topicexample.java

JMS的topic程序

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 * This is free software; you can redistribute it and/or modify it
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 * published by the Free Software Foundation; either version 2.1 of
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 *
 * This software is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this software; if not, write to the Free
 * Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
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 */
package org.jboss.example.jms.topic;

import javax.jms.Connection;
import javax.jms.ConnectionFactory;
import javax.jms.JMSException;
import javax.jms.MessageConsumer;
import javax.jms.MessageProducer;
import javax.jms.Session;
import javax.jms.TextMessage;
import javax.jms.Topic;
import javax.naming.InitialContext;

import org.jboss.example.jms.common.ExampleSupport;

/**
 * The example creates a connection to the default provider and uses the connection to send a
 * message to the topic "queue/testTopic". The message must be received by a topic subscriber.
 *
 * Since this example is also used by the smoke test, it is essential that the VM exits with exit
 * code 0 in case of successful execution and a non-zero value on failure.
 *
 * @author <a href="mailto:[e-mail]">Ovidiu Feodorov</a>
 * @author <a href="mailto:[e-mail]">Luc Texier</a>
 * @author <a href="mailto:[e-mail]">Tim Fox</a>
 * @version <tt>$Revision: 1843 $</tt>
 *
 * $Id: TopicExample.java 1843 2006-12-21 23:41:19Z timfox $
 */
public class TopicExample extends ExampleSupport
{
   public void example() throws Exception
   {
      String destinationName = getDestinationJNDIName();
      
      InitialContext ic = null;
      Connection connection = null;
      
      try
      {         
         ic = new InitialContext();
         
         ConnectionFactory cf = (ConnectionFactory)ic.lookup("/ConnectionFactory");
         Topic topic = (Topic)ic.lookup(destinationName);
         log("Topic " + destinationName + " exists");
         
         connection = cf.createConnection();
         Session session = connection.createSession(false, Session.AUTO_ACKNOWLEDGE);
         MessageProducer publisher = session.createProducer(topic);
         MessageConsumer subscriber = session.createConsumer(topic);
         
         ExampleListener messageListener = new ExampleListener();
         subscriber.setMessageListener(messageListener);
         connection.start();
         
         TextMessage message = session.createTextMessage("Hello!");
         publisher.send(message);
         log("The message was successfully published on the topic");
         
         messageListener.waitForMessage();
         
         message = (TextMessage)messageListener.getMessage();
         log("Received message: " + message.getText());
         assertEquals("Hello!", message.getText());
         
         displayProviderInfo(connection.getMetaData());
         
      }
      finally
      {
         if (ic != null)
         {
            try
            {
               ic.close();
            }
            catch(Exception e)
            {
               throw e;
            }
         }
         
         // ALWAYS close your connection in a finally block to avoid leaks.
         // Closing connection also takes care of closing its related objects e.g. sessions.
         closeConnection(connection);
      }
   }
   
   private void closeConnection(Connection con) throws JMSException
   {
      
      try
      {
         if (con != null)
         {
            con.close();
         }
      }
      catch(JMSException jmse)
      {
         log("Could not close connection " + con +" exception was " + jmse);
      }
   }
   
   protected boolean isQueueExample()
   {
      return false;
   }
   
   public static void main(String[] args)
   {
      new TopicExample().run();
   }
   
}