passes. * @param delete data to delete if check succeeds * @return {@code true} if the new delete was executed, {@code false} otherwise. The return * value will be wrapped by a {@link CompletableFuture}. @@ -293,6 +296,7 @@ default CheckAndMutateBuilder ifEquals(byte[] value) { CompletableFuture thenDelete(Delete delete); /** + * Provide a Mutation to commit if the check passes. * @param mutation mutations to perform if check succeeds * @return true if the new mutation was executed, false otherwise. The return value will be * wrapped by a {@link CompletableFuture}. @@ -308,16 +312,13 @@ default CheckAndMutateBuilder ifEquals(byte[] value) { * execute it. This is a fluent style API, the code is like: * * 
-   * 
-   * table.checkAndMutate(row, filter).thenPut(put)
-   *     .thenAccept(succ -> {
-   *       if (succ) {
-   *         System.out.println("Check and put succeeded");
-   *       } else {
-   *         System.out.println("Check and put failed");
-   *       }
-   *     });
-   * 
+   * table.checkAndMutate(row, filter).thenPut(put).thenAccept(succ -> {
+   *   if (succ) {
+   *     System.out.println("Check and put succeeded");
+   *   } else {
+   *     System.out.println("Check and put failed");
+   *   }
+   * });
    *
* * @deprecated Since 3.0.0, will be removed in 4.0.0. For internal test use only, do not use it @@ -335,11 +336,13 @@ default CheckAndMutateBuilder ifEquals(byte[] value) { interface CheckAndMutateWithFilterBuilder { /** + * Supply a time range to check. * @param timeRange time range to check. */ CheckAndMutateWithFilterBuilder timeRange(TimeRange timeRange); /** + * Provide a Put to commit if the check passes. * @param put data to put if check succeeds * @return {@code true} if the new put was executed, {@code false} otherwise. The return value * will be wrapped by a {@link CompletableFuture}. @@ -347,6 +350,7 @@ interface CheckAndMutateWithFilterBuilder { CompletableFuture thenPut(Put put); /** + * Provide a Delete to commit if the check passes. * @param delete data to delete if check succeeds * @return {@code true} if the new delete was executed, {@code false} otherwise. The return * value will be wrapped by a {@link CompletableFuture}. @@ -354,6 +358,7 @@ interface CheckAndMutateWithFilterBuilder { CompletableFuture thenDelete(Delete delete); /** + * Provide a Mutation to commit if the check passes. * @param mutation mutations to perform if check succeeds * @return true if the new mutation was executed, false otherwise. The return value will be * wrapped by a {@link CompletableFuture}. @@ -440,16 +445,14 @@ default ResultScanner getScanner(byte[] family, byte[] qualifier) { *

* * 

-   * 
-   * table.scanAll(new Scan().withStartRow(row, false).setLimit(1)).thenAccept(results -> {
+   * table.scanAll(new Scan().withStartRow(row, false).setLimit(1)).thenAccept(results -> {
    *   if (results.isEmpty()) {
-   *      System.out.println("No row after " + Bytes.toStringBinary(row));
+   *     System.out.println("No row after " + Bytes.toStringBinary(row));
    *   } else {
    *     System.out.println("The closest row after " + Bytes.toStringBinary(row) + " is "
-   *         + Bytes.toStringBinary(results.stream().findFirst().get().getRow()));
+   *       + Bytes.toStringBinary(results.stream().findFirst().get().getRow()));
    *   }
    * });
-   * 
    *
*

* If your result set is very large, you should use other scan method to get a scanner or use @@ -572,13 +575,8 @@ default CompletableFuture> batchAll(List actions) { *

* The {@code stubMaker} is just a delegation to the {@code newStub} call. Usually it is only a * one line lambda expression, like: - * - * 

-   * 
-   * channel -> xxxService.newStub(channel)
-   * 
-   *
- * + *

+ * {@code channel -> xxxService.newStub(channel) } * @param stubMaker a delegation to the actual {@code newStub} call. * @param callable a delegation to the actual protobuf rpc call. See the comment of * {@link ServiceCaller} for more details. @@ -609,7 +607,7 @@ CompletableFuture coprocessorService(Function stubMaker * * 

    * locateThenCall(byte[] row) {
-   *   locate(row).whenComplete((location, locateError) -> {
+   *   locate(row).whenComplete((location, locateError) -> {
    *     if (locateError != null) {
    *       callback.onError(locateError);
    *       return;
@@ -621,7 +619,7 @@  CompletableFuture coprocessorService(Function stubMaker
    *     } else {
    *       locateThenCall(region.getEndKey());
    *     }
-   *     sendCall().whenComplete((resp, error) -> {
+   *     sendCall().whenComplete((resp, error) -> {
    *       if (error != null) {
    *         callback.onRegionError(region, error);
    *       } else {
@@ -639,12 +637,14 @@  CompletableFuture coprocessorService(Function stubMaker
   interface CoprocessorCallback {
 
     /**
+     * Action to take when completed.
      * @param region the region that the response belongs to
      * @param resp   the response of the coprocessor call
      */
     void onRegionComplete(RegionInfo region, R resp);
 
     /**
+     * Action to take upon error.
      * @param region the region that the error belongs to
      * @param error  the response error of the coprocessor call
      */
@@ -675,6 +675,7 @@ interface CoprocessorCallback {
   interface CoprocessorServiceBuilder {
 
     /**
+     * Start the range at a given row, inclusive.
      * @param startKey start region selection with region containing this row, inclusive.
      */
     default CoprocessorServiceBuilder fromRow(byte[] startKey) {
@@ -682,12 +683,14 @@ default CoprocessorServiceBuilder fromRow(byte[] startKey) {
     }
 
     /**
+     * Start the range at a given row.
      * @param startKey  start region selection with region containing this row
      * @param inclusive whether to include the startKey
      */
     CoprocessorServiceBuilder fromRow(byte[] startKey, boolean inclusive);
 
     /**
+     * Stop the range at a given row, exclusive.
      * @param endKey select regions up to and including the region containing this row, exclusive.
      */
     default CoprocessorServiceBuilder toRow(byte[] endKey) {
@@ -695,6 +698,7 @@ default CoprocessorServiceBuilder toRow(byte[] endKey) {
     }
 
     /**
+     * Stop the range at a given row.
      * @param endKey    select regions up to and including the region containing this row
      * @param inclusive whether to include the endKey
      */
@@ -714,13 +718,8 @@ default CoprocessorServiceBuilder toRow(byte[] endKey) {
    * 

    * The {@code stubMaker} is just a delegation to the {@code xxxService.newStub} call. Usually it
    * is only a one line lambda expression, like:
-   *
-   * 
-   * 
-   * channel -> xxxService.newStub(channel)
-   * 
-   * 

-   *
+   * 

+   * {@code channel -> xxxService.newStub(channel) }
    * @param stubMaker a delegation to the actual {@code newStub} call.
    * @param callable  a delegation to the actual protobuf rpc call. See the comment of
    *                  {@link ServiceCaller} for more details.
diff --git a/hbase-client/src/main/java/org/apache/hadoop/hbase/client/CatalogReplicaLoadBalanceSimpleSelector.java b/hbase-client/src/main/java/org/apache/hadoop/hbase/client/CatalogReplicaLoadBalanceSimpleSelector.java
index 2e704c5bdc10..e990fa6d65ff 100644
--- a/hbase-client/src/main/java/org/apache/hadoop/hbase/client/CatalogReplicaLoadBalanceSimpleSelector.java
+++ b/hbase-client/src/main/java/org/apache/hadoop/hbase/client/CatalogReplicaLoadBalanceSimpleSelector.java
@@ -128,6 +128,7 @@ public String toString() {
    * Selector's internal state.
    * @param loc the location which causes exception.
    */
+  @Override
   public void onError(HRegionLocation loc) {
     ConcurrentNavigableMap tableCache = computeIfAbsent(staleCache,
       loc.getRegion().getTable(), () -> new ConcurrentSkipListMap<>(BYTES_COMPARATOR));
@@ -159,18 +160,19 @@ private int getRandomReplicaId() {
    * When it looks up a location, it will call this method to find a replica region to go. For a
    * normal case, > 99% of region locations from catalog/meta replica will be up to date. In extreme
    * cases such as region server crashes, it will depends on how fast replication catches up.
-   * @param tablename  table name it looks up
+   * @param tableName  table name it looks up
    * @param row        key it looks up.
    * @param locateType locateType, Only BEFORE and CURRENT will be passed in.
    * @return catalog replica id
    */
-  public int select(final TableName tablename, final byte[] row,
+  @Override
+  public int select(final TableName tableName, final byte[] row,
     final RegionLocateType locateType) {
     Preconditions.checkArgument(
       locateType == RegionLocateType.BEFORE || locateType == RegionLocateType.CURRENT,
       "Expected type BEFORE or CURRENT but got: %s", locateType);
 
-    ConcurrentNavigableMap tableCache = staleCache.get(tablename);
+    ConcurrentNavigableMap tableCache = staleCache.get(tableName);
 
     // If there is no entry in StaleCache, select a random replica id.
     if (tableCache == null) {
@@ -199,7 +201,7 @@ public int select(final TableName tablename, final byte[] row,
       (EnvironmentEdgeManager.currentTime() - entry.getValue().getTimestamp())
           >= STALE_CACHE_TIMEOUT_IN_MILLISECONDS
     ) {
-      LOG.debug("Entry for table {} with startKey {}, {} times out", tablename, entry.getKey(),
+      LOG.debug("Entry for table {} with startKey {}, {} times out", tableName, entry.getKey(),
         entry);
       tableCache.remove(entry.getKey());
       return getRandomReplicaId();
diff --git a/hbase-client/src/main/java/org/apache/hadoop/hbase/client/CheckAndMutate.java b/hbase-client/src/main/java/org/apache/hadoop/hbase/client/CheckAndMutate.java
index 67f30177663f..f59f378ede35 100644
--- a/hbase-client/src/main/java/org/apache/hadoop/hbase/client/CheckAndMutate.java
+++ b/hbase-client/src/main/java/org/apache/hadoop/hbase/client/CheckAndMutate.java
@@ -33,24 +33,18 @@
  * APIs, the code are like:
  *
  * 
- * 
  * // A CheckAndMutate operation where do the specified action if the column (specified by the
  * // family and the qualifier) of the row equals to the specified value
- * CheckAndMutate checkAndMutate = CheckAndMutate.newBuilder(row)
- *   .ifEquals(family, qualifier, value)
- *   .build(put);
+ * CheckAndMutate checkAndMutate =
+ *   CheckAndMutate.newBuilder(row).ifEquals(family, qualifier, value).build(put);
  *
  * // A CheckAndMutate operation where do the specified action if the column (specified by the
  * // family and the qualifier) of the row doesn't exist
- * CheckAndMutate checkAndMutate = CheckAndMutate.newBuilder(row)
- *   .ifNotExists(family, qualifier)
- *   .build(put);
+ * CheckAndMutate checkAndMutate =
+ *   CheckAndMutate.newBuilder(row).ifNotExists(family, qualifier).build(put);
  *
  * // A CheckAndMutate operation where do the specified action if the row matches the filter
- * CheckAndMutate checkAndMutate = CheckAndMutate.newBuilder(row)
- *   .ifMatches(filter)
- *   .build(delete);
- * 
+ * CheckAndMutate checkAndMutate = CheckAndMutate.newBuilder(row).ifMatches(filter).build(delete);
  * 

  */
 @InterfaceAudience.Public
@@ -97,6 +91,7 @@ public Builder ifEquals(byte[] family, byte[] qualifier, byte[] value) {
     }
 
     /**
+     * Check for a match
      * @param family    family to check
      * @param qualifier qualifier to check
      * @param compareOp comparison operator to use
@@ -113,6 +108,7 @@ public Builder ifMatches(byte[] family, byte[] qualifier, CompareOperator compar
     }
 
     /**
+     * Check for a match
      * @param filter filter to check
      * @return the CheckAndMutate object
      */
@@ -122,6 +118,7 @@ public Builder ifMatches(Filter filter) {
     }
 
     /**
+     * Set a time range to check
      * @param timeRange time range to check
      * @return the CheckAndMutate object
      */
@@ -144,6 +141,7 @@ private void preCheck(Row action) {
     }
 
     /**
+     * Build a check and mutate operation with a Put to commit if the check succeeds.
      * @param put data to put if check succeeds
      * @return a CheckAndMutate object
      */
@@ -157,6 +155,7 @@ public CheckAndMutate build(Put put) {
     }
 
     /**
+     * Build a check and mutate operation with a Delete to commit if the check succeeds.
      * @param delete data to delete if check succeeds
      * @return a CheckAndMutate object
      */
@@ -170,6 +169,7 @@ public CheckAndMutate build(Delete delete) {
     }
 
     /**
+     * Build a check and mutate operation with an Increment to commit if the check succeeds.
      * @param increment data to increment if check succeeds
      * @return a CheckAndMutate object
      */
@@ -183,6 +183,7 @@ public CheckAndMutate build(Increment increment) {
     }
 
     /**
+     * Build a check and mutate operation with an Append to commit if the check succeeds.
      * @param append data to append if check succeeds
      * @return a CheckAndMutate object
      */
@@ -196,6 +197,7 @@ public CheckAndMutate build(Append append) {
     }
 
     /**
+     * Build a check and mutate operation with a RowMutations to commit if the check succeeds.
      * @param mutations mutations to perform if check succeeds
      * @return a CheckAndMutate object
      */
@@ -251,7 +253,7 @@ private CheckAndMutate(byte[] row, Filter filter, TimeRange timeRange, Row actio
   }
 
   /**
-   * @return the row
+   * Return the row
    */
   @Override
   public byte[] getRow() {
@@ -259,56 +261,56 @@ public byte[] getRow() {
   }
 
   /**
-   * @return the family to check
+   * Return the family to check
    */
   public byte[] getFamily() {
     return family;
   }
 
   /**
-   * @return the qualifier to check
+   * Return the qualifier to check
    */
   public byte[] getQualifier() {
     return qualifier;
   }
 
   /**
-   * @return the comparison operator
+   * Return the comparison operator
    */
   public CompareOperator getCompareOp() {
     return op;
   }
 
   /**
-   * @return the expected value
+   * Return the expected value
    */
   public byte[] getValue() {
     return value;
   }
 
   /**
-   * @return the filter to check
+   * Return the filter to check
    */
   public Filter getFilter() {
     return filter;
   }
 
   /**
-   * @return whether this has a filter or not
+   * Return whether this has a filter or not
    */
   public boolean hasFilter() {
     return filter != null;
   }
 
   /**
-   * @return the time range to check
+   * Return the time range to check
    */
   public TimeRange getTimeRange() {
     return timeRange;
   }
 
   /**
-   * @return the action done if check succeeds
+   * Return the action done if check succeeds
    */
   public Row getAction() {
     return action;
diff --git a/hbase-client/src/main/java/org/apache/hadoop/hbase/client/CheckAndMutateResult.java b/hbase-client/src/main/java/org/apache/hadoop/hbase/client/CheckAndMutateResult.java
index 88b438a74a05..2717bc14ba46 100644
--- a/hbase-client/src/main/java/org/apache/hadoop/hbase/client/CheckAndMutateResult.java
+++ b/hbase-client/src/main/java/org/apache/hadoop/hbase/client/CheckAndMutateResult.java
@@ -33,14 +33,14 @@ public CheckAndMutateResult(boolean success, Result result) {
   }
 
   /**
-   * @return Whether the CheckAndMutate operation is successful or not
+   * Return whether the CheckAndMutate operation is successful or not
    */
   public boolean isSuccess() {
     return success;
   }
 
   /**
-   * @return It is used only for CheckAndMutate operations with Increment/Append. Otherwise null
+   * Return the result for CheckAndMutate operations with Increment/Append, or null otherwise
    */
   public Result getResult() {
     return result;
diff --git a/hbase-client/src/main/java/org/apache/hadoop/hbase/client/ClientIdGenerator.java b/hbase-client/src/main/java/org/apache/hadoop/hbase/client/ClientIdGenerator.java
index 758cf508578a..a333eec72d6f 100644
--- a/hbase-client/src/main/java/org/apache/hadoop/hbase/client/ClientIdGenerator.java
+++ b/hbase-client/src/main/java/org/apache/hadoop/hbase/client/ClientIdGenerator.java
@@ -38,8 +38,8 @@ private ClientIdGenerator() {
   }
 
   /**
-   * @return a unique ID incorporating IP address, PID, TID and timer. Might be an overkill... Note
-   *         though that new UUID in java by default is just a random number.
+   * Return a unique ID incorporating IP address, PID, TID and timer. Might be an overkill... Note
+   * though that new UUID in java by default is just a random number.
    */
   public static byte[] generateClientId() {
     byte[] selfBytes = getIpAddressBytes();
@@ -58,9 +58,8 @@ public static byte[] generateClientId() {
     return id;
   }
 
-  /**
-   * @return PID of the current process, if it can be extracted from JVM name, or null.
-   */
+  /** Return the PID of the current process, if it can be extracted from JVM name, or null. */
+  @SuppressWarnings("StringSplitter")
   public static Long getPid() {
     String name = ManagementFactory.getRuntimeMXBean().getName();
     String[] nameParts = name.split("@");
@@ -77,8 +76,8 @@ public static Long getPid() {
   }
 
   /**
-   * @return Some IPv4/IPv6 address available on the current machine that is up, not virtual and not
-   *         a loopback address. Empty array if none can be found or error occurred.
+   * Return an IPv4/IPv6 address available on the current machine that is up, not virtual and not a
+   * loopback address. Empty array if none can be found or error occurred.
    */
   public static byte[] getIpAddressBytes() {
     try {
diff --git a/hbase-client/src/main/java/org/apache/hadoop/hbase/client/ClusterStatusListener.java b/hbase-client/src/main/java/org/apache/hadoop/hbase/client/ClusterStatusListener.java
index cc34d59c7321..322212261bcd 100644
--- a/hbase-client/src/main/java/org/apache/hadoop/hbase/client/ClusterStatusListener.java
+++ b/hbase-client/src/main/java/org/apache/hadoop/hbase/client/ClusterStatusListener.java
@@ -19,6 +19,7 @@
 
 import java.io.Closeable;
 import java.io.IOException;
+import java.io.InterruptedIOException;
 import java.lang.reflect.Constructor;
 import java.lang.reflect.InvocationTargetException;
 import java.net.InetAddress;
@@ -26,6 +27,7 @@
 import java.net.UnknownHostException;
 import java.util.ArrayList;
 import java.util.List;
+import java.util.concurrent.ExecutionException;
 import org.apache.hadoop.conf.Configuration;
 import org.apache.hadoop.hbase.ClusterMetrics;
 import org.apache.hadoop.hbase.ClusterMetricsBuilder;
@@ -218,16 +220,30 @@ public void connect(Configuration conf) throws IOException {
       }
 
       LOG.debug("Channel bindAddress={}, networkInterface={}, INA={}", bindAddress, ni, ina);
-      channel.joinGroup(ina, ni, null, channel.newPromise());
+      try {
+        channel.joinGroup(ina, ni, null, channel.newPromise()).get();
+      } catch (InterruptedException e) {
+        throw (IOException) new InterruptedIOException().initCause(e);
+      } catch (ExecutionException e) {
+        throw new IOException(e);
+      }
     }
 
     @Override
     public void close() {
       if (channel != null) {
-        channel.close();
+        try {
+          channel.close().get();
+        } catch (InterruptedException | ExecutionException e) {
+          LOG.warn("Exception while closing", e);
+        }
         channel = null;
       }
-      group.shutdownGracefully();
+      try {
+        group.shutdownGracefully().get();
+      } catch (InterruptedException | ExecutionException e) {
+        LOG.warn("Exception while shutting down", e);
+      }
     }
 
     /**
diff --git a/hbase-client/src/main/java/org/apache/hadoop/hbase/client/ColumnFamilyDescriptor.java b/hbase-client/src/main/java/org/apache/hadoop/hbase/client/ColumnFamilyDescriptor.java
index 5f11f8d258a6..d2445e284e95 100644
--- a/hbase-client/src/main/java/org/apache/hadoop/hbase/client/ColumnFamilyDescriptor.java
+++ b/hbase-client/src/main/java/org/apache/hadoop/hbase/client/ColumnFamilyDescriptor.java
@@ -78,84 +78,85 @@ public interface ColumnFamilyDescriptor {
     };
 
   /**
-   * @return The storefile/hfile blocksize for this column family.
+   * Return the storefile/hfile blocksize for this column family.
    */
   int getBlocksize();
 
   /**
-   * @return bloom filter type used for new StoreFiles in ColumnFamily
+   * Return the bloom filter type used for new store files in the column family.
    */
   BloomType getBloomFilterType();
 
   /**
-   * @return Compression type setting.
+   * Return the compression type for compactions.
    */
   Compression.Algorithm getCompactionCompressionType();
 
   /**
-   * @return Compression type setting for major compactions.
+   * Return the compression type for major compactions.
    */
   Compression.Algorithm getMajorCompactionCompressionType();
 
   /**
-   * @return Compression type setting for minor compactions.
+   * Return the compression type for minor compactions.
    */
   Compression.Algorithm getMinorCompactionCompressionType();
 
   /**
-   * @return Compression type setting.
+   * Return the compression type.
    */
   Compression.Algorithm getCompressionType();
 
   /**
-   * @return an unmodifiable map.
+   * Return the column family attributes as an unmodifiable map.
    */
   Map getConfiguration();
 
   /**
+   * Get a configuration value by key.
    * @param key the key whose associated value is to be returned
    * @return accessing the configuration value by key.
    */
   String getConfigurationValue(String key);
 
   /**
-   * @return replication factor set for this CF
+   * Return the DFS replication factor.
    */
   short getDFSReplication();
 
   /**
-   * @return the data block encoding algorithm used in block cache and optionally on disk
+   * Return the data block encoding algorithm used in block cache and optionally on disk.
    */
   DataBlockEncoding getDataBlockEncoding();
 
   /**
-   * @return Return the raw crypto key attribute for the family, or null if not set
+   * Return the raw crypto key attribute for the family, or null if not set.
    */
   byte[] getEncryptionKey();
 
   /**
-   * @return Return the encryption algorithm in use by this family
+   * Return the encryption algorithm in use by this family.
    */
   String getEncryptionType();
 
   /**
-   * @return in-memory compaction policy if set for the cf. Returns null if no policy is set for for
-   *         this column family
+   * Return the in-memory compaction policy if set for the cf. Returns null if no policy is set for
+   * for this column family
    */
   MemoryCompactionPolicy getInMemoryCompaction();
 
   /**
-   * @return return the KeepDeletedCells
+   * Return the current KeepDeletedCells settings.
    */
   KeepDeletedCells getKeepDeletedCells();
 
   /**
-   * @return maximum number of versions
+   * Return the maximum number of versions to keep.
    */
   int getMaxVersions();
 
   /**
-   * @return The minimum number of versions to keep.
+   * Return the minimum number of versions to keep.
    */
   int getMinVersions();
 
@@ -172,91 +173,91 @@ public interface ColumnFamilyDescriptor {
   long getMobThreshold();
 
   /**
-   * @return a copy of Name of this column family
+   * Return a copy of the name of this column family
    */
   byte[] getName();
 
   /**
-   * @return Name of this column family
+   * Return the name of this column family as a String.
    */
   String getNameAsString();
 
   /**
-   * @return the scope tag
+   * Return the scope tag.
    */
   int getScope();
 
   /**
-   * Not using {@code enum} here because HDFS is not using {@code enum} for storage policy, see
-   * org.apache.hadoop.hdfs.server.blockmanagement.BlockStoragePolicySuite for more details.
-   * @return Return the storage policy in use by this family
+   * Return the storage policy in use by this family.
    */
   String getStoragePolicy();
 
   /**
-   * @return Time-to-live of cell contents, in seconds.
+   * Return the time-to-live of cell contents, in seconds.
    */
   int getTimeToLive();
 
   /**
+   * Get a configuration value by key.
    * @param key The key.
    * @return A clone value. Null if no mapping for the key
    */
   Bytes getValue(Bytes key);
 
   /**
+   * Get a configuration value by key.
    * @param key The key.
    * @return A clone value. Null if no mapping for the key
    */
   String getValue(String key);
 
   /**
+   * Get a configuration value by key.
    * @param key The key.
    * @return A clone value. Null if no mapping for the key
    */
   byte[] getValue(byte[] key);
 
   /**
-   * It clone all bytes of all elements.
-   * @return All values
+   * Return a map of all configuration values.
    */
   Map getValues();
 
   /**
-   * @return True if hfile DATA type blocks should be cached (You cannot disable caching of INDEX
-   *         and BLOOM type blocks).
+   * Return true if hfile DATA type blocks should be cached (You cannot disable caching of INDEX and
+   * BLOOM type blocks).
    */
   boolean isBlockCacheEnabled();
 
   /**
-   * @return true if we should cache bloomfilter blocks on write
+   * Return true if we should cache bloomfilter blocks on write.
    */
   boolean isCacheBloomsOnWrite();
 
   /**
-   * @return true if we should cache data blocks on write
+   * Return true if we should cache data blocks on write.
    */
   boolean isCacheDataOnWrite();
 
   /**
-   * @return true if we should cache index blocks on write
+   * Return true if we should cache index blocks on write.
    */
   boolean isCacheIndexesOnWrite();
 
   /**
-   * @return Whether KV tags should be compressed along with DataBlockEncoding. When no
-   *         DataBlockEncoding is been used, this is having no effect.
+   * Return whether KV tags should be compressed along with DataBlockEncoding. When no
+   * DataBlockEncoding is been used, this is having no effect.
    */
   boolean isCompressTags();
 
   /**
-   * @return true if we should evict cached blocks from the blockcache on close
+   * Return true if we should evict cached blocks from the blockcache on close
    */
   boolean isEvictBlocksOnClose();
 
   /**
-   * @return True if we are to favor keeping all values for this column family in the HRegionServer
-   *         cache.
+   * Return true if we are to favor keeping all values for this column family in the HRegionServer
+   * cache.
    */
   boolean isInMemory();
 
@@ -267,12 +268,12 @@ public interface ColumnFamilyDescriptor {
   boolean isMobEnabled();
 
   /**
-   * @return true if we should prefetch blocks into the blockcache on open
+   * Return true if we should prefetch blocks into the blockcache on open
    */
   boolean isPrefetchBlocksOnOpen();
 
   /**
-   * @return Column family descriptor with only the customized attributes.
+   * Return the column family descriptor with only the customized attributes.
    */
   String toStringCustomizedValues();
 
diff --git a/hbase-client/src/main/java/org/apache/hadoop/hbase/client/ColumnFamilyDescriptorBuilder.java b/hbase-client/src/main/java/org/apache/hadoop/hbase/client/ColumnFamilyDescriptorBuilder.java
index 80178027b6f2..d375c34431c9 100644
--- a/hbase-client/src/main/java/org/apache/hadoop/hbase/client/ColumnFamilyDescriptorBuilder.java
+++ b/hbase-client/src/main/java/org/apache/hadoop/hbase/client/ColumnFamilyDescriptorBuilder.java
@@ -42,9 +42,6 @@
 import org.apache.hadoop.hbase.shaded.protobuf.ProtobufUtil;
 import org.apache.hadoop.hbase.shaded.protobuf.generated.HBaseProtos.ColumnFamilySchema;
 
-/**
- * @since 2.0.0
- */
 @InterfaceAudience.Public
 public class ColumnFamilyDescriptorBuilder {
   // For future backward compatibility
@@ -330,6 +327,7 @@ public static Unit getUnit(String key) {
   }
 
   /**
+   * Assert the column family name is legal.
    * @param b Family name.
    * @return b
    * @throws IllegalArgumentException If not null and not a legitimate family name: i.e. 'printable'
@@ -398,6 +396,7 @@ private ColumnFamilyDescriptorBuilder(final ColumnFamilyDescriptor desc) {
   }
 
   /**
+   * Serialize the descriptor to a byte array.
    * @param desc The table descriptor to serialize
    * @return This instance serialized with pb with pb magic prefix
    */
@@ -690,11 +689,6 @@ public Map getValues() {
       return Collections.unmodifiableMap(values);
     }
 
-    /**
-     * @param key   The key.
-     * @param value The value.
-     * @return this (for chained invocation)
-     */
     public ModifyableColumnFamilyDescriptor setValue(byte[] key, byte[] value) {
       return setValue(toBytesOrNull(key, Function.identity()),
         toBytesOrNull(value, Function.identity()));
@@ -708,11 +702,6 @@ private ModifyableColumnFamilyDescriptor setValue(Bytes key, String value) {
       return setValue(key, toBytesOrNull(value, Bytes::toBytes));
     }
 
-    /**
-     * @param key   The key.
-     * @param value The value.
-     * @return this (for chained invocation)
-     */
     private ModifyableColumnFamilyDescriptor setValue(Bytes key, Bytes value) {
       if (value == null || value.getLength() == 0) {
         values.remove(key);
@@ -749,6 +738,7 @@ public int getMaxVersions() {
     }
 
     /**
+     * Set the maximum number of versions
      * @param maxVersions maximum number of versions
      * @return this (for chained invocation)
      */
@@ -796,6 +786,7 @@ public int getBlocksize() {
     }
 
     /**
+     * Set the blocksize to use in storefiles
      * @param s Blocksize to use when writing out storefiles/hfiles on this column family.
      * @return this (for chained invocation)
      */
@@ -814,13 +805,6 @@ public Compression.Algorithm getCompressionType() {
         n -> Compression.Algorithm.valueOf(n.toUpperCase()), DEFAULT_COMPRESSION);
     }
 
-    /**
-     * Compression types supported in hbase. LZO is not bundled as part of the hbase distribution.
-     * See See LZO Compression for
-     * how to enable it.
-     * @param type Compression type setting.
-     * @return this (for chained invocation)
-     */
     public ModifyableColumnFamilyDescriptor setCompressionType(Compression.Algorithm type) {
       return setValue(COMPRESSION_BYTES, type.name());
     }
@@ -901,6 +885,7 @@ public boolean isInMemory() {
     }
 
     /**
+     * Enable or disable in memory preference for the family
      * @param inMemory True if we are to favor keeping all values for this column family in the
      *                 HRegionServer cache
      * @return this (for chained invocation)
@@ -916,7 +901,8 @@ public MemoryCompactionPolicy getInMemoryCompaction() {
     }
 
     /**
-     * @param inMemoryCompaction the prefered in-memory compaction policy for this column family
+     * Set the preferred in-memory compaction policy.
+     * @param inMemoryCompaction the preferred in-memory compaction policy for this column family
      * @return this (for chained invocation)
      */
     public ModifyableColumnFamilyDescriptor
@@ -931,6 +917,7 @@ public KeepDeletedCells getKeepDeletedCells() {
     }
 
     /**
+     * Enable the KEEP_DELETED_CELLS feature.
      * @param keepDeletedCells True if deleted rows should not be collected immediately.
      * @return this (for chained invocation)
      */
@@ -959,6 +946,7 @@ public int getTimeToLive() {
     }
 
     /**
+     * Set the time to live of cell contents for the family
      * @param timeToLive Time-to-live of cell contents, in seconds.
      * @return this (for chained invocation)
      */
@@ -967,9 +955,10 @@ public ModifyableColumnFamilyDescriptor setTimeToLive(int timeToLive) {
     }
 
     /**
+     * Set the time to live of cell contents for the family
      * @param timeToLive Time-to-live of cell contents, in seconds.
      * @return this (for chained invocation)
-     * @throws org.apache.hadoop.hbase.exceptions.HBaseException
+     * @throws org.apache.hadoop.hbase.exceptions.HBaseException if the supplied string was invalid
      */
     public ModifyableColumnFamilyDescriptor setTimeToLive(String timeToLive) throws HBaseException {
       return setTimeToLive(Integer.parseInt(PrettyPrinter.valueOf(timeToLive, Unit.TIME_INTERVAL)));
@@ -981,6 +970,7 @@ public int getMinVersions() {
     }
 
     /**
+     * Set the minimum number of versions to keep
      * @param minVersions The minimum number of versions to keep. (used when timeToLive is set)
      * @return this (for chained invocation)
      */
@@ -1010,6 +1000,7 @@ public boolean isBlockCacheEnabled() {
     }
 
     /**
+     * Enable or disable the blockcache
      * @param blockCacheEnabled True if hfile DATA type blocks should be cached (We always cache
      *                          INDEX and BLOOM blocks; you cannot turn this off).
      * @return this (for chained invocation)
@@ -1035,6 +1026,7 @@ public int getScope() {
     }
 
     /**
+     * Set the replication scope
      * @param scope the scope tag
      * @return this (for chained invocation)
      */
@@ -1049,6 +1041,7 @@ public boolean isCacheDataOnWrite() {
     }
 
     /**
+     * Enable or disable caching of data blocks on write
      * @param value true if we should cache data blocks on write
      * @return this (for chained invocation)
      */
@@ -1063,6 +1056,7 @@ public boolean isCacheIndexesOnWrite() {
     }
 
     /**
+     * Enable or disable caching of index blocks on write
      * @param value true if we should cache index blocks on write
      * @return this (for chained invocation)
      */
@@ -1077,6 +1071,7 @@ public boolean isCacheBloomsOnWrite() {
     }
 
     /**
+     * Enable or disable caching of bloom filter blocks on write
      * @param value true if we should cache bloomfilter blocks on write
      * @return this (for chained invocation)
      */
@@ -1091,6 +1086,7 @@ public boolean isEvictBlocksOnClose() {
     }
 
     /**
+     * Enable or disable block eviction at region close time
      * @param value true if we should evict cached blocks from the blockcache on close
      * @return this (for chained invocation)
      */
@@ -1105,6 +1101,7 @@ public boolean isPrefetchBlocksOnOpen() {
     }
 
     /**
+     * Enable or disable prefetch of data blocks at region open time
      * @param value true if we should prefetch blocks into the blockcache on open
      * @return this (for chained invocation)
      */
@@ -1233,7 +1230,7 @@ public int compareTo(ModifyableColumnFamilyDescriptor other) {
     }
 
     /**
-     * @return This instance serialized with pb with pb magic prefix
+     * Return this instance serialized with pb with pb magic prefix
      * @see #parseFrom(byte[])
      */
     private byte[] toByteArray() {
@@ -1241,10 +1238,11 @@ private byte[] toByteArray() {
     }
 
     /**
+     * Parse a serialized descriptor
      * @param bytes A pb serialized {@link ModifyableColumnFamilyDescriptor} instance with pb magic
      *              prefix
      * @return An instance of {@link ModifyableColumnFamilyDescriptor} made from bytes
-     *         n * @see #toByteArray()
+     * @see #toByteArray()
      */
     private static ColumnFamilyDescriptor parseFrom(final byte[] bytes)
       throws DeserializationException {
@@ -1290,8 +1288,8 @@ public ModifyableColumnFamilyDescriptor setConfiguration(String key, String valu
     }
 
     /**
-     * Remove a configuration setting represented by the key from the {@link #configuration} map. n
-     * * @return this (for chained invocation)
+     * Remove a configuration setting represented by the key from the {@link #configuration} map.
+     * @return this (for chained invocation)
      */
     public ModifyableColumnFamilyDescriptor removeConfiguration(final String key) {
       return setConfiguration(key, null);
@@ -1303,8 +1301,8 @@ public String getEncryptionType() {
     }
 
     /**
-     * Set the encryption algorithm for use with this family n * @return this (for chained
-     * invocation)
+     * Set the encryption algorithm for use with this family
+     * @return this (for chained invocation)
      */
     public ModifyableColumnFamilyDescriptor setEncryptionType(String algorithm) {
       return setValue(ENCRYPTION_BYTES, algorithm);
@@ -1316,7 +1314,8 @@ public byte[] getEncryptionKey() {
     }
 
     /**
-     * Set the raw crypto key attribute for the family n * @return this (for chained invocation)
+     * Set the raw crypto key attribute for the family
+     * @return this (for chained invocation)
      */
     public ModifyableColumnFamilyDescriptor setEncryptionKey(byte[] keyBytes) {
       return setValue(ENCRYPTION_KEY_BYTES, new Bytes(keyBytes));
diff --git a/hbase-client/src/main/java/org/apache/hadoop/hbase/client/CompactType.java b/hbase-client/src/main/java/org/apache/hadoop/hbase/client/CompactType.java
index 225bb072db70..54502e7a89c4 100644
--- a/hbase-client/src/main/java/org/apache/hadoop/hbase/client/CompactType.java
+++ b/hbase-client/src/main/java/org/apache/hadoop/hbase/client/CompactType.java
@@ -25,10 +25,6 @@
  */
 @InterfaceAudience.Public
 public enum CompactType {
-
-  NORMAL(0),
-  MOB(1);
-
-  CompactType(int value) {
-  }
+  NORMAL,
+  MOB;
 }
diff --git a/hbase-client/src/main/java/org/apache/hadoop/hbase/client/Connection.java b/hbase-client/src/main/java/org/apache/hadoop/hbase/client/Connection.java
index 385007703e2f..b48674faaab3 100644
--- a/hbase-client/src/main/java/org/apache/hadoop/hbase/client/Connection.java
+++ b/hbase-client/src/main/java/org/apache/hadoop/hbase/client/Connection.java
@@ -60,7 +60,7 @@ public interface Connection extends Abortable, Closeable {
    */
 
   /**
-   * @return Configuration instance being used by this Connection instance.
+   * Return the configuration of this connection.
    */
   Configuration getConfiguration();
 
@@ -183,7 +183,7 @@ default BufferedMutator getBufferedMutator(TableName tableName) throws IOExcepti
   AsyncConnection toAsyncConnection();
 
   /**
-   * @return the cluster ID unique to this HBase cluster.
+   * Return the cluster ID unique to this HBase cluster.
    */
   String getClusterId();
 
diff --git a/hbase-client/src/main/java/org/apache/hadoop/hbase/client/CoprocessorDescriptor.java b/hbase-client/src/main/java/org/apache/hadoop/hbase/client/CoprocessorDescriptor.java
index 3331c8107009..1ea0415e4944 100644
--- a/hbase-client/src/main/java/org/apache/hadoop/hbase/client/CoprocessorDescriptor.java
+++ b/hbase-client/src/main/java/org/apache/hadoop/hbase/client/CoprocessorDescriptor.java
@@ -29,22 +29,23 @@
 @InterfaceAudience.Public
 public interface CoprocessorDescriptor {
   /**
-   * @return the name of the class or interface represented by this object.
+   * Return the name of the class or interface represented by this object.
    */
   String getClassName();
 
   /**
-   * @return Path of the jar file. If it's null, the class will be loaded from default classloader.
+   * Return the path of the jar file. If it's null, the class will be loaded from default
+   * classloader.
    */
   Optional getJarPath();
 
   /**
-   * @return The order to execute this coprocessor
+   * Return the order to execute this coprocessor
    */
   int getPriority();
 
   /**
-   * @return Arbitrary key-value parameter pairs passed into the coprocessor.
+   * Return the coprocessor properties as a map.
    */
   Map getProperties();
 }
diff --git a/hbase-client/src/main/java/org/apache/hadoop/hbase/client/Delete.java b/hbase-client/src/main/java/org/apache/hadoop/hbase/client/Delete.java
index 755c0ca0b8c0..ecc388cc3c8d 100644
--- a/hbase-client/src/main/java/org/apache/hadoop/hbase/client/Delete.java
+++ b/hbase-client/src/main/java/org/apache/hadoop/hbase/client/Delete.java
@@ -111,8 +111,6 @@ public Delete(final byte[] row, final int rowOffset, final int rowLength) {
    * 

    * This timestamp is ONLY used for a delete row operation. If specifying families or columns, you
    * must specify each timestamp individually.
-   * @param row We make a local copy of this passed in row. nn * @param timestamp maximum version
-   *            timestamp (only for delete row)
    */
   public Delete(final byte[] row, final int rowOffset, final int rowLength, long timestamp) {
     checkRow(row, rowOffset, rowLength);
@@ -121,6 +119,7 @@ public Delete(final byte[] row, final int rowOffset, final int rowLength, long t
   }
 
   /**
+   * Create a Delete operation given another as template.
    * @param deleteToCopy delete to copy
    */
   public Delete(final Delete deleteToCopy) {
@@ -142,8 +141,9 @@ public Delete(byte[] row, long ts, NavigableMap> familyMap) {
   /**
    * Add an existing delete marker to this Delete object.
    * @param cell An existing cell of type "delete".
-   * @return this for invocation chaining n
+   * @return this for invocation chaining
    */
+  @Override
   public Delete add(Cell cell) throws IOException {
     super.add(cell);
     return this;
diff --git a/hbase-client/src/main/java/org/apache/hadoop/hbase/client/Get.java b/hbase-client/src/main/java/org/apache/hadoop/hbase/client/Get.java
index 17975ff631de..0a3bd690063f 100644
--- a/hbase-client/src/main/java/org/apache/hadoop/hbase/client/Get.java
+++ b/hbase-client/src/main/java/org/apache/hadoop/hbase/client/Get.java
@@ -445,7 +445,7 @@ public boolean equals(Object obj) {
     if (this == obj) {
       return true;
     }
-    if (obj == null || getClass() != obj.getClass()) {
+    if (!(obj instanceof Get)) {
       return false;
     }
     Row other = (Row) obj;
diff --git a/hbase-client/src/main/java/org/apache/hadoop/hbase/client/Increment.java b/hbase-client/src/main/java/org/apache/hadoop/hbase/client/Increment.java
index 11da33d8106a..21b4bbceae72 100644
--- a/hbase-client/src/main/java/org/apache/hadoop/hbase/client/Increment.java
+++ b/hbase-client/src/main/java/org/apache/hadoop/hbase/client/Increment.java
@@ -96,6 +96,7 @@ public Increment(byte[] row, long ts, NavigableMap> familyMap
    * Add the specified KeyValue to this operation.
    * @param cell individual Cell n * @throws java.io.IOException e
    */
+  @Override
   public Increment add(Cell cell) throws IOException {
     super.add(cell);
     return this;
diff --git a/hbase-client/src/main/java/org/apache/hadoop/hbase/client/IsolationLevel.java b/hbase-client/src/main/java/org/apache/hadoop/hbase/client/IsolationLevel.java
index 7804e48de9f0..3f94fc30f9c7 100644
--- a/hbase-client/src/main/java/org/apache/hadoop/hbase/client/IsolationLevel.java
+++ b/hbase-client/src/main/java/org/apache/hadoop/hbase/client/IsolationLevel.java
@@ -29,11 +29,8 @@
 @InterfaceAudience.Public
 public enum IsolationLevel {
 
