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

39 files changed, 164 insertions, 119 deletions

diff --git a/jimfs/pom.xml b/jimfs/pom.xml
index d6a4d9d..85bd173 100644
--- a/jimfs/pom.xml
+++ b/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>
diff --git a/jimfs/src/main/java/com/google/common/jimfs/AbstractWatchService.java b/jimfs/src/main/java/com/google/common/jimfs/AbstractWatchService.java
index 46822da..6b4326d 100644
--- a/jimfs/src/main/java/com/google/common/jimfs/AbstractWatchService.java
+++ b/jimfs/src/main/java/com/google/common/jimfs/AbstractWatchService.java
@@ -41,7 +41,7 @@ import java.util.concurrent.TimeUnit;
 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 @@ abstract class AbstractWatchService implements WatchService {
     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 @@ abstract class AbstractWatchService implements WatchService {
   }
 
   /** 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 @@ abstract class AbstractWatchService implements WatchService {
     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 @@ abstract class AbstractWatchService implements WatchService {
       return count;
     }
 
-    @Nullable
+    @NullableDecl
     @Override
     public T context() {
       return context;
@@ -214,7 +214,7 @@ abstract class AbstractWatchService implements WatchService {
 
     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
diff --git a/jimfs/src/main/java/com/google/common/jimfs/AclAttributeProvider.java b/jimfs/src/main/java/com/google/common/jimfs/AclAttributeProvider.java
index 7a36a6d..1fa0f15 100644
--- a/jimfs/src/main/java/com/google/common/jimfs/AclAttributeProvider.java
+++ b/jimfs/src/main/java/com/google/common/jimfs/AclAttributeProvider.java
@@ -29,7 +29,7 @@ import java.nio.file.attribute.FileOwnerAttributeView;
 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 @@ final class AclAttributeProvider extends AttributeProvider {
     return ImmutableMap.of("acl:acl", acl);
   }
 
-  @Nullable
+  @NullableDecl
   @Override
   public Object get(File file, String attribute) {
     if (attribute.equals("acl")) {
diff --git a/jimfs/src/main/java/com/google/common/jimfs/AttributeProvider.java b/jimfs/src/main/java/com/google/common/jimfs/AttributeProvider.java
index 249602b..f5cade2 100644
--- a/jimfs/src/main/java/com/google/common/jimfs/AttributeProvider.java
+++ b/jimfs/src/main/java/com/google/common/jimfs/AttributeProvider.java
@@ -24,7 +24,7 @@ import java.nio.file.attribute.BasicFileAttributes;
 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 abstract class AttributeProvider {
    * 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 abstract class AttributeProvider {
    * 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;
   }
diff --git a/jimfs/src/main/java/com/google/common/jimfs/AttributeService.java b/jimfs/src/main/java/com/google/common/jimfs/AttributeService.java
index 5081ede..f3670fb 100644
--- a/jimfs/src/main/java/com/google/common/jimfs/AttributeService.java
+++ b/jimfs/src/main/java/com/google/common/jimfs/AttributeService.java
@@ -36,7 +36,7 @@ import java.util.HashSet;
 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 @@ final class AttributeService {
     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 @@ final class AttributeService {
    * 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);
 
diff --git a/jimfs/src/main/java/com/google/common/jimfs/BasicAttributeProvider.java b/jimfs/src/main/java/com/google/common/jimfs/BasicAttributeProvider.java
index 0d62fdb..6315ab7 100644
--- a/jimfs/src/main/java/com/google/common/jimfs/BasicAttributeProvider.java
+++ b/jimfs/src/main/java/com/google/common/jimfs/BasicAttributeProvider.java
@@ -23,7 +23,7 @@ import java.nio.file.attribute.BasicFileAttributeView;
 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 @@ final class BasicAttributeProvider extends AttributeProvider {
 
     @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();
 
diff --git a/jimfs/src/main/java/com/google/common/jimfs/Configuration.java b/jimfs/src/main/java/com/google/common/jimfs/Configuration.java
index b7ef047..06630eb 100644
--- a/jimfs/src/main/java/com/google/common/jimfs/Configuration.java
+++ b/jimfs/src/main/java/com/google/common/jimfs/Configuration.java
@@ -44,7 +44,7 @@ import java.util.List;
 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 @@ public final class Configuration {
     }
 
     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");
diff --git a/jimfs/src/main/java/com/google/common/jimfs/Directory.java b/jimfs/src/main/java/com/google/common/jimfs/Directory.java
index 5744859..d1a1ebe 100644
--- a/jimfs/src/main/java/com/google/common/jimfs/Directory.java
+++ b/jimfs/src/main/java/com/google/common/jimfs/Directory.java
@@ -20,7 +20,7 @@ import com.google.common.annotations.VisibleForTesting;
 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 @@ final class Directory extends File implements Iterable<DirectoryEntry> {
   }
 
   /** 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 @@ final class Directory extends File implements Iterable<DirectoryEntry> {
   public Iterator<DirectoryEntry> iterator() {
     return new AbstractIterator<DirectoryEntry>() {
       int index;
-      @Nullable DirectoryEntry entry;
+      @NullableDecl DirectoryEntry entry;
 
       @Override
       protected DirectoryEntry computeNext() {
diff --git a/jimfs/src/main/java/com/google/common/jimfs/DirectoryEntry.java b/jimfs/src/main/java/com/google/common/jimfs/DirectoryEntry.java
index ad609e8..5bff50f 100644
--- a/jimfs/src/main/java/com/google/common/jimfs/DirectoryEntry.java
+++ b/jimfs/src/main/java/com/google/common/jimfs/DirectoryEntry.java
@@ -26,7 +26,7 @@ import java.nio.file.NotDirectoryException;
 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 @@ final class DirectoryEntry {
   }
 
