Use try-with-resources more

artemis-cli/src/main/java/org/apache/activemq/artemis/cli/commands/tools/EncodeJournal.java

@@ -80,17 +80,11 @@ public class EncodeJournal extends LockAbstract {
                                     final int minFiles,
                                     final int fileSize,
                                     final String fileName) throws Exception {
-      FileOutputStream fileOutputStream = new FileOutputStream(fileName);
+      try (FileOutputStream fileOutputStream = new FileOutputStream(fileName);
            BufferedOutputStream bufferedOutputStream = new BufferedOutputStream(fileOutputStream);
-      PrintStream out = new PrintStream(bufferedOutputStream);
+           PrintStream out = new PrintStream(bufferedOutputStream)) {
-      try {
          exportJournal(directory, journalPrefix, journalSuffix, minFiles, fileSize, out);
       }
-      finally {
-         out.close();
-         fileOutputStream.close();
-      }
-
    }
 
    public static void exportJournal(final String directory,

artemis-cli/src/main/java/org/apache/activemq/artemis/cli/commands/tools/XmlDataImporter.java

@@ -351,9 +351,9 @@ public final class XmlDataImporter extends ActionAbstract {
       ActiveMQServerLogger.LOGGER.debug(logMessage);
 
       message.putBytesProperty(MessageImpl.HDR_ROUTE_TO_IDS, buffer.array());
-      ClientProducer producer = session.createProducer(destination);
+      try (ClientProducer producer = session.createProducer(destination)) {
          producer.send(message);
-      producer.close();
+      }
 
       if (tempFileName.length() > 0) {
          File tempFile = new File(tempFileName);

artemis-cli/src/main/java/org/apache/activemq/artemis/cli/commands/util/ProducerThread.java

@@ -182,8 +182,7 @@ public class ProducerThread extends Thread {
    }
 
    private String readInputStream(InputStream is, int size, int messageNumber) throws IOException {
-      InputStreamReader reader = new InputStreamReader(is);
+      try (InputStreamReader reader = new InputStreamReader(is)) {
-      try {
          char[] buffer;
          if (size > 0) {
             buffer = new char[size];
@@ -203,9 +202,6 @@ public class ProducerThread extends Thread {
       catch (IOException ioe) {
          return createDefaultMessage(messageNumber);
       }
-      finally {
-         reader.close();
-      }
    }
 
    private String createDefaultMessage(int messageNumber) {

artemis-cli/src/main/java/org/apache/activemq/artemis/util/ServerUtil.java

@@ -83,10 +83,8 @@ public class ServerUtil {
    public static void waitForServerToStart(String uri, long timeout) throws InterruptedException {
       long realTimeout = System.currentTimeMillis() + timeout;
       while (System.currentTimeMillis() < realTimeout) {
-         try {
+         try (ActiveMQConnectionFactory cf = ActiveMQJMSClient.createConnectionFactory(uri, null)) {
-            ActiveMQConnectionFactory cf = ActiveMQJMSClient.createConnectionFactory(uri, null);
             cf.createConnection().close();
-            cf.close();
             System.out.println("server " + uri + " started");
          }
          catch (Exception e) {

artemis-core-client/src/test/java/org/apache/activemq/artemis/util/CompressionUtilTest.java

@@ -41,15 +41,16 @@ public class CompressionUtilTest extends Assert {
       ByteArrayInputStream inputStream = new ByteArrayInputStream(input);
 
       AtomicLong counter = new AtomicLong(0);
-      DeflaterReader reader = new DeflaterReader(inputStream, counter);
-
       ArrayList<Integer> zipHolder = new ArrayList<>();
+
+      try (DeflaterReader reader = new DeflaterReader(inputStream, counter)) {
          int b = reader.read();
 
          while (b != -1) {
             zipHolder.add(b);
             b = reader.read();
          }
+      }
 
       assertEquals(input.length, counter.get());
 
@@ -65,7 +66,6 @@ public class CompressionUtilTest extends Assert {
       int compressedDataLength = compresser.deflate(output);
 
       compareByteArray(allCompressed, output, compressedDataLength);
-      reader.close();
    }
 
    @Test
@@ -76,11 +76,10 @@ public class CompressionUtilTest extends Assert {
       ByteArrayInputStream inputStream = new ByteArrayInputStream(input);
       AtomicLong counter = new AtomicLong(0);
 
-      DeflaterReader reader = new DeflaterReader(inputStream, counter);
-
       byte[] buffer = new byte[7];
       ArrayList<Integer> zipHolder = new ArrayList<>();
 
+      try (DeflaterReader reader = new DeflaterReader(inputStream, counter)) {
          int n = reader.read(buffer);
          while (n != -1) {
             for (int i = 0; i < n; i++) {
@@ -88,6 +87,7 @@ public class CompressionUtilTest extends Assert {
             }
             n = reader.read(buffer);
          }
+      }
 
       assertEquals(input.length, counter.get());
 
@@ -103,7 +103,6 @@ public class CompressionUtilTest extends Assert {
       int compressedDataLength = compresser.deflate(output);
 
       compareByteArray(allCompressed, output, compressedDataLength);
-      reader.close();
    }
 
    @Test
@@ -121,14 +120,15 @@ public class CompressionUtilTest extends Assert {
       System.arraycopy(output, 0, zipBytes, 0, compressedDataLength);
       ByteArrayInputStream byteInput = new ByteArrayInputStream(zipBytes);
 
-      InflaterReader inflater = new InflaterReader(byteInput);
       ArrayList<Integer> holder = new ArrayList<>();
+      try (InflaterReader inflater = new InflaterReader(byteInput)) {
          int read = inflater.read();
 
          while (read != -1) {
             holder.add(read);
             read = inflater.read();
          }
+      }
 
       byte[] result = new byte[holder.size()];
 
