Convert to new AutoCloseable instances coming in JGit 4.0

Repository, RevWalk, and friends have been converted to AutoCloseable.
Use them in try-with-resources blocks in order to avoid warnings about
unclosed resources or calls to deprecated release() methods. Where a
larger rewrite might have been possible to reduce try/finally blocks,
err on the side of keeping the same behavior.

The proximate goal of this change was to eliminate all Eclipse
warnings about deprecated method calls (namely release()) and leaked
resources. Some of these warnings were in fact potential leaks;
Eclipse finding such cases is a side benefit of having these classes
implement AutoCloseable. However, this change certainly does not cover
all cases where try-with-resources could have been used, where it was
not causing a leak.

Fixes all such warnings in plugin submodules as well.

Change-Id: I5d151996ae012d0e8fdfa27cce8cf5e2bfc856a2

gerrit-acceptance-tests/src/test/java/com/google/gerrit/acceptance/git/SubmitOnPushIT.java

@@ -222,53 +222,37 @@ public class SubmitOnPushIT extends AbstractDaemonTest {
   }
 
   private void assertCommit(Project.NameKey project, String branch) throws IOException {
-    Repository r = repoManager.openRepository(project);
+    try (Repository r = repoManager.openRepository(project);
-    try {
+        RevWalk rw = new RevWalk(r)) {
-      RevWalk rw = new RevWalk(r);
-      try {
       RevCommit c = rw.parseCommit(r.getRef(branch).getObjectId());
       assertThat(c.getShortMessage()).isEqualTo(PushOneCommit.SUBJECT);
       assertThat(c.getAuthorIdent().getEmailAddress()).isEqualTo(admin.email);
       assertThat(c.getCommitterIdent().getEmailAddress()).isEqualTo(
           admin.email);
-      } finally {
-        rw.release();
-      }
-    } finally {
-      r.close();
     }
   }
 
   private void assertMergeCommit(String branch, String subject) throws IOException {
-    Repository r = repoManager.openRepository(project);
+    try (Repository r = repoManager.openRepository(project);
-    try {
+        RevWalk rw = new RevWalk(r)) {
-      RevWalk rw = new RevWalk(r);
-      try {
       RevCommit c = rw.parseCommit(r.getRef(branch).getObjectId());
       assertThat(c.getParentCount()).is(2);
       assertThat(c.getShortMessage()).isEqualTo("Merge \"" + subject + "\"");
       assertThat(c.getAuthorIdent().getEmailAddress()).isEqualTo(admin.email);
       assertThat(c.getCommitterIdent().getEmailAddress()).isEqualTo(
           serverIdent.getEmailAddress());
-      } finally {
-        rw.release();
-      }
-    } finally {
-      r.close();
     }
   }
 
   private void assertTag(Project.NameKey project, String branch,
       PushOneCommit.Tag tag) throws IOException {
-    Repository repo = repoManager.openRepository(project);
+    try (Repository repo = repoManager.openRepository(project)) {
-    try {
       Ref tagRef = repo.getRef(tag.name);
       assertThat(tagRef).isNotNull();
       ObjectId taggedCommit = null;
       if (tag instanceof PushOneCommit.AnnotatedTag) {
         PushOneCommit.AnnotatedTag annotatedTag = (PushOneCommit.AnnotatedTag)tag;
-        RevWalk rw = new RevWalk(repo);
+        try (RevWalk rw = new RevWalk(repo)) {
-        try {
           RevObject object = rw.parseAny(tagRef.getObjectId());
           assertThat(object).isInstanceOf(RevTag.class);
           RevTag tagObject = (RevTag) object;
@@ -276,8 +260,6 @@ public class SubmitOnPushIT extends AbstractDaemonTest {
               .isEqualTo(annotatedTag.message);
           assertThat(tagObject.getTaggerIdent()).isEqualTo(annotatedTag.tagger);
           taggedCommit = tagObject.getObject();
-        } finally {
-          rw.dispose();
         }
       } else {
         taggedCommit = tagRef.getObjectId();
@@ -285,8 +267,6 @@ public class SubmitOnPushIT extends AbstractDaemonTest {
       ObjectId headCommit = repo.getRef(branch).getObjectId();
       assertThat(taggedCommit).isNotNull();
       assertThat(taggedCommit).isEqualTo(headCommit);
-    } finally {
-      repo.close();
     }
   }
 

gerrit-acceptance-tests/src/test/java/com/google/gerrit/acceptance/rest/change/AbstractSubmit.java

@@ -337,40 +337,23 @@ public abstract class AbstractSubmit extends AbstractDaemonTest {
   }
 
   protected RevCommit getRemoteHead() throws IOException {
-    Repository repo = repoManager.openRepository(project);
+    try (Repository repo = repoManager.openRepository(project)) {
-    try {
       return getHead(repo, "refs/heads/master");
-    } finally {
-      repo.close();
     }
   }
 
   protected List<RevCommit> getRemoteLog() throws IOException {
-    Repository repo = repoManager.openRepository(project);
+    try (Repository repo = repoManager.openRepository(project);
-    try {
+        RevWalk rw = new RevWalk(repo)) {
-      RevWalk rw = new RevWalk(repo);
-      try {
       rw.markStart(rw.parseCommit(
           repo.getRef("refs/heads/master").getObjectId()));
       return Lists.newArrayList(rw);
-      } finally {
-        rw.release();
-      }
-    } finally {
-      repo.close();
     }
   }
 
   private RevCommit getHead(Repository repo, String name) throws IOException {
-    try {
+    try (RevWalk rw = new RevWalk(repo)) {
-      RevWalk rw = new RevWalk(repo);
-      try {
       return rw.parseCommit(repo.getRef(name).getObjectId());
-      } finally {
-        rw.release();
-      }
-    } finally {
-      repo.close();
     }
   }
 
@@ -381,28 +364,22 @@ public abstract class AbstractSubmit extends AbstractDaemonTest {
   }
 
   private String getLatestRemoteDiff() throws IOException {
-    Repository repo = repoManager.openRepository(project);
+    try (Repository repo = repoManager.openRepository(project);
-    try {
+        RevWalk rw = new RevWalk(repo)) {
-      RevWalk rw = new RevWalk(repo);
-      try {
       ObjectId oldTreeId = repo.resolve("refs/heads/master~1^{tree}");
       ObjectId newTreeId = repo.resolve("refs/heads/master^{tree}");
       return getLatestDiff(repo, oldTreeId, newTreeId);
-      } finally {
-        rw.release();
-      }
-    } finally {
-      repo.close();
     }
   }
 
   private String getLatestDiff(Repository repo, ObjectId oldTreeId,
       ObjectId newTreeId) throws IOException {
     ByteArrayOutputStream out = new ByteArrayOutputStream();
-    DiffFormatter fmt = new DiffFormatter(out);
+    try (DiffFormatter fmt = new DiffFormatter(out)) {
       fmt.setRepository(repo);
       fmt.format(oldTreeId, newTreeId);
       fmt.flush();
       return out.toString();
     }
   }
+}

gerrit-acceptance-tests/src/test/java/com/google/gerrit/acceptance/rest/project/CreateProjectIT.java

@@ -238,11 +238,10 @@ public class CreateProjectIT extends AbstractDaemonTest {
 
   private void assertEmptyCommit(String projectName, String... refs)
       throws RepositoryNotFoundException, IOException {
-    Repository repo =
+    Project.NameKey projectKey = new Project.NameKey(projectName);
-        repoManager.openRepository(new Project.NameKey(projectName));
+    try (Repository repo = repoManager.openRepository(projectKey);
         RevWalk rw = new RevWalk(repo);
-    TreeWalk tw = new TreeWalk(repo);
+        TreeWalk tw = new TreeWalk(rw.getObjectReader())) {
-    try {
       for (String ref : refs) {
         RevCommit commit = rw.lookupCommit(repo.getRef(ref).getObjectId());
         rw.parseBody(commit);
@@ -250,9 +249,6 @@ public class CreateProjectIT extends AbstractDaemonTest {
         assertThat(tw.next()).isFalse();
         tw.reset();
       }
-    } finally {
-      rw.release();
-      repo.close();
     }
   }
 }

gerrit-httpd/src/main/java/com/google/gerrit/httpd/raw/CatServlet.java

@@ -202,12 +202,9 @@ public class CatServlet extends HttpServlet {
     final RevCommit fromCommit;
     final String suffix;
     final String path = patchKey.getFileName();
-    try {
+    try (ObjectReader reader = repo.newObjectReader();
-      final ObjectReader reader = repo.newObjectReader();
+        RevWalk rw = new RevWalk(reader)) {
-      try {
-        final RevWalk rw = new RevWalk(reader);
       final RevCommit c;
-        final TreeWalk tw;
 
       c = rw.parseCommit(ObjectId.fromString(revision));
       if (side == 0) {
@@ -227,7 +224,7 @@ public class CatServlet extends HttpServlet {
         return;
       }
 
-        tw = TreeWalk.forPath(reader, path, fromCommit.getTree());
+      try (TreeWalk tw = TreeWalk.forPath(reader, path, fromCommit.getTree())) {
         if (tw == null) {
           rsp.sendError(HttpServletResponse.SC_NOT_FOUND);
           return;
@@ -240,8 +237,6 @@ public class CatServlet extends HttpServlet {
           rsp.sendError(HttpServletResponse.SC_INTERNAL_SERVER_ERROR);
           return;
         }
-      } finally {
-        reader.release();
       }
     } catch (IOException e) {
       getServletContext().log("Cannot read repository", e);

gerrit-pgm/src/main/java/com/google/gerrit/pgm/RebuildNotedb.java

@@ -185,11 +185,8 @@ public class RebuildNotedb extends SiteProgram {
 
   private static void execute(BatchRefUpdate bru, Repository repo)
       throws IOException {
-    RevWalk rw = new RevWalk(repo);
+    try (RevWalk rw = new RevWalk(repo)) {
-    try {
       bru.execute(rw, NullProgressMonitor.INSTANCE);
-    } finally {
-      rw.release();
     }
   }
 

gerrit-pgm/src/main/java/com/google/gerrit/pgm/init/api/AllProjectsConfig.java

@@ -136,13 +136,10 @@ public class AllProjectsConfig extends VersionedMetaData {
       throw new IOException("All-Projects does not exist.");
     }
 