   /** Returns the file this entry links to or {@code null} if the file does not exist */
-  @Nullable
+  @NullableDecl
   public File fileOrNull() {
     return file;
   }
diff --git a/jimfs/src/main/java/com/google/common/jimfs/DosAttributeProvider.java b/jimfs/src/main/java/com/google/common/jimfs/DosAttributeProvider.java
index cfada16..51bf96b 100644
--- a/jimfs/src/main/java/com/google/common/jimfs/DosAttributeProvider.java
+++ b/jimfs/src/main/java/com/google/common/jimfs/DosAttributeProvider.java
@@ -27,7 +27,7 @@ import java.nio.file.attribute.DosFileAttributes;
 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 @@ final class DosAttributeProvider extends AttributeProvider {
     return false;
   }
 
-  @Nullable
+  @NullableDecl
   @Override
   public Object get(File file, String attribute) {
     if (ATTRIBUTES.contains(attribute)) {
diff --git a/jimfs/src/main/java/com/google/common/jimfs/File.java b/jimfs/src/main/java/com/google/common/jimfs/File.java
index d23aa98..ce1cc00 100644
--- a/jimfs/src/main/java/com/google/common/jimfs/File.java
+++ b/jimfs/src/main/java/com/google/common/jimfs/File.java
@@ -25,7 +25,7 @@ import com.google.common.collect.ImmutableSet;
 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 @@ public abstract class File {
    * 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 @@ public abstract class File {
   }
 
   /** 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 @@ public abstract class File {
     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();
diff --git a/jimfs/src/main/java/com/google/common/jimfs/FileSystemView.java b/jimfs/src/main/java/com/google/common/jimfs/FileSystemView.java
index c9ff245..62e8739 100644
--- a/jimfs/src/main/java/com/google/common/jimfs/FileSystemView.java
+++ b/jimfs/src/main/java/com/google/common/jimfs/FileSystemView.java
@@ -48,7 +48,7 @@ import java.util.Objects;
 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 @@ final class FileSystemView {
    * 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 @@ final class FileSystemView {
   }
 
   /** 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(
diff --git a/jimfs/src/main/java/com/google/common/jimfs/FileTree.java b/jimfs/src/main/java/com/google/common/jimfs/FileTree.java
index 71beb0e..93df55f 100644
--- a/jimfs/src/main/java/com/google/common/jimfs/FileTree.java
+++ b/jimfs/src/main/java/com/google/common/jimfs/FileTree.java
@@ -27,7 +27,7 @@ import java.nio.file.NoSuchFileException;
 import java.util.Iterator;
 import java.util.Map;
 import java.util.Set;
-import javax.annotation.Nullable;
+import org.checkerframework.checker.nullness.compatqual.NullableDecl;
 
 /**
  * The tree of directories and files for the file system. Contains the file system root directories
@@ -63,7 +63,7 @@ final class FileTree {
    * Gets the directory entry for the root with the given name or {@code null} if no such root
    * exists.
    */
-  @Nullable
+  @NullableDecl
   public DirectoryEntry getRoot(Name name) {
     Directory dir = roots.get(name);
     return dir == null ? null : dir.entryInParent();
@@ -83,7 +83,7 @@ final class FileTree {
     return result;
   }
 
-  @Nullable
+  @NullableDecl
   private DirectoryEntry lookUp(
       File dir, JimfsPath path, Set<? super LinkOption> options, int linkDepth) throws IOException {
     ImmutableList<Name> names = path.names();
@@ -114,7 +114,7 @@ final class FileTree {
    * Looks up the given names against the given base file. If the file is not a directory, the
    * lookup fails.
    */
-  @Nullable
+  @NullableDecl
   private DirectoryEntry lookUp(
       File dir, Iterable<Name> names, Set<? super LinkOption> options, int linkDepth)
       throws IOException {
@@ -151,9 +151,9 @@ final class FileTree {
   }
 
   /** Looks up the last element of a path. */
-  @Nullable
+  @NullableDecl
   private DirectoryEntry lookUpLast(
-      @Nullable File dir, Name name, Set<? super LinkOption> options, int linkDepth)
+      @NullableDecl File dir, Name name, Set<? super LinkOption> options, int linkDepth)
       throws IOException {
     Directory directory = toDirectory(dir);
     if (directory == null) {
@@ -177,7 +177,7 @@ final class FileTree {
    * Returns the directory entry located by the target path of the given symbolic link, resolved
    * relative to the given directory.
    */
-  @Nullable
+  @NullableDecl
   private DirectoryEntry followSymbolicLink(File dir, SymbolicLink link, int linkDepth)
       throws IOException {
     if (linkDepth >= MAX_SYMBOLIC_LINK_DEPTH) {
@@ -196,7 +196,7 @@ final class FileTree {
    * we find an entry [bar -> "." -> bar], we instead return the entry for bar in its parent, [foo
    * -> "bar" -> bar].
    */
-  @Nullable
+  @NullableDecl
   private DirectoryEntry getRealEntry(DirectoryEntry entry) {
     Name name = entry.name();
 
@@ -209,8 +209,8 @@ final class FileTree {
     }
   }
 
-  @Nullable
-  private Directory toDirectory(@Nullable File file) {
+  @NullableDecl
+  private Directory toDirectory(@NullableDecl File file) {
     return file == null || !file.isDirectory() ? null : (Directory) file;
   }
 