@@ -139,7 +139,6 @@ public class CompressionUtilTest extends Assert {
       String txt = new String(result);
 
       assertEquals(inputString, txt);
-      inflater.close();
    }
 
    @Test
@@ -158,17 +157,15 @@ public class CompressionUtilTest extends Assert {
       ByteArrayInputStream byteInput = new ByteArrayInputStream(zipBytes);
 
       ByteArrayOutputStream byteOutput = new ByteArrayOutputStream();
-      InflaterWriter writer = new InflaterWriter(byteOutput);
-
       byte[] zipBuffer = new byte[12];
 
+      try (InflaterWriter writer = new InflaterWriter(byteOutput)) {
          int n = byteInput.read(zipBuffer);
          while (n > 0) {
             writer.write(zipBuffer, 0, n);
             n = byteInput.read(zipBuffer);
          }
-
+      }
-      writer.close();
 
       byte[] outcome = byteOutput.toByteArray();
       String outStr = new String(outcome);

artemis-jms-client/src/test/java/org/apache/activemq/artemis/uri/ConnectionFactoryURITest.java

@@ -115,15 +115,16 @@ public class ConnectionFactoryURITest {
 
    private void persistIP6(String ipv6, ActiveMQConnectionFactory factory) throws IOException, ClassNotFoundException {
       ByteArrayOutputStream baos = new ByteArrayOutputStream();
-      ObjectOutputStream outStream = new ObjectOutputStream(baos);
+      try (ObjectOutputStream outStream = new ObjectOutputStream(baos)) {
          outStream.writeObject(factory);
-      outStream.close();
+      }
+      finally {
          baos.close();
-      ByteArrayInputStream bais = new ByteArrayInputStream(baos.toByteArray());
+      }
-      ObjectInputStream in = new ObjectInputStream(bais);
+      try (ByteArrayInputStream bais = new ByteArrayInputStream(baos.toByteArray());
+           ObjectInputStream in = new ObjectInputStream(bais)) {
          factory = (ActiveMQConnectionFactory) in.readObject();
-      in.close();
+      }
-      bais.close();
       Assert.assertEquals("[" + ipv6 + "]", factory.getStaticConnectors()[0].getParams().get("host"));
    }
 

artemis-protocols/artemis-openwire-protocol/src/main/java/org/apache/activemq/artemis/core/protocol/openwire/OpenWireMessageConverter.java

@@ -159,9 +159,8 @@ public class OpenWireMessageConverter implements MessageConverter {
                if (messageCompressed) {
                   InputStream ois = new ByteArrayInputStream(contents);
                   ois = new InflaterInputStream(ois);
-                  org.apache.activemq.util.ByteArrayOutputStream decompressed = new org.apache.activemq.util.ByteArrayOutputStream();
 
-                  try {
+                  try (org.apache.activemq.util.ByteArrayOutputStream decompressed = new org.apache.activemq.util.ByteArrayOutputStream()) {
                      byte[] buf = new byte[1024];
                      int n = ois.read(buf);
                      while (n != -1) {
@@ -171,9 +170,6 @@ public class OpenWireMessageConverter implements MessageConverter {
                      //read done
                      contents = decompressed.toByteSequence();
                   }
-                  finally {
-                     decompressed.close();
-                  }
                }
                body.writeInt(contents.length);
                body.writeBytes(contents.data, contents.offset, contents.length);
@@ -279,19 +275,14 @@ public class OpenWireMessageConverter implements MessageConverter {
                break;
             default:
                if (messageCompressed) {
-                  org.apache.activemq.util.ByteArrayOutputStream decompressed = new org.apache.activemq.util.ByteArrayOutputStream();
+                  try (org.apache.activemq.util.ByteArrayOutputStream decompressed = new org.apache.activemq.util.ByteArrayOutputStream();
-                  OutputStream os = new InflaterOutputStream(decompressed);
+                       OutputStream os = new InflaterOutputStream(decompressed)) {
-                  try {
                      os.write(contents.data, contents.offset, contents.getLength());
                      contents = decompressed.toByteSequence();
                   }
                   catch (Exception e) {
                      throw new IOException(e);
                   }
-                  finally {
-                     os.close();
-                     decompressed.close();
-                  }
                }
                body.writeBytes(contents.data, contents.offset, contents.length);
                break;
@@ -536,9 +527,9 @@ public class OpenWireMessageConverter implements MessageConverter {
                buffer.readBytes(bytes);
                if (isCompressed) {
                   ByteArrayOutputStream bytesOut = new ByteArrayOutputStream();
-                  DeflaterOutputStream out = new DeflaterOutputStream(bytesOut);
+                  try (DeflaterOutputStream out = new DeflaterOutputStream(bytesOut)) {
                      out.write(bytes);
-                  out.close();
+                  }
                   bytes = bytesOut.toByteArray();
                }
             }
@@ -637,16 +628,11 @@ public class OpenWireMessageConverter implements MessageConverter {
                bytes = new byte[n];
                buffer.readBytes(bytes);
                if (isCompressed) {
-                  ByteArrayOutputStream bytesOut = new ByteArrayOutputStream();
+                  try (ByteArrayOutputStream bytesOut = new ByteArrayOutputStream();
-                  DeflaterOutputStream out = new DeflaterOutputStream(bytesOut);
+                       DeflaterOutputStream out = new DeflaterOutputStream(bytesOut)) {
-                  try {
                      out.write(bytes);
                      bytes = bytesOut.toByteArray();
                   }
-                  finally {
-                     out.close();
-                     bytesOut.close();
-                  }
                }
             }
 

artemis-rest/src/main/java/org/apache/activemq/artemis/rest/queue/QueueServiceManager.java