-    Repository repo = new FileRepository(path);
+    try (Repository repo = new FileRepository(path)) {
-    try {
       inserter = repo.newObjectInserter();
       reader = repo.newObjectReader();
-      try {
+      try (RevWalk rw = new RevWalk(reader)) {
-        RevWalk rw = new RevWalk(reader);
-        try {
         RevTree srcTree = revision != null ? rw.parseTree(revision) : null;
         newTree = readTree(srcTree);
         saveConfig(ProjectConfig.PROJECT_CONFIG, cfg);
@@ -164,21 +161,16 @@ public class AllProjectsConfig extends VersionedMetaData {
         ObjectId newRevision = inserter.insert(commit);
         updateRef(repo, ident, newRevision, "commit: " + msg);
         revision = newRevision;
-        } finally {
-          rw.release();
-        }
       } finally {
         if (inserter != null) {
-          inserter.release();
+          inserter.close();
           inserter = null;
         }
         if (reader != null) {
-          reader.release();
+          reader.close();
           reader = null;
         }
       }
-    } finally {
-      repo.close();
     }
 
     // we need to invalidate the JGit cache if the group list is invalidated in

gerrit-server/src/main/java/com/google/gerrit/server/ChangeUtil.java

@@ -26,6 +26,7 @@ import com.google.gerrit.reviewdb.client.Change;
 import com.google.gerrit.reviewdb.client.ChangeMessage;
 import com.google.gerrit.reviewdb.client.PatchSet;
 import com.google.gerrit.reviewdb.client.PatchSetAncestor;
+import com.google.gerrit.reviewdb.client.Project;
 import com.google.gerrit.reviewdb.client.RevId;
 import com.google.gerrit.reviewdb.server.ReviewDb;
 import com.google.gerrit.server.change.ChangeInserter;
@@ -227,15 +228,9 @@ public class ChangeUtil {
     }
     Change changeToRevert = db.get().changes().get(changeId);
 
-    Repository git;
+    Project.NameKey project = ctl.getChange().getProject();
-    try {
+    try (Repository git = gitManager.openRepository(project);
-      git = gitManager.openRepository(ctl.getChange().getProject());
+        RevWalk revWalk = new RevWalk(git)) {
-    } catch (RepositoryNotFoundException e) {
-      throw new NoSuchChangeException(changeId, e);
-    }
-    try {
-      RevWalk revWalk = new RevWalk(git);
-      try {
       RevCommit commitToRevert =
           revWalk.parseCommit(ObjectId.fromString(patch.getRevision().get()));
 
@@ -264,13 +259,10 @@ public class ChangeUtil {
           ChangeIdUtil.insertId(message, computedChangeId, true));
 
       RevCommit revertCommit;
-        ObjectInserter oi = git.newObjectInserter();
+      try (ObjectInserter oi = git.newObjectInserter()) {
-        try {
         ObjectId id = oi.insert(revertCommitBuilder);
         oi.flush();
         revertCommit = revWalk.parseCommit(id);
-        } finally {
-          oi.release();
       }
 
       RefControl refControl = ctl.getRefControl();
@@ -334,11 +326,8 @@ public class ChangeUtil {
       }
 
       return change.getId();
-      } finally {
+    } catch (RepositoryNotFoundException e) {
-        revWalk.release();
+      throw new NoSuchChangeException(changeId, e);
-      }
-    } finally {
-      git.close();
     }
   }
 
@@ -354,15 +343,9 @@ public class ChangeUtil {
           "The commit message cannot be empty");
     }
 
-    Repository git;
+    Project.NameKey project = ctl.getChange().getProject();
-    try {
+    try (Repository git = gitManager.openRepository(project);
-      git = gitManager.openRepository(ctl.getChange().getProject());
+        RevWalk revWalk = new RevWalk(git)) {
-    } catch (RepositoryNotFoundException e) {
-      throw new NoSuchChangeException(changeId, e);
-    }
-    try {
-      RevWalk revWalk = new RevWalk(git);
-      try {
       RevCommit commit =
           revWalk.parseCommit(ObjectId.fromString(ps.getRevision()
               .get()));
@@ -383,13 +366,10 @@ public class ChangeUtil {
       commitBuilder.setMessage(message);
 
       RevCommit newCommit;
-        ObjectInserter oi = git.newObjectInserter();
+      try (ObjectInserter oi = git.newObjectInserter()) {
-        try {
         ObjectId id = oi.insert(commitBuilder);
         oi.flush();
         newCommit = revWalk.parseCommit(id);
-        } finally {
-          oi.release();
       }
 
       PatchSet.Id id = nextPatchSetId(git, change.currentPatchSetId());
@@ -410,11 +390,8 @@ public class ChangeUtil {
           .insert();
 
       return change.getId();
-      } finally {
+    } catch (RepositoryNotFoundException e) {
-        revWalk.release();
+      throw new NoSuchChangeException(changeId, e);
-      }
-    } finally {
-      git.close();
     }
   }
 
@@ -427,25 +404,14 @@ public class ChangeUtil {
       throw new NoSuchChangeException(changeId);
     }
 
-    Repository git;
+    try (Repository git = gitManager.openRepository(change.getProject());
-    try {
+        RevWalk revWalk = new RevWalk(git)) {
-      git = gitManager.openRepository(change.getProject());
+      RevCommit commit = revWalk.parseCommit(
+          ObjectId.fromString(ps.getRevision().get()));
+      return commit.getFullMessage();
     } catch (RepositoryNotFoundException e) {
       throw new NoSuchChangeException(changeId, e);
     }
-    try {
-      RevWalk revWalk = new RevWalk(git);
-      try {
-        RevCommit commit =
-            revWalk.parseCommit(ObjectId.fromString(ps.getRevision()
-                .get()));
-        return commit.getFullMessage();
-      } finally {
-        revWalk.release();
-      }
-    } finally {
-      git.close();
-    }
   }
 
   public void deleteDraftChange(Change change)

gerrit-server/src/main/java/com/google/gerrit/server/change/ChangeKindCacheImpl.java

@@ -189,8 +189,7 @@ public class ChangeKindCacheImpl implements ChangeKindCache {
         return ChangeKind.NO_CODE_CHANGE;
       }
 
-      RevWalk walk = new RevWalk(key.repo);
+      try (RevWalk walk = new RevWalk(key.repo)) {
-      try {
         RevCommit prior = walk.parseCommit(key.prior);
         walk.parseBody(prior);
         RevCommit next = walk.parseCommit(key.next);
@@ -227,7 +226,6 @@ public class ChangeKindCacheImpl implements ChangeKindCache {
         }
       } finally {
         key.repo = null;
-        walk.release();
       }
     }
 

gerrit-server/src/main/java/com/google/gerrit/server/change/CherryPickChange.java

@@ -121,16 +121,8 @@ public class CherryPickChange {
 
     Project.NameKey project = change.getProject();
     IdentifiedUser identifiedUser = (IdentifiedUser) currentUser.get();
-    final Repository git;
+    try (Repository git = gitManager.openRepository(project);
-    try {
+        RevWalk revWalk = new RevWalk(git)) {
-      git = gitManager.openRepository(project);
-    } catch (RepositoryNotFoundException e) {
-      throw new NoSuchChangeException(change.getId(), e);
-    }
-
-    try {
-      RevWalk revWalk = new RevWalk(git);
-      try {
       Ref destRef = git.getRef(destinationBranch);
       if (destRef == null) {
         throw new InvalidChangeOperationException("Branch "
@@ -154,16 +146,13 @@ public class CherryPickChange {
           ChangeIdUtil.insertId(message, computedChangeId).trim() + '\n';
 
       RevCommit cherryPickCommit;
-        ObjectInserter oi = git.newObjectInserter();
+      try (ObjectInserter oi = git.newObjectInserter()) {
-        try {
         ProjectState projectState = refControl.getProjectControl().getProjectState();
         cherryPickCommit =
             mergeUtilFactory.create(projectState).createCherryPickFromCommit(git, oi, mergeTip,
                 commitToCherryPick, committerIdent, commitMessage, revWalk);
       } catch (MergeIdenticalTreeException | MergeConflictException e) {
         throw new MergeException("Cherry pick failed: " + e.getMessage());
-        } finally {
-          oi.release();
       }
 
       Change.Key changeKey;
@@ -205,11 +194,8 @@ public class CherryPickChange {
 
         return newChange.getId();
       }
-      } finally {
+    } catch (RepositoryNotFoundException e) {
-        revWalk.release();
+      throw new NoSuchChangeException(change.getId(), e);
-      }
-    } finally {
-      git.close();
     }
   }
 

gerrit-server/src/main/java/com/google/gerrit/server/change/ConsistencyChecker.java

@@ -153,7 +153,7 @@ public class ConsistencyChecker {
       return Result.create(c, problems);
     } finally {
       if (rw != null) {
-        rw.release();
+        rw.close();
       }
       if (repo != null) {
         repo.close();

gerrit-server/src/main/java/com/google/gerrit/server/change/CreateChange.java

@@ -158,11 +158,8 @@ public class CreateChange implements
     }
 
     Project.NameKey project = rsrc.getNameKey();
-    Repository git = gitManager.openRepository(project);
+    try (Repository git = gitManager.openRepository(project);
-
+        RevWalk rw = new RevWalk(git)) {
-    try {
-      RevWalk rw = new RevWalk(git);
-      try {
       ObjectId parentCommit;
       if (input.baseChange != null) {
         List<Change> changes = changeUtil.findChanges(input.baseChange);
@@ -218,11 +215,6 @@ public class CreateChange implements
       ins.insert();
 
       return Response.created(json.format(change.getId()));
-      } finally {
-        rw.release();
-      }
-    } finally {
-      git.close();
     }
   }
 
