Build warning fixes (#75)

* Simplify Stream API
* Simplify collection creation
* Lambdas & Method refs
* Pattern variables
* Final fields
* Simplify if/else
* if/else -> switch
* isEmpty()
* Unnecessary null checks
* requireNonNullElseGet
* Diamond operator
* Boxing / unboxing
* Unnecessary StringBuilder
* Unnecessary modifier
* Unnecessary semicolon
* Visibility issues
* Static access
* Usage of raw class
* Sequenced collection

extension/persistence/eclipselink/src/main/java/io/polaris/extension/persistence/impl/eclipselink/PolarisEclipseLinkMetaStoreSessionImpl.java

@@ -76,8 +76,8 @@ public class PolarisEclipseLinkMetaStoreSessionImpl implements PolarisMetaStoreS
   private static final Logger LOG =
       LoggerFactory.getLogger(PolarisEclipseLinkMetaStoreSessionImpl.class);
 
-  private EntityManagerFactory emf;
-  private ThreadLocal<EntityManager> localSession = new ThreadLocal<>();
+  private final EntityManagerFactory emf;
+  private final ThreadLocal<EntityManager> localSession = new ThreadLocal<>();
   private final PolarisEclipseLinkStore store;
   private final PolarisStorageIntegrationProvider storageIntegrationProvider;
   private static volatile Map<String, String> properties;
@@ -119,8 +119,8 @@ public PolarisEclipseLinkMetaStoreSessionImpl(
 
   /** Load the persistence unit properties from a given configuration file */
   private Map<String, String> loadProperties(String confFile, String persistenceUnitName) {
-    if (this.properties != null) {
-      return this.properties;
+    if (properties != null) {
+      return properties;
     }
 
     try {
@@ -141,7 +141,7 @@ private Map<String, String> loadProperties(String confFile, String persistenceUn
             nodeMap.getNamedItem("value").getNodeValue());
       }
 
-      this.properties = properties;
+      PolarisEclipseLinkMetaStoreSessionImpl.properties = properties;
       return properties;
     } catch (Exception e) {
       LOG.warn(
@@ -262,10 +262,10 @@ public void writeToEntities(
 
   /** {@inheritDoc} */
   @Override
-  public void persistStorageIntegrationIfNeeded(
+  public <T extends PolarisStorageConfigurationInfo> void persistStorageIntegrationIfNeeded(
       @NotNull PolarisCallContext callContext,
       @NotNull PolarisBaseEntity entity,
-      @Nullable PolarisStorageIntegration storageIntegration) {
+      @Nullable PolarisStorageIntegration<T> storageIntegration) {
     // not implemented for eclipselink store
   }
 
@@ -373,7 +373,7 @@ public void deleteAll(@NotNull PolarisCallContext callCtx) {
   public @NotNull List<PolarisBaseEntity> lookupEntities(
       @NotNull PolarisCallContext callCtx, List<PolarisEntityId> entityIds) {
     return this.store.lookupEntities(localSession.get(), entityIds).stream()
-        .map(model -> ModelEntity.toEntity(model))
+        .map(ModelEntity::toEntity)
         .toList();
   }
 
@@ -477,7 +477,7 @@ public List<PolarisEntityActiveRecord> lookupEntityActiveBatch(
     return this.store
         .lookupFullEntitiesActive(localSession.get(), catalogId, parentId, entityType)
         .stream()
-        .map(model -> ModelEntity.toEntity(model))
+        .map(ModelEntity::toEntity)
         .filter(entityFilter)
         .limit(limit)
         .map(transformer)
@@ -534,7 +534,7 @@ public int lookupEntityGrantRecordsVersion(
     return this.store
         .lookupAllGrantRecordsOnSecurable(localSession.get(), securableCatalogId, securableId)
         .stream()
-        .map(model -> ModelGrantRecord.toGrantRecord(model))
+        .map(ModelGrantRecord::toGrantRecord)
         .toList();
   }
 