@@ -76,12 +76,12 @@ public class QueueServiceManager extends DestinationServiceManager {
          throw new Exception("You must start() this class instance before deploying");
       }
       String queueName = queueDeployment.getName();
-      ClientSession session = sessionFactory.createSession(false, false, false);
+      try (ClientSession session = sessionFactory.createSession(false, false, false)) {
          ClientSession.QueueQuery query = session.queueQuery(new SimpleString(queueName));
          if (!query.isExists()) {
             session.createQueue(queueName, queueName, queueDeployment.isDurableSend());
          }
-      session.close();
+      }
 
       destination.createQueueResource(queueName, queueDeployment.isDurableSend(), queueDeployment.getConsumerSessionTimeoutSeconds(), queueDeployment.isDuplicatesAllowed());
 

artemis-rest/src/main/java/org/apache/activemq/artemis/rest/topic/TopicServiceManager.java

@@ -77,16 +77,17 @@ public class TopicServiceManager extends DestinationServiceManager {
          throw new Exception("You must start() this class instance before deploying");
       }
       String queueName = topicDeployment.getName();
-      ClientSession session = sessionFactory.createSession(false, false, false);
+      boolean defaultDurable;
+      try (ClientSession session = sessionFactory.createSession(false, false, false)) {
          ClientSession.QueueQuery query = session.queueQuery(new SimpleString(queueName));
-      boolean defaultDurable = topicDeployment.isDurableSend();
+         defaultDurable = topicDeployment.isDurableSend();
          if (query.isExists()) {
             defaultDurable = query.isDurable();
          }
          else {
             session.createQueue(queueName, queueName, topicDeployment.isDurableSend());
          }
-      session.close();
+      }
 
       destination.createTopicResource(queueName, defaultDurable, topicDeployment.getConsumerSessionTimeoutSeconds(), topicDeployment.isDuplicatesAllowed());
    }

artemis-server/src/main/java/org/apache/activemq/artemis/core/config/impl/ConfigurationImpl.java

@@ -1666,8 +1666,10 @@ public class ConfigurationImpl implements Configuration, Serializable {
             ByteArrayOutputStream bos = new ByteArrayOutputStream();
             ObjectOutputStream os = new ObjectOutputStream(bos);
             os.writeObject(ConfigurationImpl.this);
-            ObjectInputStream ois = new ObjectInputStreamWithClassLoader(new ByteArrayInputStream(bos.toByteArray()));
+            Configuration config;
-            Configuration config = (Configuration) ois.readObject();
+            try (ObjectInputStream ois = new ObjectInputStreamWithClassLoader(new ByteArrayInputStream(bos.toByteArray()))) {
+               config = (Configuration) ois.readObject();
+            }
 
             // this is transient because of possible jgroups integration, we need to copy it manually
             config.setBroadcastGroupConfigurations(ConfigurationImpl.this.getBroadcastGroupConfigurations());

artemis-server/src/main/java/org/apache/activemq/artemis/core/management/impl/QueueControlImpl.java

@@ -406,8 +406,7 @@ public class QueueControlImpl extends AbstractControl implements QueueControl {
          Filter filter = FilterImpl.createFilter(filterStr);
          List<Map<String, Object>> messages = new ArrayList<>();
          queue.flushExecutor();
-         LinkedListIterator<MessageReference> iterator = queue.totalIterator();
+         try (LinkedListIterator<MessageReference> iterator = queue.totalIterator()) {
-         try {
             while (iterator.hasNext()) {
                MessageReference ref = iterator.next();
                if (filter == null || filter.match(ref.getMessage())) {
@@ -417,9 +416,6 @@ public class QueueControlImpl extends AbstractControl implements QueueControl {
             }
             return messages.toArray(new Map[messages.size()]);
          }
-         finally {
-            iterator.close();
-         }
       }
       catch (ActiveMQException e) {
          throw new IllegalStateException(e.getMessage());
@@ -449,8 +445,7 @@ public class QueueControlImpl extends AbstractControl implements QueueControl {
       try {
          List<Map<String, Object>> messages = new ArrayList<>();
          queue.flushExecutor();
-         LinkedListIterator<MessageReference> iterator = queue.totalIterator();
+         try (LinkedListIterator<MessageReference> iterator = queue.totalIterator()) {
-         try {
             // returns just the first, as it's the first only
             if (iterator.hasNext()) {
                MessageReference ref = iterator.next();
@@ -459,9 +454,6 @@ public class QueueControlImpl extends AbstractControl implements QueueControl {
             }
             return messages.toArray(new Map[1]);
          }
-         finally {
-            iterator.close();
-         }
       }
       finally {
          blockOnIO();
@@ -508,8 +500,7 @@ public class QueueControlImpl extends AbstractControl implements QueueControl {
             return getMessageCount();
          }
          else {
-            LinkedListIterator<MessageReference> iterator = queue.totalIterator();
+            try (LinkedListIterator<MessageReference> iterator = queue.totalIterator()) {
-            try {
                int count = 0;
                while (iterator.hasNext()) {
                   MessageReference ref = iterator.next();
@@ -519,9 +510,6 @@ public class QueueControlImpl extends AbstractControl implements QueueControl {
                }
                return count;
             }
-            finally {
-               iterator.close();
-            }
          }
       }
       finally {
@@ -919,8 +907,7 @@ public class QueueControlImpl extends AbstractControl implements QueueControl {
          ArrayList<CompositeData> c = new ArrayList<>();
          Filter filter = FilterImpl.createFilter(filterStr);
          queue.flushExecutor();
-         LinkedListIterator<MessageReference> iterator = queue.totalIterator();
+         try (LinkedListIterator<MessageReference> iterator = queue.totalIterator()) {
-         try {
             while (iterator.hasNext() && currentPageSize++ < pageSize) {
                MessageReference ref = iterator.next();
                if (filter == null || filter.match(ref.getMessage())) {
@@ -932,9 +919,6 @@ public class QueueControlImpl extends AbstractControl implements QueueControl {
             c.toArray(rc);
             return rc;
          }
-         finally {
-            iterator.close();
-         }
       }
       catch (ActiveMQException e) {
          throw new IllegalStateException(e.getMessage());

artemis-server/src/main/java/org/apache/activemq/artemis/core/paging/impl/PagingStoreFactoryNIO.java

