Transport: Implement AutoCloseable

After creating a Transport instance callers should always call
its close() method. Use AutoCloseable to document this idiom
and allow use of try-with-resources.

Change-Id: I0c6ff3e39ebecdd7a028dbcae1856a818937b186

org.eclipse.jgit.http.test/tst/org/eclipse/jgit/http/test/DumbClientDumbServerTest.java

@@ -140,8 +140,7 @@ public class DumbClientDumbServerTest extends HttpTestCase {
 		assertEquals("http", remoteURI.getScheme());
 
 		Map<String, Ref> map;
-		Transport t = Transport.open(dst, remoteURI);
+		try (Transport t = Transport.open(dst, remoteURI)) {
-		try {
 			// I didn't make up these public interface names, I just
 			// approved them for inclusion into the code base. Sorry.
 			// --spearce
@@ -149,14 +148,9 @@ public class DumbClientDumbServerTest extends HttpTestCase {
 			assertTrue("isa TransportHttp", t instanceof TransportHttp);
 			assertTrue("isa HttpTransport", t instanceof HttpTransport);
 
-			FetchConnection c = t.openFetch();
+			try (FetchConnection c = t.openFetch()) {
-			try {
 				map = c.getRefsMap();
-			} finally {
-				c.close();
 			}
-		} finally {
-			t.close();
 		}
 
 		assertNotNull("have map of refs", map);
@@ -201,11 +195,8 @@ public class DumbClientDumbServerTest extends HttpTestCase {
 		Repository dst = createBareRepository();
 		assertFalse(dst.hasObject(A_txt));
 
-		Transport t = Transport.open(dst, remoteURI);
+		try (Transport t = Transport.open(dst, remoteURI)) {
-		try {
 			t.fetch(NullProgressMonitor.INSTANCE, mirror(master));
-		} finally {
-			t.close();
 		}
 
 		assertTrue(dst.hasObject(A_txt));
@@ -226,11 +217,8 @@ public class DumbClientDumbServerTest extends HttpTestCase {
 		Repository dst = createBareRepository();
 		assertFalse(dst.hasObject(A_txt));
 
-		Transport t = Transport.open(dst, remoteURI);
+		try (Transport t = Transport.open(dst, remoteURI)) {
-		try {
 			t.fetch(NullProgressMonitor.INSTANCE, mirror(master));
-		} finally {
-			t.close();
 		}
 
 		assertTrue(dst.hasObject(A_txt));
@@ -265,8 +253,7 @@ public class DumbClientDumbServerTest extends HttpTestCase {
 		final RevCommit Q = src.commit().create();
 		final Repository db = src.getRepository();
 
-		Transport t = Transport.open(db, remoteURI);
+		try (Transport t = Transport.open(db, remoteURI)) {
-		try {
 			try {
 				t.push(NullProgressMonitor.INSTANCE, push(src, Q));
 				fail("push incorrectly completed against a dumb server");
@@ -274,8 +261,6 @@ public class DumbClientDumbServerTest extends HttpTestCase {
 				String exp = "remote does not support smart HTTP push";
 				assertEquals(exp, nse.getMessage());
 			}
-		} finally {
-			t.close();
 		}
 	}
 }

org.eclipse.jgit.http.test/tst/org/eclipse/jgit/http/test/HttpClientTests.java

@@ -157,8 +157,7 @@ public class HttpClientTests extends HttpTestCase {
 	public void testRepositoryNotFound_Dumb() throws Exception {
 		URIish uri = toURIish("/dumb.none/not-found");
 		Repository dst = createBareRepository();
-		Transport t = Transport.open(dst, uri);
+		try (Transport t = Transport.open(dst, uri)) {
-		try {
 			try {
 				t.openFetch();
 				fail("connection opened to not found repository");
@@ -167,8 +166,6 @@ public class HttpClientTests extends HttpTestCase {
 						+ "/info/refs?service=git-upload-pack not found";
 				assertEquals(exp, err.getMessage());
 			}
-		} finally {
-			t.close();
 		}
 	}
 
@@ -176,8 +173,7 @@ public class HttpClientTests extends HttpTestCase {
 	public void testRepositoryNotFound_Smart() throws Exception {
 		URIish uri = toURIish("/smart.none/not-found");
 		Repository dst = createBareRepository();
-		Transport t = Transport.open(dst, uri);
+		try (Transport t = Transport.open(dst, uri)) {
-		try {
 			try {
 				t.openFetch();
 				fail("connection opened to not found repository");
@@ -186,8 +182,6 @@ public class HttpClientTests extends HttpTestCase {
 						+ "/info/refs?service=git-upload-pack not found";
 				assertEquals(exp, err.getMessage());
 			}
-		} finally {
-			t.close();
 		}
 	}
 