diff --git a/jimfs/src/main/java/com/google/common/jimfs/GuardedBy.java b/jimfs/src/main/java/com/google/common/jimfs/GuardedBy.java
new file mode 100644
index 0000000..a653736
--- /dev/null
+++ b/jimfs/src/main/java/com/google/common/jimfs/GuardedBy.java
@@ -0,0 +1,36 @@
+/*
+ * Copyright 2017 The Error Prone Authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.google.common.jimfs;
+
+import static java.lang.annotation.ElementType.FIELD;
+import static java.lang.annotation.ElementType.METHOD;
+import static java.lang.annotation.RetentionPolicy.CLASS;
+
+import java.lang.annotation.Retention;
+import java.lang.annotation.Target;
+
+// TODO(cpovirk): Delete this in favor of the copy in Error Prone once that has a module name.
+/** Indicates that the annotated element should be used only while holding the specified lock. */
+@Target({FIELD, METHOD})
+@Retention(CLASS)
+@interface GuardedBy {
+  /**
+   * The lock that should be held, specified in the format <a
+   * href="http://jcip.net/annotations/doc/net/jcip/annotations/GuardedBy.html">given in Java
+   * Concurrency in Practice</a>.
+   */
+  String value();
+}
diff --git a/jimfs/src/main/java/com/google/common/jimfs/Jimfs.java b/jimfs/src/main/java/com/google/common/jimfs/Jimfs.java
index 1a69125..a04ce46 100644
--- a/jimfs/src/main/java/com/google/common/jimfs/Jimfs.java
+++ b/jimfs/src/main/java/com/google/common/jimfs/Jimfs.java
@@ -33,7 +33,7 @@ import java.util.ServiceLoader;
 import java.util.UUID;
 import java.util.logging.Level;
 import java.util.logging.Logger;
-import javax.annotation.Nullable;
+import org.checkerframework.checker.nullness.compatqual.NullableDecl;
 
 /**
  * Static factory methods for creating new Jimfs file systems. File systems may either be created
@@ -174,7 +174,7 @@ public final class Jimfs {
    * The system-loaded instance of {@code SystemJimfsFileSystemProvider}, or {@code null} if it
    * could not be found or loaded.
    */
-  @Nullable static final FileSystemProvider systemProvider = getSystemJimfsProvider();
+  @NullableDecl static final FileSystemProvider systemProvider = getSystemJimfsProvider();
 
   /**
    * Returns the system-loaded instance of {@code SystemJimfsFileSystemProvider} or {@code null} if
@@ -188,7 +188,7 @@ public final class Jimfs {
    * same class loader) as the class whose static cache a {@code JimfsFileSystem} instance will be
    * placed in when {@code FileSystems.newFileSystem} is called in {@code Jimfs.newFileSystem}.
    */
-  @Nullable
+  @NullableDecl
   private static FileSystemProvider getSystemJimfsProvider() {
     try {
       for (FileSystemProvider provider : FileSystemProvider.installedProviders()) {
diff --git a/jimfs/src/main/java/com/google/common/jimfs/JimfsAsynchronousFileChannel.java b/jimfs/src/main/java/com/google/common/jimfs/JimfsAsynchronousFileChannel.java
index 9401b14..c59522c 100644
--- a/jimfs/src/main/java/com/google/common/jimfs/JimfsAsynchronousFileChannel.java
+++ b/jimfs/src/main/java/com/google/common/jimfs/JimfsAsynchronousFileChannel.java
@@ -32,7 +32,7 @@ import java.nio.channels.FileLock;
 import java.util.concurrent.Callable;
 import java.util.concurrent.ExecutionException;
 import java.util.concurrent.ExecutorService;
-import javax.annotation.Nullable;
+import org.checkerframework.checker.nullness.compatqual.NullableDecl;
 
 /**
  * {@link AsynchronousFileChannel} implementation that delegates to a {@link JimfsFileChannel}.
@@ -55,7 +55,9 @@ final class JimfsAsynchronousFileChannel extends AsynchronousFileChannel {
   }
 
   private <R, A> void addCallback(
-      ListenableFuture<R> future, CompletionHandler<R, ? super A> handler, @Nullable A attachment) {
+      ListenableFuture<R> future,
+      CompletionHandler<R, ? super A> handler,
+      @NullableDecl A attachment) {
     future.addListener(new CompletionHandlerCallback<>(future, handler, attachment), executor);
   }
 
@@ -75,7 +77,7 @@ final class JimfsAsynchronousFileChannel extends AsynchronousFileChannel {
       long position,
       long size,
       boolean shared,
-      @Nullable A attachment,
+      @NullableDecl A attachment,
       CompletionHandler<FileLock, ? super A> handler) {
     checkNotNull(handler);
     addCallback(lock(position, size, shared), handler, attachment);
@@ -120,7 +122,7 @@ final class JimfsAsynchronousFileChannel extends AsynchronousFileChannel {
   public <A> void read(
       ByteBuffer dst,
       long position,
-      @Nullable A attachment,
+      @NullableDecl A attachment,
       CompletionHandler<Integer, ? super A> handler) {
     addCallback(read(dst, position), handler, attachment);
   }
@@ -146,7 +148,7 @@ final class JimfsAsynchronousFileChannel extends AsynchronousFileChannel {
   public <A> void write(
       ByteBuffer src,
       long position,
-      @Nullable A attachment,
+      @NullableDecl A attachment,
       CompletionHandler<Integer, ? super A> handler) {
     addCallback(write(src, position), handler, attachment);
   }
@@ -189,12 +191,12 @@ final class JimfsAsynchronousFileChannel extends AsynchronousFileChannel {
 
     private final ListenableFuture<R> future;
     private final CompletionHandler<R, ? super A> completionHandler;
-    @Nullable private final A attachment;
+    @NullableDecl private final A attachment;
 
     private CompletionHandlerCallback(
         ListenableFuture<R> future,
         CompletionHandler<R, ? super A> completionHandler,
-        @Nullable A attachment) {
+        @NullableDecl A attachment) {
       this.future = checkNotNull(future);
       this.completionHandler = checkNotNull(completionHandler);
       this.attachment = attachment;
diff --git a/jimfs/src/main/java/com/google/common/jimfs/JimfsFileChannel.java b/jimfs/src/main/java/com/google/common/jimfs/JimfsFileChannel.java
index bd4e95b..2ba46fc 100644
--- a/jimfs/src/main/java/com/google/common/jimfs/JimfsFileChannel.java
+++ b/jimfs/src/main/java/com/google/common/jimfs/JimfsFileChannel.java
@@ -43,7 +43,6 @@ import java.util.List;
 import java.util.Set;
 import java.util.concurrent.ExecutorService;
 import java.util.concurrent.atomic.AtomicBoolean;
-import javax.annotation.concurrent.GuardedBy;
 