@@ -110,15 +110,10 @@ public class PagingStoreFactoryNIO implements PagingStoreFactory {
          File.separatorChar +
          PagingStoreFactoryNIO.ADDRESS_FILE);
 
-      BufferedWriter writer = new BufferedWriter(new OutputStreamWriter(new FileOutputStream(fileWithID)));
+      try (BufferedWriter writer = new BufferedWriter(new OutputStreamWriter(new FileOutputStream(fileWithID)))) {
-
-      try {
          writer.write(address.toString());
          writer.newLine();
       }
-      finally {
-         writer.close();
-      }
 
       return factory;
    }
@@ -149,16 +144,11 @@ public class PagingStoreFactoryNIO implements PagingStoreFactory {
                continue;
             }
 
-            BufferedReader reader = new BufferedReader(new InputStreamReader(new FileInputStream(addressFile)));
-
             String addressString;
 
-            try {
+            try (BufferedReader reader = new BufferedReader(new InputStreamReader(new FileInputStream(addressFile)))) {
                addressString = reader.readLine();
             }
-            finally {
-               reader.close();
-            }
 
             SimpleString address = new SimpleString(addressString);
 

artemis-server/src/main/java/org/apache/activemq/artemis/core/persistence/impl/journal/AbstractJournalStorageManager.java

@@ -226,14 +226,14 @@ public abstract class AbstractJournalStorageManager implements StorageManager {
          byte[] buffer = new byte[1 << 4];
          MessageDigest md = MessageDigest.getInstance("MD5");
 
-         FileInputStream is = new FileInputStream(file);
+         byte[] digest;
-         DigestInputStream is2 = new DigestInputStream(is, md);
+         try (FileInputStream is = new FileInputStream(file);
+              DigestInputStream is2 = new DigestInputStream(is, md)) {
             while (is2.read(buffer) > 0) {
                continue;
             }
-         byte[] digest = md.digest();
+            digest = md.digest();
-         is.close();
+         }
-         is2.close();
          return Base64.encodeBytes(digest);
       }
       catch (Exception e) {

artemis-server/src/main/java/org/apache/activemq/artemis/core/replication/ReplicationManager.java

@@ -508,10 +508,8 @@ public final class ReplicationManager implements ActiveMQComponent, ReadyListene
          file.open();
       }
       try {
-         final FileInputStream fis = new FileInputStream(file.getJavaFile());
+         try (final FileInputStream fis = new FileInputStream(file.getJavaFile());
-         try {
+              final FileChannel channel = fis.getChannel()) {
-            final FileChannel channel = fis.getChannel();
-            try {
             // We can afford having a single buffer here for this entire loop
             // because sendReplicatePacket will encode the packet as a NettyBuffer
             // through ActiveMQBuffer class leaving this buffer free to be reused on the next copy
@@ -538,13 +536,6 @@ public final class ReplicationManager implements ActiveMQComponent, ReadyListene
                   break;
             }
          }
-            finally {
-               channel.close();
-            }
-         }
-         finally {
-            fis.close();
-         }
       }
       finally {
          if (file.isOpen())

artemis-server/src/main/java/org/apache/activemq/artemis/core/server/cluster/impl/ClusterConnectionBridge.java

@@ -255,14 +255,13 @@ public class ClusterConnectionBridge extends BridgeImpl {
          }
          ManagementHelper.putOperationInvocation(message, ResourceNames.CORE_SERVER, "sendQueueInfoToQueue", notifQueueName.toString(), flowRecord.getAddress());
 
-         ClientProducer prod = sessionConsumer.createProducer(managementAddress);
+         try (ClientProducer prod = sessionConsumer.createProducer(managementAddress)) {
-
             if (ActiveMQClientLogger.LOGGER.isDebugEnabled()) {
                ActiveMQClientLogger.LOGGER.debug("Cluster connection bridge on " + clusterConnection + " requesting information on queues");
             }
 
             prod.send(message);
-         prod.close();
+         }
       }
    }
 

artemis-server/src/main/java/org/apache/activemq/artemis/core/server/impl/QueueImpl.java

@@ -869,9 +869,7 @@ public class QueueImpl implements Queue {
 
    @Override
    public synchronized MessageReference removeReferenceWithID(final long id1) throws Exception {
-      LinkedListIterator<MessageReference> iterator = iterator();
+      try (LinkedListIterator<MessageReference> iterator = iterator()) {
-
-      try {
 
          MessageReference removed = null;
 
@@ -895,16 +893,11 @@ public class QueueImpl implements Queue {
 
          return removed;
       }
-      finally {
-         iterator.close();
-      }
    }
 
    @Override
    public synchronized MessageReference getReference(final long id1) throws ActiveMQException {
-      LinkedListIterator<MessageReference> iterator = iterator();
+      try (LinkedListIterator<MessageReference> iterator = iterator()) {
-
-      try {
 
          while (iterator.hasNext()) {
             MessageReference ref = iterator.next();
@@ -916,9 +909,6 @@ public class QueueImpl implements Queue {
 
          return null;
       }
-      finally {
-         iterator.close();
-      }
    }
 
