JMS easy example, Get start with JMS, JMS tutorial, JMS easy code

JMS : Java Messaging Service

I was searching an easy and running example on JMS, but could not. I saw in many tutorial they explained in very hard manner to how to setup the administrative object to run the JSM example. But in real it is very easy.
Here I am using IBM Rational Software Architect (RSA) as Java IDE and WebSphere Application Server V6.1 that comes with RSA. [ Image Source ]

NOTE : If you want to execute this tutorial on RAD [IBM Rational Architect Developer] IDE then plesae click below link.

http://binodjava.blogspot.com/2009/06/jms-easy-example-in-rad-get-started.html

Just follows these step and your example will run:

1. start the server and go to admin console
2. Service Integration -> Buses -> New -> Give Bus Name: BinodBus ->
Next -> Finish
3. click on BinodBus -> In Topology Section, click on Bus Member -> Add -> next -> Chosse File Store -> next -> next -> Finish -> Save
4. Agin click on BinodBus -> In Destination Resource, click on Destination -> check Queue Type present or not. If not present then click on Next -> Choose Queue -> Next ->
put Identifier QueueDestination -> Next -> Finish -> Save
5. Open Resources Tree from left panel

6. click on JMS -> Connection Factories -> New -> Choose Default messaging provider -> OK -> Name -> BinodConnectionProvider ->
JNDI Name -> jms/BinodConnectionProvider -> Bus Name -> BinodBus ->
click on OK -> Save

7. From left side Resources -> JMS -> Queue -> New -> choose Default messaging provider -> OK ->
Name -> BinodQueue -> JNDI -> jms/BinodQueue -> Bus Name ->
BinodBus -> QueueName -> QueueDestination -> OK -> Save

[All the bold latter is Admin object name]

8. Restart the server.
9. Create one Dynamic Web Project (JMSSECOND)and Write two servlet to check the simple example

10. Write first servlet (ProducerServlet.java)

import java.io.IOException;
import javax.jms.Connection;
import javax.jms.ConnectionFactory;
import javax.jms.Destination;
import javax.jms.JMSException;
import javax.jms.MessageProducer;
import javax.jms.Session;
import javax.jms.TextMessage;
import javax.naming.Context;
import javax.naming.InitialContext;
import javax.naming.NamingException;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

public class ProducerServlet extends javax.servlet.http.HttpServlet implements javax.servlet.Servlet {

protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
System.out.println("******** THIS IS MESSAGE PRODUCER SERVLET **********");
check();
}

public void check(){
System.out.println("********* Producer check **********");
String destName = "jms/BinodQueue";
final int NUM_MSGS = 5;
Context jndiContext = null;

try { jndiContext = new InitialContext(); }
catch (NamingException e) { System.out.println("Could not create JNDI API context: " + e.toString()); System.exit(1);
}

ConnectionFactory connectionFactory = null;
Destination dest = null;

try {
connectionFactory = (ConnectionFactory) jndiContext.lookup("jms/BinodConnectionProvider");
dest = (Destination) jndiContext.lookup(destName); }
catch (Exception e) { System.out.println("JNDI API lookup failed: " + e.toString()); e.printStackTrace(); System.exit(1);
}

Connection connection = null;
MessageProducer producer = null;
try {
connection = connectionFactory.createConnection();
Session session = connection.createSession(false, Session.AUTO_ACKNOWLEDGE); producer = session.createProducer(dest);
TextMessage message = session.createTextMessage();

for (int i = 0; i < NUM_MSGS; i++) {
message.setText("This is message from JMSSECOND DEMO " + (i + 1));
System.out.println("Sending message: " + message.getText());
producer.send(message);
}

producer.send(session.createMessage());
} catch (JMSException e) { System.out.println("Exception occurred: " + e.toString()); }
finally { if (connection != null) { try { connection.close(); }
catch (JMSException e) { }
}
}
}
}

11. Write second servlet (ConsumerServlet.java)

import java.io.IOException;
import javax.jms.Connection;
import javax.jms.ConnectionFactory;
import javax.jms.Destination;
import javax.jms.JMSException;
import javax.jms.Message;
import javax.jms.MessageConsumer;
import javax.jms.Session;
import javax.jms.TextMessage;
import javax.naming.Context;
import javax.naming.InitialContext;
import javax.naming.NamingException;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

public class ConsumerServlet extends javax.servlet.http.HttpServlet implements javax.servlet.Servlet {
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
System.out.println("********** MESSAGE CONSUMER SERVLET 2 ************");
check();
}

public void check(){
System.out.println("********* Consumer check **********");
String destName = "jms/BinodQueue";
Context jndiContext = null;
ConnectionFactory connectionFactory = null;
Connection connection = null;
Session session = null;
Destination dest = null;
MessageConsumer consumer = null;
TextMessage message = null;
System.out.println("Destination name is " + destName);

try {
jndiContext = new InitialContext();
}catch (NamingException e) { System.out.println("Could not create JNDI API context: " + e.toString()); System.exit(1);
}

try {
connectionFactory = (ConnectionFactory) jndiContext.lookup("jms/BinodConnectionProvider");
dest = (Destination) jndiContext.lookup(destName);
} catch (Exception e) { System.out.println("JNDI API lookup failed: " + e.toString()); System.exit(1);
}

try {
connection = connectionFactory.createConnection();
session = connection.createSession(false, Session.AUTO_ACKNOWLEDGE);
consumer = session.createConsumer(dest);
connection.start();
while (true) {
Message m = consumer.receive(1);
if (m != null) {
if (m instanceof TextMessage) {
message = (TextMessage) m;
System.out.println("Reading message: " + message.getText()); }
else { break; }
}
}
} catch (JMSException e) { System.out.println("Exception occurred: " + e.toString()); }
finally { if (connection != null) { try { connection.close(); }
catch (JMSException e) { }
}
}
}
}

First run Producer Servlet:
http://localhost:9080/JMSSECOND/ProducerServlet
Output:

Sending message: This is message from JMSSECOND DEMO 1
Sending message: This is message from JMSSECOND DEMO 2
Sending message: This is message from JMSSECOND DEMO 3
Sending message: This is message from JMSSECOND DEMO 4
Sending message: This is message from JMSSECOND DEMO 5

Then run Consumer Servlet:
http://localhost:9080/JMSSECOND/ConsumerServlet
Output:


Reading message: This is message from JMSSECOND DEMO 1
Reading message: This is message from JMSSECOND DEMO 2
Reading message: This is message from JMSSECOND DEMO 3
Reading message: This is message from JMSSECOND DEMO 4
Reading message: This is message from JMSSECOND DEMO 5

Please put your comments. I am able to write this article after a lot struggle.
Source of example.