 /**
  * A {@link FileChannel} implementation that reads and writes to a {@link RegularFile} object. The
diff --git a/jimfs/src/main/java/com/google/common/jimfs/JimfsFileStore.java b/jimfs/src/main/java/com/google/common/jimfs/JimfsFileStore.java
index 6a99f29..910d231 100644
--- a/jimfs/src/main/java/com/google/common/jimfs/JimfsFileStore.java
+++ b/jimfs/src/main/java/com/google/common/jimfs/JimfsFileStore.java
@@ -34,7 +34,7 @@ import java.util.Set;
 import java.util.concurrent.locks.Lock;
 import java.util.concurrent.locks.ReadWriteLock;
 import java.util.concurrent.locks.ReentrantReadWriteLock;
-import javax.annotation.Nullable;
+import org.checkerframework.checker.nullness.compatqual.NullableDecl;
 
 /**
  * {@link FileStore} implementation which provides methods for file creation, lookup and attribute
@@ -102,7 +102,7 @@ final class JimfsFileStore extends FileStore {
   }
 
   /** Returns the root directory with the given name or {@code null} if no such directory exists. */
-  @Nullable
+  @NullableDecl
   Directory getRoot(Name name) {
     DirectoryEntry entry = tree.getRoot(name);
     return entry == null ? null : (Directory) entry.file();
@@ -170,7 +170,7 @@ final class JimfsFileStore extends FileStore {
    * Returns an attribute view of the given type for the given file lookup callback, or {@code null}
    * if the view type is not supported.
    */
-  @Nullable
+  @NullableDecl
   <V extends FileAttributeView> V getFileAttributeView(FileLookup lookup, Class<V> type) {
     state.checkOpen();
     return attributes.getFileAttributeView(lookup, type);
diff --git a/jimfs/src/main/java/com/google/common/jimfs/JimfsFileSystem.java b/jimfs/src/main/java/com/google/common/jimfs/JimfsFileSystem.java
index ce85b15..dd72146 100644
--- a/jimfs/src/main/java/com/google/common/jimfs/JimfsFileSystem.java
+++ b/jimfs/src/main/java/com/google/common/jimfs/JimfsFileSystem.java
@@ -33,7 +33,7 @@ import java.nio.file.WatchService;
 import java.nio.file.attribute.UserPrincipalLookupService;
 import java.util.concurrent.ExecutorService;
 import java.util.concurrent.Executors;
-import javax.annotation.Nullable;
+import org.checkerframework.checker.nullness.compatqual.NullableDecl;
 
 /**
  * {@link FileSystem} implementation for Jimfs. Most behavior for the file system is implemented by
@@ -285,7 +285,7 @@ final class JimfsFileSystem extends FileSystem {
     return watchServiceConfig.newWatchService(defaultView, pathService);
   }
 
-  @Nullable private ExecutorService defaultThreadPool;
+  @NullableDecl private ExecutorService defaultThreadPool;
 
   /**
    * Returns a default thread pool to use for asynchronous file channels when users do not provide
diff --git a/jimfs/src/main/java/com/google/common/jimfs/JimfsFileSystemProvider.java b/jimfs/src/main/java/com/google/common/jimfs/JimfsFileSystemProvider.java
index 235be80..9b32bd7 100644
--- a/jimfs/src/main/java/com/google/common/jimfs/JimfsFileSystemProvider.java
+++ b/jimfs/src/main/java/com/google/common/jimfs/JimfsFileSystemProvider.java
@@ -48,7 +48,7 @@ import java.nio.file.spi.FileSystemProvider;
 import java.util.Map;
 import java.util.Set;
 import java.util.concurrent.ExecutorService;
-import javax.annotation.Nullable;
+import org.checkerframework.checker.nullness.compatqual.NullableDecl;
 
 /**
  * {@link FileSystemProvider} implementation for Jimfs. This provider implements the actual file
@@ -170,7 +170,7 @@ final class JimfsFileSystemProvider extends FileSystemProvider {
   public AsynchronousFileChannel newAsynchronousFileChannel(
       Path path,
       Set<? extends OpenOption> options,
-      @Nullable ExecutorService executor,
+      @NullableDecl ExecutorService executor,
       FileAttribute<?>... attrs)
       throws IOException {
     // call newFileChannel and cast so that FileChannel support is checked there
@@ -320,7 +320,7 @@ final class JimfsFileSystemProvider extends FileSystemProvider {
     getDefaultView(checkedPath).checkAccess(checkedPath);
   }
 
-  @Nullable
+  @NullableDecl
   @Override
   public <V extends FileAttributeView> V getFileAttributeView(
       Path path, Class<V> type, LinkOption... options) {
diff --git a/jimfs/src/main/java/com/google/common/jimfs/JimfsInputStream.java b/jimfs/src/main/java/com/google/common/jimfs/JimfsInputStream.java
index 5268573..750530c 100644
--- a/jimfs/src/main/java/com/google/common/jimfs/JimfsInputStream.java
+++ b/jimfs/src/main/java/com/google/common/jimfs/JimfsInputStream.java
@@ -23,7 +23,6 @@ import com.google.common.annotations.VisibleForTesting;
 import com.google.common.primitives.Ints;
 import java.io.IOException;
 import java.io.InputStream;
-import javax.annotation.concurrent.GuardedBy;
 