    @Override
@@ -1181,8 +1171,7 @@ public class QueueImpl implements Queue {
 
       Transaction tx = new TransactionImpl(storageManager);
 
-      LinkedListIterator<MessageReference> iter = iterator();
+      try (LinkedListIterator<MessageReference> iter = iterator()) {
-      try {
 
          while (iter.hasNext()) {
             MessageReference ref = iter.next();
@@ -1256,9 +1245,6 @@ public class QueueImpl implements Queue {
 
          return count;
       }
-      finally {
-         iter.close();
-      }
    }
 
    @Override
@@ -1276,8 +1262,7 @@ public class QueueImpl implements Queue {
 
       Transaction tx = new TransactionImpl(storageManager);
 
-      LinkedListIterator<MessageReference> iter = iterator();
+      try (LinkedListIterator<MessageReference> iter = iterator()) {
-      try {
 
          while (iter.hasNext()) {
             MessageReference ref = iter.next();
@@ -1300,9 +1285,6 @@ public class QueueImpl implements Queue {
 
          return deleted;
       }
-      finally {
-         iter.close();
-      }
    }
 
    @Override
@@ -1358,8 +1340,7 @@ public class QueueImpl implements Queue {
          return false;
       }
 
-      LinkedListIterator<MessageReference> iter = iterator();
+      try (LinkedListIterator<MessageReference> iter = iterator()) {
-      try {
 
          while (iter.hasNext()) {
             MessageReference ref = iter.next();
@@ -1373,9 +1354,6 @@ public class QueueImpl implements Queue {
          }
          return false;
       }
-      finally {
-         iter.close();
-      }
    }
 
    @Override
@@ -1390,9 +1368,8 @@ public class QueueImpl implements Queue {
       Transaction tx = new TransactionImpl(storageManager);
 
       int count = 0;
-      LinkedListIterator<MessageReference> iter = iterator();
 
-      try {
+      try (LinkedListIterator<MessageReference> iter = iterator()) {
 
          while (iter.hasNext()) {
             MessageReference ref = iter.next();
@@ -1409,9 +1386,6 @@ public class QueueImpl implements Queue {
 
          return count;
       }
-      finally {
-         iter.close();
-      }
    }
 
    @Override
@@ -1482,9 +1456,7 @@ public class QueueImpl implements Queue {
 
    @Override
    public synchronized boolean sendMessageToDeadLetterAddress(final long messageID) throws Exception {
-      LinkedListIterator<MessageReference> iter = iterator();
+      try (LinkedListIterator<MessageReference> iter = iterator()) {
-
-      try {
          while (iter.hasNext()) {
             MessageReference ref = iter.next();
             if (ref.getMessage().getMessageID() == messageID) {
@@ -1497,17 +1469,13 @@ public class QueueImpl implements Queue {
          }
          return false;
       }
-      finally {
-         iter.close();
-      }
    }
 
    @Override
    public synchronized int sendMessagesToDeadLetterAddress(Filter filter) throws Exception {
       int count = 0;
-      LinkedListIterator<MessageReference> iter = iterator();
 
-      try {
+      try (LinkedListIterator<MessageReference> iter = iterator()) {
          while (iter.hasNext()) {
             MessageReference ref = iter.next();
             if (filter == null || filter.match(ref.getMessage())) {
@@ -1520,9 +1488,6 @@ public class QueueImpl implements Queue {
          }
          return count;
       }
-      finally {
-         iter.close();
-      }
    }
 
    @Override
@@ -1534,9 +1499,7 @@ public class QueueImpl implements Queue {
    public synchronized boolean moveReference(final long messageID,
                                              final SimpleString toAddress,
                                              final boolean rejectDuplicate) throws Exception {
-      LinkedListIterator<MessageReference> iter = iterator();
+      try (LinkedListIterator<MessageReference> iter = iterator()) {
-
-      try {
          while (iter.hasNext()) {
             MessageReference ref = iter.next();
             if (ref.getMessage().getMessageID() == messageID) {
@@ -1555,9 +1518,6 @@ public class QueueImpl implements Queue {
          }
          return false;
       }
-      finally {
-         iter.close();
-      }
    }
 
    @Override
@@ -1651,9 +1611,7 @@ public class QueueImpl implements Queue {
 
    @Override
    public synchronized boolean changeReferencePriority(final long messageID, final byte newPriority) throws Exception {
-      LinkedListIterator<MessageReference> iter = iterator();
+      try (LinkedListIterator<MessageReference> iter = iterator()) {
-
-      try {
 
          while (iter.hasNext()) {
             MessageReference ref = iter.next();
@@ -1668,16 +1626,11 @@ public class QueueImpl implements Queue {
 
          return false;
       }
-      finally {
-         iter.close();
-      }
    }
 
    @Override
    public synchronized int changeReferencesPriority(final Filter filter, final byte newPriority) throws Exception {
-      LinkedListIterator<MessageReference> iter = iterator();
+      try (LinkedListIterator<MessageReference> iter = iterator()) {
-
-      try {
          int count = 0;
          while (iter.hasNext()) {
             MessageReference ref = iter.next();
@@ -1691,9 +1644,6 @@ public class QueueImpl implements Queue {
          }
          return count;
       }
-      finally {
-         iter.close();
-      }
    }
 
    @Override

artemis-server/src/main/java/org/apache/activemq/artemis/core/server/impl/ScaleDownHandler.java