@@ -546,7 +546,7 @@ public int lookupEntityGrantRecordsVersion(
     return this.store
         .lookupGrantRecordsOnGrantee(localSession.get(), granteeCatalogId, granteeId)
         .stream()
-        .map(model -> ModelGrantRecord.toGrantRecord(model))
+        .map(ModelGrantRecord::toGrantRecord)
         .toList();
   }
 

extension/persistence/eclipselink/src/main/java/io/polaris/extension/persistence/impl/eclipselink/PolarisEclipseLinkStore.java

@@ -48,7 +48,7 @@ public class PolarisEclipseLinkStore {
   private static final Logger LOG = LoggerFactory.getLogger(PolarisEclipseLinkStore.class);
 
   // diagnostic services
-  private PolarisDiagnostics diagnosticServices;
+  private final PolarisDiagnostics diagnosticServices;
 
   /**
    * Constructor, allocate everything at once

polaris-core/src/main/java/io/polaris/core/auth/AuthenticatedPolarisPrincipal.java

@@ -59,10 +59,11 @@ public void setActivatedPrincipalRoles(List<PrincipalRoleEntity> activatedPrinci
 
   @Override
   public String toString() {
-    StringBuilder sb = new StringBuilder();
-    sb.append("principalEntity=" + getPrincipalEntity());
-    sb.append(";activatedPrincipalRoleNames=" + getActivatedPrincipalRoleNames());
-    sb.append(";activatedPrincipalRoles=" + getActivatedPrincipalRoles());
-    return sb.toString();
+    return "principalEntity="
+        + getPrincipalEntity()
+        + ";activatedPrincipalRoleNames="
+        + getActivatedPrincipalRoleNames()
+        + ";activatedPrincipalRoles="
+        + getActivatedPrincipalRoles();
   }
 }

polaris-core/src/main/java/io/polaris/core/catalog/PolarisCatalogHelpers.java

@@ -15,6 +15,7 @@
  */
 package io.polaris.core.catalog;
 
+import com.google.common.collect.ImmutableList;
 import io.polaris.core.entity.PolarisEntity;
 import java.util.ArrayList;
 import java.util.Arrays;
@@ -36,10 +37,11 @@ public class PolarisCatalogHelpers {
   private PolarisCatalogHelpers() {}
 
   public static List<String> tableIdentifierToList(TableIdentifier identifier) {
-    List<String> fullList = new ArrayList<>();
+    ImmutableList.Builder<String> fullList =
+        ImmutableList.builderWithExpectedSize(identifier.namespace().length() + 1);
     fullList.addAll(Arrays.asList(identifier.namespace().levels()));
     fullList.add(identifier.name());
-    return fullList;
+    return fullList.build();
   }
 
   public static TableIdentifier listToTableIdentifier(List<String> ids) {

polaris-core/src/main/java/io/polaris/core/context/CallContext.java

@@ -40,7 +40,7 @@ public interface CallContext extends AutoCloseable {
 
   // For requests that make use of a Catalog instance, this holds the instance that was
   // created, scoped to the current call context.
-  public static final String REQUEST_PATH_CATALOG_INSTANCE_KEY = "REQUEST_PATH_CATALOG_INSTANCE";
+  String REQUEST_PATH_CATALOG_INSTANCE_KEY = "REQUEST_PATH_CATALOG_INSTANCE";
 
   // Authenticator filters should populate this field alongside resolving a SecurityContext.
   // Value type: AuthenticatedPolarisPrincipal

polaris-core/src/main/java/io/polaris/core/entity/PolarisEntity.java

@@ -203,15 +203,20 @@ public NameAndId nameAndId() {
 
   @Override
   public String toString() {
-    StringBuilder sb = new StringBuilder();
-    sb.append("name=" + getName());
-    sb.append(";id=" + getId());
-    sb.append(";parentId=" + getParentId());
-    sb.append(";entityVersion=" + getEntityVersion());
-    sb.append(";type=" + getType());
-    sb.append(";subType=" + getSubType());
-    sb.append(";internalProperties=" + getInternalPropertiesAsMap());
-    return sb.toString();
+    return "name="
+        + getName()
+        + ";id="
+        + getId()
+        + ";parentId="
+        + getParentId()
+        + ";entityVersion="
+        + getEntityVersion()
+        + ";type="
+        + getType()
+        + ";subType="
+        + getSubType()
+        + ";internalProperties="
+        + getInternalPropertiesAsMap();
   }
 