-  READ_COMMITTED(1),
-  READ_UNCOMMITTED(2);
-
-  IsolationLevel(int value) {
-  }
+  READ_COMMITTED,
+  READ_UNCOMMITTED;
 
   public byte[] toBytes() {
     return new byte[] { toByte() };
diff --git a/hbase-client/src/main/java/org/apache/hadoop/hbase/client/LogQueryFilter.java b/hbase-client/src/main/java/org/apache/hadoop/hbase/client/LogQueryFilter.java
index b2d217da3de0..4cbacaafb55e 100644
--- a/hbase-client/src/main/java/org/apache/hadoop/hbase/client/LogQueryFilter.java
+++ b/hbase-client/src/main/java/org/apache/hadoop/hbase/client/LogQueryFilter.java
@@ -112,8 +112,7 @@ public boolean equals(Object o) {
     if (this == o) {
       return true;
     }
-
-    if (o == null || getClass() != o.getClass()) {
+    if (!(o instanceof LogQueryFilter)) {
       return false;
     }
 
diff --git a/hbase-client/src/main/java/org/apache/hadoop/hbase/client/MasterCoprocessorRpcChannelImpl.java b/hbase-client/src/main/java/org/apache/hadoop/hbase/client/MasterCoprocessorRpcChannelImpl.java
index 4be0362be85d..f36b3e162187 100644
--- a/hbase-client/src/main/java/org/apache/hadoop/hbase/client/MasterCoprocessorRpcChannelImpl.java
+++ b/hbase-client/src/main/java/org/apache/hadoop/hbase/client/MasterCoprocessorRpcChannelImpl.java
@@ -78,11 +78,11 @@ public void callMethod(MethodDescriptor method, RpcController controller, Messag
     Message responsePrototype, RpcCallback done) {
     addListener(
       callerBuilder.action((c, s) -> rpcCall(method, request, responsePrototype, c, s)).call(),
-      ((r, e) -> {
+      (r, e) -> {
         if (e != null) {
           ((ClientCoprocessorRpcController) controller).setFailed(e);
         }
         done.run(r);
-      }));
+      });
   }
 }
diff --git a/hbase-client/src/main/java/org/apache/hadoop/hbase/client/MasterRegistry.java b/hbase-client/src/main/java/org/apache/hadoop/hbase/client/MasterRegistry.java
index a031d3530971..917badef0568 100644
--- a/hbase-client/src/main/java/org/apache/hadoop/hbase/client/MasterRegistry.java
+++ b/hbase-client/src/main/java/org/apache/hadoop/hbase/client/MasterRegistry.java
@@ -75,6 +75,7 @@ public class MasterRegistry extends AbstractRpcBasedConnectionRegistry {
    * separated host[:port] values. If no port number if specified, default master port is assumed.
    * @param conf Configuration to parse from.
    */
+  @SuppressWarnings("StringSplitter")
   public static Set parseMasterAddrs(Configuration conf) throws UnknownHostException {
     Set masterAddrs = new HashSet<>();
     String configuredMasters = getMasterAddr(conf);
diff --git a/hbase-client/src/main/java/org/apache/hadoop/hbase/client/MultiResponse.java b/hbase-client/src/main/java/org/apache/hadoop/hbase/client/MultiResponse.java
index 97a01e1bb6ec..b9eee785dfd5 100644
--- a/hbase-client/src/main/java/org/apache/hadoop/hbase/client/MultiResponse.java
+++ b/hbase-client/src/main/java/org/apache/hadoop/hbase/client/MultiResponse.java
@@ -44,9 +44,7 @@ public MultiResponse() {
     super();
   }
 
-  /**
-   * @return Number of pairs in this container
-   */
+  /** Return the number of results in this container */
   public int size() {
     int size = 0;
     for (RegionResult result : results.values()) {
@@ -56,25 +54,30 @@ public int size() {
   }
 
   /**
-   * Add the pair to the container, grouped by the regionName n * @param originalIndex the original
-   * index of the Action (request).
-   * @param resOrEx the result or error; will be empty for successful Put and Delete actions.
+   * Add the pair to the container, grouped by the regionName
+   * @param regionName    the region
+   * @param originalIndex the original index of the Action (request).
+   * @param resOrEx       the result or error; will be empty for successful Put and Delete actions.
    */
   public void add(byte[] regionName, int originalIndex, Object resOrEx) {
     getResult(regionName).addResult(originalIndex, resOrEx);
   }
 
+  /**
+   * Add the pair to the container, grouped by the regionName
+   * @param regionName the region
+   * @param ie         the error
+   */
   public void addException(byte[] regionName, Throwable ie) {
     exceptions.put(regionName, ie);
   }
 
-  /**
-   * @return the exception for the region, if any. Null otherwise.
-   */
+  /** Return the exception for the region, if any. Null otherwise. */
   public Throwable getException(byte[] regionName) {
     return exceptions.get(regionName);
   }
 
+  /** Return all exceptions for the responses, if any. */
   public Map getExceptions() {
     return exceptions;
   }
diff --git a/hbase-client/src/main/java/org/apache/hadoop/hbase/client/MutableRegionInfo.java b/hbase-client/src/main/java/org/apache/hadoop/hbase/client/MutableRegionInfo.java
index 22114f8f624a..9556bafbc07d 100644
--- a/hbase-client/src/main/java/org/apache/hadoop/hbase/client/MutableRegionInfo.java
+++ b/hbase-client/src/main/java/org/apache/hadoop/hbase/client/MutableRegionInfo.java
@@ -126,22 +126,20 @@ private static int checkReplicaId(int regionId) {
     this.encodedNameAsBytes = Bytes.toBytes(this.encodedName);
   }
 
-  /**
-   * @return Return a short, printable name for this region (usually encoded name) for us logging.
-   */
+  /** Return a short, printable name for this region (usually encoded name) for us logging. */
   @Override
   public String getShortNameToLog() {
     return RegionInfo.prettyPrint(this.getEncodedName());
   }
 
-  /** @return the regionId */
+  /** Return the region id */
   @Override
   public long getRegionId() {
     return regionId;
   }
 
   /**
-   * @return the regionName as an array of bytes.
+   * Return the regionName as an array of bytes.
    * @see #getRegionNameAsString()
    */
   @Override
@@ -150,14 +148,14 @@ public byte[] getRegionName() {
   }
 
   /**
-   * @return Region name as a String for use in logging, etc.
+   * Return the region name as a String for use in logging, etc.
    */
   @Override
   public String getRegionNameAsString() {
     return RegionInfo.getRegionNameAsString(this, this.regionName);
   }
 
-  /** @return the encoded region name */
+  /** Return the encoded region name */
   @Override
   public String getEncodedName() {
     return this.encodedName;
@@ -168,28 +166,26 @@ public byte[] getEncodedNameAsBytes() {
     return this.encodedNameAsBytes;
   }
 
-  /** @return the startKey */
+  /** Return the start key */
   @Override
   public byte[] getStartKey() {
     return startKey;
   }
 
-  /** @return the endKey */
+  /** Return the end key */
   @Override
   public byte[] getEndKey() {
     return endKey;
   }
 
-  /**
-   * Get current table name of the region n
-   */
+  /** Return the table name of the region */
   @Override
   public TableName getTable() {
     return this.tableName;
   }
 
   /**
-   * Returns true if the given inclusive range of rows is fully contained by this region. For
+   * Return true if the given inclusive range of rows is fully contained by this region. For
    * example, if the region is foo,a,g and this is passed ["b","c"] or ["a","c"] it will return
    * true, but if this is passed ["b","z"] it will return false.
    * @throws IllegalArgumentException if the range passed is invalid (ie. end < start)
@@ -208,9 +204,7 @@ public boolean containsRange(byte[] rangeStartKey, byte[] rangeEndKey) {
     return firstKeyInRange && lastKeyInRange;
   }
 
-  /**
-   * Return true if the given row falls in this region.
-   */
+  /** Return true if the given row falls in this region. */
   @Override
   public boolean containsRow(byte[] row) {
     CellComparator cellComparator = CellComparatorImpl.getCellComparator(tableName);
@@ -219,30 +213,26 @@ public boolean containsRow(byte[] row) {
         || Bytes.equals(endKey, HConstants.EMPTY_BYTE_ARRAY));
   }
 
-  /** @return true if this region is a meta region */
+  /** Return true if this region is a meta region */
   @Override
   public boolean isMetaRegion() {
     return tableName.equals(TableName.META_TABLE_NAME);
   }
 
-  /**
-   * @return True if has been split and has daughters.
-   */
+  /** Return true if has been split and has daughters. */
   @Override
   public boolean isSplit() {
     return this.split;
   }
 
-  /**
-   * @param split set split status n
-   */
+  /** Set set split status */
   public MutableRegionInfo setSplit(boolean split) {
     this.split = split;
     return this;
   }
 
   /**
-   * @return True if this region is offline.
+   * Return true if this region is offline.
    * @deprecated since 3.0.0 and will be removed in 4.0.0
    * @see HBASE-25210
    */
@@ -255,7 +245,7 @@ public boolean isOffline() {
   /**
    * The parent of a region split is offline while split daughters hold references to the parent.
    * Offlined regions are closed.
-   * @param offLine Set online/offline status. n
+   * @param offLine Set online/offline status.
    */
   public MutableRegionInfo setOffline(boolean offLine) {
     this.offLine = offLine;
@@ -263,7 +253,7 @@ public MutableRegionInfo setOffline(boolean offLine) {
   }
 
   /**
-   * @return True if this is a split parent region.
+   * Return true if this is a split parent region.
    * @deprecated since 3.0.0 and will be removed in 4.0.0, Use {@link #isSplit()} instead.
    * @see HBASE-25210
    */
@@ -279,18 +269,12 @@ public boolean isSplitParent() {
     return true;
   }
 
-  /**
-   * Returns the region replica id
-   * @return returns region replica id
-   */
+  /** Return the region replica id */
   @Override
   public int getReplicaId() {
     return replicaId;
   }
 
-  /**
-   * @see Object#toString()
-   */
   @Override
   public String toString() {
     return "{ENCODED => " + getEncodedName() + ", " + HConstants.NAME + " => '"
@@ -300,9 +284,6 @@ public String toString() {
       + ((replicaId > 0) ? ", REPLICA_ID => " + replicaId : "") + "}";
   }
 
-  /**
-   * @see Object#equals(Object)
-   */
   @Override
   public boolean equals(Object o) {
     if (this == o) {
@@ -317,9 +298,6 @@ public boolean equals(Object o) {
     return compareTo((RegionInfo) o) == 0;
   }
 
-  /**
-   * @see Object#hashCode()
-   */
   @Override
   public int hashCode() {
     return this.hashCode;
diff --git a/hbase-client/src/main/java/org/apache/hadoop/hbase/client/Mutation.java b/hbase-client/src/main/java/org/apache/hadoop/hbase/client/Mutation.java
index cecaed3388cc..5484649f03d1 100644
--- a/hbase-client/src/main/java/org/apache/hadoop/hbase/client/Mutation.java
+++ b/hbase-client/src/main/java/org/apache/hadoop/hbase/client/Mutation.java
@@ -156,27 +156,23 @@ List getCellList(byte[] family) {
     return list;
   }
 
-  /*
+  /**
    * Create a KeyValue with this objects row key and the Put identifier.
-   * @return a KeyValue with this objects row key and the Put identifier.
    */
   KeyValue createPutKeyValue(byte[] family, byte[] qualifier, long ts, byte[] value) {
     return new KeyValue(this.row, family, qualifier, ts, KeyValue.Type.Put, value);
   }
 
   /**
-   * Create a KeyValue with this objects row key and the Put identifier. nnnn * @param tags -
-   * Specify the Tags as an Array
-   * @return a KeyValue with this objects row key and the Put identifier.
+   * Create a KeyValue with this objects row key and the Put identifier.
    */
   KeyValue createPutKeyValue(byte[] family, byte[] qualifier, long ts, byte[] value, Tag[] tags) {
     KeyValue kvWithTag = new KeyValue(this.row, family, qualifier, ts, value, tags);
     return kvWithTag;
   }
 
-  /*
+  /**
    * Create a KeyValue with this objects row key and the Put identifier.
-   * @return a KeyValue with this objects row key and the Put identifier.
    */
   KeyValue createPutKeyValue(byte[] family, ByteBuffer qualifier, long ts, ByteBuffer value,
     Tag[] tags) {
@@ -261,7 +257,7 @@ private static Map cellToStringMap(Cell c) {
     if (tags != null) {
       List tagsString = new ArrayList<>(tags.size());
       for (Tag t : tags) {
-        tagsString.add((t.getType()) + ":" + Bytes.toStringBinary(Tag.cloneValue(t)));
+        tagsString.add(t.getType() + ":" + Bytes.toStringBinary(Tag.cloneValue(t)));
       }
       stringMap.put("tag", tagsString);
     }
@@ -327,7 +323,7 @@ public Mutation setClusterIds(List clusterIds) {
   }
 
   /**
-   * @return the set of clusterIds that have consumed the mutation
+   * Return the set of clusterIds that have consumed the mutation.
    */
   public List getClusterIds() {
     List clusterIds = new ArrayList<>();
@@ -343,7 +339,7 @@ public List getClusterIds() {
   }
 
   /**
-   * Sets the visibility expression associated with cells in this Mutation. n
+   * Sets the visibility expression associated with cells in this Mutation.
    */
   public Mutation setCellVisibility(CellVisibility expression) {
     this.setAttribute(VisibilityConstants.VISIBILITY_LABELS_ATTR_KEY,
@@ -352,7 +348,7 @@ public Mutation setCellVisibility(CellVisibility expression) {
   }
 
   /**
-   * @return CellVisibility associated with cells in this Mutation. n
+   * Return the cell visibility associated with cells in this Mutation.
    */
   public CellVisibility getCellVisibility() throws DeserializationException {
     byte[] cellVisibilityBytes = this.getAttribute(VisibilityConstants.VISIBILITY_LABELS_ATTR_KEY);
@@ -360,29 +356,17 @@ public CellVisibility getCellVisibility() throws DeserializationException {
     return toCellVisibility(cellVisibilityBytes);
   }
 
-  /**
-   * Create a protocol buffer CellVisibility based on a client CellVisibility. n * @return a
-   * protocol buffer CellVisibility
-   */
   static ClientProtos.CellVisibility toCellVisibility(CellVisibility cellVisibility) {
     ClientProtos.CellVisibility.Builder builder = ClientProtos.CellVisibility.newBuilder();
     builder.setExpression(cellVisibility.getExpression());
     return builder.build();
   }
 
-  /**
-   * Convert a protocol buffer CellVisibility to a client CellVisibility n * @return the converted
-   * client CellVisibility
-   */
   private static CellVisibility toCellVisibility(ClientProtos.CellVisibility proto) {
     if (proto == null) return null;
     return new CellVisibility(proto.getExpression());
   }
 
-  /**
-   * Convert a protocol buffer CellVisibility bytes to a client CellVisibility n * @return the
-   * converted client CellVisibility n
-   */
   private static CellVisibility toCellVisibility(byte[] protoBytes)
     throws DeserializationException {
     if (protoBytes == null) return null;
@@ -410,14 +394,14 @@ public int size() {
   }
 
   /**
-   * @return the number of different families
+   * Return the number of different families
    */
   public int numFamilies() {
     return getFamilyCellMap().size();
   }
 
   /**
-   * @return Calculate what Mutation adds to class heap size.
+   * Calculate and return what the Mutation adds to class heap size.
    */
   @Override
   public long heapSize() {
@@ -448,13 +432,14 @@ public long heapSize() {
   }
 
   /**
-   * @return The serialized ACL for this operation, or null if none
+   * Return the serialized ACL for this operation, or null if none
    */
   public byte[] getACL() {
     return getAttribute(AccessControlConstants.OP_ATTRIBUTE_ACL);
   }
 
   /**
+   * Set an ACL for this operation.
    * @param user  User short name
    * @param perms Permissions for the user
    */
@@ -465,6 +450,7 @@ public Mutation setACL(String user, Permission perms) {
   }
 
   /**
+   * Set an ACL for this operation.
    * @param perms A map of permissions for a user or users
    */
   public Mutation setACL(Map perms) {
@@ -499,9 +485,6 @@ public Mutation setTTL(long ttl) {
     return this;
   }
 
-  /**
-   * @return current value for returnResults
-   */
   // Used by Increment and Append only.
   @InterfaceAudience.Private
   protected boolean isReturnResults() {
@@ -509,8 +492,8 @@ protected boolean isReturnResults() {
     return v == null ? true : Bytes.toBoolean(v);
   }
 
-  @InterfaceAudience.Private
   // Used by Increment and Append only.
+  @InterfaceAudience.Private
   protected Mutation setReturnResults(boolean returnResults) {
     setAttribute(RETURN_RESULTS, Bytes.toBytes(returnResults));
     return this;
@@ -608,7 +591,7 @@ public List get(byte[] family, byte[] qualifier) {
     return filteredList;
   }
 
-  /*
+  /**
    * Private method to determine if this object's familyMap contains the given value assigned to the
    * given family, qualifier and timestamp respecting the 2 boolean arguments nnnnnn * @return
    * returns true if the given family, qualifier timestamp and value already has an existing
diff --git a/hbase-client/src/main/java/org/apache/hadoop/hbase/client/NonceGenerator.java b/hbase-client/src/main/java/org/apache/hadoop/hbase/client/NonceGenerator.java
index 3020be221059..75123eefe660 100644
--- a/hbase-client/src/main/java/org/apache/hadoop/hbase/client/NonceGenerator.java
+++ b/hbase-client/src/main/java/org/apache/hadoop/hbase/client/NonceGenerator.java
@@ -29,9 +29,9 @@ public interface NonceGenerator {
 
   static final String CLIENT_NONCES_ENABLED_KEY = "hbase.client.nonces.enabled";
 
-  /** @return the nonce group (client ID) of this client manager. */
+  /** Return the nonce group (client ID) of this client manager. */
   long getNonceGroup();
 
-  /** @return New nonce. */
+  /** Return a new nonce. */
   long newNonce();
 }
diff --git a/hbase-client/src/main/java/org/apache/hadoop/hbase/client/Put.java b/hbase-client/src/main/java/org/apache/hadoop/hbase/client/Put.java
index bcc1bda9ef02..5e821f075461 100644
--- a/hbase-client/src/main/java/org/apache/hadoop/hbase/client/Put.java
+++ b/hbase-client/src/main/java/org/apache/hadoop/hbase/client/Put.java
@@ -203,6 +203,7 @@ public Put addColumn(byte[] family, ByteBuffer qualifier, long ts, ByteBuffer va
    * immutable and its backing array will not be modified for the duration of this Put.
    * @param cell individual cell n * @throws java.io.IOException e
    */
+  @Override
   public Put add(Cell cell) throws IOException {
     super.add(cell);
     return this;
diff --git a/hbase-client/src/main/java/org/apache/hadoop/hbase/client/Query.java b/hbase-client/src/main/java/org/apache/hadoop/hbase/client/Query.java
index ab0d9887df2b..757842e0d4eb 100644
--- a/hbase-client/src/main/java/org/apache/hadoop/hbase/client/Query.java
+++ b/hbase-client/src/main/java/org/apache/hadoop/hbase/client/Query.java
@@ -67,7 +67,7 @@ public Query setFilter(Filter filter) {
   }
 
   /**
-   * Sets the authorizations to be used by this Query n
+   * Sets the authorizations to be used by this Query.
    */
   public Query setAuthorizations(Authorizations authorizations) {
     this.setAttribute(VisibilityConstants.VISIBILITY_LABELS_ATTR_KEY,
@@ -76,7 +76,7 @@ public Query setAuthorizations(Authorizations authorizations) {
   }
 
   /**
-   * @return The authorizations this Query is associated with. n
+   * Return the authorizations this Query is associated with.
    */
   public Authorizations getAuthorizations() throws DeserializationException {
     byte[] authorizationsBytes = this.getAttribute(VisibilityConstants.VISIBILITY_LABELS_ATTR_KEY);
@@ -85,6 +85,7 @@ public Authorizations getAuthorizations() throws DeserializationException {
   }
 
   /**
+   * Get the ACL for the operation.
    * @return The serialized ACL for this operation, or null if none
    */
   public byte[] getACL() {
@@ -92,6 +93,7 @@ public byte[] getACL() {
   }
 
   /**
+   * Set the ACL for the operation.
    * @param user  User short name
    * @param perms Permissions for the user
    */
@@ -102,6 +104,7 @@ public Query setACL(String user, Permission perms) {
   }
 
   /**
+   * Set the ACL for the operation.
    * @param perms A map of permissions for a user or users
    */
   public Query setACL(Map perms) {
@@ -163,9 +166,8 @@ public Query setIsolationLevel(IsolationLevel level) {
   }
 
   /**
-   * @return The isolation level of this query. If no isolation level was set for this query object,
-   *         then it returns READ_COMMITTED.
-   * @return The IsolationLevel for this query
+   * Return the isolation level of this query. If no isolation level was set for this query object,
+   * then it returns READ_COMMITTED.
    */
   public IsolationLevel getIsolationLevel() {
     byte[] attr = getAttribute(ISOLATION_LEVEL);
@@ -221,7 +223,7 @@ public Query setColumnFamilyTimeRange(byte[] cf, long minStamp, long maxStamp) {
   }
 
   /**
-   * @return A map of column families to time ranges
+   * Return a map of column families to time ranges
    */
   public Map getColumnFamilyTimeRange() {
     return this.colFamTimeRangeMap;
diff --git a/hbase-client/src/main/java/org/apache/hadoop/hbase/client/RawAsyncHBaseAdmin.java b/hbase-client/src/main/java/org/apache/hadoop/hbase/client/RawAsyncHBaseAdmin.java
index 3ec2c741293e..028808ce8baf 100644
--- a/hbase-client/src/main/java/org/apache/hadoop/hbase/client/RawAsyncHBaseAdmin.java
+++ b/hbase-client/src/main/java/org/apache/hadoop/hbase/client/RawAsyncHBaseAdmin.java
@@ -502,11 +502,6 @@ private  CompletableFuture procedureCall(
     return future;
   }
 
-  @FunctionalInterface
-  private interface TableOperator {
-    CompletableFuture operate(TableName table);
-  }
-
   @Override
   public CompletableFuture tableExists(TableName tableName) {
     if (TableName.isMetaTableName(tableName)) {
@@ -730,6 +725,7 @@ private static CompletableFuture completeCheckTableState(
   }
 
   @Override
+  @SuppressWarnings("FutureReturnValueIgnored")
   public CompletableFuture isTableEnabled(TableName tableName) {
     if (TableName.isMetaTableName(tableName)) {
       return CompletableFuture.completedFuture(true);
@@ -744,6 +740,7 @@ public CompletableFuture isTableEnabled(TableName tableName) {
   }
 
   @Override
+  @SuppressWarnings("FutureReturnValueIgnored")
   public CompletableFuture isTableDisabled(TableName tableName) {
     if (TableName.isMetaTableName(tableName)) {
       return CompletableFuture.completedFuture(false);
@@ -1559,11 +1556,13 @@ public CompletableFuture assign(byte[] regionName) {
         future.completeExceptionally(err);
         return;
       }
-      addListener(this. newMasterCaller().priority(regionInfo.getTable())
-        .action(((controller, stub) -> this. call(
-          controller, stub, RequestConverter.buildAssignRegionRequest(regionInfo.getRegionName()),
-          (s, c, req, done) -> s.assignRegion(c, req, done), resp -> null)))
-        .call(), (ret, err2) -> {
+      addListener(
+        this. newMasterCaller().priority(regionInfo.getTable())
+          .action((controller, stub) -> this. call(
+            controller, stub, RequestConverter.buildAssignRegionRequest(regionInfo.getRegionName()),
+            (s, c, req, done) -> s.assignRegion(c, req, done), resp -> null))
+          .call(),
+        (ret, err2) -> {
           if (err2 != null) {
             future.completeExceptionally(err2);
           } else {
@@ -1584,10 +1583,10 @@ public CompletableFuture unassign(byte[] regionName) {
       }
       addListener(
         this. newMasterCaller().priority(regionInfo.getTable())
-          .action(((controller, stub) -> this. this. call(controller, stub,
               RequestConverter.buildUnassignRegionRequest(regionInfo.getRegionName()),
-              (s, c, req, done) -> s.unassignRegion(c, req, done), resp -> null)))
+              (s, c, req, done) -> s.unassignRegion(c, req, done), resp -> null))
           .call(),
         (ret, err2) -> {
           if (err2 != null) {
@@ -1608,14 +1607,11 @@ public CompletableFuture offline(byte[] regionName) {
         future.completeExceptionally(err);
         return;
       }
-      addListener(
-        this. newMasterCaller().priority(regionInfo.getTable())
-          .action(((controller, stub) -> this. call(controller, stub,
-              RequestConverter.buildOfflineRegionRequest(regionInfo.getRegionName()),
-              (s, c, req, done) -> s.offlineRegion(c, req, done), resp -> null)))
-          .call(),
-        (ret, err2) -> {
+      addListener(this. newMasterCaller().priority(regionInfo.getTable())
+        .action((controller, stub) -> this. call(
+          controller, stub, RequestConverter.buildOfflineRegionRequest(regionInfo.getRegionName()),
+          (s, c, req, done) -> s.offlineRegion(c, req, done), resp -> null))
+        .call(), (ret, err2) -> {
           if (err2 != null) {
             future.completeExceptionally(err2);
           } else {
@@ -2236,7 +2232,7 @@ private CompletableFuture internalDeleteSnapshots(Pattern tableNamePattern
       listSnapshotsFuture = getCompletedSnapshots(tableNamePattern, snapshotNamePattern);
     }
     CompletableFuture future = new CompletableFuture<>();
-    addListener(listSnapshotsFuture, ((snapshotDescriptions, err) -> {
+    addListener(listSnapshotsFuture, (snapshotDescriptions, err) -> {
       if (err != null) {
         future.completeExceptionally(err);
         return;
@@ -2253,7 +2249,7 @@ private CompletableFuture internalDeleteSnapshots(Pattern tableNamePattern
             future.complete(v);
           }
         });
-    }));
+    });
     return future;
   }
 
@@ -4010,10 +4006,9 @@ public CompletableFuture moveServersToRSGroup(Set
 servers, String
   @Override
   public CompletableFuture addRSGroup(String groupName) {
     return this. newMasterCaller()
-      .action(
-        ((controller, stub) -> this. call(controller,
-          stub, AddRSGroupRequest.newBuilder().setRSGroupName(groupName).build(),
-          (s, c, req, done) -> s.addRSGroup(c, req, done), resp -> null)))
+      .action((controller, stub) -> this. call(
+        controller, stub, AddRSGroupRequest.newBuilder().setRSGroupName(groupName).build(),
+        (s, c, req, done) -> s.addRSGroup(c, req, done), resp -> null))
       .call();
   }
 
@@ -4081,9 +4076,9 @@ private CompletableFuture> getSlowLogResponseFromServer(ServerNam
 
   private CompletableFuture clearSlowLogsResponses(final ServerName serverName) {
     return this. newAdminCaller()
-      .action(((controller, stub) -> this.adminCall(controller, stub,
+      .action((controller, stub) -> this.adminCall(controller, stub,
         RequestConverter.buildClearSlowLogResponseRequest(),
-        AdminService.Interface::clearSlowLogsResponses, ProtobufUtil::toClearSlowLogPayload)))
+        AdminService.Interface::clearSlowLogsResponses, ProtobufUtil::toClearSlowLogPayload))
       .serverName(serverName).call();
   }
 
@@ -4124,15 +4119,14 @@ Pair, List>> call(controller, stub,
   @Override
   public CompletableFuture getRSGroup(Address hostPort) {
     return this. newMasterCaller()
-      .action(
-        ((controller, stub) -> this. call(controller, stub, GetRSGroupInfoOfServerRequest.newBuilder()
+      .action((controller, stub) -> this. call(controller, stub,
+          GetRSGroupInfoOfServerRequest.newBuilder()
             .setServer(HBaseProtos.ServerName.newBuilder().setHostName(hostPort.getHostname())
               .setPort(hostPort.getPort()).build())
-            .build(), (s, c, req, done) -> s.getRSGroupInfoOfServer(c, req, done),
-            resp -> resp.hasRSGroupInfo()
-              ? ProtobufUtil.toGroupInfo(resp.getRSGroupInfo())
-              : null)))
+            .build(),
+          (s, c, req, done) -> s.getRSGroupInfoOfServer(c, req, done),
+          resp -> resp.hasRSGroupInfo() ? ProtobufUtil.toGroupInfo(resp.getRSGroupInfo()) : null))
       .call();
   }
 
@@ -4160,7 +4154,7 @@ public CompletableFuture setRSGroup(Set tables, String groupNam
         }
       });
     }
-    addListener(listTableDescriptors(new ArrayList<>(tables)), ((tableDescriptions, err) -> {
+    addListener(listTableDescriptors(new ArrayList<>(tables)), (tableDescriptions, err) -> {
       if (err != null) {
         future.completeExceptionally(err);
         return;
@@ -4184,40 +4178,40 @@ public CompletableFuture setRSGroup(Set tables, String groupNam
             future.complete(v);
           }
         });
-    }));
+    });
     return future;
   }
 
   @Override
   public CompletableFuture getRSGroup(TableName table) {
     return this. newMasterCaller()
-      .action(((controller, stub) -> this. this. call(controller, stub,
           GetRSGroupInfoOfTableRequest.newBuilder()
             .setTableName(ProtobufUtil.toProtoTableName(table)).build(),
           (s, c, req, done) -> s.getRSGroupInfoOfTable(c, req, done),
-          resp -> resp.hasRSGroupInfo() ? ProtobufUtil.toGroupInfo(resp.getRSGroupInfo()) : null)))
+          resp -> resp.hasRSGroupInfo() ? ProtobufUtil.toGroupInfo(resp.getRSGroupInfo()) : null))
       .call();
   }
 
   @Override
   public CompletableFuture getRSGroup(String groupName) {
     return this. newMasterCaller()
-      .action(((controller, stub) -> this. this. call(controller, stub,
           GetRSGroupInfoRequest.newBuilder().setRSGroupName(groupName).build(),
           (s, c, req, done) -> s.getRSGroupInfo(c, req, done),
-          resp -> resp.hasRSGroupInfo() ? ProtobufUtil.toGroupInfo(resp.getRSGroupInfo()) : null)))
+          resp -> resp.hasRSGroupInfo() ? ProtobufUtil.toGroupInfo(resp.getRSGroupInfo()) : null))
       .call();
   }
 
   @Override
   public CompletableFuture renameRSGroup(String oldName, String newName) {
     return this. newMasterCaller()
-      .action(((controller, stub) -> this. call(
+      .action((controller, stub) -> this. call(
         controller, stub, RenameRSGroupRequest.newBuilder().setOldRsgroupName(oldName)
           .setNewRsgroupName(newName).build(),
-        (s, c, req, done) -> s.renameRSGroup(c, req, done), resp -> null)))
+        (s, c, req, done) -> s.renameRSGroup(c, req, done), resp -> null))
       .call();
   }
 
@@ -4231,9 +4225,9 @@ public CompletableFuture updateRSGroupConfig(String groupName,
         NameStringPair.newBuilder().setName(e.getKey()).setValue(e.getValue()).build()));
     }
     return this. newMasterCaller()
-      .action(((controller, stub) -> this. this. call(controller, stub, request.build(),
-          (s, c, req, done) -> s.updateRSGroupConfig(c, req, done), resp -> null)))
+          (s, c, req, done) -> s.updateRSGroupConfig(c, req, done), resp -> null))
       .call();
   }
 
@@ -4287,9 +4281,9 @@ public CompletableFuture> getLogEntries(Set serverNam
   public CompletableFuture flushMasterStore() {
     FlushMasterStoreRequest.Builder request = FlushMasterStoreRequest.newBuilder();
     return this. newMasterCaller()
-      .action(((controller, stub) -> this. this. call(controller, stub, request.build(),
-          (s, c, req, done) -> s.flushMasterStore(c, req, done), resp -> null)))
+          (s, c, req, done) -> s.flushMasterStore(c, req, done), resp -> null))
       .call();
   }
 }
diff --git a/hbase-client/src/main/java/org/apache/hadoop/hbase/client/RawAsyncTableImpl.java b/hbase-client/src/main/java/org/apache/hadoop/hbase/client/RawAsyncTableImpl.java
index af0b20908031..ff75c0725ce5 100644
--- a/hbase-client/src/main/java/org/apache/hadoop/hbase/client/RawAsyncTableImpl.java
+++ b/hbase-client/src/main/java/org/apache/hadoop/hbase/client/RawAsyncTableImpl.java
@@ -776,7 +776,7 @@ private boolean locateFinished(RegionInfo region, byte[] endKey, boolean endKeyI
       int c = Bytes.compareTo(endKey, region.getEndKey());
       // 1. if the region contains endKey
       // 2. endKey is equal to the region's endKey and we do not want to include endKey.
-      return c < 0 || c == 0 && !endKeyInclusive;
+      return c < 0 || (c == 0 && !endKeyInclusive);
     }
   }
 
diff --git a/hbase-client/src/main/java/org/apache/hadoop/hbase/client/RegionCoprocessorServiceExec.java b/hbase-client/src/main/java/org/apache/hadoop/hbase/client/RegionCoprocessorServiceExec.java
index 4bf726079463..de3bc9a90d4a 100644
--- a/hbase-client/src/main/java/org/apache/hadoop/hbase/client/RegionCoprocessorServiceExec.java
+++ b/hbase-client/src/main/java/org/apache/hadoop/hbase/client/RegionCoprocessorServiceExec.java
@@ -92,7 +92,7 @@ public boolean equals(Object obj) {
     if (this == obj) {
       return true;
     }
-    if (obj == null || getClass() != obj.getClass()) {
+    if (!(obj instanceof RegionCoprocessorServiceExec)) {
       return false;
     }
     return compareTo((RegionCoprocessorServiceExec) obj) == 0;
diff --git a/hbase-client/src/main/java/org/apache/hadoop/hbase/client/RegionInfo.java b/hbase-client/src/main/java/org/apache/hadoop/hbase/client/RegionInfo.java
index ca1db64719e0..9bbef1cdcc99 100644
--- a/hbase-client/src/main/java/org/apache/hadoop/hbase/client/RegionInfo.java
+++ b/hbase-client/src/main/java/org/apache/hadoop/hbase/client/RegionInfo.java
@@ -152,63 +152,63 @@ public interface RegionInfo extends Comparable {
   };
 
   /**
-   * @return Return a short, printable name for this region (usually encoded name) for us logging.
+   * Return a short, printable name for this region (usually encoded name) for us logging.
    */
   String getShortNameToLog();
 
   /**
-   * @return the regionId.
+   * Return the region id.
    */
   long getRegionId();
 
   /**
-   * @return the regionName as an array of bytes.
+   * Return the regionName as an array of bytes.
    * @see #getRegionNameAsString()
    */
   byte[] getRegionName();
 
   /**
-   * @return Region name as a String for use in logging, etc.
+   * Return the region name as a String for use in logging, etc.
    */
   String getRegionNameAsString();
 
   /**
-   * @return the encoded region name.
+   * Return the encoded region name.
    */
   String getEncodedName();
 
   /**
-   * @return the encoded region name as an array of bytes.
+   * Return the encoded region name as an array of bytes.
    */
   byte[] getEncodedNameAsBytes();
 
   /**
-   * @return the startKey.
+   * Return the startKey.
    */
   byte[] getStartKey();
 
   /**
-   * @return the endKey.
+   * Return the endKey.
    */
   byte[] getEndKey();
 
   /**
-   * @return current table name of the region
+   * Return the current table name of the region.
    */
   TableName getTable();
 
   /**
-   * @return returns region replica id
+   * Return the region replica id.
    */
   int getReplicaId();
 
   /**
-   * @return True if has been split and has daughters.
+   * Return true if the region has been split and has daughters.
    */
   boolean isSplit();
 
   /**
-   * @return True if this region is offline.
+   * Return true if this region is offline.
    * @deprecated since 3.0.0 and will be removed in 4.0.0
    * @see HBASE-25210
    */
@@ -216,7 +216,7 @@ public interface RegionInfo extends Comparable {
   boolean isOffline();
 
   /**
-   * @return True if this is a split parent region.
+   * Return true if this is a split parent region.
    * @deprecated since 3.0.0 and will be removed in 4.0.0, Use {@link #isSplit()} instead.
    * @see HBASE-25210
    */
@@ -224,20 +224,21 @@ public interface RegionInfo extends Comparable {
   boolean isSplitParent();
 
   /**
-   * @return true if this region is a meta region.
+   * Return true if this region is a meta region.
    */
   boolean isMetaRegion();
 
   /**
-   * @return true if the given inclusive range of rows is fully contained by this region. For
-   *         example, if the region is foo,a,g and this is passed ["b","c"] or ["a","c"] it will
-   *         return true, but if this is passed ["b","z"] it will return false.
+   * Return true if the given inclusive range of rows is fully contained by this region.
+   * 

+   * For example, if the region is foo,a,g and this is passed ["b","c"] or ["a","c"] it will return
+   * true, but if this is passed ["b","z"] it will return false.
    * @throws IllegalArgumentException if the range passed is invalid (ie. end < start)
    */
   boolean containsRange(byte[] rangeStartKey, byte[] rangeEndKey);
 
   /**
-   * @return true if the given row falls in this region.
+   * Return true if the given row falls in this region.
    */
   boolean containsRow(byte[] row);
 
@@ -254,7 +255,7 @@ static boolean hasEncodedName(final byte[] regionName) {
   }
 
   /**
-   * @return the encodedName
+   * Return the encoded region name.
    */
   @InterfaceAudience.Private
   static String encodeRegionName(final byte[] regionName) {
@@ -295,16 +296,16 @@ static String getRegionNameAsString(@CheckForNull RegionInfo ri, byte[] regionNa
   }
 
   /**
-   * @return Return a String of short, printable names for hris (usually encoded name)
-   *         for us logging.
+   * Return a String of short, printable names for hris (usually encoded name) for us
+   * logging.
    */
   static String getShortNameToLog(RegionInfo... hris) {
     return getShortNameToLog(Arrays.asList(hris));
   }
 
   /**
-   * @return Return a String of short, printable names for hris (usually encoded name)
-   *         for us logging.
+   * Return a String of short, printable names for hris (usually encoded name) for us
+   * logging.
    */
   static String getShortNameToLog(final List ris) {
     return ris.stream().map(RegionInfo::getEncodedName).collect(Collectors.toList()).toString();
@@ -371,7 +372,7 @@ public static boolean isEncodedRegionName(byte[] regionName) {
   }
 
   /**
-   * @return A deserialized {@link RegionInfo} or null if we failed deserialize or passed bytes null
+   * Return a deserialized {@link RegionInfo} or null if we failed deserialize or passed bytes null
    */
   @InterfaceAudience.Private
   static RegionInfo parseFromOrNull(final byte[] bytes) {
@@ -380,7 +381,7 @@ static RegionInfo parseFromOrNull(final byte[] bytes) {
   }
 
   /**
-   * @return A deserialized {@link RegionInfo} or null if we failed deserialize or passed bytes null
+   * Return a deserialized {@link RegionInfo} or null if we failed deserialize or passed bytes null
    */
   @InterfaceAudience.Private
   static RegionInfo parseFromOrNull(final byte[] bytes, int offset, int len) {
@@ -393,8 +394,8 @@ static RegionInfo parseFromOrNull(final byte[] bytes, int offset, int len) {
   }
 
   /**
+   * Return a deserialized {@link RegionInfo}
    * @param bytes A pb RegionInfo serialized with a pb magic prefix.
-   * @return A deserialized {@link RegionInfo}
    */
   @InterfaceAudience.Private
   static RegionInfo parseFrom(final byte[] bytes) throws DeserializationException {
@@ -403,10 +404,10 @@ static RegionInfo parseFrom(final byte[] bytes) throws DeserializationException
   }
 
   /**
+   * Return a deserialized {@link RegionInfo}
    * @param bytes  A pb RegionInfo serialized with a pb magic prefix.
    * @param offset starting point in the byte array
    * @param len    length to read on the byte array
-   * @return A deserialized {@link RegionInfo}
    */
   @InterfaceAudience.Private
   static RegionInfo parseFrom(final byte[] bytes, int offset, int len)
@@ -447,7 +448,7 @@ static boolean areAdjacent(RegionInfo regionA, RegionInfo regionB) {
   }
 
   /**
-   * @return This instance serialized as protobuf w/ a magic pb prefix.
+   * Return this instance serialized as protobuf with a magic pb prefix.
    * @see #parseFrom(byte[])
    */
   static byte[] toByteArray(RegionInfo ri) {
@@ -765,21 +766,21 @@ static List parseDelimitedFrom(final byte[] bytes, final int offset,
   }
 
   /**
-   * @return True if this is first Region in Table
+   * Return true if this is first Region in Table
    */
   default boolean isFirst() {
     return Bytes.equals(getStartKey(), HConstants.EMPTY_START_ROW);
   }
 
   /**
-   * @return True if this is last Region in Table
+   * Return true if this is last Region in Table
    */
   default boolean isLast() {
     return Bytes.equals(getEndKey(), HConstants.EMPTY_END_ROW);
   }
 
   /**
-   * @return True if region is next, adjacent but 'after' this one.
+   * Return true if region is next, adjacent but 'after' this one.
    * @see #isAdjacent(RegionInfo)
    * @see #areAdjacent(RegionInfo, RegionInfo)
    */
@@ -788,7 +789,7 @@ default boolean isNext(RegionInfo after) {
   }
 
   /**
-   * @return True if region is adjacent, either just before or just after this one.
+   * Return true if region is adjacent, either just before or just after this one.
    * @see #isNext(RegionInfo)
    */
   default boolean isAdjacent(RegionInfo other) {
@@ -796,14 +797,14 @@ default boolean isAdjacent(RegionInfo other) {
   }
 
   /**
-   * @return True if RegionInfo is degenerate... if startKey > endKey.
+   * Return true if RegionInfo is degenerate... if startKey > endKey.
    */
   default boolean isDegenerate() {
     return !isLast() && Bytes.compareTo(getStartKey(), getEndKey()) > 0;
   }
 
   /**
-   * @return True if an overlap in region range.
+   * Return true if an overlap in region range.
    * @see #isDegenerate()
    */
   default boolean isOverlap(RegionInfo other) {
@@ -829,7 +830,9 @@ default boolean isOverlap(RegionInfo other) {
     return Bytes.compareTo(getStartKey(), other.getEndKey()) < 0;
   }
 
+  @Override
   default int compareTo(RegionInfo other) {
     return RegionInfo.COMPARATOR.compare(this, other);
   }
+
 }
diff --git a/hbase-client/src/main/java/org/apache/hadoop/hbase/client/RegionReplicaUtil.java b/hbase-client/src/main/java/org/apache/hadoop/hbase/client/RegionReplicaUtil.java
index ea0228209500..850d37daae15 100644
--- a/hbase-client/src/main/java/org/apache/hadoop/hbase/client/RegionReplicaUtil.java
+++ b/hbase-client/src/main/java/org/apache/hadoop/hbase/client/RegionReplicaUtil.java
@@ -51,7 +51,7 @@ public class RegionReplicaUtil {
   /**
    * Returns the RegionInfo for the given replicaId. RegionInfo's correspond to a range of a table,
    * but more than one "instance" of the same range can be deployed which are differentiated by the
-   * replicaId. n * @param replicaId the replicaId to use
+   * replicaId.
    * @return an RegionInfo object corresponding to the same range (table, start and end key), but
    *         for the given replicaId.
    */
@@ -73,19 +73,17 @@ public static RegionInfo getRegionInfoForDefaultReplica(RegionInfo regionInfo) {
     return getRegionInfoForReplica(regionInfo, DEFAULT_REPLICA_ID);
   }
 
-  /** @return true if this replicaId corresponds to default replica for the region */
+  /** Return true if this replicaId corresponds to default replica for the region */
   public static boolean isDefaultReplica(int replicaId) {
     return DEFAULT_REPLICA_ID == replicaId;
   }
 
-  /** @return true if this region is a default replica for the region */
+  /** Return true if this region is a default replica for the region */
   public static boolean isDefaultReplica(RegionInfo hri) {
     return hri.getReplicaId() == DEFAULT_REPLICA_ID;
   }
 
-  /**
-   * Removes the non-default replicas from the passed regions collection n
-   */
+  /** Removes the non-default replicas from the passed regions collection */
   public static void removeNonDefaultRegions(Collection regions) {
     Iterator iterator = regions.iterator();
     while (iterator.hasNext()) {
@@ -149,7 +147,7 @@ public static List addReplicas(final List regions, int o
     if ((newReplicaCount - 1) <= 0) {
       return regions;
     }
-    List hRegionInfos = new ArrayList<>((newReplicaCount) * regions.size());
+    List hRegionInfos = new ArrayList<>(newReplicaCount * regions.size());
     for (RegionInfo ri : regions) {
       if (
         RegionReplicaUtil.isDefaultReplica(ri)
diff --git a/hbase-client/src/main/java/org/apache/hadoop/hbase/client/RegionServerCoprocessorRpcChannelImpl.java b/hbase-client/src/main/java/org/apache/hadoop/hbase/client/RegionServerCoprocessorRpcChannelImpl.java
index 29b092cad883..ed5fd16dab3f 100644
--- a/hbase-client/src/main/java/org/apache/hadoop/hbase/client/RegionServerCoprocessorRpcChannelImpl.java
+++ b/hbase-client/src/main/java/org/apache/hadoop/hbase/client/RegionServerCoprocessorRpcChannelImpl.java
@@ -78,11 +78,11 @@ public void callMethod(MethodDescriptor method, RpcController controller, Messag
     Message responsePrototype, RpcCallback done) {
     addListener(
       callerBuilder.action((c, s) -> rpcCall(method, request, responsePrototype, c, s)).call(),
-      ((r, e) -> {
+      (r, e) -> {
         if (e != null) {
           ((ClientCoprocessorRpcController) controller).setFailed(e);
         }
         done.run(r);
-      }));
+      });
   }
 }
diff --git a/hbase-client/src/main/java/org/apache/hadoop/hbase/client/RequestController.java b/hbase-client/src/main/java/org/apache/hadoop/hbase/client/RequestController.java
index 66d864be7d49..9ddddf0711aa 100644
--- a/hbase-client/src/main/java/org/apache/hadoop/hbase/client/RequestController.java
+++ b/hbase-client/src/main/java/org/apache/hadoop/hbase/client/RequestController.java
@@ -67,9 +67,7 @@ public interface Checker {
     void reset() throws InterruptedIOException;
   }
 