@@ -403,8 +403,8 @@ public class ScaleDownHandler {
                                      SimpleString managementAddress,
                                      String user,
                                      String password) throws Exception {
-      ClientSession session = sessionFactory.createSession(user, password, true, false, false, false, 0);
+      try (ClientSession session = sessionFactory.createSession(user, password, true, false, false, false, 0);
-      ClientProducer producer = session.createProducer(managementAddress);
+           ClientProducer producer = session.createProducer(managementAddress)) {
          //todo - https://issues.jboss.org/browse/HORNETQ-1336
          for (SimpleString address : duplicateIDMap.keySet()) {
             ClientMessage message = session.createMessage(false);
@@ -417,7 +417,7 @@ public class ScaleDownHandler {
             ManagementHelper.putOperationInvocation(message, ResourceNames.CORE_SERVER, "updateDuplicateIdCache", address.toString(), array);
             producer.send(message);
          }
-      session.close();
+      }
    }
 
    /**

artemis-server/src/main/java/org/apache/activemq/artemis/core/server/impl/SharedNothingLiveActivation.java

@@ -274,22 +274,15 @@ public class SharedNothingLiveActivation extends LiveActivation {
          nodeId0 = null;
       }
 
-      ServerLocatorInternal locator;
-
       ClusterConnectionConfiguration config = ConfigurationUtils.getReplicationClusterConfiguration(activeMQServer.getConfiguration(), replicatedPolicy.getClusterName());
 
-      locator = getLocator(config);
-
-      ClientSessionFactoryInternal factory = null;
-
       NodeIdListener listener = new NodeIdListener(nodeId0);
 
+      try (ServerLocatorInternal locator = getLocator(config)) {
          locator.addClusterTopologyListener(listener);
-      try {
          locator.setReconnectAttempts(0);
-         try {
+         try (ClientSessionFactoryInternal factory = locator.connectNoWarnings()) {
-            locator.addClusterTopologyListener(listener);
+            // Just try connecting
-            factory = locator.connectNoWarnings();
          }
          catch (Exception notConnected) {
             return false;
@@ -299,12 +292,6 @@ public class SharedNothingLiveActivation extends LiveActivation {
 
          return listener.isNodePresent;
       }
-      finally {
-         if (factory != null)
-            factory.close();
-         if (locator != null)
-            locator.close();
-      }
    }
 
    @Override

artemis-server/src/main/java/org/apache/activemq/artemis/spi/core/security/jaas/ReloadableProperties.java

@@ -73,8 +73,7 @@ public class ReloadableProperties {
 
    private void load(final File source,
                      Properties props) throws IOException {
-      FileInputStream in = new FileInputStream(source);
+      try (FileInputStream in = new FileInputStream(source)) {
-      try {
          props.load(in);
          //            if (key.isDecrypt()) {
          //                try {
@@ -87,9 +86,6 @@ public class ReloadableProperties {
          //            }
 
       }
-      finally {
-         in.close();
-      }
    }
 
    private boolean hasModificationAfter(long reloadTime) {

artemis-server/src/test/java/org/apache/activemq/artemis/core/message/impl/MessagePropertyTest.java

@@ -85,7 +85,7 @@ public class MessagePropertyTest extends ActiveMQTestBase {
    private void receiveMessages() throws Exception {
       ClientSession session = sf.createSession(true, true);
       session.start();
-      ClientConsumer consumer = session.createConsumer(ADDRESS);
+      try (ClientConsumer consumer = session.createConsumer(ADDRESS)) {
          for (int i = 0; i < numMessages; i++) {
             ClientMessage message = consumer.receive(100);
             assertNotNull("Expecting a message " + i, message);
@@ -103,7 +103,7 @@ public class MessagePropertyTest extends ActiveMQTestBase {
             message.acknowledge();
          }
          assertNull("no more messages", consumer.receive(50));
-      consumer.close();
+      }
       session.commit();
    }
 

artemis-server/src/test/java/org/apache/activemq/artemis/core/security/jaas/PropertiesLoginModuleRaceConditionTest.java

@@ -169,13 +169,9 @@ public class PropertiesLoginModuleRaceConditionTest {
    }
 
    private void store(Properties from, File to) throws FileNotFoundException, IOException {
-      FileOutputStream output = new FileOutputStream(to);
+      try (FileOutputStream output = new FileOutputStream(to)) {
-      try {
          from.store(output, "Generated by " + name.getMethodName());
       }
-      finally {
-         output.close();
-      }
    }
 
    private void createGroups() throws FileNotFoundException, IOException {

examples/features/clustered/client-side-load-balancing/src/main/java/org/apache/activemq/artemis/jms/example/ClientSideLoadBalancingExample.java

@@ -56,13 +56,13 @@ public class ClientSideLoadBalancingExample {
 
          // Step 4. We create 3 JMS connections from the same connection factory. Since we are using round-robin
          // load-balancing this should result in each sessions being connected to a different node of the cluster
-         Connection conn = connectionFactory.createConnection();
+         try (Connection conn = connectionFactory.createConnection()) {
             // Wait a little while to make sure broadcasts from all nodes have reached the client
             Thread.sleep(5000);
             connectionA = connectionFactory.createConnection();
             connectionB = connectionFactory.createConnection();
             connectionC = connectionFactory.createConnection();
-         conn.close();
+         }
 
          // Step 5. We create JMS Sessions
          Session sessionA = connectionA.createSession(false, Session.AUTO_ACKNOWLEDGE);

examples/features/perf/perf/src/main/java/org/apache/activemq/artemis/jms/example/PerfBase.java

@@ -73,20 +73,11 @@ public abstract class PerfBase {
    protected static PerfParams getParams(final String fileName) throws Exception {
       Properties props = null;
 