@@ -201,16 +195,9 @@ public class HttpClientTests extends HttpTestCase {
 
 		Repository dst = createBareRepository();
 		Ref head;
-		Transport t = Transport.open(dst, dumbAuthNoneURI);
+		try (Transport t = Transport.open(dst, dumbAuthNoneURI);
-		try {
+				FetchConnection c = t.openFetch()) {
-			FetchConnection c = t.openFetch();
-			try {
 			head = c.getRef(Constants.HEAD);
-			} finally {
-				c.close();
-			}
-		} finally {
-			t.close();
 		}
 		assertNotNull("has " + Constants.HEAD, head);
 		assertEquals(Q, head.getObjectId());
@@ -225,16 +212,9 @@ public class HttpClientTests extends HttpTestCase {
 
 		Repository dst = createBareRepository();
 		Ref head;
-		Transport t = Transport.open(dst, dumbAuthNoneURI);
+		try (Transport t = Transport.open(dst, dumbAuthNoneURI);
-		try {
+				FetchConnection c = t.openFetch()) {
-			FetchConnection c = t.openFetch();
-			try {
 			head = c.getRef(Constants.HEAD);
-			} finally {
-				c.close();
-			}
-		} finally {
-			t.close();
 		}
 		assertNull("has no " + Constants.HEAD, head);
 	}
@@ -249,16 +229,9 @@ public class HttpClientTests extends HttpTestCase {
 
 		Repository dst = createBareRepository();
 		Ref head;
-		Transport t = Transport.open(dst, smartAuthNoneURI);
+		try (Transport t = Transport.open(dst, smartAuthNoneURI);
-		try {
+				FetchConnection c = t.openFetch()) {
-			FetchConnection c = t.openFetch();
-			try {
 			head = c.getRef(Constants.HEAD);
-			} finally {
-				c.close();
-			}
-		} finally {
-			t.close();
 		}
 		assertNotNull("has " + Constants.HEAD, head);
 		assertEquals(Q, head.getObjectId());
@@ -268,16 +241,13 @@ public class HttpClientTests extends HttpTestCase {
 	public void testListRemote_Smart_WithQueryParameters() throws Exception {
 		URIish myURI = toURIish("/snone/do?r=1&p=test.git");
 		Repository dst = createBareRepository();
-		Transport t = Transport.open(dst, myURI);
+		try (Transport t = Transport.open(dst, myURI)) {
-		try {
 			try {
 				t.openFetch();
 				fail("test did not fail to find repository as expected");
 			} catch (NoRemoteRepositoryException err) {
 				// expected
 			}
-		} finally {
-			t.close();
 		}
 
 		List<AccessEvent> requests = getRequests();
@@ -296,8 +266,7 @@ public class HttpClientTests extends HttpTestCase {
 	@Test
 	public void testListRemote_Dumb_NeedsAuth() throws Exception {
 		Repository dst = createBareRepository();
-		Transport t = Transport.open(dst, dumbAuthBasicURI);
+		try (Transport t = Transport.open(dst, dumbAuthBasicURI)) {
-		try {
 			try {
 				t.openFetch();
 				fail("connection opened even info/refs needs auth basic");
@@ -306,23 +275,18 @@ public class HttpClientTests extends HttpTestCase {
 						+ JGitText.get().noCredentialsProvider;
 				assertEquals(exp, err.getMessage());
 			}
-		} finally {
-			t.close();
 		}
 	}
 
 	@Test
 	public void testListRemote_Dumb_Auth() throws Exception {
 		Repository dst = createBareRepository();
-		Transport t = Transport.open(dst, dumbAuthBasicURI);
+		try (Transport t = Transport.open(dst, dumbAuthBasicURI)) {
 			t.setCredentialsProvider(new UsernamePasswordCredentialsProvider(
 					AppServer.username, AppServer.password));
-		try {
+			t.openFetch().close();
-			t.openFetch();
-		} finally {
-			t.close();
 		}
-		t = Transport.open(dst, dumbAuthBasicURI);
+		try (Transport t = Transport.open(dst, dumbAuthBasicURI)) {
 			t.setCredentialsProvider(new UsernamePasswordCredentialsProvider(
 					AppServer.username, ""));
 			try {
@@ -332,16 +296,14 @@ public class HttpClientTests extends HttpTestCase {
 				String exp = dumbAuthBasicURI + ": "
 						+ JGitText.get().notAuthorized;
 				assertEquals(exp, err.getMessage());
-		} finally {
+			}
-			t.close();
 		}
 	}
 
