Mostly migrate off jsr305.

- Mostly migrate to Checker Framework declaration annotations.
- Migrate @GuardedBy to a custom annotation for now. (We would migrate to Error Prone's, but that's causing me problems as I experiment with JPMS.)

Compare to b/69411537 for Guava.

I've left @ParametersAreNonnullByDefault in place for now, but we'd need to remove it to fully eliminate the jsr305 dep.

RELNOTES=Migrated from jsr305 `@Nullable` to Checker Framework `@NullableDecl`. In addition to the new dependency on the Checker Framework annotations, we keep the dependency on jsr305 for now so that we can keep using `@ParametersAreNonNullByDefault`.

-------------
Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=272713254

jimfs/pom.xml

@@ -60,6 +60,11 @@
       <artifactId>jsr305</artifactId>
       <optional>true</optional>
     </dependency>
+    <dependency>
+      <groupId>org.checkerframework</groupId>
+      <artifactId>checker-compat-qual</artifactId>
+      <optional>true</optional>
+    </dependency>
 
     <!-- Test dependencies -->
     <dependency>

jimfs/src/main/java/com/google/common/jimfs/AbstractWatchService.java

@@ -41,7 +41,7 @@
 import java.util.concurrent.atomic.AtomicBoolean;
 import java.util.concurrent.atomic.AtomicInteger;
 import java.util.concurrent.atomic.AtomicReference;
-import javax.annotation.Nullable;
+import org.checkerframework.checker.nullness.compatqual.NullableDecl;
 
 /**
  * Abstract implementation of {@link WatchService}. Provides the means for registering and managing
@@ -90,14 +90,14 @@ ImmutableList<WatchKey> queuedKeys() {
     return ImmutableList.copyOf(queue);
   }
 
-  @Nullable
+  @NullableDecl
   @Override
   public WatchKey poll() {
     checkOpen();
     return check(queue.poll());
   }
 
-  @Nullable
+  @NullableDecl
   @Override
   public WatchKey poll(long timeout, TimeUnit unit) throws InterruptedException {
     checkOpen();
@@ -111,8 +111,8 @@ public WatchKey take() throws InterruptedException {
   }
 
   /** Returns the given key, throwing an exception if it's the poison. */
-  @Nullable
-  private WatchKey check(@Nullable WatchKey key) {
+  @NullableDecl
+  private WatchKey check(@NullableDecl WatchKey key) {
     if (key == poison) {
       // ensure other blocking threads get the poison
       queue.offer(poison);
@@ -142,9 +142,9 @@ static final class Event<T> implements WatchEvent<T> {
     private final Kind<T> kind;
     private final int count;
 
-    @Nullable private final T context;
+    @NullableDecl private final T context;
 
-    public Event(Kind<T> kind, int count, @Nullable T context) {
+    public Event(Kind<T> kind, int count, @NullableDecl T context) {
       this.kind = checkNotNull(kind);
       checkArgument(count >= 0, "count (%s) must be non-negative", count);
       this.count = count;
@@ -161,7 +161,7 @@ public int count() {
       return count;
     }
 
-    @Nullable
+    @NullableDecl
     @Override
     public T context() {
       return context;
@@ -214,7 +214,7 @@ private static WatchEvent<Object> overflowEvent(int count) {
 
     public Key(
         AbstractWatchService watcher,
-        @Nullable Watchable watchable,
+        @NullableDecl Watchable watchable,
         Iterable<? extends WatchEvent.Kind<?>> subscribedTypes) {
       this.watcher = checkNotNull(watcher);
       this.watchable = watchable; // nullable for Watcher poison

jimfs/src/main/java/com/google/common/jimfs/AclAttributeProvider.java

@@ -29,7 +29,7 @@
 import java.nio.file.attribute.UserPrincipal;
 import java.util.List;
 import java.util.Map;
-import javax.annotation.Nullable;
+import org.checkerframework.checker.nullness.compatqual.NullableDecl;
 
 /**
  * Attribute provider that provides the {@link AclFileAttributeView} ("acl").
@@ -71,7 +71,7 @@ public ImmutableSet<String> fixedAttributes() {
     return ImmutableMap.of("acl:acl", acl);
   }
 
-  @Nullable
+  @NullableDecl
   @Override
   public Object get(File file, String attribute) {
     if (attribute.equals("acl")) {

jimfs/src/main/java/com/google/common/jimfs/AttributeProvider.java

@@ -24,7 +24,7 @@
 import java.nio.file.attribute.FileAttributeView;
 import java.util.Arrays;
 import java.util.Map;
-import javax.annotation.Nullable;
+import org.checkerframework.checker.nullness.compatqual.NullableDecl;
 
 /**
  * Abstract provider for handling a specific file attribute view.
@@ -87,7 +87,7 @@ public ImmutableSet<String> attributes(File file) {
    * Returns the value of the given attribute in the given file or null if the attribute is not
    * supported by this provider.
    */
-  @Nullable
+  @NullableDecl
   public abstract Object get(File file, String attribute);
 