-  /**
-   * @return A new checker for evaluating a batch rows.
-   */
+  /** Return a new checker for evaluating a batch rows. */
   Checker newChecker();
 
   /**
@@ -86,9 +84,7 @@ public interface Checker {
    */
   void decTaskCounters(Collection regions, ServerName sn);
 
-  /**
-   * @return The number of running task.
-   */
+  /** Return The number of running tasks. */
   long getNumberOfTasksInProgress();
 
   /**
diff --git a/hbase-client/src/main/java/org/apache/hadoop/hbase/client/Result.java b/hbase-client/src/main/java/org/apache/hadoop/hbase/client/Result.java
index 46865380f757..1c379286f954 100644
--- a/hbase-client/src/main/java/org/apache/hadoop/hbase/client/Result.java
+++ b/hbase-client/src/main/java/org/apache/hadoop/hbase/client/Result.java
@@ -672,15 +672,12 @@ public boolean isEmpty() {
   }
 
   /**
-   * @return the size of the underlying Cell []
+   * Return the size of the underlying Cell []
    */
   public int size() {
     return this.cells == null ? 0 : this.cells.length;
   }
 
-  /**
-   * n
-   */
   @Override
   public String toString() {
     StringBuilder sb = new StringBuilder();
@@ -896,8 +893,8 @@ public void setStatistics(RegionLoadStats loadStats) {
   }
 
   /**
-   * @return the associated statistics about the region from which this was returned. Can be
-   *         null if stats are disabled.
+   * Return the associated statistics about the region from which this was returned. Can be
+   * null if stats are disabled.
    */
   public RegionLoadStats getStats() {
     return stats;
diff --git a/hbase-client/src/main/java/org/apache/hadoop/hbase/client/ResultScanner.java b/hbase-client/src/main/java/org/apache/hadoop/hbase/client/ResultScanner.java
index d6017a1e23fd..20c46ef65265 100644
--- a/hbase-client/src/main/java/org/apache/hadoop/hbase/client/ResultScanner.java
+++ b/hbase-client/src/main/java/org/apache/hadoop/hbase/client/ResultScanner.java
@@ -113,8 +113,6 @@ default Result[] next(int nbRows) throws IOException {
    */
   boolean renewLease();
 
-  /**
-   * @return the scan metrics, or {@code null} if we do not enable metrics.
-   */
+  /** Return the scan metrics, or {@code null} if we do not enable metrics. */
   ScanMetrics getScanMetrics();
 }
diff --git a/hbase-client/src/main/java/org/apache/hadoop/hbase/client/Row.java b/hbase-client/src/main/java/org/apache/hadoop/hbase/client/Row.java
index 179903706cae..6fc1e184e88e 100644
--- a/hbase-client/src/main/java/org/apache/hadoop/hbase/client/Row.java
+++ b/hbase-client/src/main/java/org/apache/hadoop/hbase/client/Row.java
@@ -28,8 +28,5 @@
 public interface Row {
   Comparator COMPARATOR = (v1, v2) -> Bytes.compareTo(v1.getRow(), v2.getRow());
 
-  /**
-   * @return The row.
-   */
   byte[] getRow();
 }
diff --git a/hbase-client/src/main/java/org/apache/hadoop/hbase/client/RowAccess.java b/hbase-client/src/main/java/org/apache/hadoop/hbase/client/RowAccess.java
index ba613bb17733..2456337648e0 100644
--- a/hbase-client/src/main/java/org/apache/hadoop/hbase/client/RowAccess.java
+++ b/hbase-client/src/main/java/org/apache/hadoop/hbase/client/RowAccess.java
@@ -22,17 +22,12 @@
 /**
  * Provide a way to access the inner buffer. The purpose is to reduce the elapsed time to move a
  * large number of elements between collections.
- * @param 
  */
 @InterfaceAudience.Private
 public interface RowAccess extends Iterable {
-  /**
-   * @return true if there are no elements.
-   */
+  /** Return true if there are no elements. */
   boolean isEmpty();
 
-  /**
-   * @return the number of elements in this list.
-   */
+  /** Return the number of elements in this list. */
   int size();
 }
diff --git a/hbase-client/src/main/java/org/apache/hadoop/hbase/client/RowMutations.java b/hbase-client/src/main/java/org/apache/hadoop/hbase/client/RowMutations.java
index 9e9d0f1754e8..a66d0dbfcba6 100644
--- a/hbase-client/src/main/java/org/apache/hadoop/hbase/client/RowMutations.java
+++ b/hbase-client/src/main/java/org/apache/hadoop/hbase/client/RowMutations.java
@@ -70,6 +70,7 @@ public RowMutations(byte[] row, int initialCapacity) {
   }
 
   /**
+   * Add a mutation
    * @param mutation The data to send.
    * @throws IOException if the row of added mutation doesn't match the original row
    */
@@ -78,6 +79,7 @@ public RowMutations add(Mutation mutation) throws IOException {
   }
 
   /**
+   * Add a list of mutations
    * @param mutations The data to send.
    * @throws IOException if the row of added mutation doesn't match the original row
    */
@@ -99,7 +101,7 @@ public byte[] getRow() {
   }
 
   /**
-   * @return An unmodifiable list of the current mutations.
+   * Return an unmodifiable list of the current mutations.
    */
   public List getMutations() {
     return Collections.unmodifiableList(mutations);
diff --git a/hbase-client/src/main/java/org/apache/hadoop/hbase/client/Scan.java b/hbase-client/src/main/java/org/apache/hadoop/hbase/client/Scan.java
index 51ac7e8d3140..29c81ee1a489 100644
--- a/hbase-client/src/main/java/org/apache/hadoop/hbase/client/Scan.java
+++ b/hbase-client/src/main/java/org/apache/hadoop/hbase/client/Scan.java
@@ -434,6 +434,7 @@ public Scan withStopRow(byte[] stopRow, boolean inclusive) {
    *                  {@link #setStartStopRowForPrefixScan(byte[])} instead.
    */
   @Deprecated
+  @SuppressWarnings("InlineMeSuggester")
   public Scan setRowPrefixFilter(byte[] rowPrefix) {
     return setStartStopRowForPrefixScan(rowPrefix);
   }
@@ -531,9 +532,7 @@ public Scan setCaching(int caching) {
     return this;
   }
 
-  /**
-   * @return the maximum result size in bytes. See {@link #setMaxResultSize(long)}
-   */
+  /** Return the maximum result size in bytes. See {@link #setMaxResultSize(long)} */
   public long getMaxResultSize() {
     return maxResultSize;
   }
@@ -571,9 +570,7 @@ public Map> getFamilyMap() {
     return this.familyMap;
   }
 
-  /**
-   * @return the number of families in familyMap
-   */
+  /** Return the number of families in familyMap */
   public int numFamilies() {
     if (hasFamilies()) {
       return this.familyMap.size();
@@ -581,16 +578,12 @@ public int numFamilies() {
     return 0;
   }
 
-  /**
-   * @return true if familyMap is non empty, false otherwise
-   */
+  /** Return true if familyMap is non empty, false otherwise */
   public boolean hasFamilies() {
     return !this.familyMap.isEmpty();
   }
 
-  /**
-   * @return the keys of the familyMap
-   */
+  /** Return the keys of the familyMap */
   public byte[][] getFamilies() {
     if (hasFamilies()) {
       return this.familyMap.keySet().toArray(new byte[0][0]);
@@ -598,88 +591,65 @@ public byte[][] getFamilies() {
     return null;
   }
 
-  /**
-   * @return the startrow
-   */
+  /** Return the startrow */
   public byte[] getStartRow() {
     return this.startRow;
   }
 
-  /**
-   * @return if we should include start row when scan
-   */
+  /** Return if we should include start row when scan */
   public boolean includeStartRow() {
     return includeStartRow;
   }
 
-  /**
-   * @return the stoprow
-   */
+  /** Return the stop row */
   public byte[] getStopRow() {
     return this.stopRow;
   }
 
-  /**
-   * @return if we should include stop row when scan
-   */
+  /** Return if we should include the stop row when scanning */
   public boolean includeStopRow() {
     return includeStopRow;
   }
 
-  /**
-   * @return the max number of versions to fetch
-   */
+  /** Return the max number of versions to fetch */
   public int getMaxVersions() {
     return this.maxVersions;
   }
 
-  /**
-   * @return maximum number of values to return for a single call to next()
-   */
+  /** Return the maximum number of values to return for a single call to next */
   public int getBatch() {
     return this.batch;
   }
 
-  /**
-   * @return maximum number of values to return per row per CF
-   */
+  /** Return the maximum number of values to return per row per family */
   public int getMaxResultsPerColumnFamily() {
     return this.storeLimit;
   }
 
-  /**
-   * Method for retrieving the scan's offset per row per column family (#kvs to be skipped)
-   * @return row offset
-   */
+  /** Return the scan's offset per row per column family (#kvs to be skipped) */
   public int getRowOffsetPerColumnFamily() {
     return this.storeOffset;
   }
 
   /**
-   * @return caching the number of rows fetched when calling next on a scanner
+   * Return the the number of rows that will be fetched and cached when calling next on a scanner
    */
   public int getCaching() {
     return this.caching;
   }
 
-  /**
-   * n
-   */
+  /** Return the time range */
   public TimeRange getTimeRange() {
     return this.tr;
   }
 
-  /**
-   * n
-   */
+  /** Return the filter */
   @Override
   public Filter getFilter() {
     return filter;
   }
 
-  /**
-   * @return true is a filter has been specified, false if not
-   */
+  /** Return true is a filter has been specified, false if not */
   public boolean hasFilter() {
     return filter != null;
   }
@@ -736,9 +706,9 @@ public Scan setAllowPartialResults(final boolean allowPartialResults) {
   }
 
   /**
-   * @return true when the constructor of this scan understands that the results they will see may
-   *         only represent a partial portion of a row. The entire row would be retrieved by
-   *         subsequent calls to {@link ResultScanner#next()}
+   * Return true when the constructor of this scan understands that the results they will see may
+   * only represent a partial portion of a row. The entire row would be retrieved by subsequent
+   * calls to {@link ResultScanner#next()}
    */
   public boolean getAllowPartialResults() {
     return allowPartialResults;
@@ -840,9 +810,7 @@ public Scan setRaw(boolean raw) {
     return this;
   }
 
-  /**
-   * @return True if this Scan is in "raw" mode.
-   */
+  /** Return true if this Scan is in "raw" mode. */
   public boolean isRaw() {
     byte[] attr = getAttribute(RAW_ATTR);
     return attr == null ? false : Bytes.toBoolean(attr);
@@ -902,9 +870,7 @@ public Scan setScanMetricsEnabled(final boolean enabled) {
     return this;
   }
 
-  /**
-   * @return True if collection of scan metrics is enabled. For advanced users.
-   */
+  /** Return true if collection of scan metrics is enabled. For advanced users. */
   public boolean isScanMetricsEnabled() {
     byte[] attr = getAttribute(Scan.SCAN_ATTRIBUTES_METRICS_ENABLE);
     return attr == null ? false : Bytes.toBoolean(attr);
@@ -915,6 +881,7 @@ public Boolean isAsyncPrefetch() {
   }
 
   /**
+   * Disable or enable async prefetch.
    * @deprecated Since 3.0.0, will be removed in 4.0.0. After building sync client upon async
    *             client, the implementation is always 'async prefetch', so this flag is useless now.
    */
@@ -924,9 +891,7 @@ public Scan setAsyncPrefetch(boolean asyncPrefetch) {
     return this;
   }
 
-  /**
-   * @return the limit of rows for this scan
-   */
+  /** Return the limit of rows for this scan */
   public int getLimit() {
     return limit;
   }
@@ -958,9 +923,7 @@ public enum ReadType {
     PREAD
   }
 
-  /**
-   * @return the read type for this scan
-   */
+  /** Return the read type for this scan */
   public ReadType getReadType() {
     return readType;
   }
@@ -976,24 +939,18 @@ public Scan setReadType(ReadType readType) {
     return this;
   }
 
-  /**
-   * Get the mvcc read point used to open a scanner.
-   */
+  /** Return the mvcc read point used to open the scanner. */
   long getMvccReadPoint() {
     return mvccReadPoint;
   }
 
-  /**
-   * Set the mvcc read point used to open a scanner.
-   */
+  /** Set the mvcc read point used to open the scanner. */
   Scan setMvccReadPoint(long mvccReadPoint) {
     this.mvccReadPoint = mvccReadPoint;
     return this;
   }
 
-  /**
-   * Set the mvcc read point to -1 which means do not use it.
-   */
+  /** Set the mvcc read point to -1 which means do not use it. */
   Scan resetMvccReadPoint() {
     return setMvccReadPoint(-1L);
   }
diff --git a/hbase-client/src/main/java/org/apache/hadoop/hbase/client/ScanResultConsumer.java b/hbase-client/src/main/java/org/apache/hadoop/hbase/client/ScanResultConsumer.java
index b574b2c2bd5e..de44f8563d35 100644
--- a/hbase-client/src/main/java/org/apache/hadoop/hbase/client/ScanResultConsumer.java
+++ b/hbase-client/src/main/java/org/apache/hadoop/hbase/client/ScanResultConsumer.java
@@ -30,6 +30,7 @@
 public interface ScanResultConsumer extends ScanResultConsumerBase {
 
   /**
+   * Indicate if you want to terminate the scan process.
    * @param result the data fetched from HBase service.
    * @return {@code false} if you want to terminate the scan process. Otherwise {@code true}
    */
diff --git a/hbase-client/src/main/java/org/apache/hadoop/hbase/client/ServiceCaller.java b/hbase-client/src/main/java/org/apache/hadoop/hbase/client/ServiceCaller.java
index 501f412bc575..29647892a999 100644
--- a/hbase-client/src/main/java/org/apache/hadoop/hbase/client/ServiceCaller.java
+++ b/hbase-client/src/main/java/org/apache/hadoop/hbase/client/ServiceCaller.java
@@ -28,22 +28,16 @@
  * Usually, it is just a simple lambda expression, like:
  *
  * 
- * 
- * (stub, controller, rpcCallback) -> {
- *   XXXRequest request = ...; // prepare the request
- *   stub.xxx(controller, request, rpcCallback);
- * }
- * 
- * 

+ * (stub, controller, rpcCallback) -> { XXXRequest request = ...; // prepare the request
+ * stub.xxx(controller, request, rpcCallback); }
  *
+ * 
  * And if already have the {@code request}, the lambda expression will be:
  *
  * 
- * 
  * (stub, controller, rpcCallback) -> stub.xxx(controller, request, rpcCallback)
- * 
- * 

  *
+ * 
  * @param  the type of the protobuf Service you want to call.
  * @param  the type of the return value.
  */
diff --git a/hbase-client/src/main/java/org/apache/hadoop/hbase/client/SlowLogParams.java b/hbase-client/src/main/java/org/apache/hadoop/hbase/client/SlowLogParams.java
index 3311539c2614..b1460c0b116c 100644
--- a/hbase-client/src/main/java/org/apache/hadoop/hbase/client/SlowLogParams.java
+++ b/hbase-client/src/main/java/org/apache/hadoop/hbase/client/SlowLogParams.java
@@ -62,13 +62,10 @@ public boolean equals(Object o) {
     if (this == o) {
       return true;
     }
-
-    if (o == null || getClass() != o.getClass()) {
+    if (!(o instanceof SlowLogParams)) {
       return false;
     }
-
     SlowLogParams that = (SlowLogParams) o;
-
     return new EqualsBuilder().append(regionName, that.regionName).append(params, that.params)
       .isEquals();
   }
diff --git a/hbase-client/src/main/java/org/apache/hadoop/hbase/client/SnapshotDescription.java b/hbase-client/src/main/java/org/apache/hadoop/hbase/client/SnapshotDescription.java
index 2dfb2fa7a199..aebcf56a34c0 100644
--- a/hbase-client/src/main/java/org/apache/hadoop/hbase/client/SnapshotDescription.java
+++ b/hbase-client/src/main/java/org/apache/hadoop/hbase/client/SnapshotDescription.java
@@ -28,6 +28,7 @@
  * The POJO equivalent of HBaseProtos.SnapshotDescription
  */
 @InterfaceAudience.Public
+@SuppressWarnings("InlineMeSuggester")
 public class SnapshotDescription {
   private final String name;
   private final TableName table;
diff --git a/hbase-client/src/main/java/org/apache/hadoop/hbase/client/Table.java b/hbase-client/src/main/java/org/apache/hadoop/hbase/client/Table.java
index 0f93ab21a2c1..5271b0b58f07 100644
--- a/hbase-client/src/main/java/org/apache/hadoop/hbase/client/Table.java
+++ b/hbase-client/src/main/java/org/apache/hadoop/hbase/client/Table.java
@@ -30,7 +30,6 @@
 import org.apache.hadoop.hbase.CompareOperator;
 import org.apache.hadoop.hbase.TableName;
 import org.apache.hadoop.hbase.client.coprocessor.Batch;
-import org.apache.hadoop.hbase.client.coprocessor.Batch.Callback;
 import org.apache.hadoop.hbase.filter.Filter;
 import org.apache.hadoop.hbase.io.TimeRange;
 import org.apache.hadoop.hbase.ipc.CoprocessorRpcChannel;
@@ -302,11 +301,13 @@ default CheckAndMutateBuilder checkAndMutate(byte[] row, byte[] family) {
   interface CheckAndMutateBuilder {
 
     /**
+     * Add a column qualifier to check.
      * @param qualifier column qualifier to check.
      */
     CheckAndMutateBuilder qualifier(byte[] qualifier);
 
     /**
+     * Add a time range to check
      * @param timeRange timeRange to check
      */
     CheckAndMutateBuilder timeRange(TimeRange timeRange);
@@ -325,24 +326,28 @@ default CheckAndMutateBuilder ifEquals(byte[] value) {
     }
 
     /**
+     * Check for a match.
      * @param compareOp comparison operator to use
      * @param value     the expected value
      */
     CheckAndMutateBuilder ifMatches(CompareOperator compareOp, byte[] value);
 
     /**
+     * Provide a Put to commit if the check succeeds.
      * @param put data to put if check succeeds
      * @return {@code true} if the new put was executed, {@code false} otherwise.
      */
     boolean thenPut(Put put) throws IOException;
 
     /**
+     * Provide a Delete to commit if the check succeeds.
      * @param delete data to delete if check succeeds
      * @return {@code true} if the new delete was executed, {@code false} otherwise.
      */
     boolean thenDelete(Delete delete) throws IOException;
 
     /**
+     * Provide a RowMutations to commit if the check succeeds.
      * @param mutation mutations to perform if check succeeds
      * @return true if the new mutation was executed, false otherwise.
      */
@@ -355,13 +360,8 @@ default CheckAndMutateBuilder ifEquals(byte[] value) {
    * 

    * Use the returned {@link CheckAndMutateWithFilterBuilder} to construct your request and then
    * execute it. This is a fluent style API, the code is like:
-   *
-   * 
-   * 
-   * table.checkAndMutate(row, filter).thenPut(put);
-   * 
-   * 

-   *
+   * 

+   * {@code table.checkAndMutate(row, filter).thenPut(put); }
    * @deprecated Since 3.0.0, will be removed in 4.0.0. For internal test use only, do not use it
    *             any more.
    */
@@ -379,23 +379,27 @@ default CheckAndMutateWithFilterBuilder checkAndMutate(byte[] row, Filter filter
   interface CheckAndMutateWithFilterBuilder {
 
     /**
+     * Add a time range to check
      * @param timeRange timeRange to check
      */
     CheckAndMutateWithFilterBuilder timeRange(TimeRange timeRange);
 
     /**
+     * Provide a Put to commit if the check succeeds.
      * @param put data to put if check succeeds
      * @return {@code true} if the new put was executed, {@code false} otherwise.
      */
     boolean thenPut(Put put) throws IOException;
 
     /**
+     * Provide a Delete to commit if the check succeeds.
      * @param delete data to delete if check succeeds
      * @return {@code true} if the new delete was executed, {@code false} otherwise.
      */
     boolean thenDelete(Delete delete) throws IOException;
 
     /**
+     * Provide a RowMutations to commit if the check succeeds.
      * @param mutation mutations to perform if check succeeds
      * @return true if the new mutation was executed, false otherwise.
      */
@@ -445,7 +449,7 @@ default Result mutateRow(final RowMutations rm) throws IOException {
    * write operations to a row are synchronized, and readers are guaranteed to see this operation
    * fully completed.
    * @param append object that specifies the columns and values to be appended
-   * @throws IOException e
+   * @throws IOException if a remote or network exception occurs.
    * @return values of columns after the append operation (maybe null)
    */
   default Result append(final Append append) throws IOException {
@@ -460,7 +464,7 @@ default Result append(final Append append) throws IOException {
    * fully completed.
    * @param increment object that specifies the columns and amounts to be used for the increment
    *                  operations
-   * @throws IOException e
+   * @throws IOException if a remote or network exception occurs.
    * @return values of columns after the increment
    */
   default Result increment(final Increment increment) throws IOException {
@@ -531,7 +535,6 @@ default void close() throws IOException {
    * used to access a published coprocessor {@link Service} using standard protobuf service
    * invocations:
    * 

-   * 
 

    *
    * 
    * CoprocessorRpcChannel channel = myTable.coprocessorService(rowkey);
@@ -542,7 +545,6 @@ default void close() throws IOException {
    * MyCallResponse response = service.myCall(null, request);
    * 

    *
-   * 
 

    * @param row The row key used to identify the remote region location
    * @return A CoprocessorRpcChannel instance
    * @deprecated since 3.0.0, will removed in 4.0.0. This is too low level, please stop using it any
@@ -660,7 +662,7 @@ default  Map batchCoprocessorService(
     final Map results =
       Collections.synchronizedMap(new TreeMap(Bytes.BYTES_COMPARATOR));
     batchCoprocessorService(methodDescriptor, request, startKey, endKey, responsePrototype,
-      new Callback() {
+      new Batch.Callback() {
         @Override
         public void update(byte[] region, byte[] row, R result) {
           if (region != null) {
diff --git a/hbase-client/src/main/java/org/apache/hadoop/hbase/client/TableDescriptor.java b/hbase-client/src/main/java/org/apache/hadoop/hbase/client/TableDescriptor.java
index ea60b07d63eb..6d49c313ea86 100644
--- a/hbase-client/src/main/java/org/apache/hadoop/hbase/client/TableDescriptor.java
+++ b/hbase-client/src/main/java/org/apache/hadoop/hbase/client/TableDescriptor.java
@@ -141,7 +141,7 @@ public interface TableDescriptor {
   int getPriority();
 
   /**
-   * @return Returns the configured replicas per region
+   * Return the configured number of replicas per region.
    */
   int getRegionReplication();
 
@@ -188,7 +188,7 @@ public interface TableDescriptor {
   String getValue(String key);
 
   /**
-   * @return Getter for fetching an unmodifiable map.
+   * Return a getter for fetching an unmodifiable map.
    */
   Map getValues();
 
@@ -207,7 +207,7 @@ public interface TableDescriptor {
   boolean hasColumnFamily(final byte[] name);
 
   /**
-   * @return true if the read-replicas memstore replication is enabled.
+   * Return true if the read-replicas memstore replication is enabled.
    */
   boolean hasRegionMemStoreReplication();
 
@@ -273,8 +273,8 @@ public interface TableDescriptor {
   boolean isReadOnly();
 
   /**
-   * @return Name of this table and then a map of all of the column family descriptors (with only
-   *         the non-default column family attributes)
+   * Return the name of this table and then a map of all of the column family descriptors (with only
+   * the non-default column family attributes)
    */
   String toStringCustomizedValues();
 
diff --git a/hbase-client/src/main/java/org/apache/hadoop/hbase/client/TableDescriptorBuilder.java b/hbase-client/src/main/java/org/apache/hadoop/hbase/client/TableDescriptorBuilder.java
index cf12923326c1..9b737d33ae5f 100644
--- a/hbase-client/src/main/java/org/apache/hadoop/hbase/client/TableDescriptorBuilder.java
+++ b/hbase-client/src/main/java/org/apache/hadoop/hbase/client/TableDescriptorBuilder.java
@@ -143,8 +143,6 @@ public class TableDescriptorBuilder {
   private static final Bytes REGION_MEMSTORE_REPLICATION_KEY =
     new Bytes(Bytes.toBytes(REGION_MEMSTORE_REPLICATION));
 
-  private static final Bytes REGION_REPLICA_WAIT_FOR_PRIMARY_FLUSH_CONF_KEY =
-    new Bytes(Bytes.toBytes(RegionReplicaUtil.REGION_REPLICA_WAIT_FOR_PRIMARY_FLUSH_CONF_KEY));
   /**
    * Used by shell/rest interface to access this metadata attribute which denotes if the table
    * should be treated by region normalizer.
@@ -303,6 +301,7 @@ public static PrettyPrinter.Unit getUnit(String key) {
   private final ModifyableTableDescriptor desc;
 
   /**
+   * Serialize the descriptor to a byte array
    * @param desc The table descriptor to serialize
    * @return This instance serialized with pb with pb magic prefix
    */
@@ -317,7 +316,7 @@ public static byte[] toByteArray(TableDescriptor desc) {
    * The input should be created by {@link #toByteArray}.
    * @param pbBytes A pb serialized TableDescriptor instance with pb magic prefix
    * @return This instance serialized with pb with pb magic prefix
-   * @throws org.apache.hadoop.hbase.exceptions.DeserializationException
+   * @throws org.apache.hadoop.hbase.exceptions.DeserializationException if an error occurred
    */
   public static TableDescriptor parseFrom(byte[] pbBytes) throws DeserializationException {
     return ModifyableTableDescriptor.parseFrom(pbBytes);
@@ -1083,9 +1082,7 @@ public String toStringCustomizedValues() {
       return s.toString();
     }
 
-    /**
-     * @return map of all table attributes formatted into string.
-     */
+    /** Return a map of all table attributes formatted as strings. */
     public String toStringTableAttributes() {
       return getValues(true).toString();
     }
diff --git a/hbase-client/src/main/java/org/apache/hadoop/hbase/client/TableOverAsyncTable.java b/hbase-client/src/main/java/org/apache/hadoop/hbase/client/TableOverAsyncTable.java
index d4db9eb49e67..e1565f18159a 100644
--- a/hbase-client/src/main/java/org/apache/hadoop/hbase/client/TableOverAsyncTable.java
+++ b/hbase-client/src/main/java/org/apache/hadoop/hbase/client/TableOverAsyncTable.java
@@ -47,8 +47,7 @@
 import org.apache.hadoop.hbase.HRegionLocation;
 import org.apache.hadoop.hbase.TableName;
 import org.apache.hadoop.hbase.client.RetriesExhaustedException.ThrowableWithExtraContext;
-import org.apache.hadoop.hbase.client.coprocessor.Batch.Call;
-import org.apache.hadoop.hbase.client.coprocessor.Batch.Callback;
+import org.apache.hadoop.hbase.client.coprocessor.Batch;
 import org.apache.hadoop.hbase.client.trace.TableOperationSpanBuilder;
 import org.apache.hadoop.hbase.filter.Filter;
 import org.apache.hadoop.hbase.io.TimeRange;
@@ -143,8 +142,8 @@ public void batch(List actions, Object[] results) throws IOExcept
   }
 
   @Override
-  public  void batchCallback(List actions, Object[] results, Callback callback)
-    throws IOException, InterruptedException {
+  public  void batchCallback(List actions, Object[] results,
+    Batch.Callback callback) throws IOException, InterruptedException {
     ConcurrentLinkedQueue errors = new ConcurrentLinkedQueue<>();
     CountDownLatch latch = new CountDownLatch(actions.size());
     AsyncTableRegionLocator locator = conn.getRegionLocator(getName());
@@ -467,7 +466,7 @@ private interface StubCall {
   }
 
   private  void coprocessorService(String serviceName, byte[] startKey, byte[] endKey,
-    Callback callback, StubCall call) throws Throwable {
+    Batch.Callback callback, StubCall call) throws Throwable {
     // get regions covered by the row range
     ExecutorService pool = Context.current().wrap(this.poolSupplier.get());
     List keys = getStartKeysInRange(startKey, endKey);
@@ -509,7 +508,8 @@ private  void coprocessorService(String serviceName, byte[] startKey, byte[]
 
   @Override
   public  void coprocessorService(Class service, byte[] startKey,
-    byte[] endKey, Call callable, Callback callback) throws ServiceException, Throwable {
+    byte[] endKey, Batch.Call callable, Batch.Callback callback)
+    throws ServiceException, Throwable {
     final Supplier supplier = new TableOperationSpanBuilder(conn)
       .setTableName(table.getName()).setOperation(HBaseSemanticAttributes.Operation.COPROC_EXEC);
     TraceUtil.trace(() -> {
@@ -526,8 +526,8 @@ public  void coprocessorService(Class service, byte[] s
   @SuppressWarnings("unchecked")
   @Override
   public  void batchCoprocessorService(MethodDescriptor methodDescriptor,
-    Message request, byte[] startKey, byte[] endKey, R responsePrototype, Callback callback)
-    throws ServiceException, Throwable {
+    Message request, byte[] startKey, byte[] endKey, R responsePrototype,
+    Batch.Callback callback) throws ServiceException, Throwable {
     final Supplier supplier = new TableOperationSpanBuilder(conn)
       .setTableName(table.getName()).setOperation(HBaseSemanticAttributes.Operation.COPROC_EXEC);
     TraceUtil.trace(() -> {
diff --git a/hbase-client/src/main/java/org/apache/hadoop/hbase/client/TableState.java b/hbase-client/src/main/java/org/apache/hadoop/hbase/client/TableState.java
index ffd8cf8409d4..57b20f9ce62e 100644
--- a/hbase-client/src/main/java/org/apache/hadoop/hbase/client/TableState.java
+++ b/hbase-client/src/main/java/org/apache/hadoop/hbase/client/TableState.java
@@ -95,42 +95,42 @@ public HBaseProtos.TableState.State convert() {
   private final State state;
 
   /**
-   * @return True if table is {@link State#ENABLED}.
+   * Return true if table is {@link State#ENABLED}.
    */
   public boolean isEnabled() {
     return isInStates(State.ENABLED);
   }
 
   /**
-   * @return True if table is {@link State#ENABLING}.
+   * Return true if table is {@link State#ENABLING}.
    */
   public boolean isEnabling() {
     return isInStates(State.ENABLING);
   }
 
   /**
-   * @return True if {@link State#ENABLED} or {@link State#ENABLING}
+   * Return true if {@link State#ENABLED} or {@link State#ENABLING}
    */
   public boolean isEnabledOrEnabling() {
     return isInStates(State.ENABLED, State.ENABLING);
   }
 
   /**
-   * @return True if table is disabled.
+   * Return true if table is disabled.
    */
   public boolean isDisabled() {
     return isInStates(State.DISABLED);
   }
 
   /**
-   * @return True if table is disabling.
+   * Return true if table is disabling.
    */
   public boolean isDisabling() {
     return isInStates(State.DISABLING);
   }
 
   /**
-   * @return True if {@link State#DISABLED} or {@link State#DISABLED}
+   * Return true if {@link State#DISABLED} or {@link State#DISABLED}
    */
   public boolean isDisabledOrDisabling() {
     return isInStates(State.DISABLED, State.DISABLING);
@@ -147,7 +147,7 @@ public TableState(TableName tableName, State state) {
   }
 
   /**
-   * @return table state
+   * Return the table state.
    */
   public State getState() {
     return state;
@@ -223,15 +223,19 @@ public boolean isInStates(State... target) {
 
   @Override
   public boolean equals(Object o) {
-    if (this == o) return true;
-    if (o == null || getClass() != o.getClass()) return false;
-
+    if (this == o) {
+      return true;
+    }
+    if (!(o instanceof TableState)) {
+      return false;
+    }
     TableState that = (TableState) o;
-
-    if (state != that.state) return false;
-    if (tableName != null ? !tableName.equals(that.tableName) : that.tableName != null)
+    if (state != that.state) {
       return false;
-
+    }
+    if (tableName != null ? !tableName.equals(that.tableName) : that.tableName != null) {
+      return false;
+    }
     return true;
   }
 
diff --git a/hbase-client/src/main/java/org/apache/hadoop/hbase/client/backoff/ClientBackoffPolicy.java b/hbase-client/src/main/java/org/apache/hadoop/hbase/client/backoff/ClientBackoffPolicy.java
index ee66bcada1ba..3a6467d40361 100644
--- a/hbase-client/src/main/java/org/apache/hadoop/hbase/client/backoff/ClientBackoffPolicy.java
+++ b/hbase-client/src/main/java/org/apache/hadoop/hbase/client/backoff/ClientBackoffPolicy.java
@@ -33,7 +33,7 @@ public interface ClientBackoffPolicy {
   public static final String BACKOFF_POLICY_CLASS = "hbase.client.statistics.backoff-policy";
 
   /**
-   * @return the number of ms to wait on the client based on the
+   * Return the number of milliseconds to wait on the client based on the provided statistics.
    */
   public long getBackoffTime(ServerName serverName, byte[] region, ServerStatistics stats);
 }
diff --git a/hbase-client/src/main/java/org/apache/hadoop/hbase/client/backoff/ClientBackoffPolicyFactory.java b/hbase-client/src/main/java/org/apache/hadoop/hbase/client/backoff/ClientBackoffPolicyFactory.java
index a786702b1693..5b8873a3af82 100644
--- a/hbase-client/src/main/java/org/apache/hadoop/hbase/client/backoff/ClientBackoffPolicyFactory.java
+++ b/hbase-client/src/main/java/org/apache/hadoop/hbase/client/backoff/ClientBackoffPolicyFactory.java
@@ -22,15 +22,11 @@
 import org.apache.hadoop.hbase.util.ReflectionUtils;
 import org.apache.yetus.audience.InterfaceAudience;
 import org.apache.yetus.audience.InterfaceStability;
-import org.slf4j.Logger;
-import org.slf4j.LoggerFactory;
 
 @InterfaceAudience.Private
 @InterfaceStability.Evolving
 public final class ClientBackoffPolicyFactory {
 
-  private static final Logger LOG = LoggerFactory.getLogger(ClientBackoffPolicyFactory.class);
-
   private ClientBackoffPolicyFactory() {
   }
 
@@ -42,9 +38,7 @@ public static ClientBackoffPolicy create(Configuration conf) {
       new Class[] { Configuration.class }, new Object[] { conf });
   }
 
-  /**
-   * Default backoff policy that doesn't create any backoff for the client, regardless of load
-   */
+  /** Default backoff policy that doesn't create any backoff for the client, regardless of load. */
   public static class NoBackoffPolicy implements ClientBackoffPolicy {
     public NoBackoffPolicy(Configuration conf) {
       // necessary to meet contract
diff --git a/hbase-client/src/main/java/org/apache/hadoop/hbase/client/backoff/ExponentialClientBackoffPolicy.java b/hbase-client/src/main/java/org/apache/hadoop/hbase/client/backoff/ExponentialClientBackoffPolicy.java
index aa84207e1ed1..0e3339948eaa 100644
--- a/hbase-client/src/main/java/org/apache/hadoop/hbase/client/backoff/ExponentialClientBackoffPolicy.java
+++ b/hbase-client/src/main/java/org/apache/hadoop/hbase/client/backoff/ExponentialClientBackoffPolicy.java
@@ -21,8 +21,6 @@
 import org.apache.hadoop.hbase.HConstants;
 import org.apache.hadoop.hbase.ServerName;
 import org.apache.yetus.audience.InterfaceAudience;
-import org.slf4j.Logger;
-import org.slf4j.LoggerFactory;
 
 import org.apache.hbase.thirdparty.com.google.common.base.Preconditions;
 
@@ -33,8 +31,6 @@
 @InterfaceAudience.Public
 public class ExponentialClientBackoffPolicy implements ClientBackoffPolicy {
 
-  private static final Logger LOG = LoggerFactory.getLogger(ExponentialClientBackoffPolicy.class);
-
   private static final long ONE_MINUTE = 60 * 1000;
   public static final long DEFAULT_MAX_BACKOFF = 5 * ONE_MINUTE;
   public static final String MAX_BACKOFF_KEY = "hbase.client.exponential-backoff.max";
diff --git a/hbase-client/src/main/java/org/apache/hadoop/hbase/client/coprocessor/BigDecimalColumnInterpreter.java b/hbase-client/src/main/java/org/apache/hadoop/hbase/client/coprocessor/BigDecimalColumnInterpreter.java
index 900f96440dca..1e42be4baad8 100644
--- a/hbase-client/src/main/java/org/apache/hadoop/hbase/client/coprocessor/BigDecimalColumnInterpreter.java
+++ b/hbase-client/src/main/java/org/apache/hadoop/hbase/client/coprocessor/BigDecimalColumnInterpreter.java
@@ -80,7 +80,7 @@ public BigDecimal getMaxValue() {
 
   @Override
   public BigDecimal increment(BigDecimal bd) {
-    return bd == null ? null : (bd.add(BigDecimal.ONE));
+    return bd == null ? null : bd.add(BigDecimal.ONE);
   }
 
   @Override
diff --git a/hbase-client/src/main/java/org/apache/hadoop/hbase/client/replication/ReplicationPeerConfigUtil.java b/hbase-client/src/main/java/org/apache/hadoop/hbase/client/replication/ReplicationPeerConfigUtil.java
index 4145a348b08c..e789a9fa54f6 100644
--- a/hbase-client/src/main/java/org/apache/hadoop/hbase/client/replication/ReplicationPeerConfigUtil.java
+++ b/hbase-client/src/main/java/org/apache/hadoop/hbase/client/replication/ReplicationPeerConfigUtil.java
@@ -107,6 +107,7 @@ public static String convertToString(Map
    * Convert string to TableCFs Object. This is only for read TableCFs information from TableCF
    * node. Input String Format: ns1.table1:cf1,cf2;ns2.table2:cfA,cfB;ns3.table3.
    */
+  @SuppressWarnings("StringSplitter")
   public static ReplicationProtos.TableCF[] convert(String tableCFsConfig) {
     if (tableCFsConfig == null || tableCFsConfig.trim().length() == 0) {
       return null;
@@ -241,6 +242,7 @@ public static Map> convert2Map(ReplicationProtos.TableCF
   }
 
   /**
+   * Parse the serialized representation of a peer
    * @param bytes Content of a peer znode.
    * @return ClusterKey parsed from the passed bytes.
    * @throws DeserializationException deserialization exception
@@ -384,6 +386,7 @@ public static ReplicationProtos.ReplicationPeer convert(ReplicationPeerConfig pe
   }
 
   /**
+   * Serialize the peer configuration and return it as a byte array.
    * @param peerConfig peer config of replication peer
    * @return Serialized protobuf of peerConfig with pb magic prefix prepended suitable
    *         for use as content of a this.peersZNode; i.e. the content of PEER_ID znode under
diff --git a/hbase-client/src/main/java/org/apache/hadoop/hbase/coprocessor/ColumnInterpreter.java b/hbase-client/src/main/java/org/apache/hadoop/hbase/coprocessor/ColumnInterpreter.java
index 0e24e0c98143..af9f5d9ff444 100644
--- a/hbase-client/src/main/java/org/apache/hadoop/hbase/coprocessor/ColumnInterpreter.java
+++ b/hbase-client/src/main/java/org/apache/hadoop/hbase/coprocessor/ColumnInterpreter.java
@@ -40,11 +40,6 @@
  * {@link ColumnInterpreter#castToReturnType(Object)} which takes a <T> type and returns a
  * <S> type. The AggregateIm>lementation uses PB messages to initialize the user's
  * ColumnInterpreter implementation, and for sending the responses back to AggregationClient.
- * @param T Cell value data type
- * @param S Promoted data type
- * @param P PB message that is used to transport initializer specific bytes
- * @param Q PB message that is used to transport Cell (<T>) instance
- * @param R PB message that is used to transport Promoted (<S>) instance
  */
 @InterfaceAudience.LimitedPrivate(HBaseInterfaceAudience.COPROC)
 @InterfaceStability.Evolving
diff --git a/hbase-client/src/main/java/org/apache/hadoop/hbase/exceptions/PreemptiveFastFailException.java b/hbase-client/src/main/java/org/apache/hadoop/hbase/exceptions/PreemptiveFastFailException.java
index 6d28f3288fdc..1c845fe3db16 100644
--- a/hbase-client/src/main/java/org/apache/hadoop/hbase/exceptions/PreemptiveFastFailException.java
+++ b/hbase-client/src/main/java/org/apache/hadoop/hbase/exceptions/PreemptiveFastFailException.java
@@ -67,37 +67,27 @@ public PreemptiveFastFailException(long count, long timeOfFirstFailureMilliSec,
     this.guaranteedClientSideOnly = guaranteedClientSideOnly;
   }
 
-  /**
-   * @return time of the fist failure
-   */
+  /** Return time of the first failure */
   public long getFirstFailureAt() {
     return timeOfFirstFailureMilliSec;
   }
 
-  /**
-   * @return time of the latest attempt
-   */
+  /** Return time of the latest attempt */
   public long getLastAttemptAt() {
     return timeOfLatestAttemptMilliSec;
   }
 
-  /**
-   * @return failure count
-   */
+  /** Return the failure count */
   public long getFailureCount() {
     return failureCount;
   }
 
-  /**
-   * @return true if operation was attempted by server, false otherwise.
-   */
+  /** Return true if operation was attempted by server, false otherwise. */
   public boolean wasOperationAttemptedByServer() {
     return false;
   }
 
-  /**
-   * @return true if we know no mutation made it to the server, false otherwise.
-   */
+  /** Return true if we know no mutation made it to the server, false otherwise. */
   public boolean isGuaranteedClientSideOnly() {
     return guaranteedClientSideOnly;
   }
diff --git a/hbase-client/src/main/java/org/apache/hadoop/hbase/exceptions/RegionOpeningException.java b/hbase-client/src/main/java/org/apache/hadoop/hbase/exceptions/RegionOpeningException.java
index 347c6b987a15..bef80b2cb82d 100644
--- a/hbase-client/src/main/java/org/apache/hadoop/hbase/exceptions/RegionOpeningException.java
+++ b/hbase-client/src/main/java/org/apache/hadoop/hbase/exceptions/RegionOpeningException.java
@@ -20,8 +20,6 @@
 import org.apache.hadoop.hbase.NotServingRegionException;
 import org.apache.yetus.audience.InterfaceAudience;
 import org.apache.yetus.audience.InterfaceStability;
-import org.slf4j.Logger;
-import org.slf4j.LoggerFactory;
 
 /**
  * Subclass if the server knows the region is now on another server. This allows the client to call
@@ -30,7 +28,7 @@
 @InterfaceAudience.Private
 @InterfaceStability.Evolving
 public class RegionOpeningException extends NotServingRegionException {
-  private static final Logger LOG = LoggerFactory.getLogger(RegionOpeningException.class);
+
   private static final long serialVersionUID = -7232903522310558395L;
 
   public RegionOpeningException(String message) {
diff --git a/hbase-client/src/main/java/org/apache/hadoop/hbase/filter/BigDecimalComparator.java b/hbase-client/src/main/java/org/apache/hadoop/hbase/filter/BigDecimalComparator.java
index bfd285975ff4..6caef8b35ca4 100644
--- a/hbase-client/src/main/java/org/apache/hadoop/hbase/filter/BigDecimalComparator.java
+++ b/hbase-client/src/main/java/org/apache/hadoop/hbase/filter/BigDecimalComparator.java
@@ -45,12 +45,12 @@ public BigDecimalComparator(BigDecimal value) {
 