 	@Test
 	public void testListRemote_Smart_UploadPackNeedsAuth() throws Exception {
 		Repository dst = createBareRepository();
-		Transport t = Transport.open(dst, smartAuthBasicURI);
+		try (Transport t = Transport.open(dst, smartAuthBasicURI)) {
-		try {
 			try {
 				t.openFetch();
 				fail("connection opened even though service disabled");
@@ -350,8 +312,6 @@ public class HttpClientTests extends HttpTestCase {
 						+ JGitText.get().noCredentialsProvider;
 				assertEquals(exp, err.getMessage());
 			}
-		} finally {
-			t.close();
 		}
 	}
 
@@ -363,8 +323,7 @@ public class HttpClientTests extends HttpTestCase {
 		cfg.save();
 
 		Repository dst = createBareRepository();
-		Transport t = Transport.open(dst, smartAuthNoneURI);
+		try (Transport t = Transport.open(dst, smartAuthNoneURI)) {
-		try {
 			try {
 				t.openFetch();
 				fail("connection opened even though service disabled");
@@ -373,24 +332,15 @@ public class HttpClientTests extends HttpTestCase {
 						+ JGitText.get().serviceNotEnabledNoName;
 				assertEquals(exp, err.getMessage());
 			}
-		} finally {
-			t.close();
 		}
 	}
 
 	@Test
 	public void testListRemoteWithoutLocalRepository() throws Exception {
-		Transport t = Transport.open(smartAuthNoneURI);
+		try (Transport t = Transport.open(smartAuthNoneURI);
-		try {
+				FetchConnection c = t.openFetch()) {
-			FetchConnection c = t.openFetch();
-			try {
 			Ref head = c.getRef(Constants.HEAD);
 			assertNotNull(head);
-			} finally {
-				c.close();
-			}
-		} finally {
-			t.close();
 		}
 	}
 }

org.eclipse.jgit.http.test/tst/org/eclipse/jgit/http/test/SmartClientSmartServerTest.java

@@ -211,8 +211,7 @@ public class SmartClientSmartServerTest extends HttpTestCase {
 		assertEquals("http", remoteURI.getScheme());
 
 		Map<String, Ref> map;
-		Transport t = Transport.open(dst, remoteURI);
+		try (Transport t = Transport.open(dst, remoteURI)) {
-		try {
 			// I didn't make up these public interface names, I just
 			// approved them for inclusion into the code base. Sorry.
 			// --spearce
@@ -226,8 +225,6 @@ public class SmartClientSmartServerTest extends HttpTestCase {
 			} finally {
 				c.close();
 			}
-		} finally {
-			t.close();
 		}
 
 		assertNotNull("have map of refs", map);
@@ -257,8 +254,7 @@ public class SmartClientSmartServerTest extends HttpTestCase {
 	public void testListRemote_BadName() throws IOException, URISyntaxException {
 		Repository dst = createBareRepository();
 		URIish uri = new URIish(this.remoteURI.toString() + ".invalid");
-		Transport t = Transport.open(dst, uri);
+		try (Transport t = Transport.open(dst, uri)) {
-		try {
 			try {
 				t.openFetch();
 				fail("fetch connection opened");
@@ -266,8 +262,6 @@ public class SmartClientSmartServerTest extends HttpTestCase {
 				assertEquals(uri + ": Git repository not found",
 						notFound.getMessage());
 			}
-		} finally {
-			t.close();
 		}
 
 		List<AccessEvent> requests = getRequests();
@@ -288,11 +282,8 @@ public class SmartClientSmartServerTest extends HttpTestCase {
 		Repository dst = createBareRepository();
 		assertFalse(dst.hasObject(A_txt));
 