   /**
@@ -108,7 +108,7 @@ public ImmutableSet<String> attributes(File file) {
    * Returns the type of file attributes object this provider supports, or null if it doesn't
    * support reading its attributes as an object.
    */
-  @Nullable
+  @NullableDecl
   public Class<? extends BasicFileAttributes> attributesType() {
     return null;
   }

jimfs/src/main/java/com/google/common/jimfs/AttributeService.java

@@ -36,7 +36,7 @@
 import java.util.List;
 import java.util.Map;
 import java.util.Set;
-import javax.annotation.Nullable;
+import org.checkerframework.checker.nullness.compatqual.NullableDecl;
 
 /**
  * Service providing all attribute related operations for a file store. One piece of the file store
@@ -204,7 +204,7 @@ public Object getAttribute(File file, String view, String attribute) {
     return value;
   }
 
-  @Nullable
+  @NullableDecl
   private Object getAttributeInternal(File file, String view, String attribute) {
     AttributeProvider provider = providersByName.get(view);
     if (provider == null) {
@@ -259,7 +259,7 @@ private void setAttributeInternal(
    * if the view type is not supported.
    */
   @SuppressWarnings("unchecked")
-  @Nullable
+  @NullableDecl
   public <V extends FileAttributeView> V getFileAttributeView(FileLookup lookup, Class<V> type) {
     AttributeProvider provider = providersByViewType.get(type);
 

jimfs/src/main/java/com/google/common/jimfs/BasicAttributeProvider.java

@@ -23,7 +23,7 @@
 import java.nio.file.attribute.BasicFileAttributes;
 import java.nio.file.attribute.FileAttributeView;
 import java.nio.file.attribute.FileTime;
-import javax.annotation.Nullable;
+import org.checkerframework.checker.nullness.compatqual.NullableDecl;
 
 /**
  * Attribute provider that provides attributes common to all file systems, the {@link
@@ -148,9 +148,9 @@ public BasicFileAttributes readAttributes() throws IOException {
 
     @Override
     public void setTimes(
-        @Nullable FileTime lastModifiedTime,
-        @Nullable FileTime lastAccessTime,
-        @Nullable FileTime createTime)
+        @NullableDecl FileTime lastModifiedTime,
+        @NullableDecl FileTime lastAccessTime,
+        @NullableDecl FileTime createTime)
         throws IOException {
       File file = lookupFile();
 

jimfs/src/main/java/com/google/common/jimfs/Configuration.java

@@ -44,7 +44,7 @@
 import java.util.Map;
 import java.util.Set;
 import java.util.regex.Pattern;
-import javax.annotation.Nullable;
+import org.checkerframework.checker.nullness.compatqual.NullableDecl;
 
 /**
  * Immutable configuration for an in-memory file system. A {@code Configuration} is passed to a
@@ -434,7 +434,7 @@ private ImmutableSet<PathNormalization> checkNormalizations(
     }
 
     private static void checkNormalizationNotSet(
-        PathNormalization n, @Nullable PathNormalization set) {
+        PathNormalization n, @NullableDecl PathNormalization set) {
       if (set != null) {
         throw new IllegalArgumentException(
             "can't set normalization " + n + ": normalization " + set + " already set");

jimfs/src/main/java/com/google/common/jimfs/Directory.java

@@ -20,7 +20,7 @@
 import com.google.common.collect.AbstractIterator;
 import com.google.common.collect.ImmutableSortedSet;
 import java.util.Iterator;
-import javax.annotation.Nullable;
+import org.checkerframework.checker.nullness.compatqual.NullableDecl;
 
 /**
  * A table of {@linkplain DirectoryEntry directory entries}.
@@ -103,7 +103,7 @@ public boolean isEmpty() {
   }
 
   /** Returns the entry for the given name in this table or null if no such entry exists. */
-  @Nullable
+  @NullableDecl
   public DirectoryEntry get(Name name) {
     int index = bucketIndex(name, table.length);
 
@@ -334,7 +334,7 @@ DirectoryEntry remove(Name name) {
   public Iterator<DirectoryEntry> iterator() {
     return new AbstractIterator<DirectoryEntry>() {
       int index;
-      @Nullable DirectoryEntry entry;
+      @NullableDecl DirectoryEntry entry;
 
       @Override
       protected DirectoryEntry computeNext() {

jimfs/src/main/java/com/google/common/jimfs/DirectoryEntry.java

@@ -26,7 +26,7 @@
 import java.nio.file.NotLinkException;
 import java.nio.file.Path;
 import java.util.Objects;
-import javax.annotation.Nullable;
+import org.checkerframework.checker.nullness.compatqual.NullableDecl;
 