@@ -275,8 +267,7 @@ public class CreateChange implements
       PersonIdent authorIdent, RevCommit mergeTip, String commitMessage)
       throws IOException {
     RevCommit emptyCommit;
-    ObjectInserter oi = git.newObjectInserter();
+    try (ObjectInserter oi = git.newObjectInserter()) {
-    try {
       CommitBuilder commit = new CommitBuilder();
       commit.setTreeId(mergeTip.getTree().getId());
       commit.setParentId(mergeTip);
@@ -284,8 +275,6 @@ public class CreateChange implements
       commit.setCommitter(authorIdent);
       commit.setMessage(commitMessage);
       emptyCommit = rw.parseCommit(insert(oi, commit));
-    } finally {
-      oi.release();
     }
     return emptyCommit;
   }

gerrit-server/src/main/java/com/google/gerrit/server/change/FileContentUtil.java

@@ -58,10 +58,8 @@ public class FileContentUtil {
 
   public BinaryResult getContent(ProjectState project, ObjectId revstr,
       String path) throws ResourceNotFoundException, IOException {
-    Repository repo = openRepository(project);
+    try (Repository repo = openRepository(project);
-    try {
+        RevWalk rw = new RevWalk(repo)) {
-      RevWalk rw = new RevWalk(repo);
-      try {
       RevCommit commit = rw.parseCommit(revstr);
       ObjectReader reader = rw.getObjectReader();
       TreeWalk tw = TreeWalk.forPath(reader, path, commit.getTree());
@@ -100,22 +98,17 @@ public class FileContentUtil {
         type = resolveContentType(project, path, FileMode.FILE, type);
       }
       return result.setContentType(type).base64();
-      } finally {
-        rw.release();
-      }
-    } finally {
-      repo.close();
     }
   }
 
   private static BinaryResult asBinaryResult(final ObjectLoader obj) {
-    @SuppressWarnings("resource")
     BinaryResult result = new BinaryResult() {
       @Override
       public void writeTo(OutputStream os) throws IOException {
         obj.copyTo(os);
       }
-    }.setContentLength(obj.getSize());
+    };
+    result.setContentLength(obj.getSize());
     return result;
   }
 

gerrit-server/src/main/java/com/google/gerrit/server/change/Files.java

@@ -31,6 +31,7 @@ import com.google.gerrit.reviewdb.client.Account;
 import com.google.gerrit.reviewdb.client.AccountPatchReview;
 import com.google.gerrit.reviewdb.client.Patch;
 import com.google.gerrit.reviewdb.client.PatchSet;
+import com.google.gerrit.reviewdb.client.Project;
 import com.google.gerrit.reviewdb.server.ReviewDb;
 import com.google.gerrit.server.CurrentUser;
 import com.google.gerrit.server.IdentifiedUser;
@@ -178,14 +179,13 @@ public class Files implements ChildCollection<RevisionResource, FileResource> {
 
     private List<String> query(RevisionResource resource)
         throws RepositoryNotFoundException, IOException {
-      Repository git =
+      Project.NameKey project = resource.getChange().getProject();
-          gitManager.openRepository(resource.getChange().getProject());
+      try (Repository git = gitManager.openRepository(project);
-      try {
+          ObjectReader or = git.newObjectReader();
-        TreeWalk tw = new TreeWalk(git);
+          RevWalk rw = new RevWalk(or);
-        try {
+          TreeWalk tw = new TreeWalk(or)) {
-          RevCommit c = new RevWalk(tw.getObjectReader())
+        RevCommit c = rw.parseCommit(
-            .parseCommit(ObjectId.fromString(
+            ObjectId.fromString(resource.getPatchSet().getRevision().get()));
-                resource.getPatchSet().getRevision().get()));
 
         tw.addTree(c.getTree());
         tw.setRecursive(true);
@@ -197,11 +197,6 @@ public class Files implements ChildCollection<RevisionResource, FileResource> {
           }
         }
         return paths;
-        } finally {
-          tw.release();
-        }
-      } finally {
-        git.close();
       }
     }
 
@@ -261,11 +256,11 @@ public class Files implements ChildCollection<RevisionResource, FileResource> {
     private List<String> copy(Set<String> paths, PatchSet.Id old,
         RevisionResource resource, Account.Id userId) throws IOException,
         PatchListNotAvailableException, OrmException {
-      Repository git =
+      Project.NameKey project = resource.getChange().getProject();
-          gitManager.openRepository(resource.getChange().getProject());
+      try (Repository git = gitManager.openRepository(project);
-      try {
           ObjectReader reader = git.newObjectReader();
-        try {
+          RevWalk rw = new RevWalk(reader);
+          TreeWalk tw = new TreeWalk(reader)) {
         PatchList oldList = patchListCache.get(
             resource.getChange(),
             db.get().patchSets().get(old));
@@ -278,8 +273,6 @@ public class Files implements ChildCollection<RevisionResource, FileResource> {
         List<AccountPatchReview> inserts = Lists.newArrayListWithCapacity(sz);
         List<String> pathList = Lists.newArrayListWithCapacity(sz);
 
-          RevWalk rw = new RevWalk(reader);
-          TreeWalk tw = new TreeWalk(reader);
         tw.setFilter(PathFilterGroup.createFromStrings(paths));
         tw.setRecursive(true);
         int o = tw.addTree(rw.parseCommit(oldList.getNewId()).getTree());
@@ -326,11 +319,6 @@ public class Files implements ChildCollection<RevisionResource, FileResource> {
         }
         db.get().accountPatchReviews().insert(inserts);
         return pathList;
-        } finally {
-          reader.release();
-        }
-      } finally {
-        git.close();
       }
     }
 

gerrit-server/src/main/java/com/google/gerrit/server/change/GetArchive.java

@@ -126,7 +126,7 @@ public class GetArchive implements RestReadView<RevisionResource> {
 
           @Override
           public void close() throws IOException {
-            rw.release();
+            rw.close();
             repo.close();
           }
         };
@@ -139,7 +139,7 @@ public class GetArchive implements RestReadView<RevisionResource> {
         return bin;
       } finally {
         if (close) {
-          rw.release();
+          rw.close();
         }
       }
     } finally {

gerrit-server/src/main/java/com/google/gerrit/server/change/GetPatch.java

@@ -94,15 +94,16 @@ public class GetPatch implements RestReadView<RevisionResource> {
 
           private void format(OutputStream out) throws IOException {
             out.write(formatEmailHeader(commit).getBytes(UTF_8));
-            DiffFormatter fmt = new DiffFormatter(out);
+            try (DiffFormatter fmt = new DiffFormatter(out)) {
               fmt.setRepository(repo);
               fmt.format(base.getTree(), commit.getTree());
               fmt.flush();
             }
+          }
 
           @Override
           public void close() throws IOException {
-            rw.release();
+            rw.close();
             repo.close();
           }
         };
@@ -123,7 +124,7 @@ public class GetPatch implements RestReadView<RevisionResource> {
         return bin;
       } finally {
         if (close) {
-          rw.release();
+          rw.close();
         }
       }
     } finally {

gerrit-server/src/main/java/com/google/gerrit/server/change/GetRelated.java

@@ -80,19 +80,12 @@ public class GetRelated implements RestReadView<RevisionResource> {
   @Override
   public RelatedInfo apply(RevisionResource rsrc)
       throws RepositoryNotFoundException, IOException, OrmException {
-    Repository git = gitMgr.openRepository(rsrc.getChange().getProject());
+    try (Repository git = gitMgr.openRepository(rsrc.getChange().getProject());
-    try {
+        RevWalk rw = new RevWalk(git)) {
       Ref ref = git.getRef(rsrc.getChange().getDest().get());
-      RevWalk rw = new RevWalk(git);
-      try {
       RelatedInfo info = new RelatedInfo();
       info.changes = walk(rsrc, rw, ref);
       return info;
-      } finally {
-        rw.release();
-      }
-    } finally {
-      git.close();
     }
   }
 

gerrit-server/src/main/java/com/google/gerrit/server/change/IncludedIn.java

@@ -19,6 +19,7 @@ import com.google.gerrit.extensions.restapi.BadRequestException;
 import com.google.gerrit.extensions.restapi.ResourceConflictException;
 import com.google.gerrit.extensions.restapi.RestReadView;
 import com.google.gerrit.reviewdb.client.PatchSet;
+import com.google.gerrit.reviewdb.client.Project;
 import com.google.gerrit.reviewdb.server.ReviewDb;
 import com.google.gerrit.server.git.GitRepositoryManager;
 import com.google.gerrit.server.project.ChangeControl;
@@ -55,11 +56,9 @@ class IncludedIn implements RestReadView<ChangeResource> {
     ChangeControl ctl = rsrc.getControl();
     PatchSet ps =
         db.get().patchSets().get(ctl.getChange().currentPatchSetId());
-    Repository r =
+    Project.NameKey project = ctl.getProject().getNameKey();
-        repoManager.openRepository(ctl.getProject().getNameKey());
+    try (Repository r = repoManager.openRepository(project);
-    try {
+        RevWalk rw = new RevWalk(r)) {
-      RevWalk rw = new RevWalk(r);
-      try {
       rw.setRetainBody(false);
       RevCommit rev;
       try {
@@ -70,11 +69,6 @@ class IncludedIn implements RestReadView<ChangeResource> {
         throw new ResourceConflictException(err.getMessage());
       }
       return new IncludedInInfo(IncludedInResolver.resolve(r, rw, rev));
-      } finally {
-        rw.release();
-      }
-    } finally {
-      r.close();
     }
   }
 

gerrit-server/src/main/java/com/google/gerrit/server/change/MergeabilityCacheImpl.java