-		Transport t = Transport.open(dst, remoteURI);
+		try (Transport t = Transport.open(dst, remoteURI)) {
-		try {
 			t.fetch(NullProgressMonitor.INSTANCE, mirror(master));
-		} finally {
-			t.close();
 		}
 
 		assertTrue(dst.hasObject(A_txt));
@@ -331,11 +322,8 @@ public class SmartClientSmartServerTest extends HttpTestCase {
 		// Bootstrap by doing the clone.
 		//
 		TestRepository dst = createTestRepository();
-		Transport t = Transport.open(dst.getRepository(), remoteURI);
+		try (Transport t = Transport.open(dst.getRepository(), remoteURI)) {
-		try {
 			t.fetch(NullProgressMonitor.INSTANCE, mirror(master));
-		} finally {
-			t.close();
 		}
 		assertEquals(B, dst.getRepository().exactRef(master).getObjectId());
 		List<AccessEvent> cloneRequests = getRequests();
@@ -352,11 +340,8 @@ public class SmartClientSmartServerTest extends HttpTestCase {
 
 		// Now incrementally update.
 		//
-		t = Transport.open(dst.getRepository(), remoteURI);
+		try (Transport t = Transport.open(dst.getRepository(), remoteURI)) {
-		try {
 			t.fetch(NullProgressMonitor.INSTANCE, mirror(master));
-		} finally {
-			t.close();
 		}
 		assertEquals(Z, dst.getRepository().exactRef(master).getObjectId());
 
@@ -394,11 +379,8 @@ public class SmartClientSmartServerTest extends HttpTestCase {
 		// Bootstrap by doing the clone.
 		//
 		TestRepository dst = createTestRepository();
-		Transport t = Transport.open(dst.getRepository(), remoteURI);
+		try (Transport t = Transport.open(dst.getRepository(), remoteURI)) {
-		try {
 			t.fetch(NullProgressMonitor.INSTANCE, mirror(master));
-		} finally {
-			t.close();
 		}
 		assertEquals(B, dst.getRepository().exactRef(master).getObjectId());
 		List<AccessEvent> cloneRequests = getRequests();
@@ -418,11 +400,8 @@ public class SmartClientSmartServerTest extends HttpTestCase {
 
 		// Now incrementally update.
 		//
-		t = Transport.open(dst.getRepository(), remoteURI);
+		try (Transport t = Transport.open(dst.getRepository(), remoteURI)) {
-		try {
 			t.fetch(NullProgressMonitor.INSTANCE, mirror(master));
-		} finally {
-			t.close();
 		}
 		assertEquals(Z, dst.getRepository().exactRef(master).getObjectId());
 
@@ -474,8 +453,7 @@ public class SmartClientSmartServerTest extends HttpTestCase {
 		Repository dst = createBareRepository();
 		assertFalse(dst.hasObject(A_txt));
 
-		Transport t = Transport.open(dst, brokenURI);
+		try (Transport t = Transport.open(dst, brokenURI)) {
-		try {
 			try {
 				t.fetch(NullProgressMonitor.INSTANCE, mirror(master));
 				fail("fetch completed despite upload-pack being broken");
@@ -485,8 +463,6 @@ public class SmartClientSmartServerTest extends HttpTestCase {
 						+ " received Content-Type text/plain; charset=UTF-8";
 				assertEquals(exp, err.getMessage());
 			}
-		} finally {
-			t.close();
 		}
 
 		List<AccessEvent> requests = getRequests();
@@ -517,12 +493,10 @@ public class SmartClientSmartServerTest extends HttpTestCase {
 		final RevCommit Q = src.commit().add("Q", Q_txt).create();
 		final Repository db = src.getRepository();
 		final String dstName = Constants.R_HEADS + "new.branch";
-		Transport t;
 
 		// push anonymous shouldn't be allowed.
 		//
-		t = Transport.open(db, remoteURI);
+		try (Transport t = Transport.open(db, remoteURI)) {
-		try {
 			final String srcExpr = Q.name();
 			final boolean forceUpdate = false;
 			final String localName = null;
@@ -538,8 +512,6 @@ public class SmartClientSmartServerTest extends HttpTestCase {
 						+ JGitText.get().authenticationNotSupported;
 				assertEquals(exp, e.getMessage());
 			}
-		} finally {
-			t.close();
 		}
 
 		List<AccessEvent> requests = getRequests();
@@ -560,12 +532,10 @@ public class SmartClientSmartServerTest extends HttpTestCase {
 		final RevCommit Q = src.commit().add("Q", Q_txt).create();
 		final Repository db = src.getRepository();
 		final String dstName = Constants.R_HEADS + "new.branch";
-		Transport t;
 
 		enableReceivePack();
 
