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Hi All,

In this blog we will see how to use Request/Reply model in JMS.

On a broad level,JMS supports two messaging models : Point-to-Point (PTP) and Publish-Subscribe. These are easier to create and there are many examples available.Here we will see a third kind of model called as Request-Reply model. This is an “overlay” model since it is implemented on the top of other two models.

Let us see how to create this model in JMS : We will use PTP model as the basic model. While sending the message, the Producer/Sender can specify the Reply To queue . Using this Reply To queue the Receiver/Consumer can send a reply back to the Producer.

To create a Reply To queue in the producer :

Destination replyQueue = session.createTemporaryQueue();
message.setJMSReplyTo(replyQueue);

To get the Reply To queue in the consumer :

Destination replyDestination = message.getJMSReplyTo();

Now let us see the full code for Producer :

public void sendMessage(String name) throws JustJavaRuntimeException {
	try {
		Connection connection = null;
		Session session = null;
		Destination destination = null;
		MessageProducer messageProducer = null;
		connectionFactory = (ConnectionFactory) ctx.lookup(connectionFactoryName);
		connection = connectionFactory.createConnection();
		session = connection.createSession(false, Session.AUTO_ACKNOWLEDGE);
		destination =(Destination) ctx.lookup(requestQueueName);
		messageProducer = session.createProducer(destination);
		TextMessage message = session.createTextMessage(name);

		//Create Reply To Queue
		connection.start();
		Destination replyQueue = session.createTemporaryQueue();
		message.setJMSReplyTo(replyQueue);
		replyConsumer = session.createConsumer(replyQueue);
		replyConsumer.setMessageListener(new ResponseListener());
		messageProducer.send(message, javax.jms.DeliveryMode.PERSISTENT,   javax.jms.Message.DEFAULT_PRIORITY, 1800000);
		System.out.println("++++++++++++++++++++++++++++++++++++++++++");
		System.out.println("Message sent to Bean");
		System.out.println("ReplyQueue name is : "+replyQueue.toString());
		System.out.println("++++++++++++++++++++++++++++++++++++++++++");

		synchronized (this) {
		try {
		    wait(5000);
		} catch (InterruptedException e) {
		    throw new JustJavaRuntimeException(e);
		}
	}

	messageProducer.close();
	session.close();
	connection.close();

	} catch (JMSException je) {
		throw new JustJavaRuntimeException(je);
	} catch (NamingException ne) {
		throw new JustJavaRuntimeException(ne);
	}
}

One thing you might notice here :

replyConsumer.setMessageListener(new ResponseListener());

Well replyConsumer is a MessageConsumer which is assigned a message listener.This is for listening back the reply we get from the original Consumer.

Few things which are necessary for building Request/Reply model using JMS are :

//Create Reply To Queue
connection.start();
.....
synchronized (this) {
try {
    wait(5000);
} catch (InterruptedException e) {
    throw new JustJavaRuntimeException(e);
}

Well you need to do connection.start() ; This starts a connection’s delivery of incoming messages.

Also we are usiing wait(timeout) here . We need to wait since otherwise the connection would close after sending the message to the original Consumer.We don’t want connection to close till we receive a message from the Consumer back.So I have kept a delay here.

We can also use the MessageConsumer’s receive() method for synchronous receive.

Here is the code for ResponseListener :

class ResponseQueueListener implements MessageListener {
	public void onMessage(Message m) {
		try {
 			if (m instanceof TextMessage) {
				TextMessage replyMessage = (TextMessage) m;
				System.out.println("++++++++++++++++++++++++++++++++++++++++++++++++++++");
				System.out.println("Received reply ResponseQueueListener");
				System.out.println("\tTime:       " + System.currentTimeMillis() + " ms");
				System.out.println("\tMessage ID: " + replyMessage.getJMSMessageID());
				System.out.println("\tCorrel. ID: " + replyMessage.getJMSCorrelationID());
				System.out.println("\tReply to:   " + replyMessage.getJMSReplyTo());
				System.out.println("\tContents:   " + replyMessage.getText());
				System.out.println("++++++++++++++++++++++++++++++++++++++++++++++++++++");
			}
		} catch (JMSException e) {
			e.printStackTrace();
		}
	}
}

Now let us see the code for Consumer. I have used MessageDrivenBean as Consumer.

