About JMS

A specification that describes a common way for Java programs to create,send, receive and read distributed enterprise messages.
                              JMS is a part of the Java Platform, Enterprise Edition, and is defined by a specification developed under the Java Community Process as JSR 914.  It is a messaging standard that allows application components based on the Java Enterprise Edition (Java EE) to create, send, receive, and read messages.  It allows the communication between different components of a distributed application to be loosely coupled, reliable, and asynchronous.

Messages are

    Asynchronous:
    -------------
        a client does not have to request them in order to receive them.
    Reliable:
    ----------
        can ensure message is delivered safely once and only once.

Messaging Domains
-----------------
   Point-to-Point



    Publish/Subscribe





JMS Administration With IBM WebSphere MQ
-----------------------------------------------
0. Create a Queue Manager in Websphere MQ as QM1
   Create a Local queue under a QM1 as LQ1

1.check the PROVIDER_URL in the C:\Program Files\IBM\WebSphere MQ\java\bin

2. Create a folder for PROVIDER_URL like (C:/JNDI-Directory)

3. execute the JMSAdmin.bat in C:\Program Files\IBM\WebSphere MQ\java\bin

4. define the queue connection Factory
     define qcf(MY_QCF) qmgr(QM1)
  which will create a file in the C:/JNDI-Directory as  .bindings

5.create destination object
    define q(MY_Q) queue(LQ1) qmgr(QM1)

  which will update this details in the .bindings file in C:/JNDI-Directory

6. configure JNDI in Websphere MQ   
    . click on JMS Administrated Object
    . right click and choose add initial context
    . select File System Option
    . and browse the JNDI-Directory by clicking the Browse button
    . Click Next -> Finish

JMS Client
-----------



1.  Initialize the InitialContext with the following values
    .provide the value PROVIDER_URL
    .provide the value INITIAL_CONTEXT_FACTORY

    Hashtable ht = new Hashtable();
    ht.put(Context.PROVIDER_URL,"file:/C:/JNDI-Directory");
    ht.put(Context.INITIAL_CONTEXT_FACTORY,"com.sun.jndi.fscontext.RefFSContextFactory");
    Context ctx = new InitialContext(ht);

2. Retrieve the configured QueueConnectionFactory from InitialContext by passing "MY_QCF"
    QueueConnectionFactory qcf = (QueueConnectionFactory)ctx.lookup("MY_QCF");

3. Retrieve the configured Queue from InitialContext by passing "MY_Q"
    Queue qu = (Queue) ctx.lookup("MY_Q");

4. Create the QueueConnection from QueueConnectionFactory
    QueueConnection qcon = qcf.createQueueConnection();

5. Create the QueueSession from QueueConnection
    QueueSession qsession = qcon.createQueueSession(false, Session.AUTO_ACKNOWLEDGE);

7. Create the QueueSender  from QueueSession
    QueueSender qSender =  qsession.createSender(qu);

8. Create the Text Message from QueueSession
    TextMessage msg =  qsession.createTextMessage();

9. send a text throw Text Message
   
    msg.setText(args[0]);

    qSender.send(msg);



Example Sender Program

import javax.jms.*;
import java.util.Hashtable;
import javax.naming.*;
public class JMSSender
{
    public static void main(String args[])
    {
       
        try
        {
            Hashtable ht = new Hashtable();
            ht.put(Context.PROVIDER_URL,"file:/C:/JNDI-Directory");
            ht.put(Context.INITIAL_CONTEXT_FACTORY,"com.sun.jndi.fscontext.RefFSContextFactory");
            Context ctx = new InitialContext(ht);
           
            QueueConnectionFactory qcf = (QueueConnectionFactory)ctx.lookup("MY_QCF");
           
            Queue qu = (Queue) ctx.lookup("MY_Q");

            QueueConnection qcon = qcf.createQueueConnection();