-		t = Transport.open(db, remoteURI);
+		try (Transport t = Transport.open(db, remoteURI)) {
-		try {
 			final String srcExpr = Q.name();
 			final boolean forceUpdate = false;
 			final String localName = null;
@@ -574,8 +544,6 @@ public class SmartClientSmartServerTest extends HttpTestCase {
 			RemoteRefUpdate u = new RemoteRefUpdate(src.getRepository(),
 					srcExpr, dstName, forceUpdate, localName, oldId);
 			t.push(NullProgressMonitor.INSTANCE, Collections.singleton(u));
-		} finally {
-			t.close();
 		}
 
 		assertTrue(remoteRepository.hasObject(Q_txt));
@@ -633,7 +601,6 @@ public class SmartClientSmartServerTest extends HttpTestCase {
 		final RevCommit Q = src.commit().add("Q", Q_bin).create();
 		final Repository db = src.getRepository();
 		final String dstName = Constants.R_HEADS + "new.branch";
-		Transport t;
 
 		enableReceivePack();
 
@@ -642,8 +609,7 @@ public class SmartClientSmartServerTest extends HttpTestCase {
 		cfg.setInt("http", null, "postbuffer", 8 * 1024);
 		cfg.save();
 
-		t = Transport.open(db, remoteURI);
+		try (Transport t = Transport.open(db, remoteURI)) {
-		try {
 			final String srcExpr = Q.name();
 			final boolean forceUpdate = false;
 			final String localName = null;
@@ -652,8 +618,6 @@ public class SmartClientSmartServerTest extends HttpTestCase {
 			RemoteRefUpdate u = new RemoteRefUpdate(src.getRepository(),
 					srcExpr, dstName, forceUpdate, localName, oldId);
 			t.push(NullProgressMonitor.INSTANCE, Collections.singleton(u));
-		} finally {
-			t.close();
 		}
 
 		assertTrue(remoteRepository.hasObject(Q_bin));

org.eclipse.jgit.test/tst/org/eclipse/jgit/transport/AtomicPushTest.java

@@ -112,12 +112,9 @@ public class AtomicPushTest {
 	public void pushNonAtomic() throws Exception {
 		PushResult r;
 		server.setPerformsAtomicTransactions(false);
-		Transport tn = testProtocol.open(uri, client, "server");
+		try (Transport tn = testProtocol.open(uri, client, "server")) {
-		try {
 			tn.setPushAtomic(false);
 			r = tn.push(NullProgressMonitor.INSTANCE, commands());
-		} finally {
-			tn.close();
 		}
 
 		RemoteRefUpdate one = r.getRemoteUpdate("refs/heads/one");
@@ -131,12 +128,9 @@ public class AtomicPushTest {
 	@Test
 	public void pushAtomicClientGivesUpEarly() throws Exception {
 		PushResult r;
-		Transport tn = testProtocol.open(uri, client, "server");
+		try (Transport tn = testProtocol.open(uri, client, "server")) {
-		try {
 			tn.setPushAtomic(true);
 			r = tn.push(NullProgressMonitor.INSTANCE, commands());
-		} finally {
-			tn.close();
 		}
 
 		RemoteRefUpdate one = r.getRemoteUpdate("refs/heads/one");
@@ -167,8 +161,7 @@ public class AtomicPushTest {
 				ObjectId.zeroId()));
 
 		server.setPerformsAtomicTransactions(false);
-		Transport tn = testProtocol.open(uri, client, "server");
+		try (Transport tn = testProtocol.open(uri, client, "server")) {
-		try {
 			tn.setPushAtomic(true);
 			tn.push(NullProgressMonitor.INSTANCE, cmds);
 			fail("did not throw TransportException");
@@ -176,8 +169,6 @@ public class AtomicPushTest {
 			assertEquals(
 					uri + ": " + JGitText.get().atomicPushNotSupported,
 					e.getMessage());
-		} finally {
-			tn.close();
 		}
 	}
 

org.eclipse.jgit.test/tst/org/eclipse/jgit/transport/BundleWriterTest.java

@@ -166,8 +166,10 @@ public class BundleWriterTest extends SampleDataRepositoryTestCase {
 		final ByteArrayInputStream in = new ByteArrayInputStream(bundle);
 		final RefSpec rs = new RefSpec("refs/heads/*:refs/heads/*");
 		final Set<RefSpec> refs = Collections.singleton(rs);
-		return new TransportBundleStream(newRepo, uri, in).fetch(
+		try (TransportBundleStream transport = new TransportBundleStream(
-				NullProgressMonitor.INSTANCE, refs);
+				newRepo, uri, in)) {
+			return transport.fetch(NullProgressMonitor.INSTANCE, refs);
+		}
 	}
 
 	private byte[] makeBundle(final String name,

org.eclipse.jgit.test/tst/org/eclipse/jgit/transport/ReceivePackAdvertiseRefsHookTest.java