-      InputStream is = null;
+      try (InputStream is = new FileInputStream(fileName)) {
-
-      try {
-         is = new FileInputStream(fileName);
-
          props = new Properties();
 
          props.load(is);
       }
-      finally {
-         if (is != null) {
-            is.close();
-         }
-      }
 
       int noOfMessages = Integer.valueOf(props.getProperty("num-messages"));
       int noOfWarmupMessages = Integer.valueOf(props.getProperty("num-warmup-messages"));

examples/features/perf/soak/src/main/java/org/apache/activemq/artemis/jms/soak/example/SoakBase.java

@@ -53,20 +53,11 @@ public class SoakBase {
    protected static SoakParams getParams(final String fileName) throws Exception {
       Properties props = null;
 
-      InputStream is = null;
+      try (InputStream is = new FileInputStream(fileName)) {
-
-      try {
-         is = new FileInputStream(fileName);
-
          props = new Properties();
 
          props.load(is);
       }
-      finally {
-         if (is != null) {
-            is.close();
-         }
-      }
 
       int durationInMinutes = Integer.valueOf(props.getProperty("duration-in-minutes"));
       int noOfWarmupMessages = Integer.valueOf(props.getProperty("num-warmup-messages"));

examples/features/standard/embedded-simple/src/main/java/org/apache/activemq/artemis/jms/example/EmbeddedExample.java

@@ -62,9 +62,7 @@ public class EmbeddedExample {
       Queue queue = (Queue) jmsServer.lookup("queue/exampleQueue");
 
       // Step 10. Send and receive a message using JMS API
-      Connection connection = null;
+      try (Connection connection = cf.createConnection()) {
-      try {
-         connection = cf.createConnection();
          Session session = connection.createSession(false, Session.AUTO_ACKNOWLEDGE);
          MessageProducer producer = session.createProducer(queue);
          TextMessage message = session.createTextMessage("Hello sent at " + new Date());
@@ -76,10 +74,6 @@ public class EmbeddedExample {
          System.out.println("Received message:" + messageReceived.getText());
       }
       finally {
-         if (connection != null) {
-            connection.close();
-         }
-
          // Step 11. Stop the JMS server
          jmsServer.stop();
          System.out.println("Stopped the JMS Server");

examples/features/standard/interceptor-client/src/main/java/org/apache/activemq/artemis/jms/example/InterceptorExample.java

@@ -32,11 +32,8 @@ import org.apache.activemq.artemis.jms.client.ActiveMQConnectionFactory;
 public class InterceptorExample {
 
    public static void main(final String[] args) throws Exception {
-      Connection connection = null;
-      try {
       ConnectionFactory cf = new ActiveMQConnectionFactory("tcp://localhost:61616?incomingInterceptorList=" + SimpleInterceptor.class.getName());
-         connection = cf.createConnection();
+      try (Connection connection = cf.createConnection()) {
-
          Session session = connection.createSession(false, Session.AUTO_ACKNOWLEDGE);
 
          Queue queue = session.createQueue("exampleQueue");
@@ -65,10 +62,5 @@ public class InterceptorExample {
             throw new IllegalStateException("Check your configuration as the example interceptor wasn't actually called!");
          }
       }
-      finally {
-         if (connection != null) {
-            connection.close();
-         }
-      }
    }
 }

examples/features/standard/large-message/src/main/java/org/apache/activemq/artemis/jms/example/LargeMessageExample.java

@@ -155,14 +155,12 @@ public class LargeMessageExample {
 
          File outputFile = new File("huge_message_received.dat");
 
-         FileOutputStream fileOutputStream = new FileOutputStream(outputFile);
+         try (FileOutputStream fileOutputStream = new FileOutputStream(outputFile)) {
-
             BufferedOutputStream bufferedOutput = new BufferedOutputStream(fileOutputStream);
 
             // Step 14. This will save the stream and wait until the entire message is written before continuing.
             messageReceived.setObjectProperty("JMS_AMQ_SaveStream", bufferedOutput);
-
+         }
-         fileOutputStream.close();
 
          System.out.println("File streamed to disk. Size of received file on disk is " + outputFile.length());
       }
@@ -182,12 +180,12 @@ public class LargeMessageExample {
 
    private static void createFile(final File file, final long fileSize) throws IOException {
       FileOutputStream fileOut = new FileOutputStream(file);
-      BufferedOutputStream buffOut = new BufferedOutputStream(fileOut);
+      try (BufferedOutputStream buffOut = new BufferedOutputStream(fileOut)) {
          byte[] outBuffer = new byte[1024 * 1024];
          for (long i = 0; i < fileSize; i += outBuffer.length) {
             buffOut.write(outBuffer);
          }
-      buffOut.close();
+      }
    }
 
 }

examples/features/standard/last-value-queue/src/main/java/org/apache/activemq/artemis/jms/example/LastValueQueueExample.java

@@ -67,13 +67,13 @@ public class LastValueQueueExample {
          System.out.format("Sent message: %s%n", message.getText());
 
          // Step 8. Browse the queue. There is only 1 message in it, the last sent
-         QueueBrowser browser = session.createBrowser(queue);
+         try (QueueBrowser browser = session.createBrowser(queue)) {
             Enumeration enumeration = browser.getEnumeration();
             while (enumeration.hasMoreElements()) {
                TextMessage messageInTheQueue = (TextMessage) enumeration.nextElement();
                System.out.format("Message in the queue: %s%n", messageInTheQueue.getText());
             }
-         browser.close();
+         }
 
          // Step 9. Create a JMS Message Consumer for the queue
          MessageConsumer messageConsumer = session.createConsumer(queue);

examples/features/standard/queue-requestor/src/main/java/org/apache/activemq/artemis/jms/example/TextReverserService.java