 /**
  * {@link InputStream} for reading from a file's {@link RegularFile}.
diff --git a/jimfs/src/main/java/com/google/common/jimfs/JimfsOutputStream.java b/jimfs/src/main/java/com/google/common/jimfs/JimfsOutputStream.java
index 5beffb1..0b88046 100644
--- a/jimfs/src/main/java/com/google/common/jimfs/JimfsOutputStream.java
+++ b/jimfs/src/main/java/com/google/common/jimfs/JimfsOutputStream.java
@@ -22,7 +22,6 @@ import static com.google.common.base.Preconditions.checkPositionIndexes;
 import com.google.common.annotations.VisibleForTesting;
 import java.io.IOException;
 import java.io.OutputStream;
-import javax.annotation.concurrent.GuardedBy;
 
 /**
  * {@link OutputStream} for writing to a {@link RegularFile}.
diff --git a/jimfs/src/main/java/com/google/common/jimfs/JimfsPath.java b/jimfs/src/main/java/com/google/common/jimfs/JimfsPath.java
index 9db767c..7c6b115 100644
--- a/jimfs/src/main/java/com/google/common/jimfs/JimfsPath.java
+++ b/jimfs/src/main/java/com/google/common/jimfs/JimfsPath.java
@@ -41,7 +41,7 @@ import java.util.Deque;
 import java.util.Iterator;
 import java.util.List;
 import java.util.Objects;
-import javax.annotation.Nullable;
+import org.checkerframework.checker.nullness.compatqual.NullableDecl;
 
 /**
  * Jimfs implementation of {@link Path}. Creation of new {@code Path} objects is delegated to the
@@ -51,18 +51,18 @@ import javax.annotation.Nullable;
  */
 final class JimfsPath implements Path {
 
-  @Nullable private final Name root;
+  @NullableDecl private final Name root;
   private final ImmutableList<Name> names;
   private final PathService pathService;
 
-  public JimfsPath(PathService pathService, @Nullable Name root, Iterable<Name> names) {
+  public JimfsPath(PathService pathService, @NullableDecl Name root, Iterable<Name> names) {
     this.pathService = checkNotNull(pathService);
     this.root = root;
     this.names = ImmutableList.copyOf(names);
   }
 
   /** Returns the root name, or null if there is no root. */
-  @Nullable
+  @NullableDecl
   public Name root() {
     return root;
   }
@@ -76,7 +76,7 @@ final class JimfsPath implements Path {
    * Returns the file name of this path. Unlike {@link #getFileName()}, this may return the name of
    * the root if this is a root path.
    */
-  @Nullable
+  @NullableDecl
   public Name name() {
     if (!names.isEmpty()) {
       return Iterables.getLast(names);
@@ -421,7 +421,7 @@ final class JimfsPath implements Path {
   }
 
   @Override
-  public boolean equals(@Nullable Object obj) {
+  public boolean equals(@NullableDecl Object obj) {
     return obj instanceof JimfsPath && compareTo((JimfsPath) obj) == 0;
   }
 
@@ -435,7 +435,7 @@ final class JimfsPath implements Path {
     return pathService.toString(this);
   }
 
-  @Nullable
+  @NullableDecl
   private JimfsPath checkPath(Path other) {
     if (checkNotNull(other) instanceof JimfsPath && other.getFileSystem().equals(getFileSystem())) {
       return (JimfsPath) other;
diff --git a/jimfs/src/main/java/com/google/common/jimfs/JimfsSecureDirectoryStream.java b/jimfs/src/main/java/com/google/common/jimfs/JimfsSecureDirectoryStream.java
index 81c15d7..e3391b6 100644
--- a/jimfs/src/main/java/com/google/common/jimfs/JimfsSecureDirectoryStream.java
+++ b/jimfs/src/main/java/com/google/common/jimfs/JimfsSecureDirectoryStream.java
@@ -35,7 +35,7 @@ import java.nio.file.attribute.FileAttribute;
 import java.nio.file.attribute.FileAttributeView;
 import java.util.Iterator;
 import java.util.Set;
-import javax.annotation.Nullable;
+import org.checkerframework.checker.nullness.compatqual.NullableDecl;
 
 /**
  * Secure directory stream implementation that uses a {@link FileSystemView} with the stream's
@@ -87,7 +87,7 @@ final class JimfsSecureDirectoryStream implements SecureDirectoryStream<Path> {
 
   private final class DirectoryIterator extends AbstractIterator<Path> {
 
-    @Nullable private Iterator<Name> fileNames;
+    @NullableDecl private Iterator<Name> fileNames;
 
     @Override
     protected synchronized Path computeNext() {
diff --git a/jimfs/src/main/java/com/google/common/jimfs/Name.java b/jimfs/src/main/java/com/google/common/jimfs/Name.java
index 6ff13ea..327be75 100644
--- a/jimfs/src/main/java/com/google/common/jimfs/Name.java
+++ b/jimfs/src/main/java/com/google/common/jimfs/Name.java
@@ -21,7 +21,7 @@ import static com.google.common.base.Preconditions.checkNotNull;
 import com.google.common.annotations.VisibleForTesting;
 import com.google.common.base.Function;
 import com.google.common.collect.Ordering;
-import javax.annotation.Nullable;
+import org.checkerframework.checker.nullness.compatqual.NullableDecl;
 
 /**
  * Immutable representation of a file name. Used both for the name components of paths and as the
@@ -77,7 +77,7 @@ final class Name {
   }
 
   @Override
-  public boolean equals(@Nullable Object obj) {
+  public boolean equals(@NullableDecl Object obj) {
     if (obj instanceof Name) {
       Name other = (Name) obj;
       return canonical.equals(other.canonical);
diff --git a/jimfs/src/main/java/com/google/common/jimfs/OwnerAttributeProvider.java b/jimfs/src/main/java/com/google/common/jimfs/OwnerAttributeProvider.java
index d102746..3408639 100644
--- a/jimfs/src/main/java/com/google/common/jimfs/OwnerAttributeProvider.java
+++ b/jimfs/src/main/java/com/google/common/jimfs/OwnerAttributeProvider.java
@@ -26,7 +26,7 @@ import java.nio.file.attribute.FileAttributeView;
 import java.nio.file.attribute.FileOwnerAttributeView;
 import java.nio.file.attribute.UserPrincipal;
 import java.util.Map;
-import javax.annotation.Nullable;
+import org.checkerframework.checker.nullness.compatqual.NullableDecl;
 
