package org.jboss.book.jms.ex3;import javax.jms.JMSException;import javax.jms.Message;import javax.jms.MessageListener;import javax.jms.Topic;import javax.jms.TopicConnection;import javax.jms.TopicConnectionFactory;import javax.jms.TopicPublisher;import javax.jms.TopicSubscriber;import javax.jms.TopicSession;import javax.jms.TextMessage;import javax.naming.InitialContext;import javax.naming.NamingException;import EDU.oswego.cs.dl.util.concurrent.CountDown;/** A complete JMS client example program that sends NTextMessages to a Topic A and asynchronously receives themessages as modified by TestMDB from Topic B.@author  Scott.Stark@jboss.org@version $Revision: 1.1 $*/public class SendRecvClient{   static final int N = 10;   static CountDown done = new CountDown(N);   TopicConnection conn;   TopicSession session;   Topic topicA;   Topic topicB;   public static class ExListener implements MessageListener   {      public void onMessage(Message msg)      {         done.release();         TextMessage tm = (TextMessage) msg;         try         {            System.out.println("onMessage, recv text="+tm.getText());         }         catch(Throwable t)         {            t.printStackTrace();         }      }   }   public void setupPubSub()      throws JMSException, NamingException   {      InitialContext iniCtx = new InitialContext();      Object tmp = iniCtx.lookup("ConnectionFactory");      TopicConnectionFactory qcf = (TopicConnectionFactory) tmp;      conn = qcf.createTopicConnection();      topicA = (Topic) iniCtx.lookup("topic/jms.ex3.TopicA");      topicB = (Topic) iniCtx.lookup("topic/jms.ex3.TopicB");      session = conn.createTopicSession(false,         TopicSession.AUTO_ACKNOWLEDGE);      conn.start();   }   public void sendRecvAsync(String textBase)      throws JMSException, NamingException, InterruptedException   {      System.out.println("Begin sendRecvAsync");      // Setup the PTP connection, session      setupPubSub();      // Set the async listener for topicA      TopicSubscriber recv = session.createSubscriber(topicA);      recv.setMessageListener(new ExListener());      // Send a few text msgs to topicB      TopicPublisher send = session.createPublisher(topicB);      for(int m = 0; m < 10; m ++)      {         TextMessage tm = session.createTextMessage(textBase+"#"+m);         tm.setJMSReplyTo(topicA);         send.publish(tm);         System.out.println("sendRecvAsync, sent text="+tm.getText());      }      System.out.println("End sendRecvAsync");   }   public void stop()  throws JMSException   {      conn.stop();   }   public static void main(String args[]) throws Exception   {      SendRecvClient client = new SendRecvClient();      client.sendRecvAsync("A text msg");      client.done.acquire();      client.stop();      System.exit(0);   }}