   @Override
   public boolean equals(Object obj) {
-    if (obj == null || !(obj instanceof BigDecimalComparator)) {
-      return false;
-    }
     if (this == obj) {
       return true;
     }
+    if (!(obj instanceof BigDecimalComparator)) {
+      return false;
+    }
     BigDecimalComparator bdc = (BigDecimalComparator) obj;
     return this.bigDecimal.equals(bdc.bigDecimal);
   }
@@ -72,9 +72,7 @@ public int compareTo(ByteBuffer value, int offset, int length) {
     return this.bigDecimal.compareTo(that);
   }
 
-  /**
-   * @return The comparator serialized using pb
-   */
+  /** Return The comparator serialized using pb */
   @Override
   public byte[] toByteArray() {
     ComparatorProtos.BigDecimalComparator.Builder builder =
@@ -84,9 +82,10 @@ public byte[] toByteArray() {
   }
 
   /**
+   * Parse a serialized representation of the comparator
    * @param pbBytes A pb serialized {@link BigDecimalComparator} instance
    * @return An instance of {@link BigDecimalComparator} made from bytes
-   * @throws DeserializationException A deserialization exception
+   * @throws DeserializationException if an error occurred
    * @see #toByteArray
    */
   public static BigDecimalComparator parseFrom(final byte[] pbBytes)
@@ -102,10 +101,10 @@ public static BigDecimalComparator parseFrom(final byte[] pbBytes)
   }
 
   /**
-   * @param other the other comparator
-   * @return true if and only if the fields of the comparator that are serialized are equal to the
-   *         corresponding fields in other. Used for testing.
+   * Return true if and only if the fields of the comparator that are serialized are equal to the
+   * corresponding fields in other.
    */
+  @SuppressWarnings("ReferenceEquality")
   boolean areSerializedFieldsEqual(BigDecimalComparator other) {
     if (other == this) {
       return true;
diff --git a/hbase-client/src/main/java/org/apache/hadoop/hbase/filter/BinaryComparator.java b/hbase-client/src/main/java/org/apache/hadoop/hbase/filter/BinaryComparator.java
index 0c8274a86110..d12a274686c0 100644
--- a/hbase-client/src/main/java/org/apache/hadoop/hbase/filter/BinaryComparator.java
+++ b/hbase-client/src/main/java/org/apache/hadoop/hbase/filter/BinaryComparator.java
@@ -54,9 +54,7 @@ public int compareTo(ByteBuffer value, int offset, int length) {
     return ByteBufferUtils.compareTo(this.value, 0, this.value.length, value, offset, length);
   }
 
-  /**
-   * @return The comparator serialized using pb
-   */
+  /** Return the comparator serialized using pb */
   @Override
   public byte[] toByteArray() {
     ComparatorProtos.BinaryComparator.Builder builder =
@@ -66,9 +64,10 @@ public byte[] toByteArray() {
   }
 
   /**
+   * Parse a serialized representation of this comparator
    * @param pbBytes A pb serialized {@link BinaryComparator} instance
-   * @return An instance of {@link BinaryComparator} made from bytes n * @see
-   *         #toByteArray
+   * @return An instance of {@link BinaryComparator} made from bytes
+   * @see #toByteArray
    */
   public static BinaryComparator parseFrom(final byte[] pbBytes) throws DeserializationException {
     ComparatorProtos.BinaryComparator proto;
@@ -81,8 +80,8 @@ public static BinaryComparator parseFrom(final byte[] pbBytes) throws Deserializ
   }
 
   /**
-   * n * @return true if and only if the fields of the comparator that are serialized are equal to
-   * the corresponding fields in other. Used for testing.
+   * Return true if and only if the fields of the comparator that are serialized are equal to the
+   * corresponding fields in other. Used for testing.
    */
   @Override
   boolean areSerializedFieldsEqual(ByteArrayComparable other) {
diff --git a/hbase-client/src/main/java/org/apache/hadoop/hbase/filter/BinaryComponentComparator.java b/hbase-client/src/main/java/org/apache/hadoop/hbase/filter/BinaryComponentComparator.java
index 2546227fce35..355af6e7c58f 100644
--- a/hbase-client/src/main/java/org/apache/hadoop/hbase/filter/BinaryComponentComparator.java
+++ b/hbase-client/src/main/java/org/apache/hadoop/hbase/filter/BinaryComponentComparator.java
@@ -75,9 +75,7 @@ public int hashCode() {
     return result;
   }
 
-  /**
-   * @return The comparator serialized using pb
-   */
+  /** Return the comparator serialized using pb */
   @Override
   public byte[] toByteArray() {
     ComparatorProtos.BinaryComponentComparator.Builder builder =
@@ -88,6 +86,7 @@ public byte[] toByteArray() {
   }
 
   /**
+   * Parse a serialized representation of this comparator
    * @param pbBytes A pb serialized {@link BinaryComponentComparator} instance
    * @return An instance of {@link BinaryComponentComparator} made from bytes
    * @throws DeserializationException DeserializationException
@@ -105,9 +104,8 @@ public static BinaryComponentComparator parseFrom(final byte[] pbBytes)
   }
 
   /**
-   * @param other paramemter to compare against
-   * @return true if and only if the fields of the comparator that are serialized are equal to the
-   *         corresponding fields in other. Used for testing.
+   * Return true if and only if the fields of the comparator that are serialized are equal to the
+   * corresponding fields in other. Used for testing.
    */
   @Override
   boolean areSerializedFieldsEqual(ByteArrayComparable other) {
diff --git a/hbase-client/src/main/java/org/apache/hadoop/hbase/filter/BinaryPrefixComparator.java b/hbase-client/src/main/java/org/apache/hadoop/hbase/filter/BinaryPrefixComparator.java
index f97fd070be6a..495b9ce73467 100644
--- a/hbase-client/src/main/java/org/apache/hadoop/hbase/filter/BinaryPrefixComparator.java
+++ b/hbase-client/src/main/java/org/apache/hadoop/hbase/filter/BinaryPrefixComparator.java
@@ -58,9 +58,7 @@ public int compareTo(ByteBuffer value, int offset, int length) {
     return ByteBufferUtils.compareTo(this.value, 0, this.value.length, value, offset, length);
   }
 
-  /**
-   * @return The comparator serialized using pb
-   */
+  /** Return the comparator serialized using pb */
   @Override
   public byte[] toByteArray() {
     ComparatorProtos.BinaryPrefixComparator.Builder builder =
@@ -70,9 +68,10 @@ public byte[] toByteArray() {
   }
 
   /**
+   * Parse a serialized representation of this comparator
    * @param pbBytes A pb serialized {@link BinaryPrefixComparator} instance
-   * @return An instance of {@link BinaryPrefixComparator} made from bytes n * @see
-   *         #toByteArray
+   * @return An instance of {@link BinaryPrefixComparator} made from bytes
+   * @see #toByteArray
    */
   public static BinaryPrefixComparator parseFrom(final byte[] pbBytes)
     throws DeserializationException {
@@ -86,8 +85,8 @@ public static BinaryPrefixComparator parseFrom(final byte[] pbBytes)
   }
 
   /**
-   * n * @return true if and only if the fields of the comparator that are serialized are equal to
-   * the corresponding fields in other. Used for testing.
+   * Return true if and only if the fields of the comparator that are serialized are equal to the
+   * corresponding fields in other.
    */
   @Override
   boolean areSerializedFieldsEqual(ByteArrayComparable other) {
diff --git a/hbase-client/src/main/java/org/apache/hadoop/hbase/filter/BitComparator.java b/hbase-client/src/main/java/org/apache/hadoop/hbase/filter/BitComparator.java
index 15ca8890abac..6a5bb534b114 100644
--- a/hbase-client/src/main/java/org/apache/hadoop/hbase/filter/BitComparator.java
+++ b/hbase-client/src/main/java/org/apache/hadoop/hbase/filter/BitComparator.java
@@ -57,16 +57,12 @@ public BitComparator(byte[] value, BitwiseOp bitOperator) {
     this.bitOperator = bitOperator;
   }
 
-  /**
-   * @return the bitwise operator
-   */
+  /** Return the bitwise operator */
   public BitwiseOp getOperator() {
     return bitOperator;
   }
 
-  /**
-   * @return The comparator serialized using pb
-   */
+  /** Return the comparator serialized using pb */
   @Override
   public byte[] toByteArray() {
     ComparatorProtos.BitComparator.Builder builder = ComparatorProtos.BitComparator.newBuilder();
@@ -78,8 +74,10 @@ public byte[] toByteArray() {
   }
 
   /**
+   * Parse a serialized representation of this comparator
    * @param pbBytes A pb serialized {@link BitComparator} instance
-   * @return An instance of {@link BitComparator} made from bytes n * @see #toByteArray
+   * @return An instance of {@link BitComparator} made from bytes
+   * @see #toByteArray
    */
   public static BitComparator parseFrom(final byte[] pbBytes) throws DeserializationException {
     ComparatorProtos.BitComparator proto;
@@ -93,8 +91,8 @@ public static BitComparator parseFrom(final byte[] pbBytes) throws Deserializati
   }
 
   /**
-   * n * @return true if and only if the fields of the comparator that are serialized are equal to
-   * the corresponding fields in other. Used for testing.
+   * Return true if and only if the fields of the comparator that are serialized are equal to the
+   * corresponding fields in other.
    */
   @Override
   boolean areSerializedFieldsEqual(ByteArrayComparable other) {
diff --git a/hbase-client/src/main/java/org/apache/hadoop/hbase/filter/ColumnCountGetFilter.java b/hbase-client/src/main/java/org/apache/hadoop/hbase/filter/ColumnCountGetFilter.java
index cfaf8c279930..6d78994d4c00 100644
--- a/hbase-client/src/main/java/org/apache/hadoop/hbase/filter/ColumnCountGetFilter.java
+++ b/hbase-client/src/main/java/org/apache/hadoop/hbase/filter/ColumnCountGetFilter.java
@@ -78,9 +78,7 @@ public static Filter createFilterFromArguments(ArrayList filterArguments
     return new ColumnCountGetFilter(limit);
   }
 
-  /**
-   * @return The filter serialized using pb
-   */
+  /** Return the filter serialized using pb */
   @Override
   public byte[] toByteArray() {
     FilterProtos.ColumnCountGetFilter.Builder builder =
@@ -90,6 +88,7 @@ public byte[] toByteArray() {
   }
 
   /**
+   * Parse a serialized representation of this filter
    * @param pbBytes A pb serialized {@link ColumnCountGetFilter} instance
    * @return An instance of {@link ColumnCountGetFilter} made from bytes
    * @see #toByteArray
@@ -106,15 +105,17 @@ public static ColumnCountGetFilter parseFrom(final byte[] pbBytes)
   }
 
   /**
-   * @param o the other filter to compare with
-   * @return true if and only if the fields of the filter that are serialized are equal to the
-   *         corresponding fields in other. Used for testing.
+   * Return true if and only if the fields of the filter that are serialized are equal to the
+   * corresponding fields in other. Used for testing.
    */
   @Override
   boolean areSerializedFieldsEqual(Filter o) {
-    if (o == this) return true;
-    if (!(o instanceof ColumnCountGetFilter)) return false;
-
+    if (o == this) {
+      return true;
+    }
+    if (!(o instanceof ColumnCountGetFilter)) {
+      return false;
+    }
     ColumnCountGetFilter other = (ColumnCountGetFilter) o;
     return this.getLimit() == other.getLimit();
   }
@@ -126,7 +127,7 @@ public String toString() {
 
   @Override
   public boolean equals(Object obj) {
-    return obj instanceof Filter && areSerializedFieldsEqual((Filter) obj);
+    return (obj instanceof Filter) && areSerializedFieldsEqual((Filter) obj);
   }
 
   @Override
diff --git a/hbase-client/src/main/java/org/apache/hadoop/hbase/filter/ColumnPaginationFilter.java b/hbase-client/src/main/java/org/apache/hadoop/hbase/filter/ColumnPaginationFilter.java
index 31f607c22cc8..e9cd67973748 100644
--- a/hbase-client/src/main/java/org/apache/hadoop/hbase/filter/ColumnPaginationFilter.java
+++ b/hbase-client/src/main/java/org/apache/hadoop/hbase/filter/ColumnPaginationFilter.java
@@ -78,23 +78,14 @@ public ColumnPaginationFilter(final int limit, final byte[] columnOffset) {
     this.columnOffset = columnOffset;
   }
 
-  /**
-   * n
-   */
   public int getLimit() {
     return limit;
   }
 
-  /**
-   * n
-   */
   public int getOffset() {
     return offset;
   }
 
-  /**
-   * n
-   */
   public byte[] getColumnOffset() {
     return columnOffset;
   }
@@ -151,9 +142,7 @@ public static Filter createFilterFromArguments(ArrayList filterArguments
     return new ColumnPaginationFilter(limit, offset);
   }
 
-  /**
-   * @return The filter serialized using pb
-   */
+  /** Return the filter serialized using pb */
   @Override
   public byte[] toByteArray() {
     FilterProtos.ColumnPaginationFilter.Builder builder =
@@ -169,9 +158,10 @@ public byte[] toByteArray() {
   }
 
   /**
+   * Parse a serialized representation of this filter.
    * @param pbBytes A pb serialized {@link ColumnPaginationFilter} instance
-   * @return An instance of {@link ColumnPaginationFilter} made from bytes n * @see
-   *         #toByteArray
+   * @return An instance of {@link ColumnPaginationFilter} made from bytes
+   * @see #toByteArray
    */
   public static ColumnPaginationFilter parseFrom(final byte[] pbBytes)
     throws DeserializationException {
@@ -188,15 +178,17 @@ public static ColumnPaginationFilter parseFrom(final byte[] pbBytes)
   }
 
   /**
-   * @param o the other filter to compare with
-   * @return true if and only if the fields of the filter that are serialized are equal to the
-   *         corresponding fields in other. Used for testing.
+   * Return true if and only if the fields of the filter that are serialized are equal to the
+   * corresponding fields in other.
    */
   @Override
   boolean areSerializedFieldsEqual(Filter o) {
-    if (o == this) return true;
-    if (!(o instanceof ColumnPaginationFilter)) return false;
-
+    if (o == this) {
+      return true;
+    }
+    if (!(o instanceof ColumnPaginationFilter)) {
+      return false;
+    }
     ColumnPaginationFilter other = (ColumnPaginationFilter) o;
     if (this.columnOffset != null) {
       return this.getLimit() == other.getLimit()
@@ -216,7 +208,7 @@ public String toString() {
 
   @Override
   public boolean equals(Object obj) {
-    return obj instanceof Filter && areSerializedFieldsEqual((Filter) obj);
+    return (obj instanceof Filter) && areSerializedFieldsEqual((Filter) obj);
   }
 
   @Override
diff --git a/hbase-client/src/main/java/org/apache/hadoop/hbase/filter/ColumnPrefixFilter.java b/hbase-client/src/main/java/org/apache/hadoop/hbase/filter/ColumnPrefixFilter.java
index d883c449017c..c196656e0261 100644
--- a/hbase-client/src/main/java/org/apache/hadoop/hbase/filter/ColumnPrefixFilter.java
+++ b/hbase-client/src/main/java/org/apache/hadoop/hbase/filter/ColumnPrefixFilter.java
@@ -102,9 +102,7 @@ public static Filter createFilterFromArguments(ArrayList filterArguments
     return new ColumnPrefixFilter(columnPrefix);
   }
 
-  /**
-   * @return The filter serialized using pb
-   */
+  /** Return the filter serialized using pb. */
   @Override
   public byte[] toByteArray() {
     FilterProtos.ColumnPrefixFilter.Builder builder = FilterProtos.ColumnPrefixFilter.newBuilder();
@@ -113,9 +111,10 @@ public byte[] toByteArray() {
   }
 
   /**
+   * Parse a serialized representation of the filter.
    * @param pbBytes A pb serialized {@link ColumnPrefixFilter} instance
    * @return An instance of {@link ColumnPrefixFilter} made from bytes
-   * @throws org.apache.hadoop.hbase.exceptions.DeserializationException
+   * @throws org.apache.hadoop.hbase.exceptions.DeserializationException if an error occurred
    * @see #toByteArray
    */
   public static ColumnPrefixFilter parseFrom(final byte[] pbBytes) throws DeserializationException {
@@ -129,15 +128,17 @@ public static ColumnPrefixFilter parseFrom(final byte[] pbBytes) throws Deserial
   }
 
   /**
-   * @param o the other filter to compare with
-   * @return true if and only if the fields of the filter that are serialized are equal to the
-   *         corresponding fields in other. Used for testing.
+   * Return true if and only if the fields of the filter that are serialized are equal to the
+   * corresponding fields in other.
    */
   @Override
   boolean areSerializedFieldsEqual(Filter o) {
-    if (o == this) return true;
-    if (!(o instanceof ColumnPrefixFilter)) return false;
-
+    if (o == this) {
+      return true;
+    }
+    if (!(o instanceof ColumnPrefixFilter)) {
+      return false;
+    }
     ColumnPrefixFilter other = (ColumnPrefixFilter) o;
     return Bytes.equals(this.getPrefix(), other.getPrefix());
   }
@@ -154,7 +155,7 @@ public String toString() {
 
   @Override
   public boolean equals(Object obj) {
-    return obj instanceof Filter && areSerializedFieldsEqual((Filter) obj);
+    return (obj instanceof Filter) && areSerializedFieldsEqual((Filter) obj);
   }
 
   @Override
diff --git a/hbase-client/src/main/java/org/apache/hadoop/hbase/filter/ColumnRangeFilter.java b/hbase-client/src/main/java/org/apache/hadoop/hbase/filter/ColumnRangeFilter.java
index 46465ac6d1f8..51f9a1577b3a 100644
--- a/hbase-client/src/main/java/org/apache/hadoop/hbase/filter/ColumnRangeFilter.java
+++ b/hbase-client/src/main/java/org/apache/hadoop/hbase/filter/ColumnRangeFilter.java
@@ -65,44 +65,32 @@ public ColumnRangeFilter(final byte[] minColumn, boolean minColumnInclusive,
     this.maxColumnInclusive = maxColumnInclusive;
   }
 
-  /**
-   * @return if min column range is inclusive.
-   */
+  /** Return true if min column range is inclusive. */
   public boolean isMinColumnInclusive() {
     return minColumnInclusive;
   }
 
-  /**
-   * @return if max column range is inclusive.
-   */
+  /** Return true if max column range is inclusive. */
   public boolean isMaxColumnInclusive() {
     return maxColumnInclusive;
   }
 
-  /**
-   * @return the min column range for the filter
-   */
+  /** Return the min column range for the filter */
   public byte[] getMinColumn() {
     return this.minColumn;
   }
 
-  /**
-   * @return true if min column is inclusive, false otherwise
-   */
+  /** Return true if min column is inclusive, false otherwise */
   public boolean getMinColumnInclusive() {
     return this.minColumnInclusive;
   }
 
-  /**
-   * @return the max column range for the filter
-   */
+  /** Return the max column range for the filte */
   public byte[] getMaxColumn() {
     return this.maxColumn;
   }
 
-  /**
-   * @return true if max column is inclusive, false otherwise
-   */
+  /** Return true if max column is inclusive, false otherwise */
   public boolean getMaxColumnInclusive() {
     return this.maxColumnInclusive;
   }
@@ -155,9 +143,7 @@ public static Filter createFilterFromArguments(ArrayList filterArguments
     return new ColumnRangeFilter(minColumn, minColumnInclusive, maxColumn, maxColumnInclusive);
   }
 
-  /**
-   * @return The filter serialized using pb
-   */
+  /** Return the filter serialized using pb */
   @Override
   public byte[] toByteArray() {
     FilterProtos.ColumnRangeFilter.Builder builder = FilterProtos.ColumnRangeFilter.newBuilder();
@@ -171,9 +157,10 @@ public byte[] toByteArray() {
   }
 
   /**
+   * Parse a serialized representation of this filter.
    * @param pbBytes A pb serialized {@link ColumnRangeFilter} instance
-   * @return An instance of {@link ColumnRangeFilter} made from bytes n * @see
-   *         #toByteArray
+   * @return An instance of {@link ColumnRangeFilter} made from bytes
+   * @see #toByteArray
    */
   public static ColumnRangeFilter parseFrom(final byte[] pbBytes) throws DeserializationException {
     FilterProtos.ColumnRangeFilter proto;
@@ -189,9 +176,8 @@ public static ColumnRangeFilter parseFrom(final byte[] pbBytes) throws Deseriali
   }
 
   /**
-   * @param o filter to serialize.
-   * @return true if and only if the fields of the filter that are serialized are equal to the
-   *         corresponding fields in other. Used for testing.
+   * Return true if and only if the fields of the filter that are serialized are equal to the
+   * corresponding fields in other.
    */
   @Override
   boolean areSerializedFieldsEqual(Filter o) {
@@ -222,7 +208,7 @@ public String toString() {
 
   @Override
   public boolean equals(Object obj) {
-    return obj instanceof Filter && areSerializedFieldsEqual((Filter) obj);
+    return (obj instanceof Filter) && areSerializedFieldsEqual((Filter) obj);
   }
 
   @Override
diff --git a/hbase-client/src/main/java/org/apache/hadoop/hbase/filter/ColumnValueFilter.java b/hbase-client/src/main/java/org/apache/hadoop/hbase/filter/ColumnValueFilter.java
index 0074fe40a3a4..638afd035345 100644
--- a/hbase-client/src/main/java/org/apache/hadoop/hbase/filter/ColumnValueFilter.java
+++ b/hbase-client/src/main/java/org/apache/hadoop/hbase/filter/ColumnValueFilter.java
@@ -68,30 +68,22 @@ public ColumnValueFilter(final byte[] family, final byte[] qualifier, final Comp
     this.comparator = Preconditions.checkNotNull(comparator, "Comparator should not be null");
   }
 
-  /**
-   * n
-   */
+  /** Return the comparison operator */
   public CompareOperator getCompareOperator() {
     return op;
   }
 
-  /**
-   * @return the comparator
-   */
+  /** Return the comparator */
   public ByteArrayComparable getComparator() {
     return comparator;
   }
 
-  /**
-   * @return the column family
-   */
+  /** Return the column family */
   public byte[] getFamily() {
     return family;
   }
 
-  /**
-   * @return the qualifier
-   */
+  /** Return the qualifier */
   public byte[] getQualifier() {
     return qualifier;
   }
@@ -161,9 +153,7 @@ public static Filter createFilterFromArguments(ArrayList filterArguments
     return new ColumnValueFilter(family, qualifier, operator, comparator);
   }
 
-  /**
-   * @return A pb instance to represent this instance.
-   */
+  /** Return a pb instance to represent this instance. */
   FilterProtos.ColumnValueFilter convert() {
     FilterProtos.ColumnValueFilter.Builder builder = FilterProtos.ColumnValueFilter.newBuilder();
 
@@ -213,7 +203,6 @@ boolean areSerializedFieldsEqual(Filter o) {
     } else if (!(o instanceof ColumnValueFilter)) {
       return false;
     }
-
     ColumnValueFilter other = (ColumnValueFilter) o;
     return Bytes.equals(this.getFamily(), other.getFamily())
       && Bytes.equals(this.getQualifier(), other.getQualifier())
@@ -235,7 +224,7 @@ public String toString() {
 
   @Override
   public boolean equals(Object obj) {
-    return obj instanceof Filter && areSerializedFieldsEqual((Filter) obj);
+    return (obj instanceof Filter) && areSerializedFieldsEqual((Filter) obj);
   }
 
   @Override
diff --git a/hbase-client/src/main/java/org/apache/hadoop/hbase/filter/CompareFilter.java b/hbase-client/src/main/java/org/apache/hadoop/hbase/filter/CompareFilter.java
index 1f55f8480459..7ee89821df97 100644
--- a/hbase-client/src/main/java/org/apache/hadoop/hbase/filter/CompareFilter.java
+++ b/hbase-client/src/main/java/org/apache/hadoop/hbase/filter/CompareFilter.java
@@ -69,9 +69,7 @@ public CompareOperator getCompareOperator() {
     return op;
   }
 
-  /**
-   * @return the comparator
-   */
+  /** Return the comparator */
   public ByteArrayComparable getComparator() {
     return comparator;
   }
@@ -138,7 +136,7 @@ static boolean compare(final CompareOperator op, int compareResult) {
     }
   }
 
-  // returns an array of heterogeneous objects
+  /** Returns an array of heterogeneous objects */
   public static ArrayList extractArguments(ArrayList filterArguments) {
     Preconditions.checkArgument(filterArguments.size() == 2, "Expected 2 but got: %s",
       filterArguments.size());
@@ -158,9 +156,7 @@ public static ArrayList extractArguments(ArrayList filterArgumen
     return arguments;
   }
 
-  /**
-   * @return A pb instance to represent this instance.
-   */
+  /** Return a pb instance to represent this instance. */
   FilterProtos.CompareFilter convert() {
     FilterProtos.CompareFilter.Builder builder = FilterProtos.CompareFilter.newBuilder();
     HBaseProtos.CompareType compareOp = CompareType.valueOf(this.op.name());
@@ -170,13 +166,17 @@ FilterProtos.CompareFilter convert() {
   }
 
   /**
-   * n * @return true if and only if the fields of the filter that are serialized are equal to the
-   * corresponding fields in other. Used for testing.
+   * Return true if and only if the fields of the filter that are serialized are equal to the
+   * corresponding fields in other.
    */
   @Override
   boolean areSerializedFieldsEqual(Filter o) {
-    if (o == this) return true;
-    if (!(o instanceof CompareFilter)) return false;
+    if (o == this) {
+      return true;
+    }
+    if (!(o instanceof CompareFilter)) {
+      return false;
+    }
     CompareFilter other = (CompareFilter) o;
     return this.getCompareOperator().equals(other.getCompareOperator())
       && (this.getComparator() == other.getComparator()
@@ -191,7 +191,7 @@ public String toString() {
 
   @Override
   public boolean equals(Object obj) {
-    return obj instanceof Filter && areSerializedFieldsEqual((Filter) obj);
+    return (obj instanceof Filter) && areSerializedFieldsEqual((Filter) obj);
   }
 
   @Override
diff --git a/hbase-client/src/main/java/org/apache/hadoop/hbase/filter/DependentColumnFilter.java b/hbase-client/src/main/java/org/apache/hadoop/hbase/filter/DependentColumnFilter.java
index 1f453c6f678d..039b63d860dc 100644
--- a/hbase-client/src/main/java/org/apache/hadoop/hbase/filter/DependentColumnFilter.java
+++ b/hbase-client/src/main/java/org/apache/hadoop/hbase/filter/DependentColumnFilter.java
@@ -92,23 +92,17 @@ public DependentColumnFilter(final byte[] family, final byte[] qualifier,
     this(family, qualifier, dropDependentColumn, CompareOperator.NO_OP, null);
   }
 
-  /**
-   * @return the column family
-   */
+  /** Return the column family */
   public byte[] getFamily() {
     return this.columnFamily;
   }
 
-  /**
-   * @return the column qualifier
-   */
+  /** Return the column qualifier */
   public byte[] getQualifier() {
     return this.columnQualifier;
   }
 
-  /**
-   * @return true if we should drop the dependent column, false otherwise
-   */
+  /** Return true if we should drop the dependent column, false otherwise */
   public boolean dropDependentColumn() {
     return this.dropDependentColumn;
   }
@@ -188,9 +182,7 @@ public static Filter createFilterFromArguments(ArrayList filterArguments
     }
   }
 
-  /**
-   * @return The filter serialized using pb
-   */
+  /** Return the filter serialized using pb */
   @Override
   public byte[] toByteArray() {
     FilterProtos.DependentColumnFilter.Builder builder =
@@ -207,9 +199,10 @@ public byte[] toByteArray() {
   }
 
   /**
+   * Parse a serialized representation of this filter.
    * @param pbBytes A pb serialized {@link DependentColumnFilter} instance
-   * @return An instance of {@link DependentColumnFilter} made from bytes n * @see
-   *         #toByteArray
+   * @return An instance of {@link DependentColumnFilter} made from bytes
+   * @see #toByteArray
    */
   public static DependentColumnFilter parseFrom(final byte[] pbBytes)
     throws DeserializationException {
@@ -236,16 +229,19 @@ public static DependentColumnFilter parseFrom(final byte[] pbBytes)
   }
 
   /**
-   * n * @return true if and only if the fields of the filter that are serialized are equal to the
-   * corresponding fields in other. Used for testing.
+   * Return true if and only if the fields of the filter that are serialized are equal to the
+   * corresponding fields in other.
    */
   @edu.umd.cs.findbugs.annotations.SuppressWarnings(
       value = "RCN_REDUNDANT_NULLCHECK_OF_NONNULL_VALUE")
   @Override
   boolean areSerializedFieldsEqual(Filter o) {
-    if (o == this) return true;
-    if (!(o instanceof DependentColumnFilter)) return false;
-
+    if (o == this) {
+      return true;
+    }
+    if (!(o instanceof DependentColumnFilter)) {
+      return false;
+    }
     DependentColumnFilter other = (DependentColumnFilter) o;
     return other != null && super.areSerializedFieldsEqual(other)
       && Bytes.equals(this.getFamily(), other.getFamily())
@@ -263,7 +259,7 @@ public String toString() {
 
   @Override
   public boolean equals(Object obj) {
-    return obj instanceof Filter && areSerializedFieldsEqual((Filter) obj);
+    return (obj instanceof Filter) && areSerializedFieldsEqual((Filter) obj);
   }
 
   @Override
diff --git a/hbase-client/src/main/java/org/apache/hadoop/hbase/filter/FamilyFilter.java b/hbase-client/src/main/java/org/apache/hadoop/hbase/filter/FamilyFilter.java
index 4e682eb1d37b..792bce3c6920 100644
--- a/hbase-client/src/main/java/org/apache/hadoop/hbase/filter/FamilyFilter.java
+++ b/hbase-client/src/main/java/org/apache/hadoop/hbase/filter/FamilyFilter.java
@@ -73,9 +73,7 @@ public static Filter createFilterFromArguments(ArrayList filterArguments
     return new FamilyFilter(compareOp, comparator);
   }
 
-  /**
-   * @return The filter serialized using pb
-   */
+  /** Return The filter serialized using pb */
   @Override
   public byte[] toByteArray() {
     FilterProtos.FamilyFilter.Builder builder = FilterProtos.FamilyFilter.newBuilder();
@@ -84,6 +82,7 @@ public byte[] toByteArray() {
   }
 
   /**
+   * Parse a serialized representation of the filter.
    * @param pbBytes A pb serialized {@link FamilyFilter} instance
    * @return An instance of {@link FamilyFilter} made from bytes n * @see #toByteArray
    */
@@ -108,21 +107,24 @@ public static FamilyFilter parseFrom(final byte[] pbBytes) throws Deserializatio
   }
 
   /**
-   * @return true if and only if the fields of the filter that are serialized are equal to the
-   *         corresponding fields in other. Used for testing.
+   * Return true if and only if the fields of the filter that are serialized are equal to the
+   * corresponding fields in other.
    */
   @Override
   boolean areSerializedFieldsEqual(Filter o) {
-    if (o == this) return true;
-    if (!(o instanceof FamilyFilter)) return false;
-
+    if (o == this) {
+      return true;
+    }
+    if (!(o instanceof FamilyFilter)) {
+      return false;
+    }
     FamilyFilter other = (FamilyFilter) o;
     return super.areSerializedFieldsEqual(other);
   }
 
   @Override
   public boolean equals(Object obj) {
-    return obj instanceof Filter && areSerializedFieldsEqual((Filter) obj);
+    return (obj instanceof Filter) && areSerializedFieldsEqual((Filter) obj);
   }
 
   @Override
diff --git a/hbase-client/src/main/java/org/apache/hadoop/hbase/filter/Filter.java b/hbase-client/src/main/java/org/apache/hadoop/hbase/filter/Filter.java
index 2c623306ba0b..a7ba35d401f2 100644
--- a/hbase-client/src/main/java/org/apache/hadoop/hbase/filter/Filter.java
+++ b/hbase-client/src/main/java/org/apache/hadoop/hbase/filter/Filter.java
@@ -207,6 +207,7 @@ public enum ReturnCode {
    * @param pbBytes A pb serialized {@link Filter} instance
    * @return An instance of {@link Filter} made from bytes n * @see #toByteArray
    */
+  @SuppressWarnings("DoNotCallSuggester")
   public static Filter parseFrom(final byte[] pbBytes) throws DeserializationException {
     throw new DeserializationException(
       "parseFrom called on base Filter, but should be called on derived type");
@@ -216,7 +217,6 @@ public static Filter parseFrom(final byte[] pbBytes) throws DeserializationExcep
    * Concrete implementers can signal a failure condition in their code by throwing an
    * {@link IOException}. n * @return true if and only if the fields of the filter that are
    * serialized are equal to the corresponding fields in other. Used for testing.
-   * @throws IOException in case an I/O or an filter specific failure needs to be signaled.
    */
   abstract boolean areSerializedFieldsEqual(Filter other);
 
diff --git a/hbase-client/src/main/java/org/apache/hadoop/hbase/filter/FilterBase.java b/hbase-client/src/main/java/org/apache/hadoop/hbase/filter/FilterBase.java
index ff637c7f0527..3479d81e31ae 100644
--- a/hbase-client/src/main/java/org/apache/hadoop/hbase/filter/FilterBase.java
+++ b/hbase-client/src/main/java/org/apache/hadoop/hbase/filter/FilterBase.java
@@ -71,7 +71,7 @@ public void filterRowCells(List ignored) throws IOException {
   }
 
   /**
-   * Fitlers that never filter by modifying the returned List of Cells can inherit this
+   * Filters that never filter by modifying the returned List of Cells can inherit this
    * implementation that does nothing. {@inheritDoc}
    */
   @Override
@@ -113,6 +113,7 @@ public boolean isFamilyEssential(byte[] name) throws IOException {
    * @param filterArguments the filter's arguments
    * @return constructed filter object
    */
+  @SuppressWarnings("DoNotCallSuggester")
   public static Filter createFilterFromArguments(ArrayList filterArguments) {
     throw new IllegalArgumentException("This method has not been implemented");
   }
diff --git a/hbase-client/src/main/java/org/apache/hadoop/hbase/filter/FilterList.java b/hbase-client/src/main/java/org/apache/hadoop/hbase/filter/FilterList.java
index be3035858f13..b402e50ddaec 100644
--- a/hbase-client/src/main/java/org/apache/hadoop/hbase/filter/FilterList.java
+++ b/hbase-client/src/main/java/org/apache/hadoop/hbase/filter/FilterList.java
@@ -107,16 +107,12 @@ public FilterList(final Operator operator, final Filter... filters) {
     this(operator, Arrays.asList(filters));
   }
 
-  /**
-   * Get the operator. n
-   */
+  /** Return the operator. */
   public Operator getOperator() {
     return operator;
   }
 
-  /**
-   * Get the filters. n
-   */
+  /** Return the filters. */
   public List getFilters() {
     return filterListBase.getFilters();
   }
@@ -181,9 +177,7 @@ public boolean filterRow() throws IOException {
     return filterListBase.filterRow();
   }
 
-  /**
-   * @return The filter serialized using pb
-   */
+  /** Return the filter serialized using pb */
   @Override
   public byte[] toByteArray() throws IOException {
     FilterProtos.FilterList.Builder builder = FilterProtos.FilterList.newBuilder();
@@ -196,8 +190,10 @@ public byte[] toByteArray() throws IOException {
   }
 
   /**
+   * Parse a serialized representation of this filter.
    * @param pbBytes A pb serialized {@link FilterList} instance
-   * @return An instance of {@link FilterList} made from bytes n * @see #toByteArray
+   * @return An instance of {@link FilterList} made from bytes
+   * @see #toByteArray
    */
   public static FilterList parseFrom(final byte[] pbBytes) throws DeserializationException {
     FilterProtos.FilterList proto;
@@ -220,14 +216,17 @@ public static FilterList parseFrom(final byte[] pbBytes) throws DeserializationE
   }
 
   /**
-   * n * @return true if and only if the fields of the filter that are serialized are equal to the
-   * corresponding fields in other. Used for testing.
+   * Return true if and only if the fields of the filter that are serialized are equal to the
+   * corresponding fields in other.
    */
   @Override
   boolean areSerializedFieldsEqual(Filter other) {
-    if (other == this) return true;
-    if (!(other instanceof FilterList)) return false;
-
+    if (other == this) {
+      return true;
+    }
+    if (!(other instanceof FilterList)) {
+      return false;
+    }
     FilterList o = (FilterList) other;
     return this.getOperator().equals(o.getOperator())
       && ((this.getFilters() == o.getFilters()) || this.getFilters().equals(o.getFilters()));
@@ -262,7 +261,7 @@ public String toString() {
 
   @Override
   public boolean equals(Object obj) {
-    return obj instanceof Filter && areSerializedFieldsEqual((Filter) obj);
+    return (obj instanceof Filter) && areSerializedFieldsEqual((Filter) obj);
   }
 
   @Override
diff --git a/hbase-client/src/main/java/org/apache/hadoop/hbase/filter/FilterListWithAND.java b/hbase-client/src/main/java/org/apache/hadoop/hbase/filter/FilterListWithAND.java
index 760b79d497d3..45e06f444547 100644
--- a/hbase-client/src/main/java/org/apache/hadoop/hbase/filter/FilterListWithAND.java
+++ b/hbase-client/src/main/java/org/apache/hadoop/hbase/filter/FilterListWithAND.java
@@ -270,12 +270,12 @@ public Cell getNextCellHint(Cell currentCell) throws IOException {
 
   @Override
   public boolean equals(Object obj) {
-    if (!(obj instanceof FilterListWithAND)) {
-      return false;
-    }
     if (this == obj) {
       return true;
     }
+    if (!(obj instanceof FilterListWithAND)) {
+      return false;
+    }
     FilterListWithAND f = (FilterListWithAND) obj;
     return this.filters.equals(f.getFilters()) && this.seekHintFilters.equals(f.seekHintFilters);
   }
diff --git a/hbase-client/src/main/java/org/apache/hadoop/hbase/filter/FilterListWithOR.java b/hbase-client/src/main/java/org/apache/hadoop/hbase/filter/FilterListWithOR.java
index dd50a1bbb8d9..fbe68ab13527 100644
--- a/hbase-client/src/main/java/org/apache/hadoop/hbase/filter/FilterListWithOR.java
+++ b/hbase-client/src/main/java/org/apache/hadoop/hbase/filter/FilterListWithOR.java
@@ -394,12 +394,12 @@ public Cell getNextCellHint(Cell currentCell) throws IOException {
 
   @Override
   public boolean equals(Object obj) {
-    if (obj == null || (!(obj instanceof FilterListWithOR))) {
-      return false;
-    }
     if (this == obj) {
       return true;
     }
+    if (!(obj instanceof FilterListWithOR)) {
+      return false;
+    }
     FilterListWithOR f = (FilterListWithOR) obj;
     return this.filters.equals(f.getFilters()) && this.prevFilterRCList.equals(f.prevFilterRCList)
       && this.prevCellList.equals(f.prevCellList);
diff --git a/hbase-client/src/main/java/org/apache/hadoop/hbase/filter/FirstKeyOnlyFilter.java b/hbase-client/src/main/java/org/apache/hadoop/hbase/filter/FirstKeyOnlyFilter.java
index 83f8409facc8..5e758aca41d0 100644
--- a/hbase-client/src/main/java/org/apache/hadoop/hbase/filter/FirstKeyOnlyFilter.java
+++ b/hbase-client/src/main/java/org/apache/hadoop/hbase/filter/FirstKeyOnlyFilter.java
@@ -19,7 +19,6 @@
 
 import java.io.IOException;
 import java.util.ArrayList;
-import java.util.Objects;
 import org.apache.hadoop.hbase.Cell;
 import org.apache.hadoop.hbase.exceptions.DeserializationException;
 import org.apache.yetus.audience.InterfaceAudience;
@@ -65,23 +64,17 @@ public static Filter createFilterFromArguments(ArrayList filterArguments
     return new FirstKeyOnlyFilter();
   }
 
-  /**
-   * @return true if first KV has been found.
-   */
+  /** Return true if first KV has been found. */
   protected boolean hasFoundKV() {
     return this.foundKV;
   }
 
-  /**
-   * @param value update {@link #foundKV} flag with value.
-   */
+  /** Update {@link #foundKV} flag with value. */
   protected void setFoundKV(boolean value) {
     this.foundKV = value;
   }
 
-  /**
-   * @return The filter serialized using pb
-   */
+  /** Return the filter serialized using pb */
   @Override
   public byte[] toByteArray() {
     FilterProtos.FirstKeyOnlyFilter.Builder builder = FilterProtos.FirstKeyOnlyFilter.newBuilder();
@@ -89,9 +82,10 @@ public byte[] toByteArray() {
   }
 
   /**
+   * Parses a serialized representation of the filter
    * @param pbBytes A pb serialized {@link FirstKeyOnlyFilter} instance
    * @return An instance of {@link FirstKeyOnlyFilter} made from bytes
-   * @throws org.apache.hadoop.hbase.exceptions.DeserializationException
+   * @throws org.apache.hadoop.hbase.exceptions.DeserializationException if an error occurred
    * @see #toByteArray
    */
   public static FirstKeyOnlyFilter parseFrom(final byte[] pbBytes) throws DeserializationException {
@@ -106,25 +100,27 @@ public static FirstKeyOnlyFilter parseFrom(final byte[] pbBytes) throws Deserial
   }
 
   /**
-   * @param o the other filter to compare with
-   * @return true if and only if the fields of the filter that are serialized are equal to the
-   *         corresponding fields in other. Used for testing.
+   * Return true if and only if the fields of the filter that are serialized are equal to the
+   * corresponding fields in other.
    */
   @Override
   boolean areSerializedFieldsEqual(Filter o) {
-    if (o == this) return true;
-    if (!(o instanceof FirstKeyOnlyFilter)) return false;
-
+    if (o == this) {
+      return true;
+    }
+    if (!(o instanceof FirstKeyOnlyFilter)) {
+      return false;
+    }
     return true;
   }
 
   @Override
   public boolean equals(Object obj) {
-    return obj instanceof Filter && areSerializedFieldsEqual((Filter) obj);
+    return (obj instanceof Filter) && areSerializedFieldsEqual((Filter) obj);
   }
 
   @Override
   public int hashCode() {
-    return Objects.hashCode(foundKV);
+    return Boolean.hashCode(foundKV);
   }
 }
diff --git a/hbase-client/src/main/java/org/apache/hadoop/hbase/filter/FirstKeyValueMatchingQualifiersFilter.java b/hbase-client/src/main/java/org/apache/hadoop/hbase/filter/FirstKeyValueMatchingQualifiersFilter.java
index cec4a2f06ff2..214b4010f8f4 100644
--- a/hbase-client/src/main/java/org/apache/hadoop/hbase/filter/FirstKeyValueMatchingQualifiersFilter.java
+++ b/hbase-client/src/main/java/org/apache/hadoop/hbase/filter/FirstKeyValueMatchingQualifiersFilter.java
@@ -32,10 +32,13 @@
 public class FirstKeyValueMatchingQualifiersFilter extends FirstKeyOnlyFilter {
 
   /**
+   * Parse a serialized representation of the filter.
    * @param pbBytes A pb serialized {@link FirstKeyValueMatchingQualifiersFilter} instance
    * @return An instance of {@link FirstKeyValueMatchingQualifiersFilter} made from
-   *         bytes n * @see #toByteArray
+   *         bytes
+   * @see #toByteArray
    */
+  @SuppressWarnings("DoNotCallSuggester")
   public static FirstKeyValueMatchingQualifiersFilter parseFrom(final byte[] pbBytes)
     throws DeserializationException {
     throw new DeserializationException(
diff --git a/hbase-client/src/main/java/org/apache/hadoop/hbase/filter/FuzzyRowFilter.java b/hbase-client/src/main/java/org/apache/hadoop/hbase/filter/FuzzyRowFilter.java
index a41763fcea30..9145011b1523 100644
--- a/hbase-client/src/main/java/org/apache/hadoop/hbase/filter/FuzzyRowFilter.java
+++ b/hbase-client/src/main/java/org/apache/hadoop/hbase/filter/FuzzyRowFilter.java
@@ -251,9 +251,7 @@ public boolean filterAllRemaining() {
     return done;
   }
 