@@ -116,12 +116,9 @@ public class ReceivePackAdvertiseRefsHookTest extends LocalDiskRepositoryTestCas
 
 		// Clone from dst into src
 		//
-		Transport t = Transport.open(src, uriOf(dst));
+		try (Transport t = Transport.open(src, uriOf(dst))) {
-		try {
 			t.fetch(PM, Collections.singleton(new RefSpec("+refs/*:refs/*")));
 			assertEquals(B, src.resolve(R_MASTER));
-		} finally {
-			t.close();
 		}
 
 		// Now put private stuff into dst.
@@ -144,7 +141,8 @@ public class ReceivePackAdvertiseRefsHookTest extends LocalDiskRepositoryTestCas
 	@Test
 	public void testFilterHidesPrivate() throws Exception {
 		Map<String, Ref> refs;
-		TransportLocal t = new TransportLocal(src, uriOf(dst), dst.getDirectory()) {
+		try (TransportLocal t = new TransportLocal(src, uriOf(dst),
+				dst.getDirectory()) {
 			@Override
 			ReceivePack createReceivePack(final Repository db) {
 				db.close();
@@ -154,16 +152,10 @@ public class ReceivePackAdvertiseRefsHookTest extends LocalDiskRepositoryTestCas
 				rp.setAdvertiseRefsHook(new HidePrivateHook());
 				return rp;
 			}
-		};
+		}) {
-		try {
+			try (PushConnection c = t.openPush()) {
-			PushConnection c = t.openPush();
-			try {
 				refs = c.getRefsMap();
-			} finally {
-				c.close();
 			}
-		} finally {
-			t.close();
 		}
 
 		assertNotNull(refs);

org.eclipse.jgit.test/tst/org/eclipse/jgit/transport/TransportTest.java

@@ -61,13 +61,10 @@ import org.eclipse.jgit.lib.ObjectId;
 import org.eclipse.jgit.lib.Ref;
 import org.eclipse.jgit.lib.Repository;
 import org.eclipse.jgit.test.resources.SampleDataRepositoryTestCase;
-import org.junit.After;
 import org.junit.Before;
 import org.junit.Test;
 
 public class TransportTest extends SampleDataRepositoryTestCase {
-	private Transport transport;
-
 	private RemoteConfig remoteConfig;
 
 	@Override
@@ -77,17 +74,6 @@ public class TransportTest extends SampleDataRepositoryTestCase {
 		final Config config = db.getConfig();
 		remoteConfig = new RemoteConfig(config, "test");
 		remoteConfig.addURI(new URIish("http://everyones.loves.git/u/2"));
-		transport = null;
-	}
-
-	@Override
-	@After
-	public void tearDown() throws Exception {
-		if (transport != null) {
-			transport.close();
-			transport = null;
-		}
-		super.tearDown();
 	}
 
 	/**
@@ -99,10 +85,11 @@ public class TransportTest extends SampleDataRepositoryTestCase {
 	@Test
 	public void testFindRemoteRefUpdatesNoWildcardNoTracking()
 			throws IOException {
-		transport = Transport.open(db, remoteConfig);
+		Collection<RemoteRefUpdate> result;
-		final Collection<RemoteRefUpdate> result = transport
+		try (Transport transport = Transport.open(db, remoteConfig)) {
-				.findRemoteRefUpdatesFor(Collections.nCopies(1, new RefSpec(
+			result = transport.findRemoteRefUpdatesFor(Collections.nCopies(1,
-						"refs/heads/master:refs/heads/x")));
+					new RefSpec("refs/heads/master:refs/heads/x")));
+		}
 
 		assertEquals(1, result.size());
 		final RemoteRefUpdate rru = result.iterator().next();
@@ -122,10 +109,11 @@ public class TransportTest extends SampleDataRepositoryTestCase {
 	@Test
 	public void testFindRemoteRefUpdatesNoWildcardNoDestination()
 			throws IOException {
-		transport = Transport.open(db, remoteConfig);
+		Collection<RemoteRefUpdate> result;
-		final Collection<RemoteRefUpdate> result = transport
+		try (Transport transport = Transport.open(db, remoteConfig)) {
-				.findRemoteRefUpdatesFor(Collections.nCopies(1, new RefSpec(
+			result = transport.findRemoteRefUpdatesFor(
-						"+refs/heads/master")));
+					Collections.nCopies(1, new RefSpec("+refs/heads/master")));
+		}
 