   @Override

polaris-core/src/main/java/io/polaris/core/persistence/LocalPolarisMetaStoreManagerFactory.java

@@ -43,15 +43,15 @@
 public abstract class LocalPolarisMetaStoreManagerFactory<StoreType>
     implements MetaStoreManagerFactory {
 
-  Map<String, PolarisMetaStoreManager> metaStoreManagerMap = new HashMap<>();
-  Map<String, StorageCredentialCache> storageCredentialCacheMap = new HashMap<>();
-  Map<String, StoreType> backingStoreMap = new HashMap<>();
-  Map<String, Supplier<PolarisMetaStoreSession>> sessionSupplierMap = new HashMap<>();
-  protected PolarisDiagnostics diagServices = new PolarisDefaultDiagServiceImpl();
+  final Map<String, PolarisMetaStoreManager> metaStoreManagerMap = new HashMap<>();
+  final Map<String, StorageCredentialCache> storageCredentialCacheMap = new HashMap<>();
+  final Map<String, StoreType> backingStoreMap = new HashMap<>();
+  final Map<String, Supplier<PolarisMetaStoreSession>> sessionSupplierMap = new HashMap<>();
+  protected final PolarisDiagnostics diagServices = new PolarisDefaultDiagServiceImpl();
 
   protected PolarisStorageIntegrationProvider storageIntegration;
 
-  private Logger logger =
+  private final Logger logger =
       org.slf4j.LoggerFactory.getLogger(LocalPolarisMetaStoreManagerFactory.class);
 
   protected abstract StoreType createBackingStore(@NotNull PolarisDiagnostics diagnostics);

polaris-core/src/main/java/io/polaris/core/persistence/PolarisObjectMapperUtil.java

@@ -150,20 +150,25 @@ public int getAttemptCount() {
       while (jParser.nextToken() != JsonToken.END_OBJECT) {
         if (jParser.getCurrentToken() == JsonToken.FIELD_NAME) {
           String fieldName = jParser.currentName();
-          if (fieldName.equals(PolarisTaskConstants.LAST_ATTEMPT_EXECUTOR_ID)) {
-            jParser.nextToken();
-            executorId = jParser.getText();
-          } else if (fieldName.equals(PolarisTaskConstants.LAST_ATTEMPT_START_TIME)) {
-            jParser.nextToken();
-            lastAttemptStartTime = Long.parseLong(jParser.getText());
-          } else if (fieldName.equals(PolarisTaskConstants.ATTEMPT_COUNT)) {
-            jParser.nextToken();
-            attemptCount = Integer.parseInt(jParser.getText());
-          } else {
-            JsonToken next = jParser.nextToken();
-            if (next == JsonToken.START_OBJECT || next == JsonToken.START_ARRAY) {
-              jParser.skipChildren();
-            }
+          switch (fieldName) {
+            case PolarisTaskConstants.LAST_ATTEMPT_EXECUTOR_ID:
+              jParser.nextToken();
+              executorId = jParser.getText();
+              break;
+            case PolarisTaskConstants.LAST_ATTEMPT_START_TIME:
+              jParser.nextToken();
+              lastAttemptStartTime = Long.parseLong(jParser.getText());
+              break;
+            case PolarisTaskConstants.ATTEMPT_COUNT:
+              jParser.nextToken();
+              attemptCount = Integer.parseInt(jParser.getText());
+              break;
+            default:
+              JsonToken next = jParser.nextToken();
+              if (next == JsonToken.START_OBJECT || next == JsonToken.START_ARRAY) {
+                jParser.skipChildren();
+              }
+              break;
           }
         }
       }

polaris-core/src/main/java/io/polaris/core/persistence/PolarisResolvedPathWrapper.java