 /**
  * Entry in a directory, containing references to the directory itself, the file the entry links to
@@ -40,11 +40,11 @@ final class DirectoryEntry {
   private final Directory directory;
   private final Name name;
 
-  @Nullable private final File file;
+  @NullableDecl private final File file;
 
-  @Nullable DirectoryEntry next; // for use in Directory
+  @NullableDecl DirectoryEntry next; // for use in Directory
 
-  DirectoryEntry(Directory directory, Name name, @Nullable File file) {
+  DirectoryEntry(Directory directory, Name name, @NullableDecl File file) {
     this.directory = checkNotNull(directory);
     this.name = checkNotNull(name);
     this.file = file;
@@ -135,7 +135,7 @@ public File file() {
   }
 
   /** Returns the file this entry links to or {@code null} if the file does not exist */
-  @Nullable
+  @NullableDecl
   public File fileOrNull() {
     return file;
   }

jimfs/src/main/java/com/google/common/jimfs/DosAttributeProvider.java

@@ -27,7 +27,7 @@
 import java.nio.file.attribute.FileAttributeView;
 import java.nio.file.attribute.FileTime;
 import java.util.Map;
-import javax.annotation.Nullable;
+import org.checkerframework.checker.nullness.compatqual.NullableDecl;
 
 /**
  * Attribute provider that provides the {@link DosFileAttributeView} ("dos") and allows the reading
@@ -75,7 +75,7 @@ private static Boolean getDefaultValue(String attribute, Map<String, ?> userProv
     return false;
   }
 
-  @Nullable
+  @NullableDecl
   @Override
   public Object get(File file, String attribute) {
     if (ATTRIBUTES.contains(attribute)) {

jimfs/src/main/java/com/google/common/jimfs/File.java

@@ -25,7 +25,7 @@
 import com.google.common.collect.Table;
 import java.io.IOException;
 import java.util.concurrent.locks.ReadWriteLock;
-import javax.annotation.Nullable;
+import org.checkerframework.checker.nullness.compatqual.NullableDecl;
 
 /**
  * A file object, containing both the file's metadata and content.
@@ -42,7 +42,7 @@ public abstract class File {
   private long lastAccessTime;
   private long lastModifiedTime;
 
-  @Nullable // null when only the basic view is used (default)
+  @NullableDecl // null when only the basic view is used (default)
   private Table<String, String, Object> attributes;
 
   File(int id) {
@@ -102,7 +102,7 @@ void copyContentTo(File file) throws IOException {}
    * Returns the read-write lock for this file's content, or {@code null} if there is no content
    * lock.
    */
-  @Nullable
+  @NullableDecl
   ReadWriteLock contentLock() {
     return null;
   }
@@ -223,7 +223,7 @@ final synchronized ImmutableSet<String> getAttributeKeys() {
   }
 
   /** Gets the value of the given attribute in the given view. */
-  @Nullable
+  @NullableDecl
   public final synchronized Object getAttribute(String view, String attribute) {
     if (attributes == null) {
       return null;
@@ -264,7 +264,7 @@ final synchronized void copyAttributes(File target) {
     target.putAll(attributes);
   }
 
-  private synchronized void putAll(@Nullable Table<String, String, Object> attributes) {
+  private synchronized void putAll(@NullableDecl Table<String, String, Object> attributes) {
     if (attributes != null && this.attributes != attributes) {
       if (this.attributes == null) {
         this.attributes = HashBasedTable.create();

jimfs/src/main/java/com/google/common/jimfs/FileSystemView.java

@@ -48,7 +48,7 @@
 import java.util.Set;
 import java.util.concurrent.locks.Lock;
 import java.util.concurrent.locks.ReadWriteLock;
-import javax.annotation.Nullable;
+import org.checkerframework.checker.nullness.compatqual.NullableDecl;
 
 /**
  * View of a file system with a specific working directory. As all file system operations need to
@@ -305,7 +305,7 @@ public RegularFile getOrCreateRegularFile(
    * Looks up the regular file at the given path, throwing an exception if the file isn't a regular
    * file. Returns null if the file did not exist.
    */
-  @Nullable
+  @NullableDecl
   private RegularFile lookUpRegularFile(JimfsPath path, Set<OpenOption> options)
       throws IOException {
     store.readLock().lock();
@@ -692,13 +692,13 @@ private void unlockSourceAndCopy(File sourceFile, File copyFile) {
   }
 
   /** Returns a file attribute view using the given lookup callback. */
-  @Nullable
+  @NullableDecl
   public <V extends FileAttributeView> V getFileAttributeView(FileLookup lookup, Class<V> type) {
     return store.getFileAttributeView(lookup, type);
   }
 
   /** Returns a file attribute view for the given path in this view. */
-  @Nullable
+  @NullableDecl
   public <V extends FileAttributeView> V getFileAttributeView(
       final JimfsPath path, Class<V> type, final Set<? super LinkOption> options) {
     return store.getFileAttributeView(