-  /**
-   * @return The filter serialized using pb
-   */
+  /** Return the filter serialized using pb */
   @Override
   public byte[] toByteArray() {
     FilterProtos.FuzzyRowFilter.Builder builder = FilterProtos.FuzzyRowFilter.newBuilder();
@@ -267,9 +265,10 @@ public byte[] toByteArray() {
   }
 
   /**
+   * Parse a serialized representation of the filter
    * @param pbBytes A pb serialized {@link FuzzyRowFilter} instance
-   * @return An instance of {@link FuzzyRowFilter} made from bytes n * @see
-   *         #toByteArray
+   * @return An instance of {@link FuzzyRowFilter} made from bytes
+   * @see #toByteArray
    */
   public static FuzzyRowFilter parseFrom(final byte[] pbBytes) throws DeserializationException {
     FilterProtos.FuzzyRowFilter proto;
@@ -342,7 +341,7 @@ static SatisfiesCode satisfies(boolean reverse, byte[] row, int offset, int leng
       long fuzzyBytes = Bytes.toLong(fuzzyKeyBytes, i);
       long fuzzyMeta = Bytes.toLong(fuzzyKeyMeta, i);
       long rowValue = Bytes.toLong(row, offset + i);
-      if ((rowValue & fuzzyMeta) != (fuzzyBytes)) {
+      if ((rowValue & fuzzyMeta) != fuzzyBytes) {
         // We always return NEXT_EXISTS
         return SatisfiesCode.NEXT_EXISTS;
       }
@@ -354,7 +353,7 @@ static SatisfiesCode satisfies(boolean reverse, byte[] row, int offset, int leng
       int fuzzyBytes = Bytes.toInt(fuzzyKeyBytes, off);
       int fuzzyMeta = Bytes.toInt(fuzzyKeyMeta, off);
       int rowValue = Bytes.toInt(row, offset + off);
-      if ((rowValue & fuzzyMeta) != (fuzzyBytes)) {
+      if ((rowValue & fuzzyMeta) != fuzzyBytes) {
         // We always return NEXT_EXISTS
         return SatisfiesCode.NEXT_EXISTS;
       }
@@ -365,7 +364,7 @@ static SatisfiesCode satisfies(boolean reverse, byte[] row, int offset, int leng
       short fuzzyBytes = Bytes.toShort(fuzzyKeyBytes, off);
       short fuzzyMeta = Bytes.toShort(fuzzyKeyMeta, off);
       short rowValue = Bytes.toShort(row, offset + off);
-      if ((rowValue & fuzzyMeta) != (fuzzyBytes)) {
+      if ((rowValue & fuzzyMeta) != fuzzyBytes) {
         // We always return NEXT_EXISTS
         // even if it does not (in this case getNextForFuzzyRule
         // will return null)
@@ -378,7 +377,7 @@ static SatisfiesCode satisfies(boolean reverse, byte[] row, int offset, int leng
       int fuzzyBytes = fuzzyKeyBytes[off] & 0xff;
       int fuzzyMeta = fuzzyKeyMeta[off] & 0xff;
       int rowValue = row[offset + off] & 0xff;
-      if ((rowValue & fuzzyMeta) != (fuzzyBytes)) {
+      if ((rowValue & fuzzyMeta) != fuzzyBytes) {
         // We always return NEXT_EXISTS
         return SatisfiesCode.NEXT_EXISTS;
       }
@@ -519,8 +518,8 @@ public static Order orderFor(boolean reverse) {
   }
 
   /**
-   * @return greater byte array than given (row) which satisfies the fuzzy rule if it exists, null
-   *         otherwise
+   * Return greater byte array than given (row) which satisfies the fuzzy rule if it exists, null
+   * otherwise
    */
   static byte[] getNextForFuzzyRule(boolean reverse, byte[] row, int offset, int length,
     byte[] fuzzyKeyBytes, byte[] fuzzyKeyMeta) {
@@ -605,14 +604,17 @@ private static byte[] trimTrailingZeroes(byte[] result, byte[] fuzzyKeyMeta, int
   }
 
   /**
-   * @return true if and only if the fields of the filter that are serialized are equal to the
-   *         corresponding fields in other. Used for testing.
+   * Return true if and only if the fields of the filter that are serialized are equal to the
+   * corresponding fields in other.
    */
   @Override
   boolean areSerializedFieldsEqual(Filter o) {
-    if (o == this) return true;
-    if (!(o instanceof FuzzyRowFilter)) return false;
-
+    if (o == this) {
+      return true;
+    }
+    if (!(o instanceof FuzzyRowFilter)) {
+      return false;
+    }
     FuzzyRowFilter other = (FuzzyRowFilter) o;
     if (this.fuzzyKeysData.size() != other.fuzzyKeysData.size()) return false;
     for (int i = 0; i < fuzzyKeysData.size(); ++i) {
@@ -630,7 +632,7 @@ boolean areSerializedFieldsEqual(Filter o) {
 
   @Override
   public boolean equals(Object obj) {
-    return obj instanceof Filter && areSerializedFieldsEqual((Filter) obj);
+    return (obj instanceof Filter) && areSerializedFieldsEqual((Filter) obj);
   }
 
   @Override
diff --git a/hbase-client/src/main/java/org/apache/hadoop/hbase/filter/InclusiveStopFilter.java b/hbase-client/src/main/java/org/apache/hadoop/hbase/filter/InclusiveStopFilter.java
index 7f42fb633c33..20cc8edb2d85 100644
--- a/hbase-client/src/main/java/org/apache/hadoop/hbase/filter/InclusiveStopFilter.java
+++ b/hbase-client/src/main/java/org/apache/hadoop/hbase/filter/InclusiveStopFilter.java
@@ -75,9 +75,7 @@ public static Filter createFilterFromArguments(ArrayList filterArguments
     return new InclusiveStopFilter(stopRowKey);
   }
 
-  /**
-   * @return The filter serialized using pb
-   */
+  /** Return the filter serialized using pb */
   @Override
   public byte[] toByteArray() {
     FilterProtos.InclusiveStopFilter.Builder builder =
@@ -88,9 +86,10 @@ public byte[] toByteArray() {
   }
 
   /**
+   * Parse a serialized representation of this filter.
    * @param pbBytes A pb serialized {@link InclusiveStopFilter} instance
-   * @return An instance of {@link InclusiveStopFilter} made from bytes n * @see
-   *         #toByteArray
+   * @return An instance of {@link InclusiveStopFilter} made from bytes
+   * @see #toByteArray
    */
   public static InclusiveStopFilter parseFrom(final byte[] pbBytes)
     throws DeserializationException {
@@ -105,15 +104,17 @@ public static InclusiveStopFilter parseFrom(final byte[] pbBytes)
   }
 
   /**
-   * @param o the other filter to compare with
-   * @return true if and only if the fields of the filter that are serialized are equal to the
-   *         corresponding fields in other. Used for testing.
+   * Return true if and only if the fields of the filter that are serialized are equal to the
+   * corresponding fields in other.
    */
   @Override
   boolean areSerializedFieldsEqual(Filter o) {
-    if (o == this) return true;
-    if (!(o instanceof InclusiveStopFilter)) return false;
-
+    if (o == this) {
+      return true;
+    }
+    if (!(o instanceof InclusiveStopFilter)) {
+      return false;
+    }
     InclusiveStopFilter other = (InclusiveStopFilter) o;
     return Bytes.equals(this.getStopRowKey(), other.getStopRowKey());
   }
@@ -125,7 +126,7 @@ public String toString() {
 
   @Override
   public boolean equals(Object obj) {
-    return obj instanceof Filter && areSerializedFieldsEqual((Filter) obj);
+    return (obj instanceof Filter) && areSerializedFieldsEqual((Filter) obj);
   }
 
   @Override
diff --git a/hbase-client/src/main/java/org/apache/hadoop/hbase/filter/IncompatibleFilterException.java b/hbase-client/src/main/java/org/apache/hadoop/hbase/filter/IncompatibleFilterException.java
index c91543d29af1..24d5f1c9b3a0 100644
--- a/hbase-client/src/main/java/org/apache/hadoop/hbase/filter/IncompatibleFilterException.java
+++ b/hbase-client/src/main/java/org/apache/hadoop/hbase/filter/IncompatibleFilterException.java
@@ -26,15 +26,10 @@
 public class IncompatibleFilterException extends RuntimeException {
   private static final long serialVersionUID = 3236763276623198231L;
 
-  /** constructor */
   public IncompatibleFilterException() {
     super();
   }
 
-  /**
-   * constructor
-   * @param s message
-   */
   public IncompatibleFilterException(String s) {
     super(s);
   }
diff --git a/hbase-client/src/main/java/org/apache/hadoop/hbase/filter/InvalidRowFilterException.java b/hbase-client/src/main/java/org/apache/hadoop/hbase/filter/InvalidRowFilterException.java
index 9e48cbba1fe8..4218cccdf70b 100644
--- a/hbase-client/src/main/java/org/apache/hadoop/hbase/filter/InvalidRowFilterException.java
+++ b/hbase-client/src/main/java/org/apache/hadoop/hbase/filter/InvalidRowFilterException.java
@@ -26,15 +26,10 @@
 public class InvalidRowFilterException extends RuntimeException {
   private static final long serialVersionUID = 2667894046345657865L;
 
-  /** constructor */
   public InvalidRowFilterException() {
     super();
   }
 
-  /**
-   * constructor
-   * @param s message
-   */
   public InvalidRowFilterException(String s) {
     super(s);
   }
diff --git a/hbase-client/src/main/java/org/apache/hadoop/hbase/filter/KeyOnlyFilter.java b/hbase-client/src/main/java/org/apache/hadoop/hbase/filter/KeyOnlyFilter.java
index 6aa410730d8f..782e89fc5232 100644
--- a/hbase-client/src/main/java/org/apache/hadoop/hbase/filter/KeyOnlyFilter.java
+++ b/hbase-client/src/main/java/org/apache/hadoop/hbase/filter/KeyOnlyFilter.java
@@ -93,9 +93,7 @@ public static Filter createFilterFromArguments(ArrayList filterArguments
     return filter;
   }
 
-  /**
-   * @return The filter serialized using pb
-   */
+  /** Return the filter serialized using pb */
   @Override
   public byte[] toByteArray() {
     FilterProtos.KeyOnlyFilter.Builder builder = FilterProtos.KeyOnlyFilter.newBuilder();
@@ -104,8 +102,10 @@ public byte[] toByteArray() {
   }
 
   /**
+   * Parse a serialized representation of this filter.
    * @param pbBytes A pb serialized {@link KeyOnlyFilter} instance
-   * @return An instance of {@link KeyOnlyFilter} made from bytes n * @see #toByteArray
+   * @return An instance of {@link KeyOnlyFilter} made from bytes
+   * @see #toByteArray
    */
   public static KeyOnlyFilter parseFrom(final byte[] pbBytes) throws DeserializationException {
     FilterProtos.KeyOnlyFilter proto;
@@ -118,22 +118,24 @@ public static KeyOnlyFilter parseFrom(final byte[] pbBytes) throws Deserializati
   }
 
   /**
-   * @param o the other filter to compare with
-   * @return true if and only if the fields of the filter that are serialized are equal to the
-   *         corresponding fields in other. Used for testing.
+   * Return true if and only if the fields of the filter that are serialized are equal to the
+   * corresponding fields in other.
    */
   @Override
   boolean areSerializedFieldsEqual(Filter o) {
-    if (o == this) return true;
-    if (!(o instanceof KeyOnlyFilter)) return false;
-
+    if (o == this) {
+      return true;
+    }
+    if (!(o instanceof KeyOnlyFilter)) {
+      return false;
+    }
     KeyOnlyFilter other = (KeyOnlyFilter) o;
     return this.lenAsVal == other.lenAsVal;
   }
 
   @Override
   public boolean equals(Object obj) {
-    return obj instanceof Filter && areSerializedFieldsEqual((Filter) obj);
+    return (obj instanceof Filter) && areSerializedFieldsEqual((Filter) obj);
   }
 
   @Override
diff --git a/hbase-client/src/main/java/org/apache/hadoop/hbase/filter/LongComparator.java b/hbase-client/src/main/java/org/apache/hadoop/hbase/filter/LongComparator.java
index ead0ee104470..e0c8a3518b64 100644
--- a/hbase-client/src/main/java/org/apache/hadoop/hbase/filter/LongComparator.java
+++ b/hbase-client/src/main/java/org/apache/hadoop/hbase/filter/LongComparator.java
@@ -53,9 +53,7 @@ public int compareTo(ByteBuffer value, int offset, int length) {
     return Long.compare(longValue, that);
   }
 
-  /**
-   * @return The comparator serialized using pb
-   */
+  /** Return the comparator serialized using pb */
   @Override
   public byte[] toByteArray() {
     ComparatorProtos.LongComparator.Builder builder = ComparatorProtos.LongComparator.newBuilder();
@@ -64,9 +62,9 @@ public byte[] toByteArray() {
   }
 
   /**
+   * Parse the serialized representation of this comparator.
    * @param pbBytes A pb serialized {@link LongComparator} instance
    * @return An instance of {@link LongComparator} made from bytes
-   * @throws org.apache.hadoop.hbase.exceptions.DeserializationException
    * @see #toByteArray
    */
   public static LongComparator parseFrom(final byte[] pbBytes) throws DeserializationException {
@@ -80,8 +78,8 @@ public static LongComparator parseFrom(final byte[] pbBytes) throws Deserializat
   }
 
   /**
-   * n * @return true if and only if the fields of the comparator that are serialized are equal to
-   * the corresponding fields in other. Used for testing.
+   * Return true if and only if the fields of the comparator that are serialized are equal to the
+   * corresponding fields in other.
    */
   boolean areSerializedFieldsEqual(LongComparator other) {
     if (other == this) return true;
diff --git a/hbase-client/src/main/java/org/apache/hadoop/hbase/filter/MultiRowRangeFilter.java b/hbase-client/src/main/java/org/apache/hadoop/hbase/filter/MultiRowRangeFilter.java
index 1fc22cfcdf78..aec20e4cbe5d 100644
--- a/hbase-client/src/main/java/org/apache/hadoop/hbase/filter/MultiRowRangeFilter.java
+++ b/hbase-client/src/main/java/org/apache/hadoop/hbase/filter/MultiRowRangeFilter.java
@@ -62,9 +62,6 @@ public class MultiRowRangeFilter extends FilterBase {
   private BasicRowRange range;
   private ReturnCode currentReturnCode;
 
-  /**
-   * @param list A list of RowRange
-   */
   public MultiRowRangeFilter(List list) {
     // We don't use rangeList anywhere else, but keeping it lets us pay a little
     // memory to avoid touching the serialization logic.
@@ -199,9 +196,10 @@ public byte[] toByteArray() {
   }
 
   /**
+   * Parse the serialized representation of this filter.
    * @param pbBytes A pb serialized instance
    * @return An instance of MultiRowRangeFilter
-   * @throws org.apache.hadoop.hbase.exceptions.DeserializationException
+   * @throws org.apache.hadoop.hbase.exceptions.DeserializationException if an error occurred
    */
   public static MultiRowRangeFilter parseFrom(final byte[] pbBytes)
     throws DeserializationException {
@@ -226,9 +224,8 @@ public static MultiRowRangeFilter parseFrom(final byte[] pbBytes)
   }
 
   /**
-   * @param o the filter to compare
-   * @return true if and only if the fields of the filter that are serialized are equal to the
-   *         corresponding fields in other. Used for testing.
+   * Return true if and only if the fields of the filter that are serialized are equal to the
+   * corresponding fields in other.
    */
   @Override
   boolean areSerializedFieldsEqual(Filter o) {
@@ -469,16 +466,12 @@ public byte[] getStopRow() {
       return stopRow;
     }
 
-    /**
-     * @return if start row is inclusive.
-     */
+    /** Return if start row is inclusive. */
     public boolean isStartRowInclusive() {
       return startRowInclusive;
     }
 
-    /**
-     * @return if stop row is inclusive.
-     */
+    /** Return if stop row is inclusive. */
     public boolean isStopRowInclusive() {
       return stopRowInclusive;
     }
@@ -520,12 +513,12 @@ public boolean isValid() {
 
     @Override
     public boolean equals(Object obj) {
-      if (!(obj instanceof BasicRowRange)) {
-        return false;
-      }
       if (this == obj) {
         return true;
       }
+      if (!(obj instanceof BasicRowRange)) {
+        return false;
+      }
       BasicRowRange rr = (BasicRowRange) obj;
       return Bytes.equals(this.stopRow, rr.getStopRow())
         && Bytes.equals(this.startRow, this.getStartRow())
@@ -722,45 +715,33 @@ public void setFoundFirstRange() {
       this.foundFirstRange = true;
     }
 
-    /**
-     * Gets the RowRange at the given offset.
-     */
-    @SuppressWarnings("unchecked")
+    /** Gets the RowRange at the given offset. */
+    @SuppressWarnings({ "unchecked", "TypeParameterUnusedInFormals" })
     public  T get(int i) {
       return (T) ranges.get(i);
     }
 
-    /**
-     * Returns true if the first matching row range was found.
-     */
+    /** Returns true if the first matching row range was found. */
     public boolean hasFoundFirstRange() {
       return foundFirstRange;
     }
 
-    /**
-     * Returns true if the current range's key is exclusive
-     */
+    /** Returns true if the current range's key is exclusive */
     public boolean isExclusive() {
       return exclusive;
     }
 
-    /**
-     * Resets the exclusive flag.
-     */
+    /** Resets the exclusive flag. */
     public void resetExclusive() {
       exclusive = false;
     }
 
-    /**
-     * Returns true if this class has been initialized by calling {@link #initialize(boolean)}.
-     */
+    /** Returns true if this class has been initialized by calling {@link #initialize(boolean)}. */
     public boolean isInitialized() {
       return initialized;
     }
 
-    /**
-     * Returns true if we exhausted searching all row ranges.
-     */
+    /** Returns true if we exhausted searching all row ranges. */
     public boolean isIterationComplete(int index) {
       return index >= ranges.size();
     }
@@ -768,7 +749,7 @@ public boolean isIterationComplete(int index) {
 
   @Override
   public boolean equals(Object obj) {
-    return obj instanceof Filter && areSerializedFieldsEqual((Filter) obj);
+    return (obj instanceof Filter) && areSerializedFieldsEqual((Filter) obj);
   }
 
   @Override
diff --git a/hbase-client/src/main/java/org/apache/hadoop/hbase/filter/MultipleColumnPrefixFilter.java b/hbase-client/src/main/java/org/apache/hadoop/hbase/filter/MultipleColumnPrefixFilter.java
index 0d75d16bb3b8..66fe862f9552 100644
--- a/hbase-client/src/main/java/org/apache/hadoop/hbase/filter/MultipleColumnPrefixFilter.java
+++ b/hbase-client/src/main/java/org/apache/hadoop/hbase/filter/MultipleColumnPrefixFilter.java
@@ -116,9 +116,7 @@ public static Filter createFilterFromArguments(ArrayList filterArguments
     return new MultipleColumnPrefixFilter(prefixes);
   }
 
-  /**
-   * @return The filter serialized using pb
-   */
+  /** Return the filter serialized using pb. */
   @Override
   public byte[] toByteArray() {
     FilterProtos.MultipleColumnPrefixFilter.Builder builder =
@@ -130,9 +128,10 @@ public byte[] toByteArray() {
   }
 
   /**
+   * Parse a serialized representation of this filter.
    * @param pbBytes A pb serialized {@link MultipleColumnPrefixFilter} instance
-   * @return An instance of {@link MultipleColumnPrefixFilter} made from bytes n * @see
-   *         #toByteArray
+   * @return An instance of {@link MultipleColumnPrefixFilter} made from bytes
+   * @see #toByteArray
    */
   public static MultipleColumnPrefixFilter parseFrom(final byte[] pbBytes)
     throws DeserializationException {
@@ -152,9 +151,8 @@ public static MultipleColumnPrefixFilter parseFrom(final byte[] pbBytes)
   }
 
   /**
-   * @param o the other filter to compare with
-   * @return true if and only if the fields of the filter that are serialized are equal to the
-   *         corresponding fields in other. Used for testing.
+   * Return true if and only if the fields of the comparator that are serialized are equal to the
+   * corresponding fields in other.
    */
   @Override
   boolean areSerializedFieldsEqual(Filter o) {
@@ -209,7 +207,7 @@ protected String toString(int maxPrefixes) {
 
   @Override
   public boolean equals(Object obj) {
-    return obj instanceof Filter && areSerializedFieldsEqual((Filter) obj);
+    return (obj instanceof Filter) && areSerializedFieldsEqual((Filter) obj);
   }
 
   @Override
diff --git a/hbase-client/src/main/java/org/apache/hadoop/hbase/filter/NullComparator.java b/hbase-client/src/main/java/org/apache/hadoop/hbase/filter/NullComparator.java
index fc0562ecb3e9..7fc7b991b546 100644
--- a/hbase-client/src/main/java/org/apache/hadoop/hbase/filter/NullComparator.java
+++ b/hbase-client/src/main/java/org/apache/hadoop/hbase/filter/NullComparator.java
@@ -63,9 +63,7 @@ public int compareTo(ByteBuffer value, int offset, int length) {
     return value != null ? 1 : 0;
   }
 
-  /**
-   * @return The comparator serialized using pb
-   */
+  /** Return the comparator serialized using pb */
   @Override
   public byte[] toByteArray() {
     ComparatorProtos.NullComparator.Builder builder = ComparatorProtos.NullComparator.newBuilder();
@@ -73,6 +71,7 @@ public byte[] toByteArray() {
   }
 
   /**
+   * Parse a serialized representation of the comparator.
    * @param pbBytes A pb serialized {@link NullComparator} instance
    * @return An instance of {@link NullComparator} made from bytes n * @see
    *         #toByteArray
@@ -88,8 +87,8 @@ public static NullComparator parseFrom(final byte[] pbBytes) throws Deserializat
   }
 
   /**
-   * n * @return true if and only if the fields of the comparator that are serialized are equal to
-   * the corresponding fields in other. Used for testing.
+   * Return true if and only if the fields of the comparator that are serialized are equal to the
+   * corresponding fields in other. Used for testing.
    */
   @Override
   boolean areSerializedFieldsEqual(ByteArrayComparable other) {
diff --git a/hbase-client/src/main/java/org/apache/hadoop/hbase/filter/PageFilter.java b/hbase-client/src/main/java/org/apache/hadoop/hbase/filter/PageFilter.java
index 445adf2129e9..9df42f9faebc 100644
--- a/hbase-client/src/main/java/org/apache/hadoop/hbase/filter/PageFilter.java
+++ b/hbase-client/src/main/java/org/apache/hadoop/hbase/filter/PageFilter.java
@@ -91,9 +91,7 @@ public static Filter createFilterFromArguments(ArrayList filterArguments
     return new PageFilter(pageSize);
   }
 
-  /**
-   * @return The filter serialized using pb
-   */
+  /** Return the filter serialized using pb */
   @Override
   public byte[] toByteArray() {
     FilterProtos.PageFilter.Builder builder = FilterProtos.PageFilter.newBuilder();
@@ -102,8 +100,10 @@ public byte[] toByteArray() {
   }
 
   /**
+   * Parse a serialized representation of the filter.
    * @param pbBytes A pb serialized {@link PageFilter} instance
-   * @return An instance of {@link PageFilter} made from bytes n * @see #toByteArray
+   * @return An instance of {@link PageFilter} made from bytes
+   * @see #toByteArray
    */
   public static PageFilter parseFrom(final byte[] pbBytes) throws DeserializationException {
     FilterProtos.PageFilter proto;
@@ -116,9 +116,8 @@ public static PageFilter parseFrom(final byte[] pbBytes) throws DeserializationE
   }
 
   /**
-   * @param o other Filter to compare with
-   * @return true if and only if the fields of the filter that are serialized are equal to the
-   *         corresponding fields in other. Used for testing.
+   * Return true if and only if the fields of the filter that are serialized are equal to the
+   * corresponding fields in other.
    */
   @Override
   boolean areSerializedFieldsEqual(Filter o) {
@@ -128,7 +127,6 @@ boolean areSerializedFieldsEqual(Filter o) {
     if (!(o instanceof PageFilter)) {
       return false;
     }
-
     PageFilter other = (PageFilter) o;
     return this.getPageSize() == other.getPageSize();
   }
@@ -140,7 +138,7 @@ public String toString() {
 
   @Override
   public boolean equals(Object obj) {
-    return obj instanceof Filter && areSerializedFieldsEqual((Filter) obj);
+    return (obj instanceof Filter) && areSerializedFieldsEqual((Filter) obj);
   }
 
   @Override
diff --git a/hbase-client/src/main/java/org/apache/hadoop/hbase/filter/ParseFilter.java b/hbase-client/src/main/java/org/apache/hadoop/hbase/filter/ParseFilter.java
index b08ce971c213..af672e93d934 100644
--- a/hbase-client/src/main/java/org/apache/hadoop/hbase/filter/ParseFilter.java
+++ b/hbase-client/src/main/java/org/apache/hadoop/hbase/filter/ParseFilter.java
@@ -109,6 +109,7 @@ public Filter parseFilterString(String filterString) throws CharacterCodingExcep
    * @param filterStringAsByteArray filter string given by the user
    * @return filter object we constructed
    */
+  @SuppressWarnings("JdkObsolete")
   public Filter parseFilterString(byte[] filterStringAsByteArray) throws CharacterCodingException {
     // stack for the operators and parenthesis
     Stack operatorStack = new Stack<>();
@@ -156,7 +157,7 @@ public Filter parseFilterString(byte[] filterStringAsByteArray) throws Character
           operatorStack.pop();
           continue;
         }
-        while (!(argumentOnTopOfStack.equals(ParseConstants.LPAREN_BUFFER))) {
+        while (!argumentOnTopOfStack.equals(ParseConstants.LPAREN_BUFFER)) {
           filterStack.push(popArguments(operatorStack, filterStack));
           if (operatorStack.empty()) {
             throw new IllegalArgumentException("Mismatched parenthesis");
@@ -364,10 +365,11 @@ public static ArrayList getFilterArguments(byte[] filterStringAsByteArra
    * @param filterStack   the stack containing the filters
    * @param operator      the operator found while parsing the filterString
    */
+  @SuppressWarnings("JdkObsolete")
   public void reduce(Stack operatorStack, Stack filterStack,
     ByteBuffer operator) {
     while (
-      !operatorStack.empty() && !(ParseConstants.LPAREN_BUFFER.equals(operatorStack.peek()))
+      !operatorStack.empty() && !ParseConstants.LPAREN_BUFFER.equals(operatorStack.peek())
         && hasHigherPriority(operatorStack.peek(), operator)
     ) {
       filterStack.push(popArguments(operatorStack, filterStack));
@@ -382,6 +384,7 @@ && hasHigherPriority(operatorStack.peek(), operator)
    * @param filterStack   the stack containing the filters
    * @return the evaluated filter
    */
+  @SuppressWarnings("JdkObsolete")
   public static Filter popArguments(Stack operatorStack, Stack filterStack) {
     ByteBuffer argumentOnTopOfStack = operatorStack.peek();
 
@@ -841,9 +844,7 @@ public static byte[][] parseComparator(byte[] comparator) {
     return result;
   }
 
-  /**
-   * Return a Set of filters supported by the Filter Language
-   */
+  /** Return a Set of filters supported by the Filter Language */
   public Set getSupportedFilters() {
     return filterHashMap.keySet();
   }
diff --git a/hbase-client/src/main/java/org/apache/hadoop/hbase/filter/PrefixFilter.java b/hbase-client/src/main/java/org/apache/hadoop/hbase/filter/PrefixFilter.java
index 3b40388a06f9..a28c9cf4cfe3 100644
--- a/hbase-client/src/main/java/org/apache/hadoop/hbase/filter/PrefixFilter.java
+++ b/hbase-client/src/main/java/org/apache/hadoop/hbase/filter/PrefixFilter.java
@@ -101,9 +101,7 @@ public static Filter createFilterFromArguments(ArrayList filterArguments
     return new PrefixFilter(prefix);
   }
 
-  /**
-   * @return The filter serialized using pb
-   */
+  /** Return the filter serialized using pb */
   @Override
   public byte[] toByteArray() {
     FilterProtos.PrefixFilter.Builder builder = FilterProtos.PrefixFilter.newBuilder();
@@ -112,9 +110,10 @@ public byte[] toByteArray() {
   }
 
   /**
+   * Parse a serialized representation of the filter.
    * @param pbBytes A pb serialized {@link PrefixFilter} instance
    * @return An instance of {@link PrefixFilter} made from bytes
-   * @throws org.apache.hadoop.hbase.exceptions.DeserializationException
+   * @throws org.apache.hadoop.hbase.exceptions.DeserializationException if an error occurred
    * @see #toByteArray
    */
   public static PrefixFilter parseFrom(final byte[] pbBytes) throws DeserializationException {
@@ -128,15 +127,17 @@ public static PrefixFilter parseFrom(final byte[] pbBytes) throws Deserializatio
   }
 
   /**
-   * @param o the other filter to compare with
-   * @return true if and only if the fields of the filter that are serialized are equal to the
-   *         corresponding fields in other. Used for testing.
+   * Return true if and only if the fields of the comparator that are serialized are equal to the
+   * corresponding fields in other.
    */
   @Override
   boolean areSerializedFieldsEqual(Filter o) {
-    if (o == this) return true;
-    if (!(o instanceof PrefixFilter)) return false;
-
+    if (o == this) {
+      return true;
+    }
+    if (!(o instanceof PrefixFilter)) {
+      return false;
+    }
     PrefixFilter other = (PrefixFilter) o;
     return Bytes.equals(this.getPrefix(), other.getPrefix());
   }
@@ -148,7 +149,7 @@ public String toString() {
 
   @Override
   public boolean equals(Object obj) {
-    return obj instanceof Filter && areSerializedFieldsEqual((Filter) obj);
+    return (obj instanceof Filter) && areSerializedFieldsEqual((Filter) obj);
   }
 
   @Override
diff --git a/hbase-client/src/main/java/org/apache/hadoop/hbase/filter/QualifierFilter.java b/hbase-client/src/main/java/org/apache/hadoop/hbase/filter/QualifierFilter.java
index 2d52b300ff87..98a56f9f109a 100644
--- a/hbase-client/src/main/java/org/apache/hadoop/hbase/filter/QualifierFilter.java
+++ b/hbase-client/src/main/java/org/apache/hadoop/hbase/filter/QualifierFilter.java
@@ -67,9 +67,7 @@ public static Filter createFilterFromArguments(ArrayList filterArguments
     return new QualifierFilter(compareOp, comparator);
   }
 
-  /**
-   * @return The filter serialized using pb
-   */
+  /** Return the filter serialized using pb */
   @Override
   public byte[] toByteArray() {
     FilterProtos.QualifierFilter.Builder builder = FilterProtos.QualifierFilter.newBuilder();
@@ -78,9 +76,10 @@ public byte[] toByteArray() {
   }
 
   /**
+   * Parse a serialized representation of the filter.
    * @param pbBytes A pb serialized {@link QualifierFilter} instance
    * @return An instance of {@link QualifierFilter} made from bytes
-   * @throws org.apache.hadoop.hbase.exceptions.DeserializationException
+   * @throws org.apache.hadoop.hbase.exceptions.DeserializationException if an error occurred
    * @see #toByteArray
    */
   public static QualifierFilter parseFrom(final byte[] pbBytes) throws DeserializationException {
@@ -104,20 +103,23 @@ public static QualifierFilter parseFrom(final byte[] pbBytes) throws Deserializa
   }
 
   /**
-   * @return true if and only if the fields of the filter that are serialized are equal to the
-   *         corresponding fields in other. Used for testing.
+   * Return true if and only if the fields of the filter that are serialized are equal to the
+   * corresponding fields in other.
    */
   @Override
   boolean areSerializedFieldsEqual(Filter o) {
-    if (o == this) return true;
-    if (!(o instanceof QualifierFilter)) return false;
-
+    if (o == this) {
+      return true;
+    }
+    if (!(o instanceof QualifierFilter)) {
+      return false;
+    }
     return super.areSerializedFieldsEqual(o);
   }
 
   @Override
   public boolean equals(Object obj) {
-    return obj instanceof Filter && areSerializedFieldsEqual((Filter) obj);
+    return (obj instanceof Filter) && areSerializedFieldsEqual((Filter) obj);
   }
 
   @Override
diff --git a/hbase-client/src/main/java/org/apache/hadoop/hbase/filter/RandomRowFilter.java b/hbase-client/src/main/java/org/apache/hadoop/hbase/filter/RandomRowFilter.java
index d54d7575f254..975e2abf173b 100644
--- a/hbase-client/src/main/java/org/apache/hadoop/hbase/filter/RandomRowFilter.java
+++ b/hbase-client/src/main/java/org/apache/hadoop/hbase/filter/RandomRowFilter.java
@@ -36,23 +36,17 @@ public class RandomRowFilter extends FilterBase {
   protected float chance;
   protected boolean filterOutRow;
 
-  /**
-   * Create a new filter with a specified chance for a row to be included. n
-   */
+  /** Create a new filter with a specified chance for a row to be included. */
   public RandomRowFilter(float chance) {
     this.chance = chance;
   }
 
-  /**
-   * @return The chance that a row gets included.
-   */
+  /** Return the chance that a row gets included. */
   public float getChance() {
     return chance;
   }
 
-  /**
-   * Set the chance that a row is included. n
-   */
+  /** Set the chance that a row is included. */
   public void setChance(float chance) {
     this.chance = chance;
   }
@@ -100,9 +94,7 @@ public void reset() {
     filterOutRow = false;
   }
 
-  /**
-   * @return The filter serialized using pb
-   */
+  /** Return the filter serialized using pb */
   @Override
   public byte[] toByteArray() {
     FilterProtos.RandomRowFilter.Builder builder = FilterProtos.RandomRowFilter.newBuilder();
@@ -111,9 +103,10 @@ public byte[] toByteArray() {
   }
 
   /**
+   * Parse a serialized filter instance.
    * @param pbBytes A pb serialized {@link RandomRowFilter} instance
-   * @return An instance of {@link RandomRowFilter} made from bytes n * @see
-   *         #toByteArray
+   * @return An instance of {@link RandomRowFilter} made from bytes
+   * @see #toByteArray
    */
   public static RandomRowFilter parseFrom(final byte[] pbBytes) throws DeserializationException {
     FilterProtos.RandomRowFilter proto;
@@ -126,22 +119,24 @@ public static RandomRowFilter parseFrom(final byte[] pbBytes) throws Deserializa
   }
 
   /**
-   * @param o the other filter to compare with
-   * @return true if and only if the fields of the filter that are serialized are equal to the
-   *         corresponding fields in other. Used for testing.
+   * Return true if and only if the fields of the filter that are serialized are equal to the
+   * corresponding fields in other.
    */
   @Override
   boolean areSerializedFieldsEqual(Filter o) {
-    if (o == this) return true;
-    if (!(o instanceof RandomRowFilter)) return false;
-
+    if (o == this) {
+      return true;
+    }
+    if (!(o instanceof RandomRowFilter)) {
+      return false;
+    }
     RandomRowFilter other = (RandomRowFilter) o;
     return this.getChance() == other.getChance();
   }
 
   @Override
   public boolean equals(Object obj) {
-    return obj instanceof Filter && areSerializedFieldsEqual((Filter) obj);
+    return (obj instanceof Filter) && areSerializedFieldsEqual((Filter) obj);
   }
 
   @Override
diff --git a/hbase-client/src/main/java/org/apache/hadoop/hbase/filter/RegexStringComparator.java b/hbase-client/src/main/java/org/apache/hadoop/hbase/filter/RegexStringComparator.java
index 75272c5f2413..66479d012ab6 100644
--- a/hbase-client/src/main/java/org/apache/hadoop/hbase/filter/RegexStringComparator.java
+++ b/hbase-client/src/main/java/org/apache/hadoop/hbase/filter/RegexStringComparator.java
@@ -46,7 +46,6 @@
  * Only EQUAL or NOT_EQUAL comparisons are valid with this comparator.
  * 

  * For example:
- * 

  *
  * 
  * ValueFilter vf = new ValueFilter(CompareOp.EQUAL, new RegexStringComparator(
@@ -57,9 +56,8 @@
  *     "((([\\dA-Fa-f]{1,4}:){7}[\\dA-Fa-f]{1,4})(:([\\d]{1,3}.)"
  *     + "{3}[\\d]{1,3})?)(\\/[0-9]+)?"));
  * 

- * 

+ *
  * Supports {@link java.util.regex.Pattern} flags as well:
- * 

  *
  * 
  * ValueFilter vf = new ValueFilter(CompareOp.EQUAL,
@@ -145,15 +143,14 @@ public int compareTo(byte[] value, int offset, int length) {
     return engine.compareTo(value, offset, length);
   }
 
-  /**
-   * @return The comparator serialized using pb
-   */
+  /** Return the comparator serialized using pb */
   @Override
   public byte[] toByteArray() {
     return engine.toByteArray();
   }
 
   /**
+   * Parse a serialized representation of the comparator
    * @param pbBytes A pb serialized {@link RegexStringComparator} instance
    * @return An instance of {@link RegexStringComparator} made from bytes n * @see
    *         #toByteArray
@@ -185,13 +182,17 @@ public static RegexStringComparator parseFrom(final byte[] pbBytes)
   }
 
   /**
-   * n * @return true if and only if the fields of the comparator that are serialized are equal to
-   * the corresponding fields in other. Used for testing.
+   * Return true if and only if the fields of the comparator that are serialized are equal to the
+   * corresponding fields in other.
    */
   @Override
   boolean areSerializedFieldsEqual(ByteArrayComparable other) {
-    if (other == this) return true;
-    if (!(other instanceof RegexStringComparator)) return false;
+    if (other == this) {
+      return true;
+    }
+    if (!(other instanceof RegexStringComparator)) {
+      return false;
+    }
     RegexStringComparator comparator = (RegexStringComparator) other;
     return super.areSerializedFieldsEqual(comparator)
       && engine.getClass().isInstance(comparator.getEngine())
diff --git a/hbase-client/src/main/java/org/apache/hadoop/hbase/filter/RowFilter.java b/hbase-client/src/main/java/org/apache/hadoop/hbase/filter/RowFilter.java
index dee91657f745..c28aa536fe77 100644
--- a/hbase-client/src/main/java/org/apache/hadoop/hbase/filter/RowFilter.java
+++ b/hbase-client/src/main/java/org/apache/hadoop/hbase/filter/RowFilter.java
@@ -87,9 +87,7 @@ public static Filter createFilterFromArguments(ArrayList filterArguments
     return new RowFilter(compareOp, comparator);
   }
 
-  /**
-   * @return The filter serialized using pb
-   */
+  /** Return the filter serialized using pb */
   @Override
   public byte[] toByteArray() {
     FilterProtos.RowFilter.Builder builder = FilterProtos.RowFilter.newBuilder();
@@ -98,8 +96,10 @@ public byte[] toByteArray() {
   }
 
   /**
+   * Parse a serialized representation of the filter
    * @param pbBytes A pb serialized {@link RowFilter} instance
-   * @return An instance of {@link RowFilter} made from bytes n * @see #toByteArray
+   * @return An instance of {@link RowFilter} made from bytes
+   * @see #toByteArray
    */
   public static RowFilter parseFrom(final byte[] pbBytes) throws DeserializationException {
     FilterProtos.RowFilter proto;
@@ -122,20 +122,23 @@ public static RowFilter parseFrom(final byte[] pbBytes) throws DeserializationEx
   }
 
   /**
-   * @return true if and only if the fields of the filter that are serialized are equal to the
-   *         corresponding fields in other. Used for testing.
+   * Return true if and only if the fields of the filter that are serialized are equal to the
+   * corresponding fields in other.
    */
   @Override
   boolean areSerializedFieldsEqual(Filter o) {
-    if (o == this) return true;
-    if (!(o instanceof RowFilter)) return false;
-
+    if (o == this) {
+      return true;
+    }
+    if (!(o instanceof RowFilter)) {
+      return false;
+    }
     return super.areSerializedFieldsEqual(o);
   }
 
   @Override
   public boolean equals(Object obj) {
-    return obj instanceof Filter && areSerializedFieldsEqual((Filter) obj);
+    return (obj instanceof Filter) && areSerializedFieldsEqual((Filter) obj);
   }
 
   @Override
diff --git a/hbase-client/src/main/java/org/apache/hadoop/hbase/filter/SingleColumnValueExcludeFilter.java b/hbase-client/src/main/java/org/apache/hadoop/hbase/filter/SingleColumnValueExcludeFilter.java
index f1b9413718f0..91b0a17e002f 100644
--- a/hbase-client/src/main/java/org/apache/hadoop/hbase/filter/SingleColumnValueExcludeFilter.java
+++ b/hbase-client/src/main/java/org/apache/hadoop/hbase/filter/SingleColumnValueExcludeFilter.java
@@ -112,9 +112,7 @@ public static Filter createFilterFromArguments(ArrayList filterArguments
     return filter;
   }
 
-  /**
-   * @return The filter serialized using pb
-   */
+  /** Return the filter serialized using pb */
   @Override
   public byte[] toByteArray() {
     FilterProtos.SingleColumnValueExcludeFilter.Builder builder =
@@ -124,9 +122,10 @@ public byte[] toByteArray() {
   }
 
   /**
+   * Parse a serialized representation of the filter
    * @param pbBytes A pb serialized {@link SingleColumnValueExcludeFilter} instance
-   * @return An instance of {@link SingleColumnValueExcludeFilter} made from bytes n
-   *         * @see #toByteArray
+   * @return An instance of {@link SingleColumnValueExcludeFilter} made from bytes
+   * @see #toByteArray
    */
   public static SingleColumnValueExcludeFilter parseFrom(final byte[] pbBytes)
     throws DeserializationException {
@@ -153,20 +152,23 @@ public static SingleColumnValueExcludeFilter parseFrom(final byte[] pbBytes)
   }
 
   /**
-   * @return true if and only if the fields of the filter that are serialized are equal to the
-   *         corresponding fields in other. Used for testing.
+   * Return true if and only if the fields of the filter that are serialized are equal to the
+   * corresponding fields in other.
    */
   @Override
   boolean areSerializedFieldsEqual(Filter o) {
-    if (o == this) return true;
-    if (!(o instanceof SingleColumnValueExcludeFilter)) return false;
-
+    if (o == this) {
+      return true;
+    }
+    if (!(o instanceof SingleColumnValueExcludeFilter)) {
+      return false;
+    }
     return super.areSerializedFieldsEqual(o);
   }
 
   @Override
   public boolean equals(Object obj) {
-    return obj instanceof Filter && areSerializedFieldsEqual((Filter) obj);
+    return (obj instanceof Filter) && areSerializedFieldsEqual((Filter) obj);
   }
 
   @Override
diff --git a/hbase-client/src/main/java/org/apache/hadoop/hbase/filter/SingleColumnValueFilter.java b/hbase-client/src/main/java/org/apache/hadoop/hbase/filter/SingleColumnValueFilter.java
index 365ee06b904b..38a7a5991783 100644
--- a/hbase-client/src/main/java/org/apache/hadoop/hbase/filter/SingleColumnValueFilter.java
+++ b/hbase-client/src/main/java/org/apache/hadoop/hbase/filter/SingleColumnValueFilter.java
@@ -125,23 +125,17 @@ public CompareOperator getCompareOperator() {
     return op;
   }
 
-  /**
-   * @return the comparator
-   */
+  /** Return the comparator */
   public org.apache.hadoop.hbase.filter.ByteArrayComparable getComparator() {
     return comparator;
   }
 
-  /**
-   * @return the family
-   */
+  /** Return the family */
   public byte[] getFamily() {
     return columnFamily;
   }
 
-  /**
-   * @return the qualifier
-   */
+  /** Return the qualifier */
   public byte[] getQualifier() {
     return columnQualifier;
   }
@@ -283,15 +277,14 @@ FilterProtos.SingleColumnValueFilter convert() {
     return builder.build();
   }
 
-  /**
-   * @return The filter serialized using pb
-   */
+  /** Return the filter serialized using pb */
   @Override
   public byte[] toByteArray() {
     return convert().toByteArray();
   }
 