@@ -54,7 +54,7 @@ public List<PolarisEntity> getRawFullPath() {
     if (resolvedPath == null) {
       return null;
     }
-    return resolvedPath.stream().map(resolved -> resolved.getEntity()).toList();
+    return resolvedPath.stream().map(ResolvedPolarisEntity::getEntity).toList();
   }
 
   public List<ResolvedPolarisEntity> getResolvedParentPath() {
@@ -68,14 +68,11 @@ public List<PolarisEntity> getRawParentPath() {
     if (resolvedPath == null) {
       return null;
     }
-    return getResolvedParentPath().stream().map(resolved -> resolved.getEntity()).toList();
+    return getResolvedParentPath().stream().map(ResolvedPolarisEntity::getEntity).toList();
   }
 
   @Override
   public String toString() {
-    StringBuilder sb = new StringBuilder();
-    sb.append("resolvedPath:");
-    sb.append(resolvedPath);
-    return sb.toString();
+    return "resolvedPath:" + resolvedPath;
   }
 }

polaris-core/src/main/java/io/polaris/core/persistence/PolarisTreeMapMetaStoreSessionImpl.java

@@ -104,10 +104,10 @@ public void writeToEntities(
 
   /** {@inheritDoc} */
   @Override
-  public void persistStorageIntegrationIfNeeded(
+  public <T extends PolarisStorageConfigurationInfo> void persistStorageIntegrationIfNeeded(
       @NotNull PolarisCallContext callContext,
       @NotNull PolarisBaseEntity entity,
-      @Nullable PolarisStorageIntegration storageIntegration) {
+      @Nullable PolarisStorageIntegration<T> storageIntegration) {
     // not implemented for in-memory store
   }
 

polaris-core/src/main/java/io/polaris/core/persistence/ResolvedPolarisEntity.java

@@ -67,13 +67,11 @@ public List<PolarisGrantRecord> getGrantRecordsAsSecurable() {
 
   @Override
   public String toString() {
-    StringBuilder sb = new StringBuilder();
-    sb.append("entity:");
-    sb.append(entity);
-    sb.append(";grantRecordsAsGrantee:");
-    sb.append(grantRecordsAsGrantee);
-    sb.append(";grantRecordsAsSecurable:");
-    sb.append(grantRecordsAsSecurable);
-    return sb.toString();
+    return "entity:"
+        + entity
+        + ";grantRecordsAsGrantee:"
+        + grantRecordsAsGrantee
+        + ";grantRecordsAsSecurable:"
+        + grantRecordsAsSecurable;
   }
 }

polaris-core/src/main/java/io/polaris/core/persistence/cache/EntityCacheEntry.java

@@ -26,20 +26,20 @@
 public class EntityCacheEntry {
 
   // epoch time (ns) when the cache entry was added to the cache
-  private long createdOnNanoTimestamp;
+  private final long createdOnNanoTimestamp;
 
   // epoch time (ns) when the cache entry was added to the cache
   private long lastAccessedNanoTimestamp;
 
   // the entity which have been cached.
-  private PolarisBaseEntity entity;
+  private final PolarisBaseEntity entity;
 
   // grants associated to this entity, for a principal, a principal role, or a catalog role these
   // are role usage
   // grants on that entity. For a catalog securable (i.e. a catalog, namespace, or table_like
   // securable), these are
   // the grants on this securable.
-  private List<PolarisGrantRecord> grantRecords;
+  private final List<PolarisGrantRecord> grantRecords;
 
   /**
    * Constructor used when an entry is initially created after loading the entity and its grants

polaris-core/src/main/java/io/polaris/core/persistence/resolver/PolarisResolutionManifest.java