 		assertEquals(1, result.size());
 		final RemoteRefUpdate rru = result.iterator().next();
@@ -143,10 +131,11 @@ public class TransportTest extends SampleDataRepositoryTestCase {
 	 */
 	@Test
 	public void testFindRemoteRefUpdatesWildcardNoTracking() throws IOException {
-		transport = Transport.open(db, remoteConfig);
+		Collection<RemoteRefUpdate> result;
-		final Collection<RemoteRefUpdate> result = transport
+		try (Transport transport = Transport.open(db, remoteConfig)) {
-				.findRemoteRefUpdatesFor(Collections.nCopies(1, new RefSpec(
+			result = transport.findRemoteRefUpdatesFor(Collections.nCopies(1,
-						"+refs/heads/*:refs/heads/test/*")));
+					new RefSpec("+refs/heads/*:refs/heads/test/*")));
+		}
 
 		assertEquals(12, result.size());
 		boolean foundA = false;
@@ -171,12 +160,14 @@ public class TransportTest extends SampleDataRepositoryTestCase {
 	 */
 	@Test
 	public void testFindRemoteRefUpdatesTwoRefSpecs() throws IOException {
-		transport = Transport.open(db, remoteConfig);
 		final RefSpec specA = new RefSpec("+refs/heads/a:refs/heads/b");
 		final RefSpec specC = new RefSpec("+refs/heads/c:refs/heads/d");
 		final Collection<RefSpec> specs = Arrays.asList(specA, specC);
-		final Collection<RemoteRefUpdate> result = transport
+
-				.findRemoteRefUpdatesFor(specs);
+		Collection<RemoteRefUpdate> result;
+		try (Transport transport = Transport.open(db, remoteConfig)) {
+			result = transport.findRemoteRefUpdatesFor(specs);
+		}
 
 		assertEquals(2, result.size());
 		boolean foundA = false;
@@ -202,10 +193,12 @@ public class TransportTest extends SampleDataRepositoryTestCase {
 	public void testFindRemoteRefUpdatesTrackingRef() throws IOException {
 		remoteConfig.addFetchRefSpec(new RefSpec(
 				"refs/heads/*:refs/remotes/test/*"));
-		transport = Transport.open(db, remoteConfig);
+
-		final Collection<RemoteRefUpdate> result = transport
+		Collection<RemoteRefUpdate> result;
-				.findRemoteRefUpdatesFor(Collections.nCopies(1, new RefSpec(
+		try (Transport transport = Transport.open(db, remoteConfig)) {
-						"+refs/heads/a:refs/heads/a")));
+			result = transport.findRemoteRefUpdatesFor(Collections.nCopies(1,
+					new RefSpec("+refs/heads/a:refs/heads/a")));
+		}
 
 		assertEquals(1, result.size());
 		final TrackingRefUpdate tru = result.iterator().next()
@@ -225,20 +218,18 @@ public class TransportTest extends SampleDataRepositoryTestCase {
 		config.addURI(new URIish("../" + otherDir));
 
 		// Should not throw NoRemoteRepositoryException
-		transport = Transport.open(db, config);
+		Transport.open(db, config).close();
 	}
 
 	@Test
 	public void testLocalTransportFetchWithoutLocalRepository()
 			throws Exception {
 		URIish uri = new URIish("file://" + db.getWorkTree().getAbsolutePath());
-		transport = Transport.open(uri);
+		try (Transport transport = Transport.open(uri)) {
-		FetchConnection fetchConnection = transport.openFetch();
+			try (FetchConnection fetchConnection = transport.openFetch()) {
-		try {
 				Ref head = fetchConnection.getRef(Constants.HEAD);
 				assertNotNull(head);
-		} finally {
+			}
-			fetchConnection.close();
 		}
 	}
 

org.eclipse.jgit/src/org/eclipse/jgit/api/FetchCommand.java

@@ -116,9 +116,7 @@ public class FetchCommand extends TransportCommand<FetchCommand, FetchResult> {
 			org.eclipse.jgit.api.errors.TransportException {
 		checkCallable();
 