 /**
  * Attribute provider that provides the {@link FileOwnerAttributeView} ("owner").
@@ -65,7 +65,7 @@ final class OwnerAttributeProvider extends AttributeProvider {
     return ImmutableMap.of("owner:owner", owner);
   }
 
-  @Nullable
+  @NullableDecl
   @Override
   public Object get(File file, String attribute) {
     if (attribute.equals("owner")) {
diff --git a/jimfs/src/main/java/com/google/common/jimfs/PathService.java b/jimfs/src/main/java/com/google/common/jimfs/PathService.java
index b81ebf5..39bac91 100644
--- a/jimfs/src/main/java/com/google/common/jimfs/PathService.java
+++ b/jimfs/src/main/java/com/google/common/jimfs/PathService.java
@@ -38,7 +38,7 @@ import java.nio.file.PathMatcher;
 import java.util.ArrayList;
 import java.util.Comparator;
 import java.util.List;
-import javax.annotation.Nullable;
+import org.checkerframework.checker.nullness.compatqual.NullableDecl;
 
 /**
  * Service for creating {@link JimfsPath} instances and handling other path-related operations.
@@ -162,7 +162,7 @@ final class PathService implements Comparator<JimfsPath> {
   }
 
   /** Returns a path with the given root (or no root, if null) and the given names. */
-  public JimfsPath createPath(@Nullable Name root, Iterable<Name> names) {
+  public JimfsPath createPath(@NullableDecl Name root, Iterable<Name> names) {
     ImmutableList<Name> nameList = ImmutableList.copyOf(Iterables.filter(names, NOT_EMPTY));
     if (root == null && nameList.isEmpty()) {
       // ensure the canonical empty path (one empty string name) is used rather than a path with
@@ -173,7 +173,7 @@ final class PathService implements Comparator<JimfsPath> {
   }
 
   /** Returns a path with the given root (or no root, if null) and the given names. */
-  protected final JimfsPath createPathInternal(@Nullable Name root, Iterable<Name> names) {
+  protected final JimfsPath createPathInternal(@NullableDecl Name root, Iterable<Name> names) {
     return new JimfsPath(this, root, names);
   }
 
diff --git a/jimfs/src/main/java/com/google/common/jimfs/PathType.java b/jimfs/src/main/java/com/google/common/jimfs/PathType.java
index f27e358..4e4d30e 100644
--- a/jimfs/src/main/java/com/google/common/jimfs/PathType.java
+++ b/jimfs/src/main/java/com/google/common/jimfs/PathType.java
@@ -26,7 +26,7 @@ import java.net.URI;
 import java.net.URISyntaxException;
 import java.nio.file.InvalidPathException;
 import java.util.Arrays;
-import javax.annotation.Nullable;
+import org.checkerframework.checker.nullness.compatqual.NullableDecl;
 
 /**
  * An object defining a specific type of path. Knows how to parse strings to a path and how to
@@ -164,7 +164,7 @@ public abstract class PathType {
   }
 
   /** Returns the string form of the given path. */
-  public abstract String toString(@Nullable String root, Iterable<String> names);
+  public abstract String toString(@NullableDecl String root, Iterable<String> names);
 
   /**
    * Returns the string form of the given path for use in the path part of a URI. The root element
@@ -211,10 +211,10 @@ public abstract class PathType {
   /** Simple result of parsing a path. */
   public static final class ParseResult {
 
-    @Nullable private final String root;
+    @NullableDecl private final String root;
     private final Iterable<String> names;
 
-    public ParseResult(@Nullable String root, Iterable<String> names) {
+    public ParseResult(@NullableDecl String root, Iterable<String> names) {
       this.root = root;
       this.names = checkNotNull(names);
     }
@@ -230,7 +230,7 @@ public abstract class PathType {
     }
 
     /** Returns the parsed root element, or null if there was no root. */
-    @Nullable
+    @NullableDecl
     public String root() {
       return root;
     }
diff --git a/jimfs/src/main/java/com/google/common/jimfs/PosixAttributeProvider.java b/jimfs/src/main/java/com/google/common/jimfs/PosixAttributeProvider.java
index bdb30c5..9dcd887 100644
--- a/jimfs/src/main/java/com/google/common/jimfs/PosixAttributeProvider.java
+++ b/jimfs/src/main/java/com/google/common/jimfs/PosixAttributeProvider.java
@@ -35,7 +35,7 @@ import java.nio.file.attribute.PosixFilePermissions;
 import java.nio.file.attribute.UserPrincipal;
 import java.util.Map;
 import java.util.Set;
-import javax.annotation.Nullable;
+import org.checkerframework.checker.nullness.compatqual.NullableDecl;
 
 /**
  * Attribute provider that provides the {@link PosixFileAttributeView} ("posix") and allows reading
@@ -114,7 +114,7 @@ final class PosixAttributeProvider extends AttributeProvider {
         "posix:permissions", permissions);
   }
 
-  @Nullable
+  @NullableDecl
   @Override
   public Object get(File file, String attribute) {
     switch (attribute) {
diff --git a/jimfs/src/main/java/com/google/common/jimfs/StandardAttributeProviders.java b/jimfs/src/main/java/com/google/common/jimfs/StandardAttributeProviders.java
index 8683913..973c6bb 100644
--- a/jimfs/src/main/java/com/google/common/jimfs/StandardAttributeProviders.java
+++ b/jimfs/src/main/java/com/google/common/jimfs/StandardAttributeProviders.java
@@ -17,7 +17,7 @@
 package com.google.common.jimfs;
 
 import com.google.common.collect.ImmutableMap;
-import javax.annotation.Nullable;
+import org.checkerframework.checker.nullness.compatqual.NullableDecl;
 