   /**
+   * Parse a serialized representation of this filter.
    * @param pbBytes A pb serialized {@link SingleColumnValueFilter} instance
    * @return An instance of {@link SingleColumnValueFilter} made from bytes
    * @see #toByteArray
@@ -320,14 +313,17 @@ public static SingleColumnValueFilter parseFrom(final byte[] pbBytes)
   }
 
   /**
-   * @return true if and only if the fields of the filter that are serialized are equal to the
-   *         corresponding fields in other. Used for testing.
+   * Return true if and only if the fields of the filter that are serialized are equal to the
+   * corresponding fields in other.
    */
   @Override
   boolean areSerializedFieldsEqual(Filter o) {
-    if (o == this) return true;
-    if (!(o instanceof SingleColumnValueFilter)) return false;
-
+    if (o == this) {
+      return true;
+    }
+    if (!(o instanceof SingleColumnValueFilter)) {
+      return false;
+    }
     SingleColumnValueFilter other = (SingleColumnValueFilter) o;
     return Bytes.equals(this.getFamily(), other.getFamily())
       && Bytes.equals(this.getQualifier(), other.getQualifier()) && this.op.equals(other.op)
@@ -355,7 +351,7 @@ public String toString() {
 
   @Override
   public boolean equals(Object obj) {
-    return obj instanceof Filter && areSerializedFieldsEqual((Filter) obj);
+    return (obj instanceof Filter) && areSerializedFieldsEqual((Filter) obj);
   }
 
   @Override
diff --git a/hbase-client/src/main/java/org/apache/hadoop/hbase/filter/SkipFilter.java b/hbase-client/src/main/java/org/apache/hadoop/hbase/filter/SkipFilter.java
index 3aa0ef22c151..36555e0f1162 100644
--- a/hbase-client/src/main/java/org/apache/hadoop/hbase/filter/SkipFilter.java
+++ b/hbase-client/src/main/java/org/apache/hadoop/hbase/filter/SkipFilter.java
@@ -35,14 +35,15 @@
  * the actual weights, and we want to filter out the entire row if any of its weights are zero. In
  * this case, we want to prevent rows from being emitted if a single key is filtered. Combine this
  * filter with a {@link ValueFilter}:
- * 

- * 

- * 
+ *
+ * 
  * scan.setFilter(new SkipFilter(new ValueFilter(CompareOp.NOT_EQUAL,
  *     new BinaryComparator(Bytes.toBytes(0))));
- *  Any row which contained a column whose value was 0 will be filtered out (since
- * ValueFilter will not pass that Cell). Without this filter, the other non-zero valued columns in
- * the row would still be emitted.
+ * 

+ *
+ * Any row which contained a column whose value was 0 will be filtered out (since ValueFilter will
+ * not pass that Cell). Without this filter, the other non-zero valued columns in the row would
+ * still be emitted.
  * 

  */
 @InterfaceAudience.Public
@@ -96,9 +97,7 @@ public boolean hasFilterRow() {
     return true;
   }
 
-  /**
-   * @return The filter serialized using pb
-   */
+  /** Return the filter serialized using pb */
   @Override
   public byte[] toByteArray() throws IOException {
     FilterProtos.SkipFilter.Builder builder = FilterProtos.SkipFilter.newBuilder();
@@ -107,8 +106,10 @@ public byte[] toByteArray() throws IOException {
   }
 
   /**
+   * Parse a serialized representation of the filter.
    * @param pbBytes A pb serialized {@link SkipFilter} instance
-   * @return An instance of {@link SkipFilter} made from bytes n * @see #toByteArray
+   * @return An instance of {@link SkipFilter} made from bytes
+   * @see #toByteArray
    */
   public static SkipFilter parseFrom(final byte[] pbBytes) throws DeserializationException {
     FilterProtos.SkipFilter proto;
@@ -125,15 +126,17 @@ public static SkipFilter parseFrom(final byte[] pbBytes) throws DeserializationE
   }
 
   /**
-   * @param o the other filter to compare with
-   * @return true if and only if the fields of the filter that are serialized are equal to the
-   *         corresponding fields in other. Used for testing.
+   * Return true if and only if the fields of the filter that are serialized are equal to the
+   * corresponding fields in other.
    */
   @Override
   boolean areSerializedFieldsEqual(Filter o) {
-    if (o == this) return true;
-    if (!(o instanceof SkipFilter)) return false;
-
+    if (o == this) {
+      return true;
+    }
+    if (!(o instanceof SkipFilter)) {
+      return false;
+    }
     SkipFilter other = (SkipFilter) o;
     return getFilter().areSerializedFieldsEqual(other.getFilter());
   }
@@ -150,7 +153,7 @@ public String toString() {
 
   @Override
   public boolean equals(Object obj) {
-    return obj instanceof Filter && areSerializedFieldsEqual((Filter) obj);
+    return (obj instanceof Filter) && areSerializedFieldsEqual((Filter) obj);
   }
 
   @Override
diff --git a/hbase-client/src/main/java/org/apache/hadoop/hbase/filter/SubstringComparator.java b/hbase-client/src/main/java/org/apache/hadoop/hbase/filter/SubstringComparator.java
index b8e33c438feb..3ba56be0b059 100644
--- a/hbase-client/src/main/java/org/apache/hadoop/hbase/filter/SubstringComparator.java
+++ b/hbase-client/src/main/java/org/apache/hadoop/hbase/filter/SubstringComparator.java
@@ -47,10 +47,6 @@ public class SubstringComparator extends ByteArrayComparable {
 
   private String substr;
 
-  /**
-   * Constructor
-   * @param substr the substring
-   */
   public SubstringComparator(String substr) {
     super(Bytes.toBytes(substr.toLowerCase(Locale.ROOT)));
     this.substr = substr.toLowerCase(Locale.ROOT);
@@ -66,9 +62,7 @@ public int compareTo(byte[] value, int offset, int length) {
     return Bytes.toString(value, offset, length).toLowerCase(Locale.ROOT).contains(substr) ? 0 : 1;
   }
 
-  /**
-   * @return The comparator serialized using pb
-   */
+  /** Return the comparator serialized using pb */
   @Override
   public byte[] toByteArray() {
     ComparatorProtos.SubstringComparator.Builder builder =
@@ -78,6 +72,7 @@ public byte[] toByteArray() {
   }
 
   /**
+   * Parse a serialized representation of the comparator.
    * @param pbBytes A pb serialized {@link SubstringComparator} instance
    * @return An instance of {@link SubstringComparator} made from bytes n * @see
    *         #toByteArray
@@ -94,14 +89,17 @@ public static SubstringComparator parseFrom(final byte[] pbBytes)
   }
 
   /**
-   * n * @return true if and only if the fields of the comparator that are serialized are equal to
-   * the corresponding fields in other. Used for testing.
+   * Return true if and only if the fields of the comparator that are serialized are equal to the
+   * corresponding fields in other.
    */
   @Override
   boolean areSerializedFieldsEqual(ByteArrayComparable other) {
-    if (other == this) return true;
-    if (!(other instanceof SubstringComparator)) return false;
-
+    if (other == this) {
+      return true;
+    }
+    if (!(other instanceof SubstringComparator)) {
+      return false;
+    }
     SubstringComparator comparator = (SubstringComparator) other;
     return super.areSerializedFieldsEqual(comparator) && this.substr.equals(comparator.substr);
   }
diff --git a/hbase-client/src/main/java/org/apache/hadoop/hbase/filter/TimestampsFilter.java b/hbase-client/src/main/java/org/apache/hadoop/hbase/filter/TimestampsFilter.java
index dfd2f5c537c9..05f825fcf127 100644
--- a/hbase-client/src/main/java/org/apache/hadoop/hbase/filter/TimestampsFilter.java
+++ b/hbase-client/src/main/java/org/apache/hadoop/hbase/filter/TimestampsFilter.java
@@ -77,9 +77,7 @@ public TimestampsFilter(List timestamps, boolean canHint) {
     init();
   }
 
-  /**
-   * @return the list of timestamps
-   */
+  /** Return the list of timestamps */
   public List getTimestamps() {
     List list = new ArrayList<>(timestamps.size());
     list.addAll(timestamps);
@@ -171,6 +169,7 @@ public byte[] toByteArray() {
   }
 
   /**
+   * Parse a serialized representation of the filter
    * @param pbBytes A pb serialized {@link TimestampsFilter} instance
    * @return An instance of {@link TimestampsFilter} made from bytes
    * @see #toByteArray
@@ -187,15 +186,17 @@ public static TimestampsFilter parseFrom(final byte[] pbBytes) throws Deserializ
   }
 
   /**
-   * @param o the other filter to compare with
-   * @return true if and only if the fields of the filter that are serialized are equal to the
-   *         corresponding fields in other. Used for testing.
+   * Return true if and only if the fields of the filter that are serialized are equal to the
+   * corresponding fields in other.
    */
   @Override
   boolean areSerializedFieldsEqual(Filter o) {
-    if (o == this) return true;
-    if (!(o instanceof TimestampsFilter)) return false;
-
+    if (o == this) {
+      return true;
+    }
+    if (!(o instanceof TimestampsFilter)) {
+      return false;
+    }
     TimestampsFilter other = (TimestampsFilter) o;
     return this.getTimestamps().equals(other.getTimestamps());
   }
@@ -226,7 +227,7 @@ protected String toString(int maxTimestamps) {
 
   @Override
   public boolean equals(Object obj) {
-    return obj instanceof Filter && areSerializedFieldsEqual((Filter) obj);
+    return (obj instanceof Filter) && areSerializedFieldsEqual((Filter) obj);
   }
 
   @Override
diff --git a/hbase-client/src/main/java/org/apache/hadoop/hbase/filter/ValueFilter.java b/hbase-client/src/main/java/org/apache/hadoop/hbase/filter/ValueFilter.java
index 810f71efbd67..dcbcf89b1c54 100644
--- a/hbase-client/src/main/java/org/apache/hadoop/hbase/filter/ValueFilter.java
+++ b/hbase-client/src/main/java/org/apache/hadoop/hbase/filter/ValueFilter.java
@@ -69,9 +69,7 @@ public static Filter createFilterFromArguments(ArrayList filterArguments
     return new ValueFilter(compareOp, comparator);
   }
 
-  /**
-   * @return The filter serialized using pb
-   */
+  /** Return the filter serialized using pb */
   @Override
   public byte[] toByteArray() {
     FilterProtos.ValueFilter.Builder builder = FilterProtos.ValueFilter.newBuilder();
@@ -80,8 +78,10 @@ public byte[] toByteArray() {
   }
 
   /**
+   * Parse a serialized representation of the filter
    * @param pbBytes A pb serialized {@link ValueFilter} instance
-   * @return An instance of {@link ValueFilter} made from bytes n * @see #toByteArray
+   * @return An instance of {@link ValueFilter} made from bytes
+   * @see #toByteArray
    */
   public static ValueFilter parseFrom(final byte[] pbBytes) throws DeserializationException {
     FilterProtos.ValueFilter proto;
@@ -104,20 +104,23 @@ public static ValueFilter parseFrom(final byte[] pbBytes) throws Deserialization
   }
 
   /**
-   * @return true if and only if the fields of the filter that are serialized are equal to the
-   *         corresponding fields in other. Used for testing.
+   * Return true if and only if the fields of the filter that are serialized are equal to the
+   * corresponding fields in other.
    */
   @Override
   boolean areSerializedFieldsEqual(Filter o) {
-    if (o == this) return true;
-    if (!(o instanceof ValueFilter)) return false;
-
+    if (o == this) {
+      return true;
+    }
+    if (!(o instanceof ValueFilter)) {
+      return false;
+    }
     return super.areSerializedFieldsEqual(o);
   }
 
   @Override
   public boolean equals(Object obj) {
-    return obj instanceof Filter && areSerializedFieldsEqual((Filter) obj);
+    return (obj instanceof Filter) && areSerializedFieldsEqual((Filter) obj);
   }
 
   @Override
diff --git a/hbase-client/src/main/java/org/apache/hadoop/hbase/filter/WhileMatchFilter.java b/hbase-client/src/main/java/org/apache/hadoop/hbase/filter/WhileMatchFilter.java
index 94cdd9794b3c..31bab3d19004 100644
--- a/hbase-client/src/main/java/org/apache/hadoop/hbase/filter/WhileMatchFilter.java
+++ b/hbase-client/src/main/java/org/apache/hadoop/hbase/filter/WhileMatchFilter.java
@@ -94,9 +94,7 @@ public boolean hasFilterRow() {
     return true;
   }
 
-  /**
-   * @return The filter serialized using pb
-   */
+  /** Return the filter serialized using pb */
   @Override
   public byte[] toByteArray() throws IOException {
     FilterProtos.WhileMatchFilter.Builder builder = FilterProtos.WhileMatchFilter.newBuilder();
@@ -105,9 +103,10 @@ public byte[] toByteArray() throws IOException {
   }
 
   /**
+   * Parse a serialized representation of the filter
    * @param pbBytes A pb serialized {@link WhileMatchFilter} instance
    * @return An instance of {@link WhileMatchFilter} made from bytes
-   * @throws org.apache.hadoop.hbase.exceptions.DeserializationException
+   * @throws org.apache.hadoop.hbase.exceptions.DeserializationException if an error occurred
    * @see #toByteArray
    */
   public static WhileMatchFilter parseFrom(final byte[] pbBytes) throws DeserializationException {
@@ -125,15 +124,17 @@ public static WhileMatchFilter parseFrom(final byte[] pbBytes) throws Deserializ
   }
 
   /**
-   * @param o the other filter to compare with
-   * @return true if and only if the fields of the filter that are serialized are equal to the
-   *         corresponding fields in other. Used for testing.
+   * Return true if and only if the fields of the filter that are serialized are equal to the
+   * corresponding fields in other.
    */
   @Override
   boolean areSerializedFieldsEqual(Filter o) {
-    if (o == this) return true;
-    if (!(o instanceof WhileMatchFilter)) return false;
-
+    if (o == this) {
+      return true;
+    }
+    if (!(o instanceof WhileMatchFilter)) {
+      return false;
+    }
     WhileMatchFilter other = (WhileMatchFilter) o;
     return getFilter().areSerializedFieldsEqual(other.getFilter());
   }
@@ -150,7 +151,7 @@ public String toString() {
 
   @Override
   public boolean equals(Object obj) {
-    return obj instanceof Filter && areSerializedFieldsEqual((Filter) obj);
+    return (obj instanceof Filter) && areSerializedFieldsEqual((Filter) obj);
   }
 
   @Override
diff --git a/hbase-client/src/main/java/org/apache/hadoop/hbase/ipc/AbstractRpcClient.java b/hbase-client/src/main/java/org/apache/hadoop/hbase/ipc/AbstractRpcClient.java
index 7c0149ccb8a3..9d557a98743c 100644
--- a/hbase-client/src/main/java/org/apache/hadoop/hbase/ipc/AbstractRpcClient.java
+++ b/hbase-client/src/main/java/org/apache/hadoop/hbase/ipc/AbstractRpcClient.java
@@ -238,7 +238,8 @@ Codec getCodec() {
       return null;
     }
     try {
-      return (Codec) Class.forName(className).getDeclaredConstructor().newInstance();
+      return Class.forName(className).asSubclass(Codec.class).getDeclaredConstructor()
+        .newInstance();
     } catch (Exception e) {
       throw new RuntimeException("Failed getting codec " + className, e);
     }
@@ -265,7 +266,8 @@ private static CompressionCodec getCompressor(final Configuration conf) {
       return null;
     }
     try {
-      return (CompressionCodec) Class.forName(className).getDeclaredConstructor().newInstance();
+      return Class.forName(className).asSubclass(CompressionCodec.class).getDeclaredConstructor()
+        .newInstance();
     } catch (Exception e) {
       throw new RuntimeException("Failed getting compressor " + className, e);
     }
diff --git a/hbase-client/src/main/java/org/apache/hadoop/hbase/ipc/BlockingRpcConnection.java b/hbase-client/src/main/java/org/apache/hadoop/hbase/ipc/BlockingRpcConnection.java
index c8adc6a8cc3c..da032cbeb9d1 100644
--- a/hbase-client/src/main/java/org/apache/hadoop/hbase/ipc/BlockingRpcConnection.java
+++ b/hbase-client/src/main/java/org/apache/hadoop/hbase/ipc/BlockingRpcConnection.java
@@ -67,7 +67,6 @@
 import org.slf4j.LoggerFactory;
 
 import org.apache.hbase.thirdparty.com.google.protobuf.Message;
-import org.apache.hbase.thirdparty.com.google.protobuf.Message.Builder;
 import org.apache.hbase.thirdparty.com.google.protobuf.RpcCallback;
 import org.apache.hbase.thirdparty.io.netty.buffer.ByteBuf;
 import org.apache.hbase.thirdparty.io.netty.buffer.PooledByteBufAllocator;
@@ -181,6 +180,8 @@ public void run() {
             try {
               BlockingRpcConnection.this.wait();
             } catch (InterruptedException e) {
+              // Restore interrupt status
+              Thread.currentThread().interrupt();
             }
             // check if we need to quit, so continue the main loop instead of fallback.
             continue;
@@ -333,6 +334,8 @@ private synchronized boolean waitForWork() {
       try {
         wait(Math.min(this.rpcClient.minIdleTimeBeforeClose, 1000));
       } catch (InterruptedException e) {
+        // Restore interrupt status
+        Thread.currentThread().interrupt();
       }
     }
   }
@@ -685,7 +688,7 @@ private void readResponse() {
       } else {
         Message value = null;
         if (call.responseDefaultType != null) {
-          Builder builder = call.responseDefaultType.newBuilderForType();
+          Message.Builder builder = call.responseDefaultType.newBuilderForType();
           ProtobufUtil.mergeDelimitedFrom(builder, in);
           value = builder.build();
         }
diff --git a/hbase-client/src/main/java/org/apache/hadoop/hbase/ipc/BufferCallBeforeInitHandler.java b/hbase-client/src/main/java/org/apache/hadoop/hbase/ipc/BufferCallBeforeInitHandler.java
index 3dc48ce3e00e..ec7f422e64d9 100644
--- a/hbase-client/src/main/java/org/apache/hadoop/hbase/ipc/BufferCallBeforeInitHandler.java
+++ b/hbase-client/src/main/java/org/apache/hadoop/hbase/ipc/BufferCallBeforeInitHandler.java
@@ -65,6 +65,7 @@ public static BufferCallBeforeInitHandler.BufferCallEvent fail(IOException error
   private final Map id2Call = new HashMap<>();
 
   @Override
+  @SuppressWarnings("FutureReturnValueIgnored")
   public void write(ChannelHandlerContext ctx, Object msg, ChannelPromise promise) {
     if (msg instanceof Call) {
       Call call = (Call) msg;
@@ -78,7 +79,8 @@ public void write(ChannelHandlerContext ctx, Object msg, ChannelPromise promise)
   }
 
   @Override
-  public void userEventTriggered(ChannelHandlerContext ctx, Object evt) throws Exception {
+  @SuppressWarnings("FutureReturnValueIgnored")
+  public void userEventTriggered(ChannelHandlerContext ctx, Object evt) {
     if (evt instanceof BufferCallEvent) {
       BufferCallEvent bcEvt = (BufferCallBeforeInitHandler.BufferCallEvent) evt;
       switch (bcEvt.action) {
diff --git a/hbase-client/src/main/java/org/apache/hadoop/hbase/ipc/CellBlockBuilder.java b/hbase-client/src/main/java/org/apache/hadoop/hbase/ipc/CellBlockBuilder.java
index 9e9c0688ecee..92f3bbea12c9 100644
--- a/hbase-client/src/main/java/org/apache/hadoop/hbase/ipc/CellBlockBuilder.java
+++ b/hbase-client/src/main/java/org/apache/hadoop/hbase/ipc/CellBlockBuilder.java
@@ -228,6 +228,7 @@ public ByteBufferListOutputStream buildCellBlockStream(Codec codec, CompressionC
   }
 
   /**
+   * Create a new CellScanner
    * @param codec     to use for cellblock
    * @param cellBlock to encode
    * @return CellScanner to work against the content of cellBlock
@@ -248,6 +249,7 @@ public CellScanner createCellScanner(final Codec codec, final CompressionCodec c
   }
 
   /**
+   * Create a new CellScanner, reusing provided byte buffers
    * @param codec     to use for cellblock
    * @param cellBlock ByteBuffer containing the cells written by the Codec. The buffer should be
    *                  position()'ed at the start of the cell block and limit()'ed at the end.
diff --git a/hbase-client/src/main/java/org/apache/hadoop/hbase/ipc/ConnectionId.java b/hbase-client/src/main/java/org/apache/hadoop/hbase/ipc/ConnectionId.java
index 6cb9cddd9feb..2b5c3765c170 100644
--- a/hbase-client/src/main/java/org/apache/hadoop/hbase/ipc/ConnectionId.java
+++ b/hbase-client/src/main/java/org/apache/hadoop/hbase/ipc/ConnectionId.java
@@ -57,6 +57,7 @@ public String toString() {
   }
 
   @Override
+  @SuppressWarnings("ReferenceEquality")
   public boolean equals(Object obj) {
     if (obj instanceof ConnectionId) {
       ConnectionId id = (ConnectionId) obj;
diff --git a/hbase-client/src/main/java/org/apache/hadoop/hbase/ipc/HBaseRpcController.java b/hbase-client/src/main/java/org/apache/hadoop/hbase/ipc/HBaseRpcController.java
index b33771e5b582..06342ecfe27f 100644
--- a/hbase-client/src/main/java/org/apache/hadoop/hbase/ipc/HBaseRpcController.java
+++ b/hbase-client/src/main/java/org/apache/hadoop/hbase/ipc/HBaseRpcController.java
@@ -50,19 +50,19 @@ public interface HBaseRpcController extends RpcController, CellScannable {
   void setCellScanner(CellScanner cellScanner);
 
   /**
+   * Set a priority for the request.
    * @param priority Priority for this request; should fall roughly in the range
    *                 {@link HConstants#NORMAL_QOS} to {@link HConstants#HIGH_QOS}
    */
   void setPriority(int priority);
 
   /**
+   * Set a priority for the request based on a table name.
    * @param tn Set priority based off the table we are going against.
    */
   void setPriority(final TableName tn);
 
-  /**
-   * @return The priority of this request
-   */
+  /** Return the priority of this request */
   int getPriority();
 
   int getCallTimeout();
@@ -83,6 +83,8 @@ public interface HBaseRpcController extends RpcController, CellScannable {
   IOException getFailed();
 
   /**
+   * Indicate the call has finished.
+   * 

    * IMPORTANT: always call this method if the call finished without any exception to tell
    * the {@code HBaseRpcController} that we are done.
    */
@@ -110,16 +112,12 @@ interface CancellationCallback {
    */
   void notifyOnCancel(RpcCallback callback, CancellationCallback action) throws IOException;
 
-  /**
-   * @return True if this Controller is carrying the RPC target Region's RegionInfo.
-   */
+  /** Return true if this Controller is carrying the RPC target Region's RegionInfo. */
   default boolean hasRegionInfo() {
     return false;
   }
 
-  /**
-   * @return Target Region's RegionInfo or null if not available or pertinent.
-   */
+  /** Return the target Region's RegionInfo or null if not available or pertinent. */
   default RegionInfo getRegionInfo() {
     return null;
   }
diff --git a/hbase-client/src/main/java/org/apache/hadoop/hbase/ipc/IPCUtil.java b/hbase-client/src/main/java/org/apache/hadoop/hbase/ipc/IPCUtil.java
index 57f8da98eff6..e97b9bc4d876 100644
--- a/hbase-client/src/main/java/org/apache/hadoop/hbase/ipc/IPCUtil.java
+++ b/hbase-client/src/main/java/org/apache/hadoop/hbase/ipc/IPCUtil.java
@@ -96,9 +96,7 @@ private static int write(final OutputStream dos, final Message header, final Mes
     return totalSize;
   }
 
-  /**
-   * @return Size on the wire when the two messages are written with writeDelimitedTo
-   */
+  /** Return the size on the wire when the two messages are written with writeDelimitedTo */
   public static int getTotalSizeWhenWrittenDelimited(Message... messages) {
     int totalSize = 0;
     for (Message m : messages) {
diff --git a/hbase-client/src/main/java/org/apache/hadoop/hbase/ipc/NettyRpcClient.java b/hbase-client/src/main/java/org/apache/hadoop/hbase/ipc/NettyRpcClient.java
index 7b698958ede2..f915b0cc7910 100644
--- a/hbase-client/src/main/java/org/apache/hadoop/hbase/ipc/NettyRpcClient.java
+++ b/hbase-client/src/main/java/org/apache/hadoop/hbase/ipc/NettyRpcClient.java
@@ -76,6 +76,7 @@ protected NettyRpcConnection createConnection(ConnectionId remoteId) throws IOEx
   }
 
   @Override
+  @SuppressWarnings("FutureReturnValueIgnored")
   protected void closeInternal() {
     if (shutdownGroupWhenClose) {
       group.shutdownGracefully();
diff --git a/hbase-client/src/main/java/org/apache/hadoop/hbase/ipc/NettyRpcConnection.java b/hbase-client/src/main/java/org/apache/hadoop/hbase/ipc/NettyRpcConnection.java
index 14e8cbc13d3b..9d811437ed20 100644
--- a/hbase-client/src/main/java/org/apache/hadoop/hbase/ipc/NettyRpcConnection.java
+++ b/hbase-client/src/main/java/org/apache/hadoop/hbase/ipc/NettyRpcConnection.java
@@ -126,6 +126,7 @@ public boolean isActive() {
     return channel != null;
   }
 
+  @SuppressWarnings("FutureReturnValueIgnored")
   private void shutdown0() {
     assert eventLoop.inEventLoop();
     if (channel != null) {
@@ -167,6 +168,7 @@ private void established(Channel ch) throws IOException {
 
   private boolean reloginInProgress;
 
+  @SuppressWarnings("FutureReturnValueIgnored")
   private void scheduleRelogin(Throwable error) {
     assert eventLoop.inEventLoop();
     if (error instanceof FallbackDisallowedException) {
@@ -199,6 +201,7 @@ private void failInit(Channel ch, IOException e) {
     shutdown0();
   }
 
+  @SuppressWarnings("FutureReturnValueIgnored")
   private void saslNegotiate(final Channel ch) {
     assert eventLoop.inEventLoop();
     UserGroupInformation ticket = provider.getRealUser(remoteId.getTicket());
@@ -220,6 +223,7 @@ private void saslNegotiate(final Channel ch) {
     saslPromise.addListener(new FutureListener() {
 
       @Override
+      @SuppressWarnings("FutureReturnValueIgnored")
       public void operationComplete(Future future) throws Exception {
         if (future.isSuccess()) {
           ChannelPipeline p = ch.pipeline();
@@ -281,6 +285,7 @@ private void connect() throws UnknownHostException {
       .remoteAddress(remoteAddr).connect().addListener(new ChannelFutureListener() {
 
         @Override
+        @SuppressWarnings("FutureReturnValueIgnored")
         public void operationComplete(ChannelFuture future) throws Exception {
           Channel ch = future.channel();
           if (!future.isSuccess()) {
@@ -317,6 +322,7 @@ public void run(Object parameter) {
     }, new CancellationCallback() {
 
       @Override
+      @SuppressWarnings("FutureReturnValueIgnored")
       public void run(boolean cancelled) throws IOException {
         if (cancelled) {
           setCancelled(call);
diff --git a/hbase-client/src/main/java/org/apache/hadoop/hbase/ipc/NettyRpcDuplexHandler.java b/hbase-client/src/main/java/org/apache/hadoop/hbase/ipc/NettyRpcDuplexHandler.java
index fe32189f81bd..08f972e184f2 100644
--- a/hbase-client/src/main/java/org/apache/hadoop/hbase/ipc/NettyRpcDuplexHandler.java
+++ b/hbase-client/src/main/java/org/apache/hadoop/hbase/ipc/NettyRpcDuplexHandler.java
@@ -31,7 +31,6 @@
 import org.slf4j.LoggerFactory;
 
 import org.apache.hbase.thirdparty.com.google.protobuf.Message;
-import org.apache.hbase.thirdparty.com.google.protobuf.Message.Builder;
 import org.apache.hbase.thirdparty.com.google.protobuf.TextFormat;
 import org.apache.hbase.thirdparty.io.netty.buffer.ByteBuf;
 import org.apache.hbase.thirdparty.io.netty.buffer.ByteBufInputStream;
@@ -76,6 +75,7 @@ public NettyRpcDuplexHandler(NettyRpcConnection conn, CellBlockBuilder cellBlock
 
   }
 
+  @SuppressWarnings("FutureReturnValueIgnored")
   private void writeRequest(ChannelHandlerContext ctx, Call call, ChannelPromise promise)
     throws IOException {
     id2Call.put(call.id, call);
@@ -114,6 +114,7 @@ private void writeRequest(ChannelHandlerContext ctx, Call call, ChannelPromise p
   }
 
   @Override
+  @SuppressWarnings("FutureReturnValueIgnored")
   public void write(ChannelHandlerContext ctx, Object msg, ChannelPromise promise)
     throws Exception {
     if (msg instanceof Call) {
@@ -168,7 +169,7 @@ private void readResponse(ChannelHandlerContext ctx, ByteBuf buf) throws IOExcep
     }
     Message value;
     if (call.responseDefaultType != null) {
-      Builder builder = call.responseDefaultType.newBuilderForType();
+      Message.Builder builder = call.responseDefaultType.newBuilderForType();
       builder.mergeDelimitedFrom(in);
       value = builder.build();
     } else {
@@ -202,7 +203,7 @@ public void channelRead(ChannelHandlerContext ctx, Object msg) throws Exception
     }
   }
 
-  private void cleanupCalls(ChannelHandlerContext ctx, IOException error) {
+  private void cleanupCalls(IOException error) {
     for (Call call : id2Call.values()) {
       call.setException(error);
     }
@@ -212,7 +213,7 @@ private void cleanupCalls(ChannelHandlerContext ctx, IOException error) {
   @Override
   public void channelInactive(ChannelHandlerContext ctx) throws Exception {
     if (!id2Call.isEmpty()) {
-      cleanupCalls(ctx, new ConnectionClosedException("Connection closed"));
+      cleanupCalls(new ConnectionClosedException("Connection closed"));
     }
     conn.shutdown();
     ctx.fireChannelInactive();
@@ -221,7 +222,7 @@ public void channelInactive(ChannelHandlerContext ctx) throws Exception {
   @Override
   public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) {
     if (!id2Call.isEmpty()) {
-      cleanupCalls(ctx, IPCUtil.toIOE(cause));
+      cleanupCalls(IPCUtil.toIOE(cause));
     }
     conn.shutdown();
   }
diff --git a/hbase-client/src/main/java/org/apache/hadoop/hbase/ipc/RemoteWithExtrasException.java b/hbase-client/src/main/java/org/apache/hadoop/hbase/ipc/RemoteWithExtrasException.java
index 62d0bb1d4550..ce60279ca8db 100644
--- a/hbase-client/src/main/java/org/apache/hadoop/hbase/ipc/RemoteWithExtrasException.java
+++ b/hbase-client/src/main/java/org/apache/hadoop/hbase/ipc/RemoteWithExtrasException.java
@@ -123,30 +123,22 @@ private IOException instantiateException(Class cls) throw
     return ex;
   }
 
-  /**
-   * @return null if not set
-   */
+  /** Return null if not set */
   public String getHostname() {
     return this.hostname;
   }
 
-  /**
-   * @return -1 if not set
-   */
+  /** Return -1 if not set */
   public int getPort() {
     return this.port;
   }
 
-  /**
-   * @return True if origin exception was a do not retry type.
-   */
+  /** Return true if origin exception was a do not retry type. */
   public boolean isDoNotRetry() {
     return this.doNotRetry;
   }
 
-  /**
-   * @return True if the server was considered overloaded when the exception was thrown.
-   */
+  /** Return true if the server was considered overloaded when the exception was thrown. */
   public boolean isServerOverloaded() {
     return serverOverloaded;
   }
diff --git a/hbase-client/src/main/java/org/apache/hadoop/hbase/ipc/RpcClient.java b/hbase-client/src/main/java/org/apache/hadoop/hbase/ipc/RpcClient.java
index 6ecff49e52b1..7db9cd8b585f 100644
--- a/hbase-client/src/main/java/org/apache/hadoop/hbase/ipc/RpcClient.java
+++ b/hbase-client/src/main/java/org/apache/hadoop/hbase/ipc/RpcClient.java
@@ -90,8 +90,8 @@ public interface RpcClient extends Closeable {
   void close();
 
   /**
-   * @return true when this client uses a {@link org.apache.hadoop.hbase.codec.Codec} and so
-   *         supports cell blocks.
+   * Returns true when this client uses a {@link org.apache.hadoop.hbase.codec.Codec} and so
+   * supports cell blocks.
    */
   boolean hasCellBlockSupport();
 }
diff --git a/hbase-client/src/main/java/org/apache/hadoop/hbase/ipc/ServerTooBusyException.java b/hbase-client/src/main/java/org/apache/hadoop/hbase/ipc/ServerTooBusyException.java
index 6c22ca94e428..83fc3927eb1a 100644
--- a/hbase-client/src/main/java/org/apache/hadoop/hbase/ipc/ServerTooBusyException.java
+++ b/hbase-client/src/main/java/org/apache/hadoop/hbase/ipc/ServerTooBusyException.java
@@ -34,6 +34,7 @@ public ServerTooBusyException(Address address, long count) {
   }
 
   @Deprecated
+  @SuppressWarnings("InlineMeSuggester")
   public ServerTooBusyException(InetSocketAddress address, long count) {
     super("Busy Server! " + count + " concurrent RPCs against " + address);
   }
diff --git a/hbase-client/src/main/java/org/apache/hadoop/hbase/master/RegionState.java b/hbase-client/src/main/java/org/apache/hadoop/hbase/master/RegionState.java
index 2b0f2f4509e4..065b85279b20 100644
--- a/hbase-client/src/main/java/org/apache/hadoop/hbase/master/RegionState.java
+++ b/hbase-client/src/main/java/org/apache/hadoop/hbase/master/RegionState.java
@@ -17,7 +17,6 @@
  */
 package org.apache.hadoop.hbase.master;
 
-import java.util.Date;
 import org.apache.hadoop.hbase.ServerName;
 import org.apache.hadoop.hbase.client.RegionInfo;
 import org.apache.hadoop.hbase.util.EnvironmentEdgeManager;
@@ -386,7 +385,7 @@ public String toString() {
    */
   public String toDescriptiveString() {
     long relTime = EnvironmentEdgeManager.currentTime() - stamp;
-    return hri.getRegionNameAsString() + " state=" + state + ", ts=" + new Date(stamp) + " ("
+    return hri.getRegionNameAsString() + " state=" + state + ", ts=" + stamp + " ("
       + (relTime / 1000) + "s ago)" + ", server=" + serverName;
   }
 
@@ -417,12 +416,13 @@ public static RegionState convert(ClusterStatusProtos.RegionState proto) {
    */
   @Override
   public boolean equals(Object obj) {
-    if (this == obj) return true;
-    if (obj == null || getClass() != obj.getClass()) {
+    if (this == obj) {
+      return true;
+    }
+    if (!(obj instanceof RegionState)) {
       return false;
     }
     RegionState tmp = (RegionState) obj;
-
     return RegionInfo.COMPARATOR.compare(tmp.hri, hri) == 0 && tmp.state == state
       && ((serverName != null && serverName.equals(tmp.serverName))
         || (tmp.serverName == null && serverName == null));
diff --git a/hbase-client/src/main/java/org/apache/hadoop/hbase/protobuf/ProtobufMagic.java b/hbase-client/src/main/java/org/apache/hadoop/hbase/protobuf/ProtobufMagic.java
index 7c6f780e069d..2f56a0c87446 100644
--- a/hbase-client/src/main/java/org/apache/hadoop/hbase/protobuf/ProtobufMagic.java
+++ b/hbase-client/src/main/java/org/apache/hadoop/hbase/protobuf/ProtobufMagic.java
@@ -35,6 +35,7 @@ private ProtobufMagic() {
   public static final byte[] PB_MAGIC = new byte[] { 'P', 'B', 'U', 'F' };
 
   /**
+   * Check if the byte array has {@link #PB_MAGIC} for a prefix.
    * @param bytes Bytes to check.
    * @return True if passed bytes has {@link #PB_MAGIC} for a prefix.
    */
@@ -43,10 +44,8 @@ public static boolean isPBMagicPrefix(final byte[] bytes) {
     return isPBMagicPrefix(bytes, 0, bytes.length);
   }
 
-  /*
-   * Copied from Bytes.java to here hbase-common now depends on hbase-protocol Referencing
-   * Bytes.java directly would create circular dependency
-   */
+  // Copied from Bytes.java to here hbase-common now depends on hbase-protocol Referencing
+  // Bytes.java directly would create circular dependency
   private static int compareTo(byte[] buffer1, int offset1, int length1, byte[] buffer2,
     int offset2, int length2) {
     // Short circuit equal case
@@ -67,6 +66,7 @@ private static int compareTo(byte[] buffer1, int offset1, int length1, byte[] bu
   }
 
   /**
+   * Check if the byte array has {@link #PB_MAGIC} for a prefix.
    * @param bytes  Bytes to check.
    * @param offset offset to start at
    * @param len    length to use
@@ -77,9 +77,7 @@ public static boolean isPBMagicPrefix(final byte[] bytes, int offset, int len) {
     return compareTo(PB_MAGIC, 0, PB_MAGIC.length, bytes, offset, PB_MAGIC.length) == 0;
   }
 
-  /**
-   * @return Length of {@link #PB_MAGIC}
-   */
+  /** Return length of {@link #PB_MAGIC} */
   public static int lengthOfPBMagic() {
     return PB_MAGIC.length;
   }
diff --git a/hbase-client/src/main/java/org/apache/hadoop/hbase/quotas/QuotaFilter.java b/hbase-client/src/main/java/org/apache/hadoop/hbase/quotas/QuotaFilter.java
index 9ddd408f845c..930393c1e546 100644
--- a/hbase-client/src/main/java/org/apache/hadoop/hbase/quotas/QuotaFilter.java
+++ b/hbase-client/src/main/java/org/apache/hadoop/hbase/quotas/QuotaFilter.java
@@ -92,32 +92,32 @@ public QuotaFilter addTypeFilter(final QuotaType type) {
     return this;
   }
 
-  /** @return true if the filter is empty */
+  /** Return true if the filter is empty */
   public boolean isNull() {
     return !hasFilters;
   }
 
-  /** @return the QuotaType types that we want to filter one */
+  /** Return the QuotaType types that we want to filter one */
   public Set getTypeFilters() {
     return types;
   }
 
-  /** @return the Namespace filter regex */
+  /** Return the Namespace filter regex */
   public String getNamespaceFilter() {
     return namespaceRegex;
   }
 
-  /** @return the Table filter regex */
+  /** Return the Table filter regex */
   public String getTableFilter() {
     return tableRegex;
   }
 
-  /** @return the User filter regex */
+  /** Return the User filter regex */
   public String getUserFilter() {
     return userRegex;
   }
 
-  /** @return the RegionServer filter regex */
+  /** Return the RegionServer filter regex */
   public String getRegionServerFilter() {
     return regionServerRegex;
   }
diff --git a/hbase-client/src/main/java/org/apache/hadoop/hbase/quotas/QuotaRetriever.java b/hbase-client/src/main/java/org/apache/hadoop/hbase/quotas/QuotaRetriever.java
index 728959e0a0ca..1dd5bf275bba 100644
--- a/hbase-client/src/main/java/org/apache/hadoop/hbase/quotas/QuotaRetriever.java
+++ b/hbase-client/src/main/java/org/apache/hadoop/hbase/quotas/QuotaRetriever.java
@@ -19,8 +19,8 @@
 
 import java.io.Closeable;
 import java.io.IOException;
+import java.util.ArrayDeque;
 import java.util.Iterator;
-import java.util.LinkedList;
 import java.util.Objects;
 import java.util.Queue;
 import org.apache.hadoop.conf.Configuration;
@@ -43,7 +43,7 @@
 public class QuotaRetriever implements Closeable, Iterable {
   private static final Logger LOG = LoggerFactory.getLogger(QuotaRetriever.class);
 
-  private final Queue cache = new LinkedList<>();
+  private final Queue cache = new ArrayDeque<>();
   private ResultScanner scanner;
   /**
    * Connection to use. Could pass one in and have this class use it but this class wants to be
diff --git a/hbase-client/src/main/java/org/apache/hadoop/hbase/quotas/SpaceLimitSettings.java b/hbase-client/src/main/java/org/apache/hadoop/hbase/quotas/SpaceLimitSettings.java
index 878cbe871e57..34cf40046732 100644
--- a/hbase-client/src/main/java/org/apache/hadoop/hbase/quotas/SpaceLimitSettings.java
+++ b/hbase-client/src/main/java/org/apache/hadoop/hbase/quotas/SpaceLimitSettings.java
@@ -23,10 +23,8 @@
 import org.apache.yetus.audience.InterfaceStability;
 
 import org.apache.hadoop.hbase.shaded.protobuf.ProtobufUtil;
-import org.apache.hadoop.hbase.shaded.protobuf.generated.MasterProtos.SetQuotaRequest.Builder;
+import org.apache.hadoop.hbase.shaded.protobuf.generated.MasterProtos;
 import org.apache.hadoop.hbase.shaded.protobuf.generated.QuotaProtos;
-import org.apache.hadoop.hbase.shaded.protobuf.generated.QuotaProtos.SpaceLimitRequest;
-import org.apache.hadoop.hbase.shaded.protobuf.generated.QuotaProtos.SpaceQuota;
 
 /**
  * A {@link QuotaSettings} implementation for configuring filesystem-use quotas.
@@ -35,7 +33,7 @@
 @InterfaceStability.Evolving
 class SpaceLimitSettings extends QuotaSettings {
 
-  private final SpaceLimitRequest proto;
+  private final QuotaProtos.SpaceLimitRequest proto;
 
   SpaceLimitSettings(TableName tableName, long sizeLimit, SpaceViolationPolicy violationPolicy) {
     super(null, Objects.requireNonNull(tableName), null, null);
@@ -65,45 +63,46 @@ class SpaceLimitSettings extends QuotaSettings {
     proto = buildProtoRemoveQuota();
   }
 
-  SpaceLimitSettings(TableName tableName, String namespace, SpaceLimitRequest req) {
+  SpaceLimitSettings(TableName tableName, String namespace, QuotaProtos.SpaceLimitRequest req) {
     super(null, tableName, namespace, null);
     proto = req;
   }
 
   /**
-   * Build a {@link SpaceLimitRequest} protobuf object from the given {@link SpaceQuota}.
+   * Build a {@link QuotaProtos.SpaceLimitRequest} protobuf object from the given
+   * {@link SpaceQuota}.
    * @param protoQuota The preconstructed SpaceQuota protobuf
    * @return A protobuf request to change a space limit quota
    */
-  private SpaceLimitRequest buildProtoFromQuota(SpaceQuota protoQuota) {
-    return SpaceLimitRequest.newBuilder().setQuota(protoQuota).build();
+  private QuotaProtos.SpaceLimitRequest buildProtoFromQuota(QuotaProtos.SpaceQuota protoQuota) {
+    return QuotaProtos.SpaceLimitRequest.newBuilder().setQuota(protoQuota).build();
   }
 
   /**
-   * Builds a {@link SpaceQuota} protobuf object given the arguments.
+   * Builds a {@link QuotaProtos.SpaceQuota} protobuf object given the arguments.
    * @param sizeLimit       The size limit of the quota.
    * @param violationPolicy The action to take when the quota is exceeded.
    * @return The protobuf SpaceQuota representation.
    */
-  private SpaceLimitRequest buildProtoAddQuota(long sizeLimit,
+  private QuotaProtos.SpaceLimitRequest buildProtoAddQuota(long sizeLimit,
     SpaceViolationPolicy violationPolicy) {
-    return buildProtoFromQuota(SpaceQuota.newBuilder().setSoftLimit(sizeLimit)
+    return buildProtoFromQuota(QuotaProtos.SpaceQuota.newBuilder().setSoftLimit(sizeLimit)
       .setViolationPolicy(ProtobufUtil.toProtoViolationPolicy(violationPolicy)).build());
   }
 