@@ -225,8 +225,7 @@ public class MergeabilityCacheImpl implements MergeabilityCache {
       }
       try {
         Map<String, Ref> refs = key.load.repo.getAllRefs();
-        RevWalk rw = CodeReviewCommit.newRevWalk(key.load.repo);
+        try (RevWalk rw = CodeReviewCommit.newRevWalk(key.load.repo)) {
-        try {
           RevFlag canMerge = rw.newFlag("CAN_MERGE");
           CodeReviewCommit rev = parse(rw, key.commit);
           rev.add(canMerge);
@@ -243,8 +242,6 @@ public class MergeabilityCacheImpl implements MergeabilityCache {
               canMerge,
               accepted,
               key.load.dest).dryRun(tip, rev);
-        } finally {
-          rw.release();
         }
       } finally {
         key.load = null;

gerrit-server/src/main/java/com/google/gerrit/server/changedetail/RebaseChange.java

@@ -119,14 +119,9 @@ public class RebaseChange {
           "Cannot rebase: New patch sets are not allowed to be added to change: "
               + changeId.toString());
     }
-    Repository git = null;
+    try (Repository git = gitManager.openRepository(change.getProject());
-    RevWalk rw = null;
+        RevWalk rw = new RevWalk(git);
-    ObjectInserter inserter = null;
+        ObjectInserter inserter = git.newObjectInserter()) {
-    try {
-      git = gitManager.openRepository(change.getProject());
-      rw = new RevWalk(git);
-      inserter = git.newObjectInserter();
-
       String baseRev = newBaseRev;
       if (baseRev == null) {
           baseRev = findBaseRevision(patchSetId, db.get(),
@@ -149,16 +144,6 @@ public class RebaseChange {
           committerIdent, true, ValidatePolicy.GERRIT);
     } catch (MergeConflictException e) {
       throw new IOException(e.getMessage());
-    } finally {
-      if (inserter != null) {
-        inserter.release();
-      }
-      if (rw != null) {
-        rw.release();
-      }
-      if (git != null) {
-        git.close();
-      }
     }
   }
 

gerrit-server/src/main/java/com/google/gerrit/server/edit/ChangeEditModifier.java

@@ -29,6 +29,7 @@ import com.google.gerrit.extensions.restapi.RawInput;
 import com.google.gerrit.extensions.restapi.ResourceConflictException;
 import com.google.gerrit.reviewdb.client.Change;
 import com.google.gerrit.reviewdb.client.PatchSet;
+import com.google.gerrit.reviewdb.client.Project;
 import com.google.gerrit.server.CurrentUser;
 import com.google.gerrit.server.GerritPersonIdent;
 import com.google.gerrit.server.IdentifiedUser;
@@ -115,26 +116,20 @@ public class ChangeEditModifier {
     }
 
     IdentifiedUser me = (IdentifiedUser) currentUser.get();
-    Repository repo = gitManager.openRepository(change.getProject());
     String refPrefix = editRefPrefix(me.getAccountId(), change.getId());
 
-    try {
+    try (Repository repo = gitManager.openRepository(change.getProject())) {
       Map<String, Ref> refs = repo.getRefDatabase().getRefs(refPrefix);
       if (!refs.isEmpty()) {
         throw new ResourceConflictException("edit already exists");
       }
 
-      RevWalk rw = new RevWalk(repo);
+      try (RevWalk rw = new RevWalk(repo)) {
-      try {
         ObjectId revision = ObjectId.fromString(ps.getRevision().get());
         String editRefName = editRefName(me.getAccountId(), change.getId(),
             ps.getId());
         return update(repo, me, editRefName, rw, ObjectId.zeroId(), revision);
-      } finally {
-        rw.release();
       }
-    } finally {
-      repo.close();
     }
   }
 
@@ -159,12 +154,10 @@ public class ChangeEditModifier {
     IdentifiedUser me = (IdentifiedUser) currentUser.get();
     String refName = editRefName(me.getAccountId(), change.getId(),
         current.getId());
-    Repository repo = gitManager.openRepository(change.getProject());
+    try (Repository repo = gitManager.openRepository(change.getProject());
-    try {
         RevWalk rw = new RevWalk(repo);
+        ObjectInserter inserter = repo.newObjectInserter()) {
       BatchRefUpdate ru = repo.getRefDatabase().newBatchUpdate();
-      ObjectInserter inserter = repo.newObjectInserter();
-      try {
       RevCommit editCommit = edit.getEditCommit();
       if (editCommit.getParentCount() == 0) {
         throw new InvalidChangeOperationException(
@@ -206,12 +199,6 @@ public class ChangeEditModifier {
         // TODO(davido): Allow to resolve conflicts inline
         throw new ResourceConflictException("merge conflict");
       }
-      } finally {
-        rw.release();
-        inserter.release();
-      }
-    } finally {
-      repo.close();
     }
   }
 
@@ -240,23 +227,16 @@ public class ChangeEditModifier {
     }
 
     IdentifiedUser me = (IdentifiedUser) currentUser.get();
-    Repository repo = gitManager.openRepository(edit.getChange().getProject());
+    Project.NameKey project = edit.getChange().getProject();
-    try {
+    try (Repository repo = gitManager.openRepository(project);
         RevWalk rw = new RevWalk(repo);
-      ObjectInserter inserter = repo.newObjectInserter();
+        ObjectInserter inserter = repo.newObjectInserter()) {
-      try {
       String refName = edit.getRefName();
       ObjectId commit = createCommit(me, inserter, prevEdit,
           prevEdit.getTree(),
           msg);
       inserter.flush();
       return update(repo, me, refName, rw, prevEdit, commit);
-      } finally {
-        rw.release();
-        inserter.release();
-      }
-    } finally {
-      repo.close();
     }
   }
 
@@ -333,12 +313,11 @@ public class ChangeEditModifier {
       throw new AuthException("Authentication required");
     }
     IdentifiedUser me = (IdentifiedUser) currentUser.get();
-    Repository repo = gitManager.openRepository(edit.getChange().getProject());
+    Project.NameKey project = edit.getChange().getProject();
-    try {
+    try (Repository repo = gitManager.openRepository(project);
         RevWalk rw = new RevWalk(repo);
         ObjectInserter inserter = repo.newObjectInserter();
-      ObjectReader reader = repo.newObjectReader();
+        ObjectReader reader = repo.newObjectReader()) {
-      try {
       String refName = edit.getRefName();
       RevCommit prevEdit = edit.getEditCommit();
       ObjectId newTree = writeNewTree(op,
@@ -356,13 +335,6 @@ public class ChangeEditModifier {
       ObjectId commit = createCommit(me, inserter, prevEdit, newTree);
       inserter.flush();
       return update(repo, me, refName, rw, prevEdit, commit);
-      } finally {
-        rw.release();
-        inserter.release();
-        reader.release();
-      }
-    } finally {
-      repo.close();
     }
   }
 

gerrit-server/src/main/java/com/google/gerrit/server/edit/ChangeEditUtil.java

@@ -109,8 +109,7 @@ public class ChangeEditUtil {
    */
   public Optional<ChangeEdit> byChange(Change change, IdentifiedUser user)
       throws IOException {
-    Repository repo = gitManager.openRepository(change.getProject());
+    try (Repository repo = gitManager.openRepository(change.getProject())) {
-    try {
       String editRefPrefix = editRefPrefix(user.getAccountId(), change.getId());
       Map<String, Ref> refs = repo.getRefDatabase().getRefs(editRefPrefix);
       if (refs.isEmpty()) {
@@ -121,16 +120,11 @@ public class ChangeEditUtil {
       // where there is more than one ref, we could silently delete all but the
       // current one.
       Ref ref = Iterables.getOnlyElement(refs.values());
-      RevWalk rw = new RevWalk(repo);
+      try (RevWalk rw = new RevWalk(repo)) {
-      try {
         RevCommit commit = rw.parseCommit(ref.getObjectId());
         PatchSet basePs = getBasePatchSet(change, ref);
         return Optional.of(new ChangeEdit(user, change, ref, commit, basePs));
-      } finally {
-        rw.release();
       }
-    } finally {
-      repo.close();
     }
   }
 