@@ -215,8 +215,7 @@ public PolarisResolvedPathWrapper getPassthroughResolvedPath(Object key) {
     List<ResolvedPolarisEntity> resolvedEntities = new ArrayList<>();
     resolvedEntities.add(
         new ResolvedPolarisEntity(passthroughResolver.getResolvedReferenceCatalog()));
-    resolvedPath.stream()
-        .forEach(cacheEntry -> resolvedEntities.add(new ResolvedPolarisEntity(cacheEntry)));
+    resolvedPath.forEach(cacheEntry -> resolvedEntities.add(new ResolvedPolarisEntity(cacheEntry)));
     LOG.debug("Returning resolvedEntities from getPassthroughResolvedPath: {}", resolvedEntities);
     return new PolarisResolvedPathWrapper(resolvedEntities);
   }
@@ -320,7 +319,7 @@ public PolarisEntitySubType getLeafSubType(Object key) {
         pathLookup);
     int index = pathLookup.get(key);
     List<EntityCacheEntry> resolved = primaryResolver.getResolvedPaths().get(index);
-    if (resolved.size() == 0) {
+    if (resolved.isEmpty()) {
       return PolarisEntitySubType.NULL_SUBTYPE;
     }
     return resolved.get(resolved.size() - 1).getEntity().getSubType();
@@ -360,8 +359,7 @@ public PolarisResolvedPathWrapper getResolvedPath(Object key, boolean prependRoo
       resolvedEntities.add(getResolvedRootContainerEntity());
     }
     resolvedEntities.add(new ResolvedPolarisEntity(primaryResolver.getResolvedReferenceCatalog()));
-    resolvedPath.stream()
-        .forEach(cacheEntry -> resolvedEntities.add(new ResolvedPolarisEntity(cacheEntry)));
+    resolvedPath.forEach(cacheEntry -> resolvedEntities.add(new ResolvedPolarisEntity(cacheEntry)));
     return new PolarisResolvedPathWrapper(resolvedEntities);
   }
 

polaris-core/src/main/java/io/polaris/core/persistence/resolver/ResolverPath.java

@@ -73,13 +73,11 @@ public boolean isOptional() {
 
   @Override
   public String toString() {
-    StringBuilder sb = new StringBuilder();
-    sb.append("entityNames:");
-    sb.append(entityNames.toString());
-    sb.append(";lastEntityType:");
-    sb.append(lastEntityType.toString());
-    sb.append(";isOptional:");
-    sb.append(isOptional);
-    return sb.toString();
+    return "entityNames:"
+        + entityNames.toString()
+        + ";lastEntityType:"
+        + lastEntityType.toString()
+        + ";isOptional:"
+        + isOptional;
   }
 }

polaris-core/src/main/java/io/polaris/core/persistence/resolver/ResolverStatus.java

@@ -37,7 +37,7 @@ public enum StatusEnum {
 
     // error, an entity could not be resolved
     ENTITY_COULD_NOT_BE_RESOLVED,
-  };
+  }
 
   private final StatusEnum status;
 

polaris-core/src/main/java/io/polaris/core/storage/aws/AwsStorageConfigurationInfo.java

@@ -33,7 +33,7 @@ public class AwsStorageConfigurationInfo extends PolarisStorageConfigurationInfo
   @JsonIgnore private static final int MAX_ALLOWED_LOCATIONS = 5;
 
   // Technically, it should be ^arn:(aws|aws-cn|aws-us-gov):iam::\d{12}:role/.+$,
-  @JsonIgnore public static String ROLE_ARN_PATTERN = "^arn:aws:iam::\\d{12}:role/.+$";
+  @JsonIgnore public static final String ROLE_ARN_PATTERN = "^arn:aws:iam::\\d{12}:role/.+$";
 
   // AWS role to be assumed
   private final @NotNull String roleARN;

polaris-core/src/main/java/io/polaris/core/storage/aws/PolarisS3FileIOClientFactory.java

@@ -54,10 +54,9 @@ public S3Client s3() {
         .applyMutation(s3FileIOProperties::applyEndpointConfigurations)
         .applyMutation(s3FileIOProperties::applyServiceConfigurations)
         .applyMutation(
-            s3ClientBuilder -> {
-              s3FileIOProperties.applyCredentialConfigurations(
-                  awsClientProperties, s3ClientBuilder);
-            })
+            s3ClientBuilder ->
+                s3FileIOProperties.applyCredentialConfigurations(
+                    awsClientProperties, s3ClientBuilder))
         .applyMutation(s3FileIOProperties::applySignerConfiguration)
         .applyMutation(s3FileIOProperties::applyS3AccessGrantsConfigurations)
         .applyMutation(s3ClientBuilder -> s3ClientBuilder.crossRegionAccessEnabled(true))