Jboss Messaging JMS

Question

I successfully managed to send the message to queue name ReceiverQueue on my localhost Jboss server, how can I retrieve message I sent to it or how do I check if there is any messages in the queue if any retrieve them. or can I get an explanation of some sort what is the best way to do this. Thank you

A working send/receive tutorial would be accept as well. Anything that will get me to just send to the queue and receive message from that queue will get accepted answer.

I'm using Spring.

I want a solution that does it using application context with bean injection ..

Answer 1

Standard JMS API steps:
1. Create a javax.naming.Context with the access details of the server

context = new InitialContext(environment)

2. Look up javax.jms.QueueConnectionFactory in the context. Factory name is specific to the JMS server

factory = (QueueConnectionFactory)context.lookup(factoryName)

3. Create a javax.jms.QueueConnection

connection = factory.createQueueConnection(...)

4. Create a javax.jms.QueueSession

session = connection.createQueueSession(...)

5. Look up your javax.jms.Queue in the context

queue = (Queue) context.lookup(qJndiName)

Till now it is the same as sending....
6. Create a javax.jms.QueueReceiver with the session

receiver = session.createReceiver(queue)

7. JMS API provides 2 ways to retrieve a message:
7.a Wait for a message with one of the receiver.receive() methods
7.b Implement javax.jms.MessageListener in your class and register it as the listener

receiver.setMessageListener(this)

JMS API will call your onMessage() method whenever a new message arrives
8. Don't forget to start the listener:

connection.start()

9. Close the context (very important, when you access multiple JMS servers from the same program):

context.close()

The above is a typical solution from a stand-alone application. In EJB environment you should use message driven beans. You can find ino on them on http://java.sun.com/javaee/6/docs/tutorial/doc/gipko.html and a tutorial on http://schuchert.wikispaces.com/EJB3+Tutorial+5+-+Message+Driven+Beans

Here is the working example you've asked for:

import java.util.Hashtable;
import javax.naming.*;
import javax.jms.*;

public class JMSJNDISample implements MessageListener {

    public static final String JNDI_URL = "jnp://localhost:1099";
    public static final String JNDI_CONTEXT_FACTORY = "org.jnp.interfaces.NamingContextFactory";
    public static final String JMS_USER = null;
    public static final String JMS_PASSWORD = null;
    public static final String JMS_CONNECTION_FACTORY = "MyConnectionFactory";
    public static final String QUEUE_JNDI_NAME = "ReceiverQueue";

    QueueConnection qConn = null;
    QueueSession qSession = null;
    QueueSender qSender = null;
    QueueReceiver qReceiver = null;

    public JMSJNDISample () {
    }


    public void init() throws JMSException, NamingException {
        // Set up JNDI Context
        Hashtable env = new Hashtable();
        env.put(Context.INITIAL_CONTEXT_FACTORY, JNDI_CONTEXT_FACTORY);
        env.put(Context.PROVIDER_URL, JNDI_URL);
        if (JMS_USER != null)
            env.put(Context.SECURITY_PRINCIPAL, JMS_USER);
        if (JMS_PASSWORD != null)
            env.put(Context.SECURITY_CREDENTIALS, JMS_PASSWORD);
        Context jndiContext = new InitialContext(env);

        // Lookup queue connection factory
        QueueConnectionFactory cFactory = (QueueConnectionFactory)jndiContext.lookup(JMS_CONNECTION_FACTORY);

        // Create Connection
        if (JMS_USER == null || JMS_PASSWORD == null)
            qConn = cFactory.createQueueConnection();
        else {
            qConn = cFactory.createQueueConnection(JMS_USER, JMS_PASSWORD);
        }

        // Create Session
        qSession = qConn.createQueueSession(false, Session.AUTO_ACKNOWLEDGE);

        // Lookup Queue
        Queue queue = (Queue) jndiContext.lookup(QUEUE_JNDI_NAME);

        // Create Queue Sender
        qSender = qSession.createSender(queue);

        // Create Queue Receiver
        qReceiver = qSession.createReceiver(queue);
        qReceiver.setMessageListener(this);

        // Start receiving messages
        qConn.start();

        // Close JNDI context
        jndiContext.close();
    }


    public void sendMessage (String str) throws JMSException {
        TextMessage msg = qSession.createTextMessage(str);
        qSender.send(msg);
    }


    public void onMessage (Message message) {
        try {
            if (message instanceof TextMessage) {
                TextMessage textMessage = (TextMessage)message;
                System.out.println("Text Message Received: "+textMessage.getText());
            } else {
                System.out.println(message.getJMSType()+" Message Received");
            }
        } catch (JMSException je) {
            je.printStackTrace();
        }
    }


    public void destroy() throws JMSException {
        if (qSender != null) qSender.close();
        if (qReceiver != null) qReceiver.close();
        if (qSession != null) qSession.close();
        if (qConn != null) qConn.close();
    }


    public static void main(String args[]) {
        try {
            JMSJNDISample sample = new JMSJNDISample();
            // Initialize connetion
            sample.init();
            // Send Message
            sample.sendMessage("Hello World");
            // Wait 2 sec for answer
            Thread.sleep(2000);
            // Disconnect
            sample.destroy();
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}