@@ -150,12 +144,9 @@ public class ChangeEditUtil {
       NoSuchChangeException, IOException, InvalidChangeOperationException,
       OrmException, ResourceConflictException {
     Change change = edit.getChange();
-    Repository repo = gitManager.openRepository(change.getProject());
+    try (Repository repo = gitManager.openRepository(change.getProject());
-    try {
         RevWalk rw = new RevWalk(repo);
-      ObjectInserter inserter = repo.newObjectInserter();
+        ObjectInserter inserter = repo.newObjectInserter()) {
-      try {
-
       PatchSet basePatchSet = edit.getBasePatchSet();
       if (!basePatchSet.getId().equals(change.currentPatchSetId())) {
         throw new ResourceConflictException(
@@ -164,15 +155,8 @@ public class ChangeEditUtil {
 
       insertPatchSet(edit, change, repo, rw, basePatchSet,
           squashEdit(rw, inserter, edit.getEditCommit(), basePatchSet));
-      } finally {
-        inserter.release();
-        rw.release();
-      }
-
       // TODO(davido): This should happen in the same BatchRefUpdate.
       deleteRef(repo, edit);
-    } finally {
-      repo.close();
     }
   }
 

gerrit-server/src/main/java/com/google/gerrit/server/git/BanCommit.java

@@ -101,11 +101,9 @@ public class BanCommit {
     NoteMap banCommitNotes = NoteMap.newEmptyMap();
     // Add a note for each banned commit to notes.
     final Project.NameKey project = projectControl.getProject().getNameKey();
-    final Repository repo = repoManager.openRepository(project);
+    try (Repository repo = repoManager.openRepository(project);
-    try {
+        RevWalk revWalk = new RevWalk(repo);
-      final RevWalk revWalk = new RevWalk(repo);
+        ObjectInserter inserter = repo.newObjectInserter()) {
-      final ObjectInserter inserter = repo.newObjectInserter();
-      try {
       ObjectId noteId = null;
       for (final ObjectId commitToBan : commitsToBan) {
         try {
@@ -135,12 +133,6 @@ public class BanCommit {
         }
       }
       return result;
-      } finally {
-        revWalk.release();
-        inserter.release();
-      }
-    } finally {
-      repo.close();
     }
   }
 

gerrit-server/src/main/java/com/google/gerrit/server/git/MergeOp.java

@@ -332,10 +332,10 @@ public class MergeOp {
       throw new MergeException("Cannot query the database", e);
     } finally {
       if (inserter != null) {
-        inserter.release();
+        inserter.close();
       }
       if (rw != null) {
-        rw.release();
+        rw.close();
       }
       if (repo != null) {
         repo.close();

gerrit-server/src/main/java/com/google/gerrit/server/git/NotesBranchUtil.java

@@ -153,8 +153,8 @@ public class NotesBranchUtil {
       }
       updateRef(notesBranch);
     } finally {
-      revWalk.release();
+      revWalk.close();
-      reader.release();
+      reader.close();
     }
   }
 

gerrit-server/src/main/java/com/google/gerrit/server/git/SubmoduleOp.java

@@ -382,7 +382,7 @@ public class SubmoduleOp {
             + subscriber.get(), e);
     } finally {
       if (recRw != null) {
-        recRw.release();
+        recRw.close();
       }
       if (pdb != null) {
         pdb.close();
@@ -392,8 +392,7 @@ public class SubmoduleOp {
 
   private static DirCache readTree(final Repository pdb, final Ref branch)
       throws MissingObjectException, IncorrectObjectTypeException, IOException {
-    final RevWalk rw = new RevWalk(pdb);
+    try (RevWalk rw = new RevWalk(pdb)) {
-    try {
       final DirCache dc = DirCache.newInCore();
       final DirCacheBuilder b = dc.builder();
       b.addTree(new byte[0], // no prefix path
@@ -401,8 +400,6 @@ public class SubmoduleOp {
           pdb.newObjectReader(), rw.parseTree(branch.getObjectId()));
       b.finish();
       return dc;
-    } finally {
-      rw.release();
     }
   }
 

gerrit-server/src/main/java/com/google/gerrit/server/git/TagSet.java

@@ -147,7 +147,7 @@ class TagSet {
       }
     } finally {
       if (rw != null) {
-        rw.release();
+        rw.close();
       }
     }
   }
@@ -157,9 +157,8 @@ class TagSet {
       return;
     }
 
-    TagWalk rw = new TagWalk(git);
+    try (TagWalk rw = new TagWalk(git)) {
       rw.setRetainBody(false);
-    try {
       for (Ref ref : git.getRefDatabase().getRefs(RefDatabase.ALL).values()) {
         if (skip(ref)) {
           continue;
@@ -188,8 +187,6 @@ class TagSet {
       }
     } catch (IOException e) {
       log.warn("Error building tags for repository " + projectName, e);
-    } finally {
-      rw.release();
     }
   }
 

gerrit-server/src/main/java/com/google/gerrit/server/git/VersionedMetaData.java

@@ -122,7 +122,7 @@ public abstract class VersionedMetaData {
       revision = id != null ? new RevWalk(reader).parseCommit(id) : null;
       onLoad();
     } finally {
-      reader.release();
+      reader.close();
       reader = null;
     }
   }
@@ -319,13 +319,14 @@ public abstract class VersionedMetaData {
       public void close() {
         newTree = null;
 
+        rw.close();
         if (inserter != null) {
-          inserter.release();
+          inserter.close();
           inserter = null;
         }
 
         if (reader != null) {
-          reader.release();
+          reader.close();
           reader = null;
         }
       }

gerrit-server/src/main/java/com/google/gerrit/server/index/SiteIndexer.java

@@ -323,19 +323,17 @@ public class SiteIndexer {
           getPathsAndIndex(id);
         }
       } finally {
-        walk.release();
+        walk.close();
       }
       return null;
     }
 
     private void getPathsAndIndex(ObjectId b) throws Exception {
       List<ChangeData> cds = Lists.newArrayList(byId.get(b));
-      try {
+      try (DiffFormatter df = new DiffFormatter(DisabledOutputStream.INSTANCE)) {
         RevCommit bCommit = walk.parseCommit(b);
         RevTree bTree = bCommit.getTree();
         RevTree aTree = aFor(bCommit, walk);
-        DiffFormatter df = new DiffFormatter(DisabledOutputStream.INSTANCE);
-        try {
         df.setRepository(repo);
         if (!cds.isEmpty()) {
           List<String> paths = (aTree != null)
@@ -356,9 +354,6 @@ public class SiteIndexer {
             }
           }
         }
-        } finally {
-          df.release();
-        }
       } catch (Exception e) {
         fail("Failed to index commit " + b.name(), false, e);
         for (ChangeData cd : cds) {
@@ -396,13 +391,10 @@ public class SiteIndexer {
     }
 
     private ObjectId emptyTree() throws IOException {
-      ObjectInserter oi = repo.newObjectInserter();
+      try (ObjectInserter oi = repo.newObjectInserter()) {
-      try {
         ObjectId id = oi.insert(Constants.OBJ_TREE, new byte[] {});
         oi.flush();
         return id;
-      } finally {
-        oi.release();
       }
     }
 

gerrit-server/src/main/java/com/google/gerrit/server/mail/ChangeEmail.java

@@ -396,7 +396,7 @@ public abstract class ChangeEmail extends NotificationEmail {
 
     TemporaryBuffer.Heap buf =
         new TemporaryBuffer.Heap(args.settings.maximumDiffSize);
-    DiffFormatter fmt = new DiffFormatter(buf);
+    try (DiffFormatter fmt = new DiffFormatter(buf)) {
       Repository git;
       try {
         git = args.server.openRepository(change.getProject());
@@ -416,8 +416,8 @@ public abstract class ChangeEmail extends NotificationEmail {
         log.error("Cannot format patch", e);
         return "";
       } finally {
-      fmt.release();
         git.close();
       }
     }
   }
+}

gerrit-server/src/main/java/com/google/gerrit/server/mail/PatchSetNotificationSender.java

@@ -82,15 +82,11 @@ public class PatchSetNotificationSender {
       final Change updatedChange, final PatchSet updatedPatchSet,
       final LabelTypes labelTypes)
       throws OrmException, IOException {
-    final Repository git = repoManager.openRepository(updatedChange.getProject());
+    try (Repository git = repoManager.openRepository(updatedChange.getProject())) {
-    try {
-      final RevWalk revWalk = new RevWalk(git);
       final RevCommit commit;
-      try {
+      try (RevWalk revWalk = new RevWalk(git)) {
         commit = revWalk.parseCommit(ObjectId.fromString(
             updatedPatchSet.getRevision().get()));
-      } finally {
-        revWalk.release();
       }
       final PatchSetInfo info = patchSetInfoFactory.get(commit, updatedPatchSet.getId());
       final List<FooterLine> footerLines = commit.getFooterLines();
@@ -134,8 +130,6 @@ public class PatchSetNotificationSender {
           log.error("Cannot send email for new patch set " + updatedPatchSet.getId(), e);
         }
       }
-    } finally {
-      git.close();
     }
   }
 }

gerrit-server/src/main/java/com/google/gerrit/server/notedb/ChangeNotes.java

@@ -272,8 +272,8 @@ public class ChangeNotes extends AbstractChangeNotes<ChangeNotes> {
       loadDefaults();
       return;
     }
-    RevWalk walk = new RevWalk(reader);
+    try (RevWalk walk = new RevWalk(reader);
-    try (ChangeNotesParser parser =
+        ChangeNotesParser parser =
           new ChangeNotesParser(change, rev, walk, repoManager)) {
       parser.parseAll();
 
@@ -301,8 +301,6 @@ public class ChangeNotes extends AbstractChangeNotes<ChangeNotes> {
       this.allPastReviewers = ImmutableList.copyOf(parser.allPastReviewers);
 
       submitRecords = ImmutableList.copyOf(parser.submitRecords);
-    } finally {
-      walk.release();
     }
   }
 

gerrit-server/src/main/java/com/google/gerrit/server/notedb/ChangeRebuilder.java

@@ -200,12 +200,9 @@ public class ChangeRebuilder {
   private void writeToBatch(BatchMetaDataUpdate batch,
       AbstractChangeUpdate update, Repository repo) throws IOException,
       OrmException {
-    ObjectInserter inserter = repo.newObjectInserter();
+    try (ObjectInserter inserter = repo.newObjectInserter()) {
-    try {
       update.setInserter(inserter);
       update.writeCommit(batch);
-    } finally {
-      inserter.release();
     }
   }
 

gerrit-server/src/main/java/com/google/gerrit/server/notedb/DraftCommentNotes.java

@@ -132,16 +132,14 @@ public class DraftCommentNotes extends AbstractChangeNotes<DraftCommentNotes> {
       return;
     }
 