 /**
  * Static registry of {@link AttributeProvider} implementations for the standard set of file
@@ -43,7 +43,7 @@ final class StandardAttributeProviders {
    * Returns the attribute provider for the given view, or {@code null} if the given view is not one
    * of the attribute views this supports.
    */
-  @Nullable
+  @NullableDecl
   public static AttributeProvider get(String view) {
     AttributeProvider provider = PROVIDERS.get(view);
 
diff --git a/jimfs/src/main/java/com/google/common/jimfs/UnixPathType.java b/jimfs/src/main/java/com/google/common/jimfs/UnixPathType.java
index 126d8e1..76f1339 100644
--- a/jimfs/src/main/java/com/google/common/jimfs/UnixPathType.java
+++ b/jimfs/src/main/java/com/google/common/jimfs/UnixPathType.java
@@ -19,7 +19,7 @@ package com.google.common.jimfs;
 import static com.google.common.base.Preconditions.checkArgument;
 
 import java.nio.file.InvalidPathException;
-import javax.annotation.Nullable;
+import org.checkerframework.checker.nullness.compatqual.NullableDecl;
 
 /**
  * Unix-style path type.
@@ -55,7 +55,7 @@ final class UnixPathType extends PathType {
   }
 
   @Override
-  public String toString(@Nullable String root, Iterable<String> names) {
+  public String toString(@NullableDecl String root, Iterable<String> names) {
     StringBuilder builder = new StringBuilder();
     if (root != null) {
       builder.append(root);
diff --git a/jimfs/src/main/java/com/google/common/jimfs/WindowsPathType.java b/jimfs/src/main/java/com/google/common/jimfs/WindowsPathType.java
index 0e68b26..7cdf0c4 100644
--- a/jimfs/src/main/java/com/google/common/jimfs/WindowsPathType.java
+++ b/jimfs/src/main/java/com/google/common/jimfs/WindowsPathType.java
@@ -20,7 +20,7 @@ import java.nio.file.InvalidPathException;
 import java.util.Iterator;
 import java.util.regex.Matcher;
 import java.util.regex.Pattern;
-import javax.annotation.Nullable;
+import org.checkerframework.checker.nullness.compatqual.NullableDecl;
 
 /**
  * Windows-style path type.
@@ -134,7 +134,7 @@ final class WindowsPathType extends PathType {
   private static final Pattern DRIVE_LETTER_ROOT = Pattern.compile("^[a-zA-Z]:\\\\");
 
   /** Parses a normal drive-letter root, e.g. "C:\". */
-  @Nullable
+  @NullableDecl
   private String parseDriveRoot(String path) {
     Matcher drivePathMatcher = DRIVE_LETTER_ROOT.matcher(path);
     if (drivePathMatcher.find()) {
@@ -160,7 +160,7 @@ final class WindowsPathType extends PathType {
   }
 
   @Override
-  public String toString(@Nullable String root, Iterable<String> names) {
+  public String toString(@NullableDecl String root, Iterable<String> names) {
     StringBuilder builder = new StringBuilder();
     if (root != null) {
       builder.append(root);
diff --git a/jimfs/src/test/java/com/google/common/jimfs/AbstractPathMatcherTest.java b/jimfs/src/test/java/com/google/common/jimfs/AbstractPathMatcherTest.java
index 79b3946..70ac0e9 100644
--- a/jimfs/src/test/java/com/google/common/jimfs/AbstractPathMatcherTest.java
+++ b/jimfs/src/test/java/com/google/common/jimfs/AbstractPathMatcherTest.java
@@ -33,7 +33,7 @@ import java.nio.file.WatchKey;
 import java.nio.file.WatchService;
 import java.util.Iterator;
 import java.util.regex.PatternSyntaxException;
-import javax.annotation.Nullable;
+import org.checkerframework.checker.nullness.compatqual.NullableDecl;
 
 /**
  * Abstract base class for tests of {@link PathMatcher} implementations.
@@ -48,7 +48,7 @@ public abstract class AbstractPathMatcherTest {
   protected abstract PathMatcher matcher(String pattern);
 
   /** Override to return a real matcher for the given pattern. */
-  @Nullable
+  @NullableDecl
   protected PathMatcher realMatcher(String pattern) {
     return null;
   }
@@ -77,7 +77,7 @@ public abstract class AbstractPathMatcherTest {
 
     private final PathMatcher matcher;
 
-    @Nullable private final PathMatcher realMatcher;
+    @NullableDecl private final PathMatcher realMatcher;
 
     PatternAsserter(String pattern) {
       this.matcher = matcher(pattern);
diff --git a/jimfs/src/test/java/com/google/common/jimfs/DirectoryTest.java b/jimfs/src/test/java/com/google/common/jimfs/DirectoryTest.java
index 03f7f6a..217509d 100644
--- a/jimfs/src/test/java/com/google/common/jimfs/DirectoryTest.java
+++ b/jimfs/src/test/java/com/google/common/jimfs/DirectoryTest.java
@@ -28,7 +28,7 @@ import com.google.common.collect.ImmutableSortedSet;
 import com.google.common.collect.Iterables;
 import java.util.HashSet;
 import java.util.Set;
-import javax.annotation.Nullable;
+import org.checkerframework.checker.nullness.compatqual.NullableDecl;
 import org.junit.Before;
 import org.junit.Test;
 import org.junit.runner.RunWith;
@@ -365,7 +365,7 @@ public class DirectoryTest {
     return new DirectoryEntry(A, Name.simple(name), A);
   }
 