@@ -78,11 +78,10 @@ public class TextReverserService implements MessageListener {
          // retrieve the destination to reply to
          Destination replyTo = request.getJMSReplyTo();
          // create a producer to send the reply
-         MessageProducer producer = session.createProducer(replyTo);
+         try (MessageProducer producer = session.createProducer(replyTo)) {
             // send the reply
             producer.send(reply);
-         // close the producer
+         }
-         producer.close();
       }
       catch (JMSException e) {
          e.printStackTrace();

examples/features/standard/rest/jms-to-rest/src/main/java/JmsReceive.java

@@ -33,8 +33,7 @@ public class JmsReceive {
       ConnectionFactory factory = JmsHelper.createConnectionFactory("activemq-client.xml");
       Destination destination = ActiveMQDestination.fromAddress("jms.queue.orders");
 
-      Connection conn = factory.createConnection();
+      try (Connection conn = factory.createConnection()) {
-      try {
          Session session = conn.createSession(false, Session.AUTO_ACKNOWLEDGE);
          MessageConsumer consumer = session.createConsumer(destination);
          consumer.setMessageListener(new MessageListener() {
@@ -48,8 +47,5 @@ public class JmsReceive {
          conn.start();
          Thread.sleep(1000000);
       }
-      finally {
-         conn.close();
-      }
    }
 }

examples/features/standard/rest/jms-to-rest/src/main/java/JmsSend.java

@@ -30,8 +30,7 @@ public class JmsSend {
       ConnectionFactory factory = JmsHelper.createConnectionFactory("activemq-client.xml");
       Destination destination = ActiveMQDestination.fromAddress("jms.queue.orders");
 
-      Connection conn = factory.createConnection();
+      try (Connection conn = factory.createConnection()) {
-      try {
          Session session = conn.createSession(false, Session.AUTO_ACKNOWLEDGE);
          MessageProducer producer = session.createProducer(destination);
          ObjectMessage message = session.createObjectMessage();
@@ -40,8 +39,5 @@ public class JmsSend {
          message.setObject(order);
          producer.send(message);
       }
-      finally {
-         conn.close();
-      }
    }
 }

examples/features/standard/rest/push/src/main/java/PostOrder.java

@@ -30,8 +30,7 @@ public class PostOrder {
       ConnectionFactory factory = JmsHelper.createConnectionFactory("activemq-client.xml");
       Destination destination = ActiveMQDestination.fromAddress("jms.queue.orders");
 
-      Connection conn = factory.createConnection();
+      try (Connection conn = factory.createConnection()) {
-      try {
          Session session = conn.createSession(false, Session.AUTO_ACKNOWLEDGE);
          MessageProducer producer = session.createProducer(destination);
          ObjectMessage message = session.createObjectMessage();
@@ -40,8 +39,5 @@ public class PostOrder {
          message.setObject(order);
          producer.send(message);
       }
-      finally {
-         conn.close();
-      }
    }
 }

examples/features/standard/rest/push/src/main/java/ReceiveShipping.java

@@ -32,8 +32,7 @@ public class ReceiveShipping {
       ConnectionFactory factory = JmsHelper.createConnectionFactory("activemq-client.xml");
       Destination destination = ActiveMQDestination.fromAddress("jms.queue.shipping");
 
-      Connection conn = factory.createConnection();
+      try (Connection conn = factory.createConnection()) {
-      try {
          Session session = conn.createSession(false, Session.AUTO_ACKNOWLEDGE);
          MessageConsumer consumer = session.createConsumer(destination);
          consumer.setMessageListener(new MessageListener() {
@@ -47,8 +46,5 @@ public class ReceiveShipping {
          conn.start();
          Thread.sleep(1000000);
       }
-      finally {
-         conn.close();
-      }
    }
 }

examples/protocols/stomp/stomp-embedded-interceptor/src/main/java/org/apache/activemq/artemis/jms/example/StompEmbeddedWithInterceptorExample.java

@@ -35,7 +35,7 @@ public class StompEmbeddedWithInterceptorExample {
 
    public static void main(final String[] args) throws Exception {
       // Step 1. Create a TCP socket to connect to the Stomp port
-      Socket socket = new Socket("localhost", 61616);
+      try (Socket socket = new Socket("localhost", 61616)) {
 
          // Step 2. Send a CONNECT frame to connect to the server
          String connectFrame = "CONNECT\n" +
@@ -64,16 +64,13 @@ public class StompEmbeddedWithInterceptorExample {
             "\n" +
             END_OF_FRAME;
          sendFrame(socket, disconnectFrame);
-
+      }
-      // Step 5. Slose the TCP socket
-      socket.close();
-
 
       // It will use a regular JMS connection to show how the injected data will appear at the final message
 
-      ActiveMQConnectionFactory factory = new ActiveMQConnectionFactory();
+      try (ActiveMQConnectionFactory factory = new ActiveMQConnectionFactory();
            Connection connection = factory.createConnection();
-      Session session = connection.createSession();
+           Session session = connection.createSession()) {
          connection.start();
 
          MessageConsumer consumer = session.createConsumer(session.createQueue("exampleQueue"));
@@ -85,11 +82,7 @@ public class StompEmbeddedWithInterceptorExample {
 
          System.out.println("propStomp is Hello!! - " + propStomp.equals("Hello"));
          System.out.println("propRegular is HelloAgain!! - " + propRegular.equals("HelloAgain"));
-
+      }
-      session.close();
-      connection.close();
-
-      factory.close();
    }
 
    private static void sendFrame(Socket socket, String data) throws Exception {