-    RevWalk walk = new RevWalk(reader);
+    try (RevWalk walk = new RevWalk(reader);
-    try (DraftCommentNotesParser parser = new DraftCommentNotesParser(
+        DraftCommentNotesParser parser = new DraftCommentNotesParser(
           getChangeId(), walk, rev, repoManager, draftsProject, author)) {
       parser.parseDraftComments();
 
       buildCommentTable(draftBaseComments, parser.draftBaseComments);
       buildCommentTable(draftPsComments, parser.draftPsComments);
       noteMap = parser.noteMap;
-    } finally {
-      walk.release();
     }
   }
 

gerrit-server/src/main/java/com/google/gerrit/server/patch/PatchFile.java

@@ -48,9 +48,8 @@ public class PatchFile {
     this.repo = repo;
     this.entry = patchList.get(fileName);
 
-    final ObjectReader reader = repo.newObjectReader();
+    try (ObjectReader reader = repo.newObjectReader();
-    try {
+        RevWalk rw = new RevWalk(reader)) {
-      final RevWalk rw = new RevWalk(reader);
       final RevCommit bCommit = rw.parseCommit(patchList.getNewId());
 
       if (Patch.COMMIT_MSG.equals(fileName)) {
@@ -74,8 +73,6 @@ public class PatchFile {
         }
         bTree = bCommit.getTree();
       }
-    } finally {
-      reader.release();
     }
   }
 

gerrit-server/src/main/java/com/google/gerrit/server/patch/PatchListLoader.java

@@ -133,9 +133,9 @@ public class PatchListLoader extends CacheLoader<PatchListKey, PatchList> {
   private PatchList readPatchList(final PatchListKey key, final Repository repo)
       throws IOException, PatchListNotAvailableException {
     final RawTextComparator cmp = comparatorFor(key.getWhitespace());
-    final ObjectReader reader = repo.newObjectReader();
+    try (ObjectReader reader = repo.newObjectReader();
-    try {
+        RevWalk rw = new RevWalk(reader);
-      final RevWalk rw = new RevWalk(reader);
+        DiffFormatter df = new DiffFormatter(DisabledOutputStream.INSTANCE)) {
       final RevCommit b = rw.parseCommit(key.getNewId());
       final RevObject a = aFor(key, repo, rw, b);
 
@@ -155,7 +155,6 @@ public class PatchListLoader extends CacheLoader<PatchListKey, PatchList> {
       RevTree aTree = rw.parseTree(a);
       RevTree bTree = b.getTree();
 
-      DiffFormatter df = new DiffFormatter(DisabledOutputStream.INSTANCE);
       df.setRepository(repo);
       df.setDiffComparator(cmp);
       df.setDetectRenames(true);
@@ -187,8 +186,6 @@ public class PatchListLoader extends CacheLoader<PatchListKey, PatchList> {
       }
       return new PatchList(a, b, againstParent,
           entries.toArray(new PatchListEntry[entries.size()]));
-    } finally {
-      reader.release();
     }
   }
 
@@ -326,8 +323,7 @@ public class PatchListLoader extends CacheLoader<PatchListKey, PatchList> {
     }
 
     ResolveMerger m = (ResolveMerger) mergeStrategy.newMerger(repo, true);
-    final ObjectInserter ins = repo.newObjectInserter();
+    try (ObjectInserter ins = repo.newObjectInserter()) {
-    try {
       DirCache dc = DirCache.newInCore();
       m.setDirCache(dc);
       m.setObjectInserter(new ObjectInserter.Filter() {
@@ -452,19 +448,14 @@ public class PatchListLoader extends CacheLoader<PatchListKey, PatchList> {
       }
 
       return rw.lookupTree(treeId);
-    } finally {
-      ins.release();
     }
   }
 
   private static ObjectId emptyTree(final Repository repo) throws IOException {
-    ObjectInserter oi = repo.newObjectInserter();
+    try (ObjectInserter oi = repo.newObjectInserter()) {
-    try {
       ObjectId id = oi.insert(Constants.OBJ_TREE, new byte[] {});
       oi.flush();
       return id;
-    } finally {
-      oi.release();
     }
   }
 }

gerrit-server/src/main/java/com/google/gerrit/server/patch/PatchScriptBuilder.java

@@ -119,7 +119,7 @@ class PatchScriptBuilder {
     try {
       return build(content, comments, history);
     } finally {
-      reader.release();
+      reader.close();
     }
   }
 
@@ -514,11 +514,12 @@ class PatchScriptBuilder {
       if (path == null || within == null) {
         return null;
       }
-      final RevWalk rw = new RevWalk(reader);
+      try (RevWalk rw = new RevWalk(reader)) {
         final RevTree tree = rw.parseTree(within);
         return TreeWalk.forPath(reader, path, tree);
       }
     }
+  }
 
   private static boolean isBothFile(FileMode a, FileMode b) {
     return (a.getBits() & FileMode.TYPE_FILE) == FileMode.TYPE_FILE

gerrit-server/src/main/java/com/google/gerrit/server/patch/PatchSetInfoFactory.java

@@ -85,17 +85,12 @@ public class PatchSetInfoFactory {
     } catch (IOException e) {
       throw new PatchSetInfoNotAvailableException(e);
     }
-    try {
+    try (RevWalk rw = new RevWalk(repo)) {
-      final RevWalk rw = new RevWalk(repo);
-      try {
       final RevCommit src =
           rw.parseCommit(ObjectId.fromString(patchSet.getRevision().get()));
       PatchSetInfo info = get(src, patchSet.getId());
       info.setParents(toParentInfos(src.getParents(), rw));
       return info;
-      } finally {
-        rw.release();
-      }
     } catch (IOException e) {
       throw new PatchSetInfoNotAvailableException(e);
     } finally {

gerrit-server/src/main/java/com/google/gerrit/server/patch/Text.java

@@ -44,7 +44,7 @@ public class Text extends RawText {
   public static final Text EMPTY = new Text(NO_BYTES);
 
   public static Text forCommit(ObjectReader reader, AnyObjectId commitId) throws IOException {
-    RevWalk rw = new RevWalk(reader);
+    try (RevWalk rw = new RevWalk(reader)) {
       RevCommit c;
       if (commitId instanceof RevCommit) {
         c = (RevCommit) commitId;
@@ -83,6 +83,7 @@ public class Text extends RawText {
       b.append(c.getFullMessage());
       return new Text(b.toString().getBytes("UTF-8"));
     }
+  }
 
   private static void appendPersonIdent(StringBuilder b, String field,
       PersonIdent person) {

gerrit-server/src/main/java/com/google/gerrit/server/project/CommitsCollection.java

@@ -65,10 +65,8 @@ public class CommitsCollection implements
       throw new ResourceNotFoundException(id);
     }
 
-    Repository repo = repoManager.openRepository(parent.getNameKey());
+    try (Repository repo = repoManager.openRepository(parent.getNameKey());
-    try {
+        RevWalk rw = new RevWalk(repo)) {
-      RevWalk rw = new RevWalk(repo);
-      try {
       RevCommit commit = rw.parseCommit(objectId);
       rw.parseBody(commit);
       if (!parent.getControl().canReadCommit(db.get(), rw, commit)) {
@@ -80,11 +78,6 @@ public class CommitsCollection implements
       return new CommitResource(parent, commit);
     } catch (MissingObjectException | IncorrectObjectTypeException e) {
       throw new ResourceNotFoundException(id);
-      } finally {
-        rw.release();
-      }
-    } finally {
-      repo.close();
     }
   }
 

gerrit-server/src/main/java/com/google/gerrit/server/project/DeleteBranches.java

@@ -99,11 +99,8 @@ class DeleteBranches implements RestModifyView<ProjectResource, Input> {
       for (String branch : input.branches) {
         batchUpdate.addCommand(createDeleteCommand(project, r, branch));
       }
-      RevWalk rw = new RevWalk(r);
+      try (RevWalk rw = new RevWalk(r)) {
-      try {
         batchUpdate.execute(rw, NullProgressMonitor.INSTANCE);
-      } finally {
-        rw.release();
       }
       StringBuilder errorMessages = new StringBuilder();
       for (ReceiveCommand command : batchUpdate.getCommands()) {

gerrit-server/src/main/java/com/google/gerrit/server/project/GetHead.java

@@ -49,9 +49,7 @@ public class GetHead implements RestReadView<ProjectResource> {
   @Override
   public String apply(ProjectResource rsrc) throws AuthException,
       ResourceNotFoundException, IOException {
-    Repository repo = null;
+    try (Repository repo = repoManager.openRepository(rsrc.getNameKey())) {
-    try {
-      repo = repoManager.openRepository(rsrc.getNameKey());
       Ref head = repo.getRef(Constants.HEAD);
       if (head == null) {
         throw new ResourceNotFoundException(Constants.HEAD);
@@ -62,8 +60,7 @@ public class GetHead implements RestReadView<ProjectResource> {
         }
         throw new AuthException("not allowed to see HEAD");
       } else if (head.getObjectId() != null) {
-        RevWalk rw = new RevWalk(repo);
+        try (RevWalk rw = new RevWalk(repo)) {
-        try {
           RevCommit commit = rw.parseCommit(head.getObjectId());
           if (rsrc.getControl().canReadCommit(db.get(), rw, commit)) {
             return head.getObjectId().name();
@@ -74,17 +71,11 @@ public class GetHead implements RestReadView<ProjectResource> {
             return head.getObjectId().name();
           }
           throw new AuthException("not allowed to see HEAD");
-        } finally {
-          rw.release();
         }
       }
       throw new ResourceNotFoundException(Constants.HEAD);
     } catch (RepositoryNotFoundException e) {
       throw new ResourceNotFoundException(rsrc.getName());
-    } finally {
-      if (repo != null) {
-        repo.close();
-      }
     }
   }
 }

gerrit-server/src/main/java/com/google/gerrit/server/project/ListDashboards.java

@@ -82,15 +82,9 @@ class ListDashboards implements RestReadView<ProjectResource> {
 
   private List<DashboardInfo> scan(ProjectControl ctl, String project,
       boolean setDefault) throws ResourceNotFoundException, IOException {
-    Repository git;
+    Project.NameKey projectName = ctl.getProject().getNameKey();
-    try {
+    try (Repository git = gitManager.openRepository(projectName);
-      git = gitManager.openRepository(ctl.getProject().getNameKey());
+        RevWalk rw = new RevWalk(git)) {
-    } catch (RepositoryNotFoundException e) {
-      throw new ResourceNotFoundException();
-    }
-    try {
-      RevWalk rw = new RevWalk(git);
-      try {
       List<DashboardInfo> all = Lists.newArrayList();
       for (Ref ref : git.getRefDatabase().getRefs(REFS_DASHBOARDS).values()) {
         if (ctl.controlForRef(ref.getName()).canRead()) {
@@ -99,11 +93,8 @@ class ListDashboards implements RestReadView<ProjectResource> {
         }
       }
       return all;
-      } finally {
+    } catch (RepositoryNotFoundException e) {
-        rw.release();
+      throw new ResourceNotFoundException();
-      }
-    } finally {
-      git.close();
     }
   }
 