-		try {
+		try (Transport transport = Transport.open(repo, remote)) {
-			Transport transport = Transport.open(repo, remote);
-			try {
 			transport.setCheckFetchedObjects(checkFetchedObjects);
 			transport.setRemoveDeletedRefs(isRemoveDeletedRefs());
 			transport.setDryRun(dryRun);
@@ -129,9 +127,6 @@ public class FetchCommand extends TransportCommand<FetchCommand, FetchResult> {
 
 			FetchResult result = transport.fetch(monitor, refSpecs);
 			return result;
-			} finally {
-				transport.close();
-			}
 		} catch (NoRemoteRepositoryException e) {
 			throw new InvalidRemoteException(MessageFormat.format(
 					JGitText.get().invalidRemote, remote), e);

org.eclipse.jgit/src/org/eclipse/jgit/api/LsRemoteCommand.java

@@ -182,13 +182,9 @@ public class LsRemoteCommand extends
 			org.eclipse.jgit.api.errors.TransportException {
 		checkCallable();
 
-		Transport transport = null;
+		try (Transport transport = repo != null
-		FetchConnection fc = null;
+				? Transport.open(repo, remote)
-		try {
+				: Transport.open(new URIish(remote))) {
-			if (repo != null)
-				transport = Transport.open(repo, remote);
-			else
-				transport = Transport.open(new URIish(remote));
 			transport.setOptionUploadPack(uploadPack);
 			configure(transport);
 			Collection<RefSpec> refSpecs = new ArrayList<RefSpec>(1);
@@ -199,7 +195,7 @@ public class LsRemoteCommand extends
 				refSpecs.add(new RefSpec("refs/heads/*:refs/remotes/origin/*")); //$NON-NLS-1$
 			Collection<Ref> refs;
 			Map<String, Ref> refmap = new HashMap<String, Ref>();
-			fc = transport.openFetch();
+			try (FetchConnection fc = transport.openFetch()) {
 				refs = fc.getRefs();
 				if (refSpecs.isEmpty())
 					for (Ref r : refs)
@@ -212,6 +208,7 @@ public class LsRemoteCommand extends
 								break;
 							}
 				return refmap;
+			}
 		} catch (URISyntaxException e) {
 			throw new InvalidRemoteException(MessageFormat.format(
 					JGitText.get().invalidRemote, remote));
@@ -223,11 +220,6 @@ public class LsRemoteCommand extends
 			throw new org.eclipse.jgit.api.errors.TransportException(
 					e.getMessage(),
 					e);
-		} finally {
-			if (fc != null)
-				fc.close();
-			if (transport != null)
-				transport.close();
 		}
 	}
 

org.eclipse.jgit/src/org/eclipse/jgit/transport/Connection.java

@@ -59,8 +59,7 @@ import org.eclipse.jgit.lib.Ref;
  *
  * @see Transport
  */
-public interface Connection {
+public interface Connection extends AutoCloseable {
-
 	/**
 	 * Get the complete map of refs advertised as available for fetching or
 	 * pushing.
@@ -108,6 +107,10 @@ public interface Connection {
 	 * <p>
 	 * If additional messages were produced by the remote peer, these should
 	 * still be retained in the connection instance for {@link #getMessages()}.
+	 * <p>
+	 * {@code AutoClosable.close()} declares that it throws {@link Exception}.
+	 * Implementers shouldn't throw checked exceptions. This override narrows
+	 * the signature to prevent them from doing so.
 	 */
 	public void close();
 

org.eclipse.jgit/src/org/eclipse/jgit/transport/Transport.java

@@ -98,7 +98,7 @@ import org.eclipse.jgit.storage.pack.PackConfig;
  * Transport instances and the connections they create are not thread-safe.
  * Callers must ensure a transport is accessed by only one thread at a time.
  */
-public abstract class Transport {
+public abstract class Transport implements AutoCloseable {
 	/** Type of operation a Transport is being opened for. */
 	public enum Operation {
 		/** Transport is to fetch objects locally. */
@@ -1353,6 +1353,10 @@ public abstract class Transport {
 	 * must close that network socket, disconnecting the two peers. If the
 	 * remote repository is actually local (same system) this method must close
 	 * any open file handles used to read the "remote" repository.
+	 * <p>
+	 * {@code AutoClosable.close()} declares that it throws {@link Exception}.
+	 * Implementers shouldn't throw checked exceptions. This override narrows
+	 * the signature to prevent them from doing so.
 	 */
 	public abstract void close();
 }