JBoss - JMS - A Point-To-Point Example

http://docs.jboss.org/jbossas/docs/Server_Configuration_Guide/4/html/Messaging_on_JBoss-JMS_Examples.html

Let's start out with a point-to-point (P2P) example. In the P2P model, a sender delivers messages to a queue and a single receiver pulls the message off of the queue. The receiver does not need to be listening to the queue at the time the message is sent. Example 7.1, “A P2P JMS client example” shows a complete P2P example that sends a javax.jms.TextMessage to the queue queue/testQueue and asynchronously receives the message from the same queue.

package org.jboss.book.jms.ex1;

import javax.jms.JMSException;
import javax.jms.Message;
import javax.jms.MessageListener;
import javax.jms.Queue;
import javax.jms.QueueConnection;
import javax.jms.QueueConnectionFactory;
import javax.jms.QueueReceiver;
import javax.jms.QueueSender;
import javax.jms.QueueSession;
import javax.jms.TextMessage;
import javax.naming.InitialContext;
import javax.naming.NamingException;

import EDU.oswego.cs.dl.util.concurrent.CountDown;
import org.apache.log4j.Logger;
import org.jboss.util.ChapterExRepository;

/** 
 * A complete JMS client example program that sends a
 * TextMessage to a Queue and asynchronously receives the
 * message from the same Queue.
 * 
 * @author  Scott.Stark@jboss.org
 * @version $Revision: 1.9 $
 */
public class SendRecvClient
{
    static Logger log;
    static CountDown done = new CountDown(1);
    
    QueueConnection conn;
    QueueSession session;
    Queue que;
    
    public static class ExListener 
        implements MessageListener
    {
        public void onMessage(Message msg)
        {
            done.release();
            TextMessage tm = (TextMessage) msg;
            try {
                log.info("onMessage, recv text=" + tm.getText());
            } catch(Throwable t) {
                t.printStackTrace();
            }
        }
    }
    
    public void setupPTP()
        throws JMSException, 
               NamingException
    {
        InitialContext iniCtx = new InitialContext();
        Object tmp = iniCtx.lookup("ConnectionFactory");
        QueueConnectionFactory qcf = (QueueConnectionFactory) tmp;
        conn = qcf.createQueueConnection();
        que = (Queue) iniCtx.lookup("queue/testQueue");
        session = conn.createQueueSession(false,
                                          QueueSession.AUTO_ACKNOWLEDGE);
        conn.start();
    }
    
    public void sendRecvAsync(String text)
        throws JMSException, 
               NamingException
    {
        log.info("Begin sendRecvAsync");
        // Setup the PTP connection, session
        setupPTP();

        // Set the async listener
        QueueReceiver recv = session.createReceiver(que);
        recv.setMessageListener(new ExListener());

        // Send a text msg
        QueueSender send = session.createSender(que);
        TextMessage tm = session.createTextMessage(text);
        send.send(tm);
        log.info("sendRecvAsync, sent text=" + tm.getText());
        send.close();
        log.info("End sendRecvAsync");
    }
    
    public void stop()
        throws JMSException
    {
        conn.stop();
        session.close();
        conn.close();
    }
    
    public static void main(String args[]) 
        throws Exception
    {
        ChapterExRepository.init(SendRecvClient.class);
        log = Logger.getLogger("SendRecvClient");
        
        log.info("Begin SendRecvClient, now=" + System.currentTimeMillis());
        SendRecvClient client = new SendRecvClient();
        client.sendRecvAsync("A text msg");
        client.done.acquire();
        client.stop();
        log.info("End SendRecvClient");
        System.exit(0);
    }
}

Example 7.1. A P2P JMS client example

The client may be run using the following command line:

[examples]$ ant -Dchap=jms -Dex=1p2p run-example
...
run-example1p2p:
     [java] [INFO,SendRecvClient] Begin SendRecvClient, now=1102808673386
     [java] [INFO,SendRecvClient] Begin sendRecvAsync
     [java] [INFO,SendRecvClient] onMessage, recv text=A text msg
     [java] [INFO,SendRecvClient] sendRecvAsync, sent text=A text msg
     [java] [INFO,SendRecvClient] End sendRecvAsync
     [java] [INFO,SendRecvClient] End SendRecvClient