   /**
-   * Builds a {@link SpaceQuota} protobuf object to remove a quota.
+   * Builds a {@link QuotaProtos.SpaceQuota} protobuf object to remove a quota.
    * @return The protobuf SpaceQuota representation.
    */
-  private SpaceLimitRequest buildProtoRemoveQuota() {
-    return SpaceLimitRequest.newBuilder().setQuota(SpaceQuota.newBuilder().setRemove(true).build())
-      .build();
+  private QuotaProtos.SpaceLimitRequest buildProtoRemoveQuota() {
+    return QuotaProtos.SpaceLimitRequest.newBuilder()
+      .setQuota(QuotaProtos.SpaceQuota.newBuilder().setRemove(true).build()).build();
   }
 
   /**
    * Returns a copy of the internal state of this
    */
-  SpaceLimitRequest getProto() {
+  QuotaProtos.SpaceLimitRequest getProto() {
     return proto.toBuilder().build();
   }
 
@@ -113,7 +112,7 @@ public QuotaType getQuotaType() {
   }
 
   @Override
-  protected void setupSetQuotaRequest(Builder builder) {
+  protected void setupSetQuotaRequest(MasterProtos.SetQuotaRequest.Builder builder) {
     // TableName/Namespace are serialized in QuotaSettings
     builder.setSpaceLimit(proto);
   }
@@ -203,7 +202,7 @@ protected QuotaSettings merge(QuotaSettings newSettings) {
 
       // The message contained the expect SpaceQuota object
       if (settingsToMerge.proto.hasQuota()) {
-        SpaceQuota quotaToMerge = settingsToMerge.proto.getQuota();
+        QuotaProtos.SpaceQuota quotaToMerge = settingsToMerge.proto.getQuota();
         if (quotaToMerge.getRemove()) {
           return settingsToMerge;
         } else {
@@ -216,7 +215,7 @@ protected QuotaSettings merge(QuotaSettings newSettings) {
             throw new IllegalArgumentException("Cannot merge " + newSettings + " into " + this);
           }
           // Create a builder from the old settings
-          SpaceQuota.Builder mergedBuilder = this.proto.getQuota().toBuilder();
+          QuotaProtos.SpaceQuota.Builder mergedBuilder = this.proto.getQuota().toBuilder();
           // Build a new SpaceQuotas object from merging in the new settings
           return new SpaceLimitSettings(getTableName(), getNamespace(),
             buildProtoFromQuota(mergedBuilder.mergeFrom(quotaToMerge).build()));
diff --git a/hbase-client/src/main/java/org/apache/hadoop/hbase/quotas/SpaceQuotaSnapshotView.java b/hbase-client/src/main/java/org/apache/hadoop/hbase/quotas/SpaceQuotaSnapshotView.java
index 4bc47b9cddd3..9db7282e59b0 100644
--- a/hbase-client/src/main/java/org/apache/hadoop/hbase/quotas/SpaceQuotaSnapshotView.java
+++ b/hbase-client/src/main/java/org/apache/hadoop/hbase/quotas/SpaceQuotaSnapshotView.java
@@ -40,7 +40,7 @@ interface SpaceQuotaStatusView {
     Optional getPolicy();
 
     /**
-     * @return {@code true} if the quota is being violated, {@code false} otherwise.
+     * Return {@code true} if the quota is being violated, {@code false} otherwise.
      */
     boolean isInViolation();
   }
diff --git a/hbase-client/src/main/java/org/apache/hadoop/hbase/security/NettyHBaseRpcConnectionHeaderHandler.java b/hbase-client/src/main/java/org/apache/hadoop/hbase/security/NettyHBaseRpcConnectionHeaderHandler.java
index a75091c5293d..b21d987c8ebd 100644
--- a/hbase-client/src/main/java/org/apache/hadoop/hbase/security/NettyHBaseRpcConnectionHeaderHandler.java
+++ b/hbase-client/src/main/java/org/apache/hadoop/hbase/security/NettyHBaseRpcConnectionHeaderHandler.java
@@ -51,6 +51,7 @@ public NettyHBaseRpcConnectionHeaderHandler(Promise saslPromise, Config
   }
 
   @Override
+  @SuppressWarnings("FutureReturnValueIgnored")
   protected void channelRead0(ChannelHandlerContext ctx, ByteBuf msg) throws Exception {
     // read the ConnectionHeaderResponse from server
     int len = msg.readInt();
@@ -72,6 +73,7 @@ protected void channelRead0(ChannelHandlerContext ctx, ByteBuf msg) throws Excep
   }
 
   @Override
+  @SuppressWarnings("FutureReturnValueIgnored")
   public void handlerAdded(ChannelHandlerContext ctx) {
     try {
       // send the connection header to server first
diff --git a/hbase-client/src/main/java/org/apache/hadoop/hbase/security/NettyHBaseSaslRpcClientHandler.java b/hbase-client/src/main/java/org/apache/hadoop/hbase/security/NettyHBaseSaslRpcClientHandler.java
index 7473c3269b04..172dc6619f65 100644
--- a/hbase-client/src/main/java/org/apache/hadoop/hbase/security/NettyHBaseSaslRpcClientHandler.java
+++ b/hbase-client/src/main/java/org/apache/hadoop/hbase/security/NettyHBaseSaslRpcClientHandler.java
@@ -75,12 +75,14 @@ public NettyHBaseSaslRpcClientHandler(Promise saslPromise, UserGroupInf
         SaslUtil.QualityOfProtection.AUTHENTICATION.name().toLowerCase()));
   }
 
+  @SuppressWarnings("FutureReturnValueIgnored")
   private void writeResponse(ChannelHandlerContext ctx, byte[] response) {
     LOG.trace("Sending token size={} from initSASLContext.", response.length);
     ctx.writeAndFlush(
       ctx.alloc().buffer(4 + response.length).writeInt(response.length).writeBytes(response));
   }
 
+  @SuppressWarnings("FutureReturnValueIgnored")
   private void tryComplete(ChannelHandlerContext ctx) {
     if (!saslRpcClient.isComplete()) {
       return;
diff --git a/hbase-client/src/main/java/org/apache/hadoop/hbase/security/SaslUtil.java b/hbase-client/src/main/java/org/apache/hadoop/hbase/security/SaslUtil.java
index c2dc1042c913..f16c1e2d0069 100644
--- a/hbase-client/src/main/java/org/apache/hadoop/hbase/security/SaslUtil.java
+++ b/hbase-client/src/main/java/org/apache/hadoop/hbase/security/SaslUtil.java
@@ -93,9 +93,10 @@ public static QualityOfProtection getQop(String stringQop) {
   }
 
   /**
+   * Return a map with values for SASL properties.
    * @param rpcProtection Value of 'hbase.rpc.protection' configuration.
-   * @return Map with values for SASL properties.
    */
+  @SuppressWarnings("StringSplitter")
   public static Map initSaslProperties(String rpcProtection) {
     String saslQop;
     if (rpcProtection.isEmpty()) {
diff --git a/hbase-client/src/main/java/org/apache/hadoop/hbase/security/access/AccessControlClient.java b/hbase-client/src/main/java/org/apache/hadoop/hbase/security/access/AccessControlClient.java
index b6986b564ac8..a1c673180c75 100644
--- a/hbase-client/src/main/java/org/apache/hadoop/hbase/security/access/AccessControlClient.java
+++ b/hbase-client/src/main/java/org/apache/hadoop/hbase/security/access/AccessControlClient.java
@@ -29,16 +29,11 @@
 import org.apache.hadoop.hbase.ZooKeeperConnectionException;
 import org.apache.hadoop.hbase.client.Admin;
 import org.apache.hadoop.hbase.client.Connection;
-import org.apache.hadoop.hbase.client.Table;
 import org.apache.hadoop.hbase.client.TableDescriptor;
 import org.apache.hadoop.hbase.client.security.SecurityCapability;
-import org.apache.hadoop.hbase.ipc.CoprocessorRpcChannel;
 import org.apache.hadoop.hbase.util.Bytes;
 import org.apache.yetus.audience.InterfaceAudience;
 
-import org.apache.hadoop.hbase.shaded.protobuf.generated.AccessControlProtos;
-import org.apache.hadoop.hbase.shaded.protobuf.generated.AccessControlProtos.AccessControlService.BlockingInterface;
-
 /**
  * Utility client for doing access control admin operations.
  */
@@ -67,17 +62,11 @@ public static boolean isCellAuthorizationEnabled(Connection connection) throws I
       .contains(SecurityCapability.CELL_AUTHORIZATION);
   }
 
-  private static BlockingInterface getAccessControlServiceStub(Table ht) throws IOException {
-    CoprocessorRpcChannel service = ht.coprocessorService(HConstants.EMPTY_START_ROW);
-    BlockingInterface protocol = AccessControlProtos.AccessControlService.newBlockingStub(service);
-    return protocol;
-  }
-
   /**
-   * Grants permission on the specified table for the specified user
-   * @param connection The Connection instance to use nnnn * @param mergeExistingPermissions If set
-   *                   to false, later granted permissions will override previous granted
-   *                   permissions. otherwise, it'll merge with previous granted permissions. nn
+   * Grants permission on the specified table for the specified user.
+   * 

+   * If mergeExistingPermissions is set to false, later granted permissions will override previous
+   * granted permissions. otherwise, it'll merge with previous granted permissions.
    */
   private static void grant(Connection connection, final TableName tableName, final String userName,
     final byte[] family, final byte[] qual, boolean mergeExistingPermissions,
@@ -90,7 +79,6 @@ private static void grant(Connection connection, final TableName tableName, fina
   /**
    * Grants permission on the specified table for the specified user. If permissions for a specified
    * user exists, later granted permissions will override previous granted permissions.
-   * @param connection The Connection instance to use nnnnnn
    */
   public static void grant(Connection connection, final TableName tableName, final String userName,
     final byte[] family, final byte[] qual, final Permission.Action... actions) throws Throwable {
@@ -98,9 +86,10 @@ public static void grant(Connection connection, final TableName tableName, final
   }
 
   /**
-   * Grants permission on the specified namespace for the specified user. nnn * @param
-   * mergeExistingPermissions If set to false, later granted permissions will override previous
-   * granted permissions. otherwise, it'll merge with previous granted permissions. nn
+   * Grants permission on the specified namespace for the specified user.
+   * 

+   * If mergeExistingPermissions is set to false, later granted permissions will override previous
+   * granted permissions. otherwise, it'll merge with previous granted permissions.
    */
   private static void grant(Connection connection, final String namespace, final String userName,
     boolean mergeExistingPermissions, final Permission.Action... actions) throws Throwable {
@@ -113,7 +102,6 @@ private static void grant(Connection connection, final String namespace, final S
    * Grants permission on the specified namespace for the specified user. If permissions on the
    * specified namespace exists, later granted permissions will override previous granted
    * permissions.
-   * @param connection The Connection instance to use nnnn
    */
   public static void grant(Connection connection, final String namespace, final String userName,
     final Permission.Action... actions) throws Throwable {
@@ -121,9 +109,10 @@ public static void grant(Connection connection, final String namespace, final St
   }
 
   /**
-   * Grant global permissions for the specified user. nn * @param mergeExistingPermissions If set to
-   * false, later granted permissions will override previous granted permissions. otherwise, it'll
-   * merge with previous granted permissions. nn
+   * Grant global permissions for the specified user.
+   * 

+   * If mergeExistingPermissions is set to false, later granted permissions will override previous
+   * granted permissions. otherwise, it'll merge with previous granted permissions.
    */
   private static void grant(Connection connection, final String userName,
     boolean mergeExistingPermissions, final Permission.Action... actions) throws Throwable {
@@ -134,7 +123,7 @@ private static void grant(Connection connection, final String userName,
 
   /**
    * Grant global permissions for the specified user. If permissions for the specified user exists,
-   * later granted permissions will override previous granted permissions. nnnn
+   * later granted permissions will override previous granted permissions.
    */
   public static void grant(Connection connection, final String userName,
     final Permission.Action... actions) throws Throwable {
@@ -148,10 +137,7 @@ public static boolean isAccessControllerRunning(Connection connection)
     }
   }
 
-  /**
-   * Revokes the permission on the table
-   * @param connection The Connection instance to use nnnnnn
-   */
+  /** Revokes the permission on the table. */
   public static void revoke(Connection connection, final TableName tableName, final String username,
     final byte[] family, final byte[] qualifier, final Permission.Action... actions)
     throws Throwable {
@@ -159,20 +145,14 @@ public static void revoke(Connection connection, final TableName tableName, fina
       .withFamily(family).withQualifier(qualifier).withActions(actions).build()));
   }
 
-  /**
-   * Revokes the permission on the namespace for the specified user.
-   * @param connection The Connection instance to use nnnn
-   */
+  /** Revokes the permission on the namespace for the specified user. */
   public static void revoke(Connection connection, final String namespace, final String userName,
     final Permission.Action... actions) throws Throwable {
     connection.getAdmin().revoke(
       new UserPermission(userName, Permission.newBuilder(namespace).withActions(actions).build()));
   }
 
-  /**
-   * Revoke global permissions for the specified user.
-   * @param connection The Connection instance to use
-   */
+  /** Revoke global permissions for the specified user. */
   public static void revoke(Connection connection, final String userName,
     final Permission.Action... actions) throws Throwable {
     connection.getAdmin()
diff --git a/hbase-client/src/main/java/org/apache/hadoop/hbase/security/access/AccessControlUtil.java b/hbase-client/src/main/java/org/apache/hadoop/hbase/security/access/AccessControlUtil.java
index 066e6f4e04da..3f5d121179f3 100644
--- a/hbase-client/src/main/java/org/apache/hadoop/hbase/security/access/AccessControlUtil.java
+++ b/hbase-client/src/main/java/org/apache/hadoop/hbase/security/access/AccessControlUtil.java
@@ -42,9 +42,6 @@
 import org.apache.hadoop.hbase.shaded.protobuf.generated.AccessControlProtos.AccessControlService;
 import org.apache.hadoop.hbase.shaded.protobuf.generated.AccessControlProtos.GetUserPermissionsResponse;
 
-/**
- * @since 2.0.0
- */
 @InterfaceAudience.Private
 public class AccessControlUtil {
   private AccessControlUtil() {
@@ -226,13 +223,12 @@ public static AccessControlProtos.UsersAndPermissions toUsersAndPermissions(Stri
    */
   public static TablePermission toTablePermission(AccessControlProtos.TablePermission proto) {
     Permission.Action[] actions = toPermissionActions(proto.getActionList());
-    TableName table = null;
     byte[] qualifier = null;
     byte[] family = null;
     if (!proto.hasTableName()) {
       throw new IllegalStateException("TableName cannot be empty");
     }
-    table = ProtobufUtil.toTableName(proto.getTableName());
+    TableName table = ProtobufUtil.toTableName(proto.getTableName());
     if (proto.hasFamily()) {
       family = proto.getFamily().toByteArray();
     }
@@ -267,11 +263,10 @@ public static Permission toPermission(AccessControlProtos.Permission proto) {
       Permission.Action[] actions = toPermissionActions(perm.getActionList());
       byte[] qualifier = null;
       byte[] family = null;
-      TableName table = null;
       if (!perm.hasTableName()) {
         throw new IllegalStateException("TableName cannot be empty");
       }
-      table = ProtobufUtil.toTableName(perm.getTableName());
+      TableName table = ProtobufUtil.toTableName(perm.getTableName());
       if (perm.hasFamily()) {
         family = perm.getFamily().toByteArray();
       }
diff --git a/hbase-client/src/main/java/org/apache/hadoop/hbase/security/access/ShadedAccessControlUtil.java b/hbase-client/src/main/java/org/apache/hadoop/hbase/security/access/ShadedAccessControlUtil.java
index b6df2c94a044..604e705315f7 100644
--- a/hbase-client/src/main/java/org/apache/hadoop/hbase/security/access/ShadedAccessControlUtil.java
+++ b/hbase-client/src/main/java/org/apache/hadoop/hbase/security/access/ShadedAccessControlUtil.java
@@ -32,7 +32,6 @@
 import org.apache.hadoop.hbase.shaded.protobuf.generated.AccessControlProtos.GetUserPermissionsResponse;
 import org.apache.hadoop.hbase.shaded.protobuf.generated.AccessControlProtos.GrantRequest;
 import org.apache.hadoop.hbase.shaded.protobuf.generated.AccessControlProtos.HasUserPermissionsRequest;
-import org.apache.hadoop.hbase.shaded.protobuf.generated.AccessControlProtos.Permission.Type;
 import org.apache.hadoop.hbase.shaded.protobuf.generated.AccessControlProtos.RevokeRequest;
 import org.apache.hadoop.hbase.shaded.protobuf.generated.HBaseProtos;
 
@@ -292,14 +291,14 @@ public static RevokeRequest buildRevokeRequest(UserPermission userPermission) {
     }
     if (request.getNamespace() != null && !request.getNamespace().isEmpty()) {
       builder.setNamespaceName(ByteString.copyFromUtf8(request.getNamespace()));
-      builder.setType(Type.Namespace);
+      builder.setType(AccessControlProtos.Permission.Type.Namespace);
     }
     if (request.getTableName() != null) {
       builder.setTableName(toProtoTableName(request.getTableName()));
-      builder.setType(Type.Table);
+      builder.setType(AccessControlProtos.Permission.Type.Table);
     }
     if (!builder.hasType()) {
-      builder.setType(Type.Global);
+      builder.setType(AccessControlProtos.Permission.Type.Global);
     }
     if (request.getFamily() != null && request.getFamily().length > 0) {
       builder.setColumnFamily(ByteString.copyFrom(request.getFamily()));
diff --git a/hbase-client/src/main/java/org/apache/hadoop/hbase/security/access/TablePermission.java b/hbase-client/src/main/java/org/apache/hadoop/hbase/security/access/TablePermission.java
index e0a12c7d431f..65ebbef7da09 100644
--- a/hbase-client/src/main/java/org/apache/hadoop/hbase/security/access/TablePermission.java
+++ b/hbase-client/src/main/java/org/apache/hadoop/hbase/security/access/TablePermission.java
@@ -141,11 +141,11 @@ public boolean implies(TableName table, KeyValue kv, Action action) {
       return false;
     }
 
-    if (family != null && !(CellUtil.matchingFamily(kv, family))) {
+    if (family != null && !CellUtil.matchingFamily(kv, family)) {
       return false;
     }
 
-    if (qualifier != null && !(CellUtil.matchingQualifier(kv, qualifier))) {
+    if (qualifier != null && !CellUtil.matchingQualifier(kv, qualifier)) {
       return false;
     }
 
diff --git a/hbase-client/src/main/java/org/apache/hadoop/hbase/security/provider/AbstractSaslClientAuthenticationProvider.java b/hbase-client/src/main/java/org/apache/hadoop/hbase/security/provider/AbstractSaslClientAuthenticationProvider.java
index e9990066050e..9fed3a9c624d 100644
--- a/hbase-client/src/main/java/org/apache/hadoop/hbase/security/provider/AbstractSaslClientAuthenticationProvider.java
+++ b/hbase-client/src/main/java/org/apache/hadoop/hbase/security/provider/AbstractSaslClientAuthenticationProvider.java
@@ -48,11 +48,14 @@ public final int hashCode() {
   }
 
   @Override
+  @SuppressWarnings("EqualsUsingHashCode")
   public final boolean equals(Object o) {
-    // SaslClientAuthProviders should be unique via their hashCode().
-    if (o instanceof AbstractSaslClientAuthenticationProvider) {
-      return this.hashCode() == o.hashCode();
+    if (this == o) {
+      return true;
     }
-    return false;
+    if (!(o instanceof AbstractSaslClientAuthenticationProvider)) {
+      return false;
+    }
+    return this.hashCode() == ((AbstractSaslClientAuthenticationProvider) o).hashCode();
   }
 }
diff --git a/hbase-client/src/main/java/org/apache/hadoop/hbase/security/token/ClientTokenUtil.java b/hbase-client/src/main/java/org/apache/hadoop/hbase/security/token/ClientTokenUtil.java
index 40ff0373c36c..71df9cd9bc41 100644
--- a/hbase-client/src/main/java/org/apache/hadoop/hbase/security/token/ClientTokenUtil.java
+++ b/hbase-client/src/main/java/org/apache/hadoop/hbase/security/token/ClientTokenUtil.java
@@ -66,6 +66,7 @@ private static void injectFault() throws ServiceException {
    * @return the authentication token instance, wrapped by a {@link CompletableFuture}.
    */
   @InterfaceAudience.Private
+  @SuppressWarnings("FutureReturnValueIgnored")
   public static CompletableFuture>
     obtainToken(AsyncConnection conn) {
     CompletableFuture> future = new CompletableFuture<>();
diff --git a/hbase-client/src/main/java/org/apache/hadoop/hbase/security/visibility/CellVisibility.java b/hbase-client/src/main/java/org/apache/hadoop/hbase/security/visibility/CellVisibility.java
index 8abaee005094..4343df594cf9 100644
--- a/hbase-client/src/main/java/org/apache/hadoop/hbase/security/visibility/CellVisibility.java
+++ b/hbase-client/src/main/java/org/apache/hadoop/hbase/security/visibility/CellVisibility.java
@@ -36,7 +36,7 @@ public CellVisibility(String expression) {
   }
 
   /**
-   * @return The visibility expression
+   * Return The visibility expression
    */
   public String getExpression() {
     return this.expression;
diff --git a/hbase-client/src/main/java/org/apache/hadoop/hbase/security/visibility/VisibilityClient.java b/hbase-client/src/main/java/org/apache/hadoop/hbase/security/visibility/VisibilityClient.java
index 42508782d1a7..5f2fe2ccf74a 100644
--- a/hbase-client/src/main/java/org/apache/hadoop/hbase/security/visibility/VisibilityClient.java
+++ b/hbase-client/src/main/java/org/apache/hadoop/hbase/security/visibility/VisibilityClient.java
@@ -88,7 +88,7 @@ public VisibilityLabelsResponse call(VisibilityLabelsService service) throws IOE
             for (String label : labels) {
               if (label.length() > 0) {
                 VisibilityLabel.Builder newBuilder = VisibilityLabel.newBuilder();
-                newBuilder.setLabel(UnsafeByteOperations.unsafeWrap((Bytes.toBytes(label))));
+                newBuilder.setLabel(UnsafeByteOperations.unsafeWrap(Bytes.toBytes(label)));
                 builder.addVisLabel(newBuilder.build());
               }
             }
@@ -108,18 +108,13 @@ public VisibilityLabelsResponse call(VisibilityLabelsService service) throws IOE
     }
   }
 
-  /**
-   * Sets given labels globally authorized for the user. nnnnn
-   */
+  /** Sets given labels globally authorized for the user. */
   public static VisibilityLabelsResponse setAuths(Connection connection, final String[] auths,
     final String user) throws Throwable {
     return setOrClearAuths(connection, auths, user, true);
   }
 
-  /**
-   * @param connection the Connection instance to use. n * @return labels, the given user is
-   *                   globally authorized for. n
-   */
+  /** Get the authentication details for a given user. */
   public static GetAuthsResponse getAuths(Connection connection, final String user)
     throws Throwable {
     try (Table table = connection.getTable(LABELS_TABLE_NAME)) {
@@ -212,7 +207,7 @@ public VisibilityLabelsResponse call(VisibilityLabelsService service) throws IOE
             setAuthReqBuilder.setUser(UnsafeByteOperations.unsafeWrap(Bytes.toBytes(user)));
             for (String auth : auths) {
               if (auth.length() > 0) {
-                setAuthReqBuilder.addAuth((ByteString.copyFromUtf8(auth)));
+                setAuthReqBuilder.addAuth(ByteString.copyFromUtf8(auth));
               }
             }
             if (setOrClear) {
diff --git a/hbase-client/src/main/java/org/apache/hadoop/hbase/shaded/protobuf/ProtobufUtil.java b/hbase-client/src/main/java/org/apache/hadoop/hbase/shaded/protobuf/ProtobufUtil.java
index 40b32d53c39e..c54676c0656c 100644
--- a/hbase-client/src/main/java/org/apache/hadoop/hbase/shaded/protobuf/ProtobufUtil.java
+++ b/hbase-client/src/main/java/org/apache/hadoop/hbase/shaded/protobuf/ProtobufUtil.java
@@ -51,7 +51,6 @@
 import org.apache.hadoop.hbase.CacheEvictionStats;
 import org.apache.hadoop.hbase.CacheEvictionStatsBuilder;
 import org.apache.hadoop.hbase.Cell;
-import org.apache.hadoop.hbase.Cell.Type;
 import org.apache.hadoop.hbase.CellBuilderType;
 import org.apache.hadoop.hbase.CellScanner;
 import org.apache.hadoop.hbase.CellUtil;
@@ -310,6 +309,7 @@ public static byte[] prependPBMagic(final byte[] bytes) {
   }
 
   /**
+   * Check if the passed bytes has {@link ProtobufMagic#PB_MAGIC} for a prefix.
    * @param bytes Bytes to check.
    * @return True if passed bytes has {@link ProtobufMagic#PB_MAGIC} for a prefix.
    */
@@ -318,6 +318,7 @@ public static boolean isPBMagicPrefix(final byte[] bytes) {
   }
 
   /**
+   * Check if the passed bytes has {@link ProtobufMagic#PB_MAGIC} for a prefix.
    * @param bytes  Bytes to check.
    * @param offset offset to start at
    * @param len    length to use
@@ -328,6 +329,7 @@ public static boolean isPBMagicPrefix(final byte[] bytes, int offset, int len) {
   }
 
   /**
+   * Assert the passed bytes has {@link ProtobufMagic#PB_MAGIC} for a prefix.
    * @param bytes bytes to check
    * @throws DeserializationException if we are missing the pb magic prefix
    */
@@ -339,9 +341,7 @@ public static void expectPBMagicPrefix(final byte[] bytes) throws Deserializatio
     }
   }
 
-  /**
-   * @return Length of {@link ProtobufMagic#lengthOfPBMagic()}
-   */
+  /** Return the length of {@link ProtobufMagic#lengthOfPBMagic()} */
   public static int lengthOfPBMagic() {
     return ProtobufMagic.lengthOfPBMagic();
   }
@@ -734,7 +734,7 @@ public static Put toPut(final MutationProto proto, final CellScanner cellScanner
             } else {
               put.add(cellBuilder.clear().setRow(put.getRow()).setFamily(family)
                 .setQualifier(qv.hasQualifier() ? qv.getQualifier().toByteArray() : null)
-                .setTimestamp(ts).setType(Type.Put)
+                .setTimestamp(ts).setType(Cell.Type.Put)
                 .setValue(qv.hasValue() ? qv.getValue().toByteArray() : null).build());
             }
           }
@@ -891,9 +891,9 @@ private static long cellTimestampOrLatest(QualifierValue cell) {
   }
 
   /**
-   * Convert a protocol buffer Mutate to an Append n * @param proto the protocol buffer Mutate to
-   * convert
-   * @return the converted client Append n
+   * Convert a protocol buffer Mutate to an Append
+   * @param proto the protocol buffer Mutate to convert
+   * @return the converted client Append
    */
   public static Append toAppend(final MutationProto proto, final CellScanner cellScanner)
     throws IOException {
@@ -911,7 +911,7 @@ public static Append toAppend(final MutationProto proto, final CellScanner cellS
   /**
    * Convert a protocol buffer Mutate to an Increment
    * @param proto the protocol buffer Mutate to convert
-   * @return the converted client Increment n
+   * @return the converted client Increment
    */
   public static Increment toIncrement(final MutationProto proto, final CellScanner cellScanner)
     throws IOException {
@@ -930,7 +930,7 @@ public static Increment toIncrement(final MutationProto proto, final CellScanner
   /**
    * Convert a MutateRequest to Mutation
    * @param proto the protocol buffer Mutate to convert
-   * @return the converted Mutation n
+   * @return the converted Mutation
    */
   public static Mutation toMutation(final MutationProto proto) throws IOException {
     MutationType type = proto.getMutateType();
@@ -978,7 +978,7 @@ public static Scan.ReadType toReadType(ClientProtos.Scan.ReadType readType) {
   /**
    * Convert a client Scan to a protocol buffer Scan
    * @param scan the client Scan to convert
-   * @return the converted protocol buffer Scan n
+   * @return the converted protocol buffer Scan
    */
   public static ClientProtos.Scan toScan(final Scan scan) throws IOException {
     ClientProtos.Scan.Builder scanBuilder = ClientProtos.Scan.newBuilder();
@@ -1072,7 +1072,7 @@ public static ClientProtos.Scan toScan(final Scan scan) throws IOException {
   /**
    * Convert a protocol buffer Scan to a client Scan
    * @param proto the protocol buffer Scan to convert
-   * @return the converted client Scan n
+   * @return the converted client Scan
    */
   public static Scan toScan(final ClientProtos.Scan proto) throws IOException {
     byte[] startRow = HConstants.EMPTY_START_ROW;
@@ -1192,7 +1192,7 @@ public static Cursor toCursor(ClientProtos.Cursor cursor) {
   /**
    * Create a protocol buffer Get based on a client Get.
    * @param get the client Get
-   * @return a protocol buffer Get n
+   * @return a protocol buffer Get
    */
   public static ClientProtos.Get toGet(final Get get) throws IOException {
     ClientProtos.Get.Builder builder = ClientProtos.Get.newBuilder();
@@ -1258,7 +1258,8 @@ public static MutationProto toMutation(final MutationType type, final Mutation m
   }
 
   /**
-   * Create a protocol buffer Mutate based on a client Mutation nn * @return a protobuf'd Mutation n
+   * Create a protocol buffer Mutate based on a client Mutation
+   * @return a protobuf'd Mutation
    */
   public static MutationProto toMutation(final MutationType type, final Mutation mutation,
     final long nonce) throws IOException {
@@ -1307,8 +1308,8 @@ public static MutationProto toMutation(final MutationType type, final Mutation m
 
   /**
    * Create a protocol buffer MutationProto based on a client Mutation. Does NOT include data.
-   * Understanding is that the Cell will be transported other than via protobuf. nnn * @return a
-   * protobuf'd Mutation n
+   * Understanding is that the Cell will be transported other than via protobuf.
+   * @return a protobuf'd Mutation
    */
   public static MutationProto toMutationNoData(final MutationType type, final Mutation mutation,
     final MutationProto.Builder builder) throws IOException {
@@ -1317,8 +1318,8 @@ public static MutationProto toMutationNoData(final MutationType type, final Muta
 
   /**
    * Create a protocol buffer MutationProto based on a client Mutation. Does NOT include data.
-   * Understanding is that the Cell will be transported other than via protobuf. nn * @return a
-   * protobuf'd Mutation n
+   * Understanding is that the Cell will be transported other than via protobuf.
+   * @return a protobuf'd Mutation
    */
   public static MutationProto toMutationNoData(final MutationType type, final Mutation mutation)
     throws IOException {
@@ -1344,8 +1345,8 @@ public static MutationProto toMutationNoData(final MutationType type, final Muta
 
   /**
    * Code shared by {@link #toMutation(MutationType, Mutation)} and
-   * {@link #toMutationNoData(MutationType, Mutation)} nn * @return A partly-filled out protobuf'd
-   * Mutation.
+   * {@link #toMutationNoData(MutationType, Mutation)}
+   * @return A partly-filled out protobuf'd Mutation.
    */
   private static MutationProto.Builder getMutationBuilderAndSetCommonFields(final MutationType type,
     final Mutation mutation, MutationProto.Builder builder) {
@@ -1478,7 +1479,7 @@ public static Result toResult(final ClientProtos.Result proto, boolean decodeTag
    * Convert a protocol buffer Result to a client Result
    * @param proto   the protocol buffer Result to convert
    * @param scanner Optional cell scanner.
-   * @return the converted client Result n
+   * @return the converted client Result
    */
   public static Result toResult(final ClientProtos.Result proto, final CellScanner scanner)
     throws IOException {
@@ -1593,8 +1594,8 @@ public static FilterProtos.Filter toFilter(Filter filter) throws IOException {
   }
 
   /**
-   * Convert a delete KeyValue type to protocol buffer DeleteType. n * @return protocol buffer
-   * DeleteType n
+   * Convert a delete KeyValue type to protocol buffer DeleteType.
+   * @return protocol buffer DeleteType
    */
   public static DeleteType toDeleteType(KeyValue.Type type) throws IOException {
     switch (type) {
@@ -1614,7 +1615,7 @@ public static DeleteType toDeleteType(KeyValue.Type type) throws IOException {
   /**
    * Convert a protocol buffer DeleteType to delete KeyValue type.
    * @param type The DeleteType
-   * @return The type. n
+   * @return The type
    */
   public static KeyValue.Type fromDeleteType(DeleteType type) throws IOException {
     switch (type) {
@@ -1680,7 +1681,6 @@ public static org.apache.hadoop.hbase.client.RegionInfo getRegionInfo(
     final RpcController controller, final AdminService.BlockingInterface admin,
     final byte[] regionName) throws IOException {
     try {
-      GetRegionInfoRequest request = getGetRegionInfoRequest(regionName);
       GetRegionInfoResponse response =
         admin.getRegionInfo(controller, getGetRegionInfoRequest(regionName));
       return toRegionInfo(response.getRegionInfo());
@@ -1689,9 +1689,7 @@ public static org.apache.hadoop.hbase.client.RegionInfo getRegionInfo(
     }
   }
 
-  /**
-   * @return A GetRegionInfoRequest for the passed in regionName.
-   */
+  /** Return a GetRegionInfoRequest for the passed in regionName. */
   public static GetRegionInfoRequest getGetRegionInfoRequest(final byte[] regionName)
     throws IOException {
     return org.apache.hadoop.hbase.client.RegionInfo.isEncodedRegionName(regionName)
@@ -1702,9 +1700,7 @@ public static GetRegionInfoRequest getGetRegionInfoRequest(final byte[] regionNa
       : RequestConverter.buildGetRegionInfoRequest(regionName);
   }
 
-  /**
-   * A helper to close a region given a region name using admin protocol. nnn
-   */
+  /** A helper to close a region given a region name using admin protocol. */
   public static void closeRegion(final RpcController controller,
     final AdminService.BlockingInterface admin, final ServerName server, final byte[] regionName)
     throws IOException {
@@ -1717,9 +1713,7 @@ public static void closeRegion(final RpcController controller,
     }
   }
 
-  /**
-   * A helper to warmup a region given a region name using admin protocol nn *
-   */
+  /** A helper to warmup a region given a region name using admin protocol */
   public static void warmupRegion(final RpcController controller,
     final AdminService.BlockingInterface admin,
     final org.apache.hadoop.hbase.client.RegionInfo regionInfo) throws IOException {
@@ -1734,9 +1728,7 @@ public static void warmupRegion(final RpcController controller,
     }
   }
 
-  /**
-   * A helper to open a region using admin protocol. nnn
-   */
+  /** A helper to open a region using admin protocol. */
   public static void openRegion(final RpcController controller,
     final AdminService.BlockingInterface admin, ServerName server,
     final org.apache.hadoop.hbase.client.RegionInfo region) throws IOException {
@@ -1748,19 +1740,13 @@ public static void openRegion(final RpcController controller,
     }
   }
 
-  /**
-   * A helper to get the all the online regions on a region server using admin protocol. n * @return
-   * a list of online region info n
-   */
+  /** A helper to get the all the online regions on a region server using admin protocol. */
   public static List
     getOnlineRegions(final AdminService.BlockingInterface admin) throws IOException {
     return getOnlineRegions(null, admin);
   }
 
-  /**
-   * A helper to get the all the online regions on a region server using admin protocol.
-   * @return a list of online region info
-   */
+  /** A helper to get the all the online regions on a region server using admin protocol. */
   public static List getOnlineRegions(
     final RpcController controller, final AdminService.BlockingInterface admin) throws IOException {
     GetOnlineRegionRequest request = RequestConverter.buildGetOnlineRegionRequest();
@@ -1789,10 +1775,7 @@ public static List getOnlineRegions(
     return regionInfos;
   }
 
-  /**
-   * A helper to get the info of a region server using admin protocol.
-   * @return the server name
-   */
+  /** A helper to get the info of a region server using admin protocol. */
   public static ServerInfo getServerInfo(final RpcController controller,
     final AdminService.BlockingInterface admin) throws IOException {
     GetServerInfoRequest request = RequestConverter.buildGetServerInfoRequest();
@@ -1806,7 +1789,6 @@ public static ServerInfo getServerInfo(final RpcController controller,
 
   /**
    * A helper to get the list of files of a column family on a given region using admin protocol.
-   * @return the list of store files
    */
   public static List getStoreFiles(final AdminService.BlockingInterface admin,
     final byte[] regionName, final byte[] family) throws IOException {
@@ -1815,7 +1797,6 @@ public static List getStoreFiles(final AdminService.BlockingInterface ad
 
   /**
    * A helper to get the list of files of a column family on a given region using admin protocol.
-   * @return the list of store files
    */
   public static List getStoreFiles(final RpcController controller,
     final AdminService.BlockingInterface admin, final byte[] regionName, final byte[] family)
@@ -1844,9 +1825,7 @@ public static long getTotalRequestsCount(RegionLoad rl) {
     return rl.getReadRequestsCount() + rl.getWriteRequestsCount();
   }
 
-  /**
-   * @param m Message to get delimited pb serialization of (with pb magic prefix)
-   */
+  /** Convert a Message to delimited pb serialization of (with pb magic prefix) */
   public static byte[] toDelimitedByteArray(final Message m) throws IOException {
     // Allocate arbitrary big size so we avoid resizing.
     ByteArrayOutputStream baos = new ByteArrayOutputStream(4096);
@@ -2085,7 +2064,8 @@ public static RegionEventDescriptor toRegionEventDescriptor(EventType eventType,
   /**
    * Return short version of Message toString'd, shorter than TextFormat#shortDebugString. Tries to
    * NOT print out data both because it can be big but also so we do not have data in our logs. Use
-   * judiciously. n * @return toString of passed m
+   * judiciously.
+   * @return toString of passed m
    */
   public static String getShortTextFormat(Message m) {
     if (m == null) return "null";
@@ -2231,19 +2211,13 @@ public static TableName[] getTableNameArray(List tableNam
     return tableNames;
   }
 
-  /**
-   * Convert a protocol buffer CellVisibility to a client CellVisibility n * @return the converted
-   * client CellVisibility
-   */
+  /** Convert a protocol buffer CellVisibility to a client CellVisibility */
   public static CellVisibility toCellVisibility(ClientProtos.CellVisibility proto) {
     if (proto == null) return null;
     return new CellVisibility(proto.getExpression());
   }
 
-  /**
-   * Convert a protocol buffer CellVisibility bytes to a client CellVisibility n * @return the
-   * converted client CellVisibility n
-   */
+  /** Convert a protocol buffer CellVisibility bytes to a client CellVisibility */
   public static CellVisibility toCellVisibility(byte[] protoBytes) throws DeserializationException {
     if (protoBytes == null) return null;
     ClientProtos.CellVisibility.Builder builder = ClientProtos.CellVisibility.newBuilder();
@@ -2257,29 +2231,20 @@ public static CellVisibility toCellVisibility(byte[] protoBytes) throws Deserial
     return toCellVisibility(proto);
   }
 
-  /**
-   * Create a protocol buffer CellVisibility based on a client CellVisibility. n * @return a
-   * protocol buffer CellVisibility
-   */
+  /** Create a protocol buffer CellVisibility based on a client CellVisibility. */
   public static ClientProtos.CellVisibility toCellVisibility(CellVisibility cellVisibility) {
     ClientProtos.CellVisibility.Builder builder = ClientProtos.CellVisibility.newBuilder();
     builder.setExpression(cellVisibility.getExpression());
     return builder.build();
   }
 
-  /**
-   * Convert a protocol buffer Authorizations to a client Authorizations n * @return the converted
-   * client Authorizations
-   */
+  /** Convert a protocol buffer Authorizations to a client Authorizations */
   public static Authorizations toAuthorizations(ClientProtos.Authorizations proto) {
     if (proto == null) return null;
     return new Authorizations(proto.getLabelList());
   }
 
-  /**
-   * Convert a protocol buffer Authorizations bytes to a client Authorizations n * @return the
-   * converted client Authorizations n
-   */
+  /** Convert a protocol buffer Authorizations bytes to a client Authorizations */
   public static Authorizations toAuthorizations(byte[] protoBytes) throws DeserializationException {
     if (protoBytes == null) return null;
     ClientProtos.Authorizations.Builder builder = ClientProtos.Authorizations.newBuilder();
@@ -2293,10 +2258,7 @@ public static Authorizations toAuthorizations(byte[] protoBytes) throws Deserial
     return toAuthorizations(proto);
   }
 
-  /**
-   * Create a protocol buffer Authorizations based on a client Authorizations. n * @return a
-   * protocol buffer Authorizations
-   */
+  /** Create a protocol buffer Authorizations based on a client Authorizations. */
   public static ClientProtos.Authorizations toAuthorizations(Authorizations authorizations) {
     ClientProtos.Authorizations.Builder builder = ClientProtos.Authorizations.newBuilder();
     for (String label : authorizations.getLabels()) {
@@ -2305,10 +2267,7 @@ public static ClientProtos.Authorizations toAuthorizations(Authorizations author
     return builder.build();
   }
 
-  /**
-   * Convert a protocol buffer TimeUnit to a client TimeUnit n * @return the converted client
-   * TimeUnit
-   */
+  /** Convert a protocol buffer TimeUnit to a client TimeUnit */
   public static TimeUnit toTimeUnit(final HBaseProtos.TimeUnit proto) {
     switch (proto) {
       case NANOSECONDS:
@@ -2329,10 +2288,7 @@ public static TimeUnit toTimeUnit(final HBaseProtos.TimeUnit proto) {
     throw new RuntimeException("Invalid TimeUnit " + proto);
   }
 
-  /**
-   * Convert a client TimeUnit to a protocol buffer TimeUnit n * @return the converted protocol
-   * buffer TimeUnit
-   */
+  /** Convert a client TimeUnit to a protocol buffer TimeUnit */
   public static HBaseProtos.TimeUnit toProtoTimeUnit(final TimeUnit timeUnit) {
     switch (timeUnit) {
       case NANOSECONDS:
@@ -2353,10 +2309,7 @@ public static HBaseProtos.TimeUnit toProtoTimeUnit(final TimeUnit timeUnit) {
     throw new RuntimeException("Invalid TimeUnit " + timeUnit);
   }
 
-  /**
-   * Convert a protocol buffer ThrottleType to a client ThrottleType n * @return the converted
-   * client ThrottleType
-   */
+  /** Convert a protocol buffer ThrottleType to a client ThrottleType */
   public static ThrottleType toThrottleType(final QuotaProtos.ThrottleType proto) {
     switch (proto) {
       case REQUEST_NUMBER:
@@ -2382,10 +2335,7 @@ public static ThrottleType toThrottleType(final QuotaProtos.ThrottleType proto)
     }
   }
 
-  /**
-   * Convert a client ThrottleType to a protocol buffer ThrottleType n * @return the converted
-   * protocol buffer ThrottleType
-   */
+  /** Convert a client ThrottleType to a protocol buffer ThrottleType */
   public static QuotaProtos.ThrottleType toProtoThrottleType(final ThrottleType type) {
     switch (type) {
       case REQUEST_NUMBER:
@@ -2411,10 +2361,7 @@ public static QuotaProtos.ThrottleType toProtoThrottleType(final ThrottleType ty
     }
   }
 
-  /**
-   * Convert a protocol buffer QuotaScope to a client QuotaScope n * @return the converted client
-   * QuotaScope
-   */
+  /** Convert a protocol buffer QuotaScope to a client QuotaScope */
   public static QuotaScope toQuotaScope(final QuotaProtos.QuotaScope proto) {
     switch (proto) {
       case CLUSTER:
@@ -2425,10 +2372,7 @@ public static QuotaScope toQuotaScope(final QuotaProtos.QuotaScope proto) {
     throw new RuntimeException("Invalid QuotaScope " + proto);
   }
 
-  /**
-   * Convert a client QuotaScope to a protocol buffer QuotaScope n * @return the converted protocol
-   * buffer QuotaScope
-   */
+  /** Convert a client QuotaScope to a protocol buffer QuotaScope */
   public static QuotaProtos.QuotaScope toProtoQuotaScope(final QuotaScope scope) {
     switch (scope) {
       case CLUSTER:
@@ -2439,10 +2383,7 @@ public static QuotaProtos.QuotaScope toProtoQuotaScope(final QuotaScope scope) {
     throw new RuntimeException("Invalid QuotaScope " + scope);
   }
 