@@ -111,7 +102,7 @@ class ListDashboards implements RestReadView<ProjectResource> {
       Repository git, RevWalk rw, Ref ref, String project, boolean setDefault)
       throws IOException {
     List<DashboardInfo> list = Lists.newArrayList();
-    TreeWalk tw = new TreeWalk(rw.getObjectReader());
+    try (TreeWalk tw = new TreeWalk(rw.getObjectReader())) {
       tw.addTree(rw.parseTree(ref.getObjectId()));
       tw.setRecursive(true);
       while (tw.next()) {
@@ -132,6 +123,7 @@ class ListDashboards implements RestReadView<ProjectResource> {
           }
         }
       }
+    }
     return list;
   }
 }

gerrit-server/src/main/java/com/google/gerrit/server/project/ListTags.java

@@ -98,26 +98,17 @@ public class ListTags implements RestReadView<ProjectResource> {
 
   public TagInfo get(ProjectResource resource, IdString id)
       throws ResourceNotFoundException, IOException {
-    Repository repo = getRepository(resource.getNameKey());
+    try (Repository repo = getRepository(resource.getNameKey());
-
+        RevWalk rw = new RevWalk(repo)) {
       String tagName = id.get();
       if (!tagName.startsWith(Constants.R_TAGS)) {
         tagName = Constants.R_TAGS + tagName;
       }
-
-    try {
-      RevWalk rw = new RevWalk(repo);
-      try {
       Ref ref = repo.getRefDatabase().getRef(tagName);
       if (ref != null && !visibleTags(resource.getControl(), repo,
           ImmutableMap.of(ref.getName(), ref)).isEmpty()) {
         return createTagInfo(ref, rw);
       }
-      } finally {
-        rw.dispose();
-      }
-    } finally {
-      repo.close();
     }
     throw new ResourceNotFoundException(id);
   }

gerrit-server/src/main/java/com/google/gerrit/server/project/PerformCreateProject.java

@@ -270,8 +270,7 @@ public class PerformCreateProject {
   private void createEmptyCommits(final Repository repo,
       final Project.NameKey project, final List<String> refs)
       throws IOException {
-    ObjectInserter oi = repo.newObjectInserter();
+    try (ObjectInserter oi = repo.newObjectInserter()) {
-    try {
       CommitBuilder cb = new CommitBuilder();
       cb.setTreeId(oi.insert(Constants.OBJ_TREE, new byte[] {}));
       cb.setAuthor(metaDataUpdateFactory.getUserPersonIdent());
@@ -300,8 +299,6 @@ public class PerformCreateProject {
           "Cannot create empty commit for "
               + createProjectArgs.getProjectName(), e);
       throw e;
-    } finally {
-      oi.release();
     }
   }
 }

gerrit-server/src/main/java/com/google/gerrit/server/query/change/ChangeData.java

@@ -523,18 +523,11 @@ public class ChangeData {
       return false;
     }
     String sha1 = ps.getRevision().get();
-    Repository repo = repoManager.openRepository(change().getProject());
+    try (Repository repo = repoManager.openRepository(change().getProject());
-    try {
+        RevWalk walk = new RevWalk(repo)) {
-      RevWalk walk = new RevWalk(repo);
-      try {
       RevCommit c = walk.parseCommit(ObjectId.fromString(sha1));
       commitMessage = c.getFullMessage();
       commitFooters = c.getFooterLines();
-      } finally {
-        walk.release();
-      }
-    } finally {
-      repo.close();
     }
     return true;
   }

gerrit-server/src/main/java/com/google/gerrit/server/query/change/ConflictsPredicate.java

@@ -107,12 +107,9 @@ class ConflictsPredicate extends OrPredicate<ChangeData> {
           if (conflicts != null) {
             return conflicts;
           }
-          try {
+          try (Repository repo =
-            Repository repo =
                 args.repoManager.openRepository(otherChange.getProject());
-            try {
+              RevWalk rw = CodeReviewCommit.newRevWalk(repo)) {
-              RevWalk rw = CodeReviewCommit.newRevWalk(repo);
-              try {
             RevFlag canMergeFlag = rw.newFlag("CAN_MERGE");
             CodeReviewCommit commit =
                 (CodeReviewCommit) rw.parseCommit(changeDataCache.getTestAgainst());
@@ -127,17 +124,7 @@ class ConflictsPredicate extends OrPredicate<ChangeData> {
             conflicts = !strategy.dryRun(commit, otherCommit);
             args.conflictsCache.put(conflictsKey, conflicts);
             return conflicts;
-              } catch (MergeException e) {
+          } catch (MergeException | NoSuchProjectException | IOException e) {
-                throw new IllegalStateException(e);
-              } catch (NoSuchProjectException e) {
-                throw new IllegalStateException(e);
-              } finally {
-                rw.release();
-              }
-            } finally {
-              repo.close();
-            }
-          } catch (IOException e) {
             throw new IllegalStateException(e);
           }
         }

gerrit-server/src/main/java/com/google/gerrit/server/query/change/RevWalkPredicate.java

@@ -102,18 +102,9 @@ public abstract class RevWalkPredicate extends OperatorPredicate<ChangeData> {
 
     Arguments args = new Arguments(patchSet, revision, objectId, change, projectName);
 
-    try {
+    try (Repository repo = repoManager.openRepository(projectName);
-      final Repository repo = repoManager.openRepository(projectName);
+        RevWalk rw = new RevWalk(repo)) {
-      try {
-        final RevWalk rw = new RevWalk(repo);
-        try {
       return match(repo, rw, args);
-        } finally {
-          rw.release();
-        }
-      } finally {
-        repo.close();
-      }
     } catch (RepositoryNotFoundException e) {
       log.error("Repository \"" + projectName.get() + "\" unknown.", e);
     } catch (IOException e) {

gerrit-server/src/main/java/gerrit/PRED_commit_edits_2.java

@@ -73,11 +73,10 @@ public class PRED_commit_edits_2 extends Predicate.P2 {
     PatchList pl = StoredValues.PATCH_LIST.get(engine);
     Repository repo = StoredValues.REPOSITORY.get(engine);
 
-    final ObjectReader reader = repo.newObjectReader();
+    try (ObjectReader reader = repo.newObjectReader();
+        RevWalk rw = new RevWalk(reader)) {
       final RevTree aTree;
       final RevTree bTree;
-    try {
-      final RevWalk rw = new RevWalk(reader);
       final RevCommit bCommit = rw.parseCommit(pl.getNewId());
 
       if (pl.getOldId() != null) {
@@ -129,8 +128,6 @@ public class PRED_commit_edits_2 extends Predicate.P2 {
       }
     } catch (IOException err) {
       throw new JavaException(this, 1, err);
-    } finally {
-      reader.release();
     }
 
     return engine.fail();

gerrit-server/src/test/java/com/google/gerrit/server/change/IncludedInResolverTest.java

@@ -86,6 +86,8 @@ public class IncludedInResolverTest extends RepositoryTestCase {
 
      */
 
+    // TODO(dborowitz): Use try/finally when this doesn't double-close the repo.
+    @SuppressWarnings("resource")
     Git git = new Git(db);
     revWalk = new RevWalk(db);
     // Version 1.0
@@ -129,7 +131,7 @@ public class IncludedInResolverTest extends RepositoryTestCase {
   @Override
   @After
   public void tearDown() throws Exception {
-    revWalk.release();
+    revWalk.close();
     super.tearDown();
   }
 

gerrit-server/src/test/java/com/google/gerrit/server/git/SubmoduleOpTest.java

@@ -118,7 +118,9 @@ public class SubmoduleOpTest extends LocalDiskRepositoryTestCase {
   public void testEmptyCommit() throws Exception {
     expect(schemaFactory.open()).andReturn(schema);
 
-    final Repository realDb = createWorkRepository();
+    try (Repository realDb = createWorkRepository()) {
+      // TODO(dborowitz): Use try/finally when this doesn't double-close the repo.
+      @SuppressWarnings("resource")
       final Git git = new Git(realDb);
 
       final RevCommit mergeTip = git.commit().setMessage("test").call();
@@ -147,6 +149,7 @@ public class SubmoduleOpTest extends LocalDiskRepositoryTestCase {
 
       doVerify();
     }
+  }
 
   /**
    * It tests SubmoduleOp.update in a scenario considering:
@@ -588,8 +591,14 @@ public class SubmoduleOpTest extends LocalDiskRepositoryTestCase {
   public void testOneSubscriberToUpdate() throws Exception {
     expect(schemaFactory.open()).andReturn(schema);
 
-    final Repository sourceRepository = createWorkRepository();
+    try (Repository sourceRepository = createWorkRepository();
+        Repository targetRepository = createWorkRepository()) {
+      // TODO(dborowitz): Use try/finally when this doesn't double-close the repo.
+      @SuppressWarnings("resource")
       final Git sourceGit = new Git(sourceRepository);
+      // TODO(dborowitz): Use try/finally when this doesn't double-close the repo.
+      @SuppressWarnings("resource")
+      final Git targetGit = new Git(targetRepository);
 
       addRegularFileToIndex("file.txt", "test content", sourceRepository);
 
