Following are the main Source files of this application

/*
 * @author Rajat Gupta
 * @version 1.0
 *
 * Name of the Application        : ListenerMDBBean.java

 * Development Environment       : Oracle9i JDeveloper
 * Creation/Modification History  :
 *
 *
 *   Rajat Gupta        28-May-2003        Created
 */

package oracle.otnsamples.oc4jjms.impl;

// EJB Imports

import javax.ejb.MessageDrivenBean;
import javax.ejb.MessageDrivenContext;

// JMS Imports
import javax.jms.DeliveryMode;
import javax.jms.Message;
import javax.jms.MessageListener;
import javax.jms.Session;
import javax.jms.Topic;
import javax.jms.TopicConnection;
import javax.jms.TopicConnectionFactory;

import javax.jms.TopicPublisher;
import javax.jms.TopicSession;

// Naming Imports
import javax.naming.Context;
import javax.naming.InitialContext;


/**
 * This Message Driven Bean listens to a queue. If any message is enqueued to
 * the queue, then this bean is invoked. On invocation, the bean first dequeues
 * the message and then enqueues this message to other topic.

 *
 */
public class ListenerMDBBean implements MessageDrivenBean, MessageListener  {

  /**
   * Context for the MDB
   */
  private MessageDrivenContext context;

  /**
   * TopicConnectionFactory Object
   */
//  TopicConnectionFactory topicCF;


  /**
   * TopicConnection Object
   */
  TopicConnection topicConnection;

  /**
   * TopicSession Object
   */
  TopicSession topicSession;

  /**
   * Topic Object
   */

  Topic topic;

  /**
   * Object to publish the message to the topic.
   */
  TopicPublisher sender;

  /**
   * This method will be invoked when this MDB is created. The method
   * initializes some objects needed by the bean.
   */
  public void ejbCreate() {
    try{
      // Get the Initial Context
      Context jndiContext = new InitialContext();


      // Lookup the Topic Connection factory and create the
      // QueueConnectionFactory.
      TopicConnectionFactory topicCF = (TopicConnectionFactory)jndiContext.lookup
            ("jms/ChatTopicConnectionFactory");

      // Create a Connection to the Topic
      topicConnection = topicCF.createTopicConnection();

      // Create a Session to the topic.
      topicSession = topicConnection.createTopicSession
                                           (true, Session.AUTO_ACKNOWLEDGE);

      // Lookup the Topic and create its object.
      topic = (Topic)jndiContext.lookup
                              ("jms/ChatTopic");


      // Creates an object to send messages to the specified topic
      sender = topicSession.createPublisher(topic);

      // Un-comment the following line if you want the message in the topic
      // to expire after 10 minutes. As of now, the message will be present
      // in the topic until all the subscribed users have received the
      // message.
      //sender.setTimeToLive(600000);

      // Set the message to be stored persistently.
      sender.setDeliveryMode(DeliveryMode.PERSISTENT);

      // This application does not need a unique ID for each message. So, we
      // will disable its generation. This will save time and improve
      // performance as the application does not have to go through elaborate
      // algorithms to generate unique ID for each message.

      sender.setDisableMessageID(true);

      // Close the JNDI Context
      jndiContext.close();

      // Start the Connection
      topicConnection.start();
    }catch(Exception e){
      // Print the exception on the console
      e.printStackTrace();
    }
  }

  /**
   * This method will be invoked when a message is enqueued to the queue on
   * which the MDB is listening to.
   *
   * @param message Message enqueued in the queue

   */
  public void onMessage(Message message) {
    try{
      // Enqueue the message in the queue. This method uses the default
      // delivery mode, priority, and time to live. But, you can also
      // specify these parameters explicitly through other overloaded
      // methods within the QueueSender Class.
      sender.publish(message);

      // Commit the transaction
      topicSession.commit();

    }catch (Exception e){
      // Print the exception on the console
      e.printStackTrace();
    }
  }

  /**

   * This method will be called when this MBD is removed from memory. The
   * method closes the objects that are no longer required.
   */
  public void ejbRemove() {
    try{
      // Close the connection
      topicConnection.stop();

      // Close Resources
      sender.close();
      topicSession.close();
      topicConnection.close();

    }catch (Exception e){
      // Print the exception on the console
      e.printStackTrace();
    }
  }

  /**

   * This method sets the MDB Context.
   *
   * @param ctx MBD Context
   */
  public void setMessageDrivenContext(MessageDrivenContext ctx) {
    this.context = ctx;
  }
}