-  /**
-   * Convert a protocol buffer QuotaType to a client QuotaType n * @return the converted client
-   * QuotaType
-   */
+  /** Convert a protocol buffer QuotaType to a client QuotaType */
   public static QuotaType toQuotaScope(final QuotaProtos.QuotaType proto) {
     switch (proto) {
       case THROTTLE:
@@ -2453,10 +2394,7 @@ public static QuotaType toQuotaScope(final QuotaProtos.QuotaType proto) {
     throw new RuntimeException("Invalid QuotaType " + proto);
   }
 
-  /**
-   * Convert a client QuotaType to a protocol buffer QuotaType n * @return the converted protocol
-   * buffer QuotaType
-   */
+  /** Convert a client QuotaType to a protocol buffer QuotaType */
   public static QuotaProtos.QuotaType toProtoQuotaScope(final QuotaType type) {
     switch (type) {
       case THROTTLE:
@@ -2468,11 +2406,7 @@ public static QuotaProtos.QuotaType toProtoQuotaScope(final QuotaType type) {
     }
   }
 
-  /**
-   * Converts a protocol buffer SpaceViolationPolicy to a client SpaceViolationPolicy.
-   * @param proto The protocol buffer space violation policy.
-   * @return The corresponding client SpaceViolationPolicy.
-   */
+  /** Converts a protocol buffer SpaceViolationPolicy to a client SpaceViolationPolicy. */
   public static SpaceViolationPolicy
     toViolationPolicy(final QuotaProtos.SpaceViolationPolicy proto) {
     switch (proto) {
@@ -2488,11 +2422,7 @@ public static QuotaProtos.QuotaType toProtoQuotaScope(final QuotaType type) {
     throw new RuntimeException("Invalid SpaceViolationPolicy " + proto);
   }
 
-  /**
-   * Converts a client SpaceViolationPolicy to a protocol buffer SpaceViolationPolicy.
-   * @param policy The client SpaceViolationPolicy object.
-   * @return The corresponding protocol buffer SpaceViolationPolicy.
-   */
+  /** Converts a client SpaceViolationPolicy to a protocol buffer SpaceViolationPolicy. */
   public static QuotaProtos.SpaceViolationPolicy
     toProtoViolationPolicy(final SpaceViolationPolicy policy) {
     switch (policy) {
@@ -2954,9 +2884,7 @@ public static RegionLoadStats createRegionLoadStats(ClientProtos.RegionLoadStats
       stats.getCompactionPressure());
   }
 
-  /**
-   * n * @return A String version of the passed in msg
-   */
+  /** Return a String version of the passed in msg */
   public static String toText(Message msg) {
     return TextFormat.shortDebugString(msg);
   }
@@ -2965,9 +2893,7 @@ public static byte[] toBytes(ByteString bs) {
     return bs.toByteArray();
   }
 
-  /**
-   * Contain ServiceException inside here. Take a callable that is doing our pb rpc and run it. n
-   */
+  /** Contain ServiceException inside. Take a callable that is doing our pb rpc and run it. */
   public static  T call(Callable callable) throws IOException {
     try {
       return callable.call();
diff --git a/hbase-client/src/main/java/org/apache/hadoop/hbase/shaded/protobuf/RequestConverter.java b/hbase-client/src/main/java/org/apache/hadoop/hbase/shaded/protobuf/RequestConverter.java
index addda9c59860..d2b1fb7ea078 100644
--- a/hbase-client/src/main/java/org/apache/hadoop/hbase/shaded/protobuf/RequestConverter.java
+++ b/hbase-client/src/main/java/org/apache/hadoop/hbase/shaded/protobuf/RequestConverter.java
@@ -706,6 +706,7 @@ public static GetRegionInfoRequest buildGetRegionInfoRequest(final byte[] region
   }
 
   /**
+   * Create a protocol buffer GetRegionInfo for all regions/regions of a table.
    * @param regionName             the name of the region to get info
    * @param includeCompactionState indicate if the compaction state is requested
    * @param includeBestSplitRow    indicate if the bestSplitRow is requested
@@ -914,7 +915,7 @@ public static AddColumnRequest buildAddColumnRequest(final TableName tableName,
   public static DeleteColumnRequest buildDeleteColumnRequest(final TableName tableName,
     final byte[] columnName, final long nonceGroup, final long nonce) {
     DeleteColumnRequest.Builder builder = DeleteColumnRequest.newBuilder();
-    builder.setTableName(ProtobufUtil.toProtoTableName((tableName)));
+    builder.setTableName(ProtobufUtil.toProtoTableName(tableName));
     builder.setColumnName(UnsafeByteOperations.unsafeWrap(columnName));
     builder.setNonceGroup(nonceGroup);
     builder.setNonce(nonce);
@@ -927,7 +928,7 @@ public static DeleteColumnRequest buildDeleteColumnRequest(final TableName table
   public static ModifyColumnRequest buildModifyColumnRequest(final TableName tableName,
     final ColumnFamilyDescriptor column, final long nonceGroup, final long nonce) {
     ModifyColumnRequest.Builder builder = ModifyColumnRequest.newBuilder();
-    builder.setTableName(ProtobufUtil.toProtoTableName((tableName)));
+    builder.setTableName(ProtobufUtil.toProtoTableName(tableName));
     builder.setColumnFamilies(ProtobufUtil.toColumnFamilySchema(column));
     builder.setNonceGroup(nonceGroup);
     builder.setNonce(nonce);
@@ -939,7 +940,7 @@ public static ModifyColumnStoreFileTrackerRequest buildModifyColumnStoreFileTrac
     final long nonce) {
     ModifyColumnStoreFileTrackerRequest.Builder builder =
       ModifyColumnStoreFileTrackerRequest.newBuilder();
-    builder.setTableName(ProtobufUtil.toProtoTableName((tableName)));
+    builder.setTableName(ProtobufUtil.toProtoTableName(tableName));
     builder.setFamily(ByteString.copyFrom(family));
     builder.setDstSft(dstSFT);
     builder.setNonceGroup(nonceGroup);
@@ -1061,7 +1062,7 @@ public static EnableTableRequest buildEnableTableRequest(final TableName tableNa
   public static DisableTableRequest buildDisableTableRequest(final TableName tableName,
     final long nonceGroup, final long nonce) {
     DisableTableRequest.Builder builder = DisableTableRequest.newBuilder();
-    builder.setTableName(ProtobufUtil.toProtoTableName((tableName)));
+    builder.setTableName(ProtobufUtil.toProtoTableName(tableName));
     builder.setNonceGroup(nonceGroup);
     builder.setNonce(nonce);
     return builder.build();
@@ -1090,7 +1091,7 @@ public static CreateTableRequest buildCreateTableRequest(final TableDescriptor t
   public static ModifyTableRequest buildModifyTableRequest(final TableName tableName,
     final TableDescriptor tableDesc, final long nonceGroup, final long nonce) {
     ModifyTableRequest.Builder builder = ModifyTableRequest.newBuilder();
-    builder.setTableName(ProtobufUtil.toProtoTableName((tableName)));
+    builder.setTableName(ProtobufUtil.toProtoTableName(tableName));
     builder.setTableSchema(ProtobufUtil.toTableSchema(tableDesc));
     builder.setNonceGroup(nonceGroup);
     builder.setNonce(nonce);
@@ -1101,7 +1102,7 @@ public static ModifyTableStoreFileTrackerRequest buildModifyTableStoreFileTracke
     final TableName tableName, final String dstSFT, final long nonceGroup, final long nonce) {
     ModifyTableStoreFileTrackerRequest.Builder builder =
       ModifyTableStoreFileTrackerRequest.newBuilder();
-    builder.setTableName(ProtobufUtil.toProtoTableName((tableName)));
+    builder.setTableName(ProtobufUtil.toProtoTableName(tableName));
     builder.setDstSft(dstSFT);
     builder.setNonceGroup(nonceGroup);
     builder.setNonce(nonce);
diff --git a/hbase-client/src/main/java/org/apache/hadoop/hbase/snapshot/HBaseSnapshotException.java b/hbase-client/src/main/java/org/apache/hadoop/hbase/snapshot/HBaseSnapshotException.java
index 5fd62a86008c..4db5c7f1f3d5 100644
--- a/hbase-client/src/main/java/org/apache/hadoop/hbase/snapshot/HBaseSnapshotException.java
+++ b/hbase-client/src/main/java/org/apache/hadoop/hbase/snapshot/HBaseSnapshotException.java
@@ -69,9 +69,7 @@ public HBaseSnapshotException(String message, Throwable cause) {
     super(message, cause);
   }
 
-  /**
-   * @return the description of the snapshot that is being failed
-   */
+  /** Return the description of the snapshot that failed */
   public SnapshotDescription getSnapshotDescription() {
     return this.description;
   }
diff --git a/hbase-client/src/main/java/org/apache/hadoop/hbase/util/Writables.java b/hbase-client/src/main/java/org/apache/hadoop/hbase/util/Writables.java
index 7ebbbf44cebd..0cc8e6ad5f0d 100644
--- a/hbase-client/src/main/java/org/apache/hadoop/hbase/util/Writables.java
+++ b/hbase-client/src/main/java/org/apache/hadoop/hbase/util/Writables.java
@@ -34,6 +34,7 @@
 @InterfaceAudience.Private
 public class Writables {
   /**
+   * Write the writeable into a byte array and return it.
    * @param w writable
    * @return The bytes of w gotten by running its
    *         {@link Writable#write(java.io.DataOutput)} method.
diff --git a/hbase-client/src/main/java/org/apache/hadoop/hbase/zookeeper/ReadOnlyZKClient.java b/hbase-client/src/main/java/org/apache/hadoop/hbase/zookeeper/ReadOnlyZKClient.java
index 96170736208b..979094fda80b 100644
--- a/hbase-client/src/main/java/org/apache/hadoop/hbase/zookeeper/ReadOnlyZKClient.java
+++ b/hbase-client/src/main/java/org/apache/hadoop/hbase/zookeeper/ReadOnlyZKClient.java
@@ -183,6 +183,8 @@ public void exec(ZooKeeper alwaysNull) {
               try {
                 zk.close();
               } catch (InterruptedException e) {
+                // Restore interrupt status
+                Thread.currentThread().interrupt();
               }
             }
             if (ZKTask.this.delay(retryIntervalMs, maxRetries)) {
@@ -303,6 +305,8 @@ private void closeZk() {
       try {
         zookeeper.close();
       } catch (InterruptedException e) {
+        // Restore interrupt status
+        Thread.currentThread().interrupt();
       }
       zookeeper = null;
     }
diff --git a/hbase-client/src/main/java/org/apache/hadoop/hbase/zookeeper/ZKMetadata.java b/hbase-client/src/main/java/org/apache/hadoop/hbase/zookeeper/ZKMetadata.java
index f0fae958a66a..b795ad45aa1c 100644
--- a/hbase-client/src/main/java/org/apache/hadoop/hbase/zookeeper/ZKMetadata.java
+++ b/hbase-client/src/main/java/org/apache/hadoop/hbase/zookeeper/ZKMetadata.java
@@ -54,7 +54,7 @@ public static byte[] appendMetaData(byte[] id, byte[] data) {
     pos = Bytes.putInt(newData, pos, idLength);
     pos = Bytes.putBytes(newData, pos, id, 0, id.length);
     pos = Bytes.putBytes(newData, pos, salt, 0, salt.length);
-    pos = Bytes.putBytes(newData, pos, data, 0, data.length);
+    Bytes.putBytes(newData, pos, data, 0, data.length);
     return newData;
   }
 
diff --git a/hbase-client/src/main/java/org/apache/hadoop/hbase/zookeeper/ZNodePaths.java b/hbase-client/src/main/java/org/apache/hadoop/hbase/zookeeper/ZNodePaths.java
index 5d73504164ef..8f286b406697 100644
--- a/hbase-client/src/main/java/org/apache/hadoop/hbase/zookeeper/ZNodePaths.java
+++ b/hbase-client/src/main/java/org/apache/hadoop/hbase/zookeeper/ZNodePaths.java
@@ -133,9 +133,7 @@ public String toString() {
       .append(snapshotCleanupZNode).append("]").toString();
   }
 
-  /**
-   * @return the znode string corresponding to a replicaId
-   */
+  /** Return the znode string corresponding to a replicaId */
   public String getZNodeForReplica(int replicaId) {
     if (RegionReplicaUtil.isDefaultReplica(replicaId)) {
       return joinZNode(baseZNode, metaZNodePrefix);
@@ -165,16 +163,12 @@ public int getMetaReplicaIdFromZNode(String znode) {
       : Integer.parseInt(znode.substring(metaZNodePrefix.length() + 1));
   }
 
-  /**
-   * @return True if meta znode.
-   */
+  /** Return true if meta znode. */
   public boolean isMetaZNodePrefix(String znode) {
     return znode != null && znode.startsWith(this.metaZNodePrefix);
   }
 
-  /**
-   * @return True is the fully qualified path is for meta location
-   */
+  /** Return true is the fully qualified path is for meta location */
   public boolean isMetaZNodePath(String path) {
     int prefixLen = baseZNode.length() + 1;
     return path.length() > prefixLen && isMetaZNodePrefix(path.substring(prefixLen));
diff --git a/hbase-client/src/test/java/org/apache/hadoop/hbase/client/TestAsyncTableRpcPriority.java b/hbase-client/src/test/java/org/apache/hadoop/hbase/client/TestAsyncTableRpcPriority.java
index db3ccebe89d2..e57967ae7211 100644
--- a/hbase-client/src/test/java/org/apache/hadoop/hbase/client/TestAsyncTableRpcPriority.java
+++ b/hbase-client/src/test/java/org/apache/hadoop/hbase/client/TestAsyncTableRpcPriority.java
@@ -45,7 +45,6 @@
 import java.util.concurrent.atomic.AtomicInteger;
 import org.apache.hadoop.conf.Configuration;
 import org.apache.hadoop.hbase.Cell;
-import org.apache.hadoop.hbase.Cell.Type;
 import org.apache.hadoop.hbase.CellBuilderFactory;
 import org.apache.hadoop.hbase.CellBuilderType;
 import org.apache.hadoop.hbase.HBaseClassTestRule;
@@ -135,10 +134,11 @@ public Void answer(InvocationOnMock invocation) throws Throwable {
           case INCREMENT:
             ColumnValue value = req.getColumnValue(0);
             QualifierValue qvalue = value.getQualifierValue(0);
-            Cell cell = CellBuilderFactory.create(CellBuilderType.SHALLOW_COPY).setType(Type.Put)
-              .setRow(req.getRow().toByteArray()).setFamily(value.getFamily().toByteArray())
-              .setQualifier(qvalue.getQualifier().toByteArray())
-              .setValue(qvalue.getValue().toByteArray()).build();
+            Cell cell =
+              CellBuilderFactory.create(CellBuilderType.SHALLOW_COPY).setType(Cell.Type.Put)
+                .setRow(req.getRow().toByteArray()).setFamily(value.getFamily().toByteArray())
+                .setQualifier(qvalue.getQualifier().toByteArray())
+                .setValue(qvalue.getValue().toByteArray()).build();
             resp = MutateResponse.newBuilder()
               .setResult(ProtobufUtil.toResult(Result.create(Arrays.asList(cell)))).build();
             break;
@@ -496,8 +496,8 @@ public Void answer(InvocationOnMock invocation) throws Throwable {
             assertFalse("close scanner should not come in with scan priority " + scanPriority,
               req.hasCloseScanner() && req.getCloseScanner());
 
-            Cell cell = CellBuilderFactory.create(CellBuilderType.SHALLOW_COPY).setType(Type.Put)
-              .setRow(Bytes.toBytes(scanNextCalled.incrementAndGet()))
+            Cell cell = CellBuilderFactory.create(CellBuilderType.SHALLOW_COPY)
+              .setType(Cell.Type.Put).setRow(Bytes.toBytes(scanNextCalled.incrementAndGet()))
               .setFamily(Bytes.toBytes("cf")).setQualifier(Bytes.toBytes("cq"))
               .setValue(Bytes.toBytes("v")).build();
             Result result = Result.create(Arrays.asList(cell));
diff --git a/hbase-client/src/test/java/org/apache/hadoop/hbase/client/TestAsyncTableTracing.java b/hbase-client/src/test/java/org/apache/hadoop/hbase/client/TestAsyncTableTracing.java
index 99e52361109c..f9b86221af1e 100644
--- a/hbase-client/src/test/java/org/apache/hadoop/hbase/client/TestAsyncTableTracing.java
+++ b/hbase-client/src/test/java/org/apache/hadoop/hbase/client/TestAsyncTableTracing.java
@@ -54,7 +54,6 @@
 import java.util.stream.Collectors;
 import org.apache.hadoop.conf.Configuration;
 import org.apache.hadoop.hbase.Cell;
-import org.apache.hadoop.hbase.Cell.Type;
 import org.apache.hadoop.hbase.CellBuilderFactory;
 import org.apache.hadoop.hbase.CellBuilderType;
 import org.apache.hadoop.hbase.HBaseClassTestRule;
@@ -135,8 +134,8 @@ public Void answer(InvocationOnMock invocation) throws Throwable {
           if (req.hasCloseScanner() && req.getCloseScanner()) {
             done.run(ScanResponse.getDefaultInstance());
           } else {
-            Cell cell = CellBuilderFactory.create(CellBuilderType.SHALLOW_COPY).setType(Type.Put)
-              .setRow(Bytes.toBytes(scanNextCalled.incrementAndGet()))
+            Cell cell = CellBuilderFactory.create(CellBuilderType.SHALLOW_COPY)
+              .setType(Cell.Type.Put).setRow(Bytes.toBytes(scanNextCalled.incrementAndGet()))
               .setFamily(Bytes.toBytes("cf")).setQualifier(Bytes.toBytes("cq"))
               .setValue(Bytes.toBytes("v")).build();
             Result result = Result.create(Arrays.asList(cell));
@@ -183,10 +182,11 @@ public Void answer(InvocationOnMock invocation) throws Throwable {
           case INCREMENT:
             ColumnValue value = req.getColumnValue(0);
             QualifierValue qvalue = value.getQualifierValue(0);
-            Cell cell = CellBuilderFactory.create(CellBuilderType.SHALLOW_COPY).setType(Type.Put)
-              .setRow(req.getRow().toByteArray()).setFamily(value.getFamily().toByteArray())
-              .setQualifier(qvalue.getQualifier().toByteArray())
-              .setValue(qvalue.getValue().toByteArray()).build();
+            Cell cell =
+              CellBuilderFactory.create(CellBuilderType.SHALLOW_COPY).setType(Cell.Type.Put)
+                .setRow(req.getRow().toByteArray()).setFamily(value.getFamily().toByteArray())
+                .setQualifier(qvalue.getQualifier().toByteArray())
+                .setValue(qvalue.getValue().toByteArray()).build();
             resp = MutateResponse.newBuilder()
               .setResult(ProtobufUtil.toResult(Result.create(Arrays.asList(cell)))).build();
             break;
diff --git a/hbase-client/src/test/java/org/apache/hadoop/hbase/client/TestCoprocessorDescriptor.java b/hbase-client/src/test/java/org/apache/hadoop/hbase/client/TestCoprocessorDescriptor.java
index f1a8e000136d..a56c863ce614 100644
--- a/hbase-client/src/test/java/org/apache/hadoop/hbase/client/TestCoprocessorDescriptor.java
+++ b/hbase-client/src/test/java/org/apache/hadoop/hbase/client/TestCoprocessorDescriptor.java
@@ -33,8 +33,6 @@
 import org.junit.Test;
 import org.junit.experimental.categories.Category;
 import org.junit.rules.TestName;
-import org.slf4j.Logger;
-import org.slf4j.LoggerFactory;
 
 @Category({ MiscTests.class, SmallTests.class })
 public class TestCoprocessorDescriptor {
@@ -43,8 +41,6 @@ public class TestCoprocessorDescriptor {
   public static final HBaseClassTestRule CLASS_RULE =
     HBaseClassTestRule.forClass(TestCoprocessorDescriptor.class);
 
-  private static final Logger LOG = LoggerFactory.getLogger(TestCoprocessorDescriptor.class);
-
   @Rule
   public TestName name = new TestName();
 
diff --git a/hbase-client/src/test/java/org/apache/hadoop/hbase/client/TestGet.java b/hbase-client/src/test/java/org/apache/hadoop/hbase/client/TestGet.java
index 44a1c577b10d..69c33c833b0c 100644
--- a/hbase-client/src/test/java/org/apache/hadoop/hbase/client/TestGet.java
+++ b/hbase-client/src/test/java/org/apache/hadoop/hbase/client/TestGet.java
@@ -250,8 +250,7 @@ public void testDynamicFilter() throws Exception {
   public void testGetRowConstructor() {
     byte[] row1 = Bytes.toBytes("testRow");
     byte[] row2 = Bytes.toBytes("testtestRow");
-    ByteBuffer rowBuffer = ByteBuffer.allocate(16);
-    rowBuffer = ByteBuffer.wrap(row1);
+    ByteBuffer rowBuffer = ByteBuffer.wrap(row1);
     Get get1 = new Get(rowBuffer);
     Get get2 = new Get(row2, 4, 7);
     Assert.assertArrayEquals(get1.getRow(), get2.getRow());
diff --git a/hbase-client/src/test/java/org/apache/hadoop/hbase/client/TestMutation.java b/hbase-client/src/test/java/org/apache/hadoop/hbase/client/TestMutation.java
index dcb4d6eb88ad..718ca05b92f3 100644
--- a/hbase-client/src/test/java/org/apache/hadoop/hbase/client/TestMutation.java
+++ b/hbase-client/src/test/java/org/apache/hadoop/hbase/client/TestMutation.java
@@ -23,7 +23,6 @@
 import java.io.IOException;
 import java.util.List;
 import org.apache.hadoop.hbase.Cell;
-import org.apache.hadoop.hbase.Cell.Type;
 import org.apache.hadoop.hbase.CellBuilderFactory;
 import org.apache.hadoop.hbase.CellBuilderType;
 import org.apache.hadoop.hbase.CellUtil;
@@ -51,7 +50,7 @@ public void testAppendCopyConstructor() throws IOException {
     byte[] family = Bytes.toBytes("CF-01");
 
     origin.add(CellBuilderFactory.create(CellBuilderType.SHALLOW_COPY).setRow(origin.getRow())
-      .setFamily(family).setQualifier(Bytes.toBytes("q")).setType(Type.Put)
+      .setFamily(family).setQualifier(Bytes.toBytes("q")).setType(Cell.Type.Put)
       .setValue(Bytes.toBytes(100)).build());
     origin.addColumn(family, Bytes.toBytes("q0"), Bytes.toBytes("value"));
     origin.setTimeRange(100, 1000);
@@ -89,7 +88,7 @@ public void testDeleteCopyConstructor() throws IOException {
     byte[] family = Bytes.toBytes("CF-01");
 
     origin.add(CellBuilderFactory.create(CellBuilderType.SHALLOW_COPY).setRow(origin.getRow())
-      .setFamily(family).setQualifier(Bytes.toBytes("q")).setType(Type.Delete).build());
+      .setFamily(family).setQualifier(Bytes.toBytes("q")).setType(Cell.Type.Delete).build());
     origin.addColumn(family, Bytes.toBytes("q0"));
     origin.addColumns(family, Bytes.toBytes("q1"));
     origin.addFamily(family);
@@ -187,10 +186,11 @@ public void testAddImmutableToPut() throws IOException {
     Put put = new Put(row, true);
     put
       .add(CellBuilderFactory.create(CellBuilderType.SHALLOW_COPY).setRow(row).setFamily(family)
-        .setQualifier(qualifier0).setTimestamp(put.getTimestamp()).setType(Type.Put)
+        .setQualifier(qualifier0).setTimestamp(put.getTimestamp()).setType(Cell.Type.Put)
         .setValue(value0).build())
       .add(CellBuilderFactory.create(CellBuilderType.SHALLOW_COPY).setRow(row).setFamily(family)
-        .setQualifier(qualifier1).setTimestamp(ts1).setType(Type.Put).setValue(value1).build());
+        .setQualifier(qualifier1).setTimestamp(ts1).setType(Cell.Type.Put).setValue(value1)
+        .build());
 
     // Verify the cell of family:qualifier0
     Cell cell0 = put.get(family, qualifier0).get(0);
diff --git a/hbase-client/src/test/java/org/apache/hadoop/hbase/client/TestRegionInfoDisplay.java b/hbase-client/src/test/java/org/apache/hadoop/hbase/client/TestRegionInfoDisplay.java
index 0403ca647355..6e665dd55fc2 100644
--- a/hbase-client/src/test/java/org/apache/hadoop/hbase/client/TestRegionInfoDisplay.java
+++ b/hbase-client/src/test/java/org/apache/hadoop/hbase/client/TestRegionInfoDisplay.java
@@ -87,8 +87,8 @@ private void checkDescriptiveNameEquality(String descriptiveNameForDisplay, Stri
     String firstPartOrig = origDesc.substring(0, origDesc.indexOf(Bytes.toStringBinary(startKey)));
     String secondPartOrig = origDesc.substring(
       origDesc.indexOf(Bytes.toStringBinary(startKey)) + Bytes.toStringBinary(startKey).length());
-    assert (firstPart.equals(firstPartOrig));
-    assert (secondPart.equals(secondPartOrig));
+    Assert.assertTrue(firstPart.equals(firstPartOrig));
+    Assert.assertTrue(secondPart.equals(secondPartOrig));
   }
 
   private void checkEquality(RegionInfo ri, Configuration conf) throws IOException {
diff --git a/hbase-client/src/test/java/org/apache/hadoop/hbase/client/TestScan.java b/hbase-client/src/test/java/org/apache/hadoop/hbase/client/TestScan.java
index 4023d745c065..4b124c68f862 100644
--- a/hbase-client/src/test/java/org/apache/hadoop/hbase/client/TestScan.java
+++ b/hbase-client/src/test/java/org/apache/hadoop/hbase/client/TestScan.java
@@ -164,22 +164,17 @@ public void testNullQualifier() {
   @Test
   public void testSetAuthorizations() {
     Scan scan = new Scan();
-    try {
-      scan.setAuthorizations(new Authorizations("\u002b|\u0029"));
-      scan.setAuthorizations(new Authorizations("A", "B", "0123", "A0", "1A1", "_a"));
-      scan.setAuthorizations(new Authorizations("A|B"));
-      scan.setAuthorizations(new Authorizations("A&B"));
-      scan.setAuthorizations(new Authorizations("!B"));
-      scan.setAuthorizations(new Authorizations("A", "(A)"));
-      scan.setAuthorizations(new Authorizations("A", "{A"));
-      scan.setAuthorizations(new Authorizations(" "));
-      scan.setAuthorizations(new Authorizations(":B"));
-      scan.setAuthorizations(new Authorizations("-B"));
-      scan.setAuthorizations(new Authorizations(".B"));
-      scan.setAuthorizations(new Authorizations("/B"));
-    } catch (IllegalArgumentException e) {
-      fail("should not throw exception");
-    }
+    scan.setAuthorizations(new Authorizations("A", "B", "0123", "A0", "1A1", "_a"));
+    scan.setAuthorizations(new Authorizations("A|B"));
+    scan.setAuthorizations(new Authorizations("A&B"));
+    scan.setAuthorizations(new Authorizations("!B"));
+    scan.setAuthorizations(new Authorizations("A", "(A)"));
+    scan.setAuthorizations(new Authorizations("A", "{A"));
+    scan.setAuthorizations(new Authorizations(" "));
+    scan.setAuthorizations(new Authorizations(":B"));
+    scan.setAuthorizations(new Authorizations("-B"));
+    scan.setAuthorizations(new Authorizations(".B"));
+    scan.setAuthorizations(new Authorizations("/B"));
   }
 
   @Test
@@ -192,8 +187,7 @@ public void testSetStartRowAndSetStopRow() {
       scan.withStartRow(new byte[HConstants.MAX_ROW_LENGTH + 1]);
       fail("should've thrown exception");
     } catch (IllegalArgumentException iae) {
-    } catch (Exception e) {
-      fail("expected IllegalArgumentException to be thrown");
+      // Expected
     }
 
     scan.withStopRow(null);
@@ -203,8 +197,7 @@ public void testSetStartRowAndSetStopRow() {
       scan.withStopRow(new byte[HConstants.MAX_ROW_LENGTH + 1]);
       fail("should've thrown exception");
     } catch (IllegalArgumentException iae) {
-    } catch (Exception e) {
-      fail("expected IllegalArgumentException to be thrown");
+      // Expected
     }
   }
 
diff --git a/hbase-client/src/test/java/org/apache/hadoop/hbase/client/TestSimpleRequestController.java b/hbase-client/src/test/java/org/apache/hadoop/hbase/client/TestSimpleRequestController.java
index a7fcac95ee95..30fdbc367ff8 100644
--- a/hbase-client/src/test/java/org/apache/hadoop/hbase/client/TestSimpleRequestController.java
+++ b/hbase-client/src/test/java/org/apache/hadoop/hbase/client/TestSimpleRequestController.java
@@ -102,6 +102,7 @@ private void testIllegalArgument(String key, long value) {
       new SimpleRequestController(conf);
       fail("The " + key + " must be bigger than zero");
     } catch (IllegalArgumentException e) {
+      // Expected
     }
   }
 
@@ -115,6 +116,7 @@ public long heapSize() {
   }
 
   @Test
+  @SuppressWarnings("ArrayAsKeyOfSetOrMap")
   public void testTaskCheckerHost() throws IOException {
     final int maxTotalConcurrentTasks = 100;
     final int maxConcurrentTasksPerServer = 2;
@@ -277,6 +279,7 @@ public void testSubmittedSizeChecker() {
   }
 
   @Test
+  @SuppressWarnings("ArrayAsKeyOfSetOrMap")
   public void testTaskCountChecker() throws InterruptedIOException {
     long heapSizeOfRow = 12345;
     int maxTotalConcurrentTasks = 100;
@@ -358,10 +361,8 @@ public void testWaitForMaximumCurrentTasks() throws Exception {
       try {
         barrier.await();
         controller.waitForMaximumCurrentTasks(max.get(), 123, 1, null);
-      } catch (InterruptedIOException e) {
+      } catch (InterruptedIOException | InterruptedException | BrokenBarrierException e) {
         Assert.fail(e.getMessage());
-      } catch (InterruptedException | BrokenBarrierException e) {
-        e.printStackTrace();
       }
     };
     // First test that our runnable thread only exits when tasks is zero.
diff --git a/hbase-client/src/test/java/org/apache/hadoop/hbase/filter/TestKeyOnlyFilter.java b/hbase-client/src/test/java/org/apache/hadoop/hbase/filter/TestKeyOnlyFilter.java
index 860544ba1350..0a888e838c1c 100644
--- a/hbase-client/src/test/java/org/apache/hadoop/hbase/filter/TestKeyOnlyFilter.java
+++ b/hbase-client/src/test/java/org/apache/hadoop/hbase/filter/TestKeyOnlyFilter.java
@@ -27,7 +27,6 @@
 import org.apache.hadoop.hbase.HBaseClassTestRule;
 import org.apache.hadoop.hbase.HBaseCommonTestingUtil;
 import org.apache.hadoop.hbase.KeyValue;
-import org.apache.hadoop.hbase.KeyValue.Type;
 import org.apache.hadoop.hbase.KeyValueUtil;
 import org.apache.hadoop.hbase.filter.KeyOnlyFilter.KeyOnlyByteBufferExtendedCell;
 import org.apache.hadoop.hbase.filter.KeyOnlyFilter.KeyOnlyCell;
@@ -64,7 +63,8 @@ public void testKeyOnly() throws Exception {
     byte[] q = Bytes.toBytes("qual1");
     byte[] v = Bytes.toBytes("val1");
     byte[] tags = Bytes.toBytes("tag1");
-    KeyValue kv = new KeyValue(r, f, q, 0, q.length, 1234L, Type.Put, v, 0, v.length, tags);
+    KeyValue kv =
+      new KeyValue(r, f, q, 0, q.length, 1234L, KeyValue.Type.Put, v, 0, v.length, tags);
 
     ByteBuffer buffer = ByteBuffer.wrap(kv.getBuffer());
     ByteBufferKeyValue bbCell = new ByteBufferKeyValue(buffer, 0, buffer.remaining());
diff --git a/hbase-client/src/test/java/org/apache/hadoop/hbase/ipc/TestCellBlockBuilder.java b/hbase-client/src/test/java/org/apache/hadoop/hbase/ipc/TestCellBlockBuilder.java
index f9c93811b4eb..fccea923635a 100644
--- a/hbase-client/src/test/java/org/apache/hadoop/hbase/ipc/TestCellBlockBuilder.java
+++ b/hbase-client/src/test/java/org/apache/hadoop/hbase/ipc/TestCellBlockBuilder.java
@@ -154,7 +154,7 @@ private static void timerTests(final CellBlockBuilder builder, final int count,
     StopWatch timer = new StopWatch();
     timer.start();
     for (int i = 0; i < cycles; i++) {
-      timerTest(builder, timer, count, size, codec, compressor, false);
+      timerTest(builder, count, size, codec, compressor, false);
     }
     timer.stop();
     LOG.info("Codec=" + codec + ", compression=" + compressor + ", sized=" + false + ", count="
@@ -162,16 +162,15 @@ private static void timerTests(final CellBlockBuilder builder, final int count,
     timer.reset();
     timer.start();
     for (int i = 0; i < cycles; i++) {
-      timerTest(builder, timer, count, size, codec, compressor, true);
+      timerTest(builder, count, size, codec, compressor, true);
     }
     timer.stop();
     LOG.info("Codec=" + codec + ", compression=" + compressor + ", sized=" + true + ", count="
       + count + ", size=" + size + ", + took=" + timer.getTime() + "ms");
   }
 
-  private static void timerTest(final CellBlockBuilder builder, final StopWatch timer,
-    final int count, final int size, final Codec codec, final CompressionCodec compressor,
-    final boolean sized) throws IOException {
+  private static void timerTest(final CellBlockBuilder builder, final int count, final int size,
+    final Codec codec, final CompressionCodec compressor, final boolean sized) throws IOException {
     doBuildCellBlockUndoCellBlock(builder, codec, compressor, count, size, sized);
   }
 
diff --git a/hbase-client/src/test/java/org/apache/hadoop/hbase/ipc/TestIPCUtil.java b/hbase-client/src/test/java/org/apache/hadoop/hbase/ipc/TestIPCUtil.java
index c327896f72ab..67a8d15c1d02 100644
--- a/hbase-client/src/test/java/org/apache/hadoop/hbase/ipc/TestIPCUtil.java
+++ b/hbase-client/src/test/java/org/apache/hadoop/hbase/ipc/TestIPCUtil.java
@@ -121,7 +121,7 @@ public void testWrapConnectionException() throws Exception {
   }
 
   @Test
-  public void testExecute() throws IOException {
+  public void testExecute() throws Exception {
     EventLoop eventLoop = new DefaultEventLoop();
     MutableInt executed = new MutableInt(0);
     MutableInt numStackTraceElements = new MutableInt(0);
@@ -156,7 +156,7 @@ public void run() {
       });
       FutureUtils.get(future);
     } finally {
-      eventLoop.shutdownGracefully();
+      eventLoop.shutdownGracefully().get();
     }
   }
 }
diff --git a/hbase-client/src/test/java/org/apache/hadoop/hbase/ipc/TestNettyRpcConnection.java b/hbase-client/src/test/java/org/apache/hadoop/hbase/ipc/TestNettyRpcConnection.java
index a9c40fd3bb79..73f3653a9026 100644
--- a/hbase-client/src/test/java/org/apache/hadoop/hbase/ipc/TestNettyRpcConnection.java
+++ b/hbase-client/src/test/java/org/apache/hadoop/hbase/ipc/TestNettyRpcConnection.java
@@ -20,6 +20,7 @@
 import static org.hamcrest.CoreMatchers.instanceOf;
 import static org.hamcrest.MatcherAssert.assertThat;
 import static org.junit.Assert.assertThrows;
+import static org.junit.Assert.assertTrue;
 import static org.junit.Assert.fail;
 
 import java.io.IOException;
@@ -69,9 +70,8 @@ public static void tearDown() throws IOException {
 
   @Test
   public void testPrivateMethodExecutedInEventLoop() throws IllegalAccessException {
-    // make sure the test is executed with "-ea"
     assertThrows(AssertionError.class, () -> {
-      assert false;
+      assertTrue(false);
     });
     for (Method method : NettyRpcConnection.class.getDeclaredMethods()) {
       if (Modifier.isPrivate(method.getModifiers()) && !method.getName().contains("$")) {
diff --git a/hbase-client/src/test/java/org/apache/hadoop/hbase/quotas/TestQuotaGlobalsSettingsBypass.java b/hbase-client/src/test/java/org/apache/hadoop/hbase/quotas/TestQuotaGlobalsSettingsBypass.java
index e2843180938e..a3c96eb45aa9 100644
--- a/hbase-client/src/test/java/org/apache/hadoop/hbase/quotas/TestQuotaGlobalsSettingsBypass.java
+++ b/hbase-client/src/test/java/org/apache/hadoop/hbase/quotas/TestQuotaGlobalsSettingsBypass.java
@@ -143,6 +143,7 @@ void expectFailure(QuotaSettings one, QuotaSettings two) throws IOException {
       one.merge(two);
       fail("Expected to see an Exception merging " + two + " into " + one);
     } catch (IllegalArgumentException e) {
+      // Expected
     }
   }
 }
diff --git a/hbase-client/src/test/java/org/apache/hadoop/hbase/security/TestHBaseSaslRpcClient.java b/hbase-client/src/test/java/org/apache/hadoop/hbase/security/TestHBaseSaslRpcClient.java
index 8d82ba538bda..b2758b408d8b 100644
--- a/hbase-client/src/test/java/org/apache/hadoop/hbase/security/TestHBaseSaslRpcClient.java
+++ b/hbase-client/src/test/java/org/apache/hadoop/hbase/security/TestHBaseSaslRpcClient.java
@@ -140,14 +140,8 @@ public void testDigestSaslClientCallbackHandlerWithException() {
   @Test
   public void testHBaseSaslRpcClientCreation() throws Exception {
     // creation kerberos principal check section
-    assertFalse(assertSuccessCreationKerberosPrincipal(null));
-    assertFalse(assertSuccessCreationKerberosPrincipal("DOMAIN.COM"));
-    assertFalse(assertSuccessCreationKerberosPrincipal("principal/DOMAIN.COM"));
-    if (!assertSuccessCreationKerberosPrincipal("principal/localhost@DOMAIN.COM")) {
-      // XXX: This can fail if kerberos support in the OS is not sane, see HBASE-10107.
-      // For now, don't assert, just warn
-      LOG.warn("Could not create a SASL client with valid Kerberos credential");
-    }
+    // Note this is mocked in a way that doesn't care about principal names
+    assertFalse(assertSuccessCreationKerberos());
 
     // creation digest principal check section
     assertFalse(assertSuccessCreationDigestPrincipal(null, null));
@@ -157,9 +151,8 @@ public void testHBaseSaslRpcClientCreation() throws Exception {
     assertTrue(assertSuccessCreationDigestPrincipal(DEFAULT_USER_NAME, DEFAULT_USER_PASSWORD));
 
     // creation simple principal check section
-    assertFalse(assertSuccessCreationSimplePrincipal("", ""));
-    assertFalse(assertSuccessCreationSimplePrincipal(null, null));
-    assertFalse(assertSuccessCreationSimplePrincipal(DEFAULT_USER_NAME, DEFAULT_USER_PASSWORD));
+    // Note this is mocked in a way that doesn't care about principal names
+    assertFalse(assertSuccessCreationSimple());
 
     // exceptions check section
     assertTrue(assertIOExceptionThenSaslClientIsNull(DEFAULT_USER_NAME, DEFAULT_USER_PASSWORD));
@@ -247,10 +240,11 @@ public SaslClient createClient(Configuration conf, InetAddress serverAddress,
     }
   }
 
-  private boolean assertSuccessCreationKerberosPrincipal(String principal) {
+  private boolean assertSuccessCreationKerberos() {
     HBaseSaslRpcClient rpcClient = null;
     try {
-      rpcClient = createSaslRpcClientForKerberos(principal);
+      // createSaslRpcClientForKerberos is mocked in a way that doesn't care about principal names
+      rpcClient = createSaslRpcClientForKerberos();
     } catch (Exception ex) {
       LOG.error(ex.getMessage(), ex);
     }
@@ -270,17 +264,17 @@ private boolean assertSuccessCreationDigestPrincipal(String principal, String pa
     return rpcClient != null;
   }
 
-  private boolean assertSuccessCreationSimplePrincipal(String principal, String password) {
+  private boolean assertSuccessCreationSimple() {
     HBaseSaslRpcClient rpcClient = null;
     try {
-      rpcClient = createSaslRpcClientSimple(principal, password);
+      rpcClient = createSaslRpcClientSimple();
     } catch (Exception ex) {
       LOG.error(ex.getMessage(), ex);
     }
     return rpcClient != null;
   }
 
-  private HBaseSaslRpcClient createSaslRpcClientForKerberos(String principal) throws IOException {
+  private HBaseSaslRpcClient createSaslRpcClientForKerberos() throws IOException {
     return new HBaseSaslRpcClient(HBaseConfiguration.create(),
       new GssSaslClientAuthenticationProvider(), createTokenMock(), Mockito.mock(InetAddress.class),
       Mockito.mock(SecurityInfo.class), false);
@@ -296,8 +290,7 @@ private Token createTokenMockWithCredentials(String p
     return token;
   }
 
-  private HBaseSaslRpcClient createSaslRpcClientSimple(String principal, String password)
-    throws IOException {
+  private HBaseSaslRpcClient createSaslRpcClientSimple() throws IOException {
     return new HBaseSaslRpcClient(HBaseConfiguration.create(),
       new SimpleSaslClientAuthenticationProvider(), createTokenMock(),
       Mockito.mock(InetAddress.class), Mockito.mock(SecurityInfo.class), false);
diff --git a/hbase-client/src/test/java/org/apache/hadoop/hbase/util/TestRoundRobinPoolMap.java b/hbase-client/src/test/java/org/apache/hadoop/hbase/util/TestRoundRobinPoolMap.java
index d7ce6265b8c5..04ba2570eac8 100644
--- a/hbase-client/src/test/java/org/apache/hadoop/hbase/util/TestRoundRobinPoolMap.java
+++ b/hbase-client/src/test/java/org/apache/hadoop/hbase/util/TestRoundRobinPoolMap.java
@@ -120,10 +120,10 @@ public void testMultiThreadedRoundRobin() throws ExecutionException, Interrupted
           String value = Integer.toString(id.getAndIncrement());
           String result = poolMap.getOrCreate(key, () -> value);
           results.add(result);
-
-          Thread.yield();
+          // Sleep for a short time to ensure a yield. Thread#yield has platform dependent behavior.
+          Thread.sleep(10);
         }
-      } catch (IOException e) {
+      } catch (Exception e) {
         throw new CompletionException(e);
       }
     };
diff --git a/hbase-client/src/test/java/org/apache/hadoop/hbase/util/TestThreadLocalPoolMap.java b/hbase-client/src/test/java/org/apache/hadoop/hbase/util/TestThreadLocalPoolMap.java
index 45f533f1a730..d83944ef7f3a 100644
--- a/hbase-client/src/test/java/org/apache/hadoop/hbase/util/TestThreadLocalPoolMap.java
+++ b/hbase-client/src/test/java/org/apache/hadoop/hbase/util/TestThreadLocalPoolMap.java
@@ -95,10 +95,10 @@ public void testLocality() throws ExecutionException, InterruptedException {
         for (int i = 0; i < 3; i++) {
           String result = poolMap.getOrCreate(key, () -> myId);
           assertEquals(myId, result);
-
-          Thread.yield();
+          // Sleep for a short period of time to yield. Thread#yield is platform dependent.
+          Thread.sleep(10);
         }
-      } catch (IOException e) {
+      } catch (Exception e) {
         throw new CompletionException(e);
       }
     };