@@ -612,9 +621,6 @@ public class SubmoduleOpTest extends LocalDiskRepositoryTestCase {
       final List<Change> submitted = new ArrayList<>();
       submitted.add(submittedChange);
 
-    final Repository targetRepository = createWorkRepository();
-    final Git targetGit = new Git(targetRepository);
-
       addGitLinkToIndex("a", sourceMergeTip.copy(), targetRepository);
 
       targetGit.commit().setMessage("test").call();
@@ -668,6 +674,7 @@ public class SubmoduleOpTest extends LocalDiskRepositoryTestCase {
       RefUpdate ru = ruCapture.getValue();
       assertEquals(ru.getName(), targetBranchNameKey.get());
     }
+  }
 
   /**
    * It tests SubmoduleOp.update in a scenario considering established circular
@@ -693,8 +700,14 @@ public class SubmoduleOpTest extends LocalDiskRepositoryTestCase {
   public void testAvoidingCircularReference() throws Exception {
     expect(schemaFactory.open()).andReturn(schema);
 
-    final Repository sourceRepository = createWorkRepository();
+    try (Repository sourceRepository = createWorkRepository();
+        Repository targetRepository = createWorkRepository()) {
+      // TODO(dborowitz): Use try/finally when this doesn't double-close the repo.
+      @SuppressWarnings("resource")
       final Git sourceGit = new Git(sourceRepository);
+      // TODO(dborowitz): Use try/finally when this doesn't double-close the repo.
+      @SuppressWarnings("resource")
+      final Git targetGit = new Git(targetRepository);
 
       addRegularFileToIndex("file.txt", "test content", sourceRepository);
 
@@ -717,9 +730,6 @@ public class SubmoduleOpTest extends LocalDiskRepositoryTestCase {
       final List<Change> submitted = new ArrayList<>();
       submitted.add(submittedChange);
 
-    final Repository targetRepository = createWorkRepository();
-    final Git targetGit = new Git(targetRepository);
-
       addGitLinkToIndex("a", sourceMergeTip.copy(), targetRepository);
 
       targetGit.commit().setMessage("test").call();
@@ -774,6 +784,7 @@ public class SubmoduleOpTest extends LocalDiskRepositoryTestCase {
       RefUpdate ru = ruCapture.getValue();
       assertEquals(ru.getName(), targetBranchNameKey.get());
     }
+  }
 
   /**
    * It calls SubmoduleOp.update considering only one insert on Subscriptions
@@ -862,7 +873,9 @@ public class SubmoduleOpTest extends LocalDiskRepositoryTestCase {
       final List<SubmoduleSubscription> previousSubscriptions) throws Exception {
     expect(schemaFactory.open()).andReturn(schema);
 
-    final Repository realDb = createWorkRepository();
+    try (Repository realDb = createWorkRepository()) {
+      // TODO(dborowitz): Use try/finally when this doesn't double-close the repo.
+      @SuppressWarnings("resource")
       final Git git = new Git(realDb);
 
       addRegularFileToIndex(".gitmodules", gitModulesFileContent, realDb);
@@ -924,6 +937,7 @@ public class SubmoduleOpTest extends LocalDiskRepositoryTestCase {
 
       submoduleOp.update();
     }
+  }
 
   /**
    * It creates and adds a regular file to git index of a repository.

gerrit-server/src/test/java/com/google/gerrit/server/notedb/ChangeNotesParserTest.java

@@ -43,7 +43,7 @@ public class ChangeNotesParserTest extends AbstractChangeNotesTest {
 
   @After
   public void tearDownTestRepo() throws Exception {
-    walk.release();
+    walk.close();
   }
 
   @Test
@@ -176,8 +176,7 @@ public class ChangeNotesParserTest extends AbstractChangeNotesTest {
 
   private RevCommit writeCommit(String body, PersonIdent author)
       throws Exception {
-    ObjectInserter ins = testRepo.getRepository().newObjectInserter();
+    try (ObjectInserter ins = testRepo.getRepository().newObjectInserter()) {
-    try {
       CommitBuilder cb = new CommitBuilder();
       cb.setAuthor(author);
       cb.setCommitter(new PersonIdent(serverIdent, author.getWhen()));
@@ -188,8 +187,6 @@ public class ChangeNotesParserTest extends AbstractChangeNotesTest {
       RevCommit commit = walk.parseCommit(id);
       walk.parseBody(commit);
       return commit;
-    } finally {
-      ins.release();
     }
   }
 

gerrit-server/src/test/java/com/google/gerrit/server/notedb/ChangeNotesTest.java

@@ -348,13 +348,10 @@ public class ChangeNotesTest extends AbstractChangeNotesTest {
     hashtags.add("tag2");
     update.setHashtags(hashtags);
     update.commit();
-    RevWalk walk = new RevWalk(repo);
+    try (RevWalk walk = new RevWalk(repo)) {
-    try {
       RevCommit commit = walk.parseCommit(update.getRevision());
       walk.parseBody(commit);
       assertTrue(commit.getFullMessage().endsWith("Hashtags: tag1,tag2\n"));
-    } finally {
-      walk.release();
     }
   }
 
@@ -433,8 +430,7 @@ public class ChangeNotesTest extends AbstractChangeNotesTest {
     update2.putApproval("Code-Review", (short) 2);
     update2.writeCommit(batch);
 
-    RevWalk rw = new RevWalk(repo);
+    try (RevWalk rw = new RevWalk(repo)) {
-    try {
       batch.commit();
       bru.execute(rw, NullProgressMonitor.INSTANCE);
 
@@ -464,7 +460,6 @@ public class ChangeNotesTest extends AbstractChangeNotesTest {
       notesWithApprovals.close();
     } finally {
       batch.close();
-      rw.release();
     }
   }
 
@@ -506,11 +501,8 @@ public class ChangeNotesTest extends AbstractChangeNotesTest {
     assertEquals(update1.getRefName(), cmds.get(0).getRefName());
     assertEquals(update2.getRefName(), cmds.get(1).getRefName());
 
-    RevWalk rw = new RevWalk(repo);
+    try (RevWalk rw = new RevWalk(repo)) {
-    try {
       bru.execute(rw, NullProgressMonitor.INSTANCE);
-    } finally {
-      rw.release();
     }
 
     assertEquals(ReceiveCommand.Result.OK, cmds.get(0).getResult());
@@ -712,7 +704,7 @@ public class ChangeNotesTest extends AbstractChangeNotesTest {
 
     ChangeNotes notes = newNotes(c);
 
-    RevWalk walk = new RevWalk(repo);
+    try (RevWalk walk = new RevWalk(repo)) {
       ArrayList<Note> notesInTree =
           Lists.newArrayList(notes.getNoteMap().iterator());
       Note note = Iterables.getOnlyElement(notesInTree);
@@ -750,6 +742,7 @@ public class ChangeNotesTest extends AbstractChangeNotesTest {
           + "\n",
           noteString);
     }
+  }
 
   @Test
   public void patchLineCommentNotesFormatSide0() throws Exception {
@@ -782,7 +775,7 @@ public class ChangeNotesTest extends AbstractChangeNotesTest {
 
     ChangeNotes notes = newNotes(c);
 
-    RevWalk walk = new RevWalk(repo);
+    try (RevWalk walk = new RevWalk(repo)) {
       ArrayList<Note> notesInTree =
           Lists.newArrayList(notes.getNoteMap().iterator());
       Note note = Iterables.getOnlyElement(notesInTree);
@@ -811,6 +804,7 @@ public class ChangeNotesTest extends AbstractChangeNotesTest {
           + "\n",
           noteString);
     }
+  }
 
   @Test
   public void patchLineCommentMultipleOnePatchsetOneFileBothSides()

gerrit-server/src/test/java/com/google/gerrit/server/notedb/CommitMessageOutputTest.java

@@ -242,13 +242,10 @@ public class CommitMessageOutputTest extends AbstractChangeNotesTest {
     if (id instanceof RevCommit) {
       return (RevCommit) id;
     }
-    RevWalk walk = new RevWalk(repo);
+    try (RevWalk walk = new RevWalk(repo)) {
-    try {
       RevCommit commit = walk.parseCommit(id);
       walk.parseBody(commit);
       return commit;
-    } finally {
-      walk.release();
     }
   }
 

gerrit-server/src/test/java/com/google/gerrit/server/tools/hooks/CommitMsgHookTest.java

@@ -423,21 +423,17 @@ public class CommitMsgHookTest extends HookTestCase {
   }
 
   private DirCacheEntry file(final String name) throws IOException {
-    final ObjectInserter oi = repository.newObjectInserter();
+    try (ObjectInserter oi = repository.newObjectInserter()) {
-    try {
       final DirCacheEntry e = new DirCacheEntry(name);
       e.setFileMode(FileMode.REGULAR_FILE);
       e.setObjectId(oi.insert(Constants.OBJ_BLOB, Constants.encode(name)));
       oi.flush();
       return e;
-    } finally {
-      oi.release();
     }
   }
 
   private void setHEAD() throws Exception {
-    final ObjectInserter oi = repository.newObjectInserter();
+    try (ObjectInserter oi = repository.newObjectInserter()) {
-    try {
       final CommitBuilder commit = new CommitBuilder();
       commit.setTreeId(oi.insert(Constants.OBJ_TREE, new byte[] {}));
       commit.setAuthor(author);
@@ -456,8 +452,6 @@ public class CommitMsgHookTest extends HookTestCase {
         default:
           fail(Constants.HEAD + " did not change: " + ref.getResult());
       }
-    } finally {
-      oi.release();
     }
   }
 }