Java tutorial
/** * Licensed to the Apache Software Foundation (ASF) under one or more * contributor license agreements. See the NOTICE file distributed with * this work for additional information regarding copyright ownership. * The ASF licenses this file to You under the Apache License, Version 2.0 * (the "License"); you may not use this file except in compliance with * the License. You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ package org.apache.activemq; import java.util.Random; import java.util.Vector; import java.util.concurrent.SynchronousQueue; import java.util.concurrent.ThreadPoolExecutor; import java.util.concurrent.TimeUnit; import javax.jms.Connection; import javax.jms.JMSException; import javax.jms.Message; import javax.jms.MessageConsumer; import javax.jms.MessageProducer; import javax.jms.Session; import javax.jms.TextMessage; import javax.jms.Topic; /** * */ public class JmsConnectionStartStopTest extends TestSupport { private static final org.apache.commons.logging.Log LOG = org.apache.commons.logging.LogFactory .getLog(JmsConnectionStartStopTest.class); private Connection startedConnection; private Connection stoppedConnection; /** * @see junit.framework.TestCase#setUp() */ @Override protected void setUp() throws Exception { LOG.info(getClass().getClassLoader().getResource("log4j.properties")); ActiveMQConnectionFactory factory = createConnectionFactory(); startedConnection = factory.createConnection(); startedConnection.start(); stoppedConnection = factory.createConnection(); } /** * @see junit.framework.TestCase#tearDown() */ @Override protected void tearDown() throws Exception { stoppedConnection.close(); startedConnection.close(); } /** * Tests if the consumer receives the messages that were sent before the * connection was started. * * @throws JMSException */ public void testStoppedConsumerHoldsMessagesTillStarted() throws JMSException { Session startedSession = startedConnection.createSession(false, Session.AUTO_ACKNOWLEDGE); Session stoppedSession = stoppedConnection.createSession(false, Session.AUTO_ACKNOWLEDGE); // Setup the consumers. Topic topic = startedSession.createTopic("test"); MessageConsumer startedConsumer = startedSession.createConsumer(topic); MessageConsumer stoppedConsumer = stoppedSession.createConsumer(topic); // Send the message. MessageProducer producer = startedSession.createProducer(topic); TextMessage message = startedSession.createTextMessage("Hello"); producer.send(message); // Test the assertions. Message m = startedConsumer.receive(1000); assertNotNull(m); m = stoppedConsumer.receive(1000); assertNull(m); stoppedConnection.start(); m = stoppedConsumer.receive(5000); assertNotNull(m); startedSession.close(); stoppedSession.close(); } /** * Tests if the consumer is able to receive messages eveb when the * connecction restarts multiple times. * * @throws Exception */ public void testMultipleConnectionStops() throws Exception { testStoppedConsumerHoldsMessagesTillStarted(); stoppedConnection.stop(); testStoppedConsumerHoldsMessagesTillStarted(); stoppedConnection.stop(); testStoppedConsumerHoldsMessagesTillStarted(); } public void testConcurrentSessionCreateWithStart() throws Exception { ThreadPoolExecutor executor = new ThreadPoolExecutor(50, Integer.MAX_VALUE, 60L, TimeUnit.SECONDS, new SynchronousQueue<Runnable>()); final Vector<Throwable> exceptions = new Vector<Throwable>(); final Random rand = new Random(); Runnable createSessionTask = new Runnable() { @Override public void run() { try { TimeUnit.MILLISECONDS.sleep(rand.nextInt(10)); stoppedConnection.createSession(false, Session.AUTO_ACKNOWLEDGE); } catch (Exception e) { exceptions.add(e); } } }; Runnable startStopTask = new Runnable() { @Override public void run() { try { TimeUnit.MILLISECONDS.sleep(rand.nextInt(10)); stoppedConnection.start(); stoppedConnection.stop(); } catch (Exception e) { exceptions.add(e); } } }; for (int i = 0; i < 1000; i++) { executor.execute(createSessionTask); executor.execute(startStopTask); } executor.shutdown(); assertTrue("executor terminated", executor.awaitTermination(30, TimeUnit.SECONDS)); assertTrue("no exceptions: " + exceptions, exceptions.isEmpty()); } }