-  private static DirectoryEntry entry(Directory dir, String name, @Nullable File file) {
+  private static DirectoryEntry entry(Directory dir, String name, @NullableDecl File file) {
     return new DirectoryEntry(dir, Name.simple(name), file);
   }
 
diff --git a/jimfs/src/test/java/com/google/common/jimfs/FileTreeTest.java b/jimfs/src/test/java/com/google/common/jimfs/FileTreeTest.java
index 9390a5d..54f590d 100644
--- a/jimfs/src/test/java/com/google/common/jimfs/FileTreeTest.java
+++ b/jimfs/src/test/java/com/google/common/jimfs/FileTreeTest.java
@@ -31,7 +31,7 @@ import java.nio.file.NoSuchFileException;
 import java.util.HashMap;
 import java.util.Map;
 import java.util.Random;
-import javax.annotation.Nullable;
+import org.checkerframework.checker.nullness.compatqual.NullableDecl;
 import org.junit.Before;
 import org.junit.Test;
 import org.junit.runner.RunWith;
@@ -87,7 +87,7 @@ public class FileTreeTest {
             }
 
             @Override
-            public String toString(@Nullable String root, Iterable<String> names) {
+            public String toString(@NullableDecl String root, Iterable<String> names) {
               root = Strings.nullToEmpty(root);
               return root + Joiner.on('/').join(names);
             }
diff --git a/jimfs/src/test/java/com/google/common/jimfs/PathSubject.java b/jimfs/src/test/java/com/google/common/jimfs/PathSubject.java
index 5cbe3dd..f6927a5 100644
--- a/jimfs/src/test/java/com/google/common/jimfs/PathSubject.java
+++ b/jimfs/src/test/java/com/google/common/jimfs/PathSubject.java
@@ -36,7 +36,7 @@ import java.nio.file.PathMatcher;
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.List;
-import javax.annotation.Nullable;
+import org.checkerframework.checker.nullness.compatqual.NullableDecl;
 
 /**
  * Subject for doing assertions on file system paths.
@@ -103,7 +103,7 @@ public final class PathSubject extends Subject {
   }
 
   /** Asserts that the path has the given root component. */
-  public PathSubject hasRootComponent(@Nullable String root) {
+  public PathSubject hasRootComponent(@NullableDecl String root) {
     Path rootComponent = actual.getRoot();
     if (root == null && rootComponent != null) {
       failWithActual("expected to have root component", root);
diff --git a/jimfs/src/test/java/com/google/common/jimfs/PathTypeTest.java b/jimfs/src/test/java/com/google/common/jimfs/PathTypeTest.java
index dd64940..59fc114 100644
--- a/jimfs/src/test/java/com/google/common/jimfs/PathTypeTest.java
+++ b/jimfs/src/test/java/com/google/common/jimfs/PathTypeTest.java
@@ -22,7 +22,7 @@ import static com.google.common.truth.Truth.assertThat;
 
 import com.google.common.collect.ImmutableList;
 import java.net.URI;
-import javax.annotation.Nullable;
+import org.checkerframework.checker.nullness.compatqual.NullableDecl;
 import org.junit.Test;
 import org.junit.runner.RunWith;
 import org.junit.runners.JUnit4;
@@ -94,7 +94,7 @@ public class PathTypeTest {
     assertUriRoundTripsCorrectly(type, "$foo/bar baz");
   }
 
-  static void assertParseResult(ParseResult result, @Nullable String root, String... names) {
+  static void assertParseResult(ParseResult result, @NullableDecl String root, String... names) {
     assertThat(result.root()).isEqualTo(root);
     assertThat(result.names()).containsExactly((Object[]) names).inOrder();
   }
@@ -126,7 +126,7 @@ public class PathTypeTest {
     }
 
     @Override
-    public String toString(@Nullable String root, Iterable<String> names) {
+    public String toString(@NullableDecl String root, Iterable<String> names) {
       StringBuilder builder = new StringBuilder();
       if (root != null) {
         builder.append(root);
diff --git a/jimfs/src/test/java/com/google/common/jimfs/TestAttributeProvider.java b/jimfs/src/test/java/com/google/common/jimfs/TestAttributeProvider.java
index 9dbeee9..4518132 100644
--- a/jimfs/src/test/java/com/google/common/jimfs/TestAttributeProvider.java
+++ b/jimfs/src/test/java/com/google/common/jimfs/TestAttributeProvider.java
@@ -26,7 +26,7 @@ import java.nio.file.attribute.FileAttributeView;
 import java.nio.file.attribute.FileTime;
 import java.util.HashMap;
 import java.util.Map;
-import javax.annotation.Nullable;
+import org.checkerframework.checker.nullness.compatqual.NullableDecl;
 
 /** @author Colin Decker */
 public final class TestAttributeProvider extends AttributeProvider {
@@ -133,9 +133,9 @@ public final class TestAttributeProvider extends AttributeProvider {
 
     @Override
     public void setTimes(
-        @Nullable FileTime lastModifiedTime,
-        @Nullable FileTime lastAccessTime,
-        @Nullable FileTime createTime)
+        @NullableDecl FileTime lastModifiedTime,
+        @NullableDecl FileTime lastAccessTime,
+        @NullableDecl FileTime createTime)
         throws IOException {
       basicView.setTimes(lastModifiedTime, lastAccessTime, createTime);
     }
diff --git a/pom.xml b/pom.xml
index 6c0187b..32e13bc 100644
--- a/pom.xml
+++ b/pom.xml
@@ -117,6 +117,11 @@
         <artifactId>jsr305</artifactId>
         <version>3.0.2</version>
       </dependency>
+      <dependency>
+        <groupId>org.checkerframework</groupId>
+        <artifactId>checker-compat-qual</artifactId>
+        <version>2.5.5</version>
+      </dependency>
 
       <!-- Test dependencies -->
       <dependency>