            QueueSession qsession = qcon.createQueueSession(false, Session.AUTO_ACKNOWLEDGE);
           
            QueueSender qSender =  qsession.createSender(qu);

            TextMessage msg =  qsession.createTextMessage();

            msg.setText(args[0]);
           
            qSender.send(msg);

        }
        catch(Exception e)
        {
            e.printStackTrace();
        }
    }
}


Example Receiver Program


import javax.jms.*;
import java.util.Hashtable;
import javax.naming.*;
public class JMSReceiver
{
    public static void main(String args[])
    {
       
        try
        {
            Hashtable ht = new Hashtable();
            ht.put(Context.PROVIDER_URL,"file:/C:/JNDI-Directory");
            ht.put(Context.INITIAL_CONTEXT_FACTORY,"com.sun.jndi.fscontext.RefFSContextFactory");

            Context ctx = new InitialContext(ht);
           
            QueueConnectionFactory qcf = (QueueConnectionFactory)ctx.lookup("MY_QCF");
           
            Queue qu = (Queue) ctx.lookup("MY_Q");

            QueueConnection qcon = qcf.createQueueConnection();
           
            qcon.start();

            QueueSession qsession = qcon.createQueueSession(false, Session.AUTO_ACKNOWLEDGE);
           
            QueueReceiver qReceiver = qsession.createReceiver(qu);
           
            TextMessage tmsg= (TextMessage) qReceiver.receive(30000);
           
            System.out.println(tmsg.getText());
        }
        catch(Exception e)
        {
            e.printStackTrace();
        }
    }
}


Example Publisher Program

import javax.jms.*;
import java.util.Hashtable;
import javax.naming.*;
public class JMSPublisher
{
    public static void main(String args[])
    {
       
        try
        {
            Hashtable ht = new Hashtable();
            ht.put(Context.PROVIDER_URL,"file:/C:/JNDI-Directory");
            ht.put(Context.INITIAL_CONTEXT_FACTORY,"com.sun.jndi.fscontext.RefFSContextFactory");
           
            Context ctx = new InitialContext(ht);
           
            TopicConnectionFactory tcf = (TopicConnectionFactory)ctx.lookup("MY_TCF");

            Topic topic= (Topic ) ctx.lookup("MY_T");

            TopicConnection tcon = tcf.createTopicConnection();
           
            TopicSession tsession = tcon.createTopicSession(false, Session.AUTO_ACKNOWLEDGE);
           
            TopicPublisher tp = tsession.createPublisher(topic);

            TextMessage msg =  tsession.createTextMessage();

            msg.setText(args[0]);
           
            tp.publish(msg);
           
            tsession.close();

            tcon.close();
        }
        catch(Exception e)
        {
            e.printStackTrace();
        }
    }
}

Example Subscriber Program

import javax.jms.*;
import java.util.Hashtable;
import javax.naming.*;
public class JMSSubscriber
{
    public static void main(String args[])
    {
       
        try
        {
            Hashtable ht = new Hashtable();
            ht.put(Context.PROVIDER_URL,"file:/C:/JNDI-Directory");
            ht.put(Context.INITIAL_CONTEXT_FACTORY,"com.sun.jndi.fscontext.RefFSContextFactory");
            Context ctx = new InitialContext(ht);
           
            TopicConnectionFactory tcf = (TopicConnectionFactory)ctx.lookup("MY_TCF");
           
            Topic topic = (Topic) ctx.lookup("MY_T");

            TopicConnection tcon = tcf.createTopicConnection();
           
            tcon.start();

            TopicSession tsession = tcon.createTopicSession(false, Session.AUTO_ACKNOWLEDGE);
           
            TopicSubscriber tSubscriber= tsession.createSubscriber(topic);
           
            TextMessage tmsg= (TextMessage) tSubscriber.receive(3000000);
           
            System.out.println(tmsg);
        }
        catch(Exception e)
        {
            e.printStackTrace();
        }
    }
}