@MessageDriven(name = "AsyncMDBean", activationConfig = {
	@ActivationConfigProperty(propertyName = "destinationType", propertyValue = "javax.jms.Queue"),
	@ActivationConfigProperty(propertyName = "destination", propertyValue = "queue/RequestQueue")

})
public class AsyncMDBean implements MessageListener {

	private Session session;
	Context ctx;

	public AsyncMDBean() {
 	   	try {
			ctx = new InitialContext();
		} catch (NamingException e) {
			throw new JustJavaRuntimeException(e);
		}
	}

	public void onMessage(Message message) {
		String text = null;
		try {

            	if (message instanceof TextMessage) {

			TextMessage textMessage = (TextMessage) message;
			text = textMessage.getText();
			System.out.println("****************************************************");
			System.out.println("Received message in AsyncMDBean. Name: "+text);
			System.out.println("****************************************************");

			//Send the reply
			Destination replyDestination = message.getJMSReplyTo();
			Connection connection = null;
			ConnectionFactory connectionFactory = (ConnectionFactory) ctx.lookup("ConnectionFactory");
			connection = connectionFactory.createConnection();
			session = connection.createSession(false, Session.AUTO_ACKNOWLEDGE);
			MessageProducer replyProducer = session.createProducer(replyDestination);
			TextMessage replyMessage = session.createTextMessage();
			replyMessage.setText("ABCD");
			replyProducer.send(replyMessage);

			System.out.println("****************************************************");
			System.out.println("Sent reply");
			System.out.println("\tTime:       " + System.currentTimeMillis() + " ms");
			System.out.println("\tMessage ID: " + replyMessage.getJMSMessageID());
			System.out.println("\tCorrel. ID: " + replyMessage.getJMSCorrelationID());
			System.out.println("\tReply to:   " + replyMessage.getJMSReplyTo());
			System.out.println("\tContents:   " + replyMessage.getText());
			System.out.println("****************************************************");

        	} else {
		       	System.err.println("Expected a Text Message");
        	}

        	System.out.println("*******************************************");
        	System.out.println("Leaving AsyncMDBean. Name: "+text );
        	System.out.println("*******************************************");
        	} catch (Throwable t) {
            		t.printStackTrace();
        	}
	}
}

Well thats it !!!

Please let me how did you find this code ….. I have deployed it successfully on JBoss 4.2.3 … There were some issues on Glassfish.

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10 Comments

  1. HI,
    I am also looking at the same issue, but in my case i am sending the message from SLSB EJB, container managed transaction.

    getting some exception becuase of the same transaction.
    the sequence is as follows…
    1.Servlet controller calls SLSB
    2.SLSB sends a message (setting with temporary queue as reply queue).
    3.MDB consumes the message and sends a reply message.
    4.SLSB receives the reply message and will do some business logic.

    so could you please post me some POC with this case.

    advance thanks

  2. conti…it is working in a JUnit test case but not working as in application.
    I am using Jboss4.2.2

  3. Given Exampple of JMS Request Reply Pattern will not work in CMT of EJB3…
    why?

  4. Sesh,

    What exception you are getting ? Can you please give the details ?

  5. Rahul,

    Can you post your code ?

  6. hi justjava,
    i am creating a similar request jms reply pattern with MDB as a consumer. What I want to ask you is if jndi.properties need to be set in MDB just like normal jms producer. I see that you just use the normal
    Context ctx = new InitialContext();
    please let me know.

    • Hi wangdu,

      I used glassfish for all these examples and didn’t do anything with jndi properties . What is the issue u r facing . I need to search for the example again and try to run it .

        • wangdu
        • Posted May 10, 2009 at 12:24 pm
        • Permalink

        Thanks for the reply. The issue i am facing is that the MDB (which is replier/responser) is not able to get the connection factory. I am using Jboss AS. I have tried:
        1. no properties when instantiating the InitialContext.
        2. with properties i.e new InitialContext(env);
        3. then finally i tried to use also the activconfig annotation where i have set the propertyName to “connectionFactoryJndiName” which gives error: no such property found.

        Could you try to do the same example on jboss and let me know how u did it? thanks

  7. The response message is sended after commit? How can i do to ensure the message is sended if commit is executed and not sended if rollback?

    Thanks

  8. Hi
    Nice JMS article. Could you have this available as a download?


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