looking for MDB

[prasanna pati]

hi I want to do a sample project with message driven beans , can anyone send me a step by step guide ? If I can do the sample project then I will be able to add some complexes also .

[prasanna pati]

i have this : http://www.eclipse.org/webtools/community/tutorials/ejbtutorial/buildingejbs.html
but its all for session beans or so......what I am looking for a step by step of message driven bean .

[Mahesh Desai]

Hi,

You can try this: http://java.sun.com/j2ee/tutorial/1_3-fcs/doc/MDB.html

Thanks,
Mahesh

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SCJP 1.4 | SCWCD 1.4 | SCBCD 1.3 | SCEA Part I - In Progress

[prasanna pati]

i have a sample program of Java messaging service . One is sending a message , another is receiving a message . I want to know I should run it using only Jdk or I have to do it using EJB compilation all those stuff . here are those 2:

messageSender.java


/*
* MessageSender.java
*
* Created on April 18, 2007, 9:44 AM
*
* To change this template, choose Tools | Template Manager
* and open the template in the editor.
*/

/**
*
* @author 278085
*/


import javax.jms.*;
import javax.naming.*;


public class MessageSender {

public static void main(String[] args) {
QueueConnection queueConnection = null;

try {
Context context = new InitialContext();
QueueConnectionFactory queueConnectionFactory =
(QueueConnectionFactory) context.lookup("QueueConnectionFactory");
String queueName = "MyQueue";
Queue queue = (Queue) context.lookup(queueName);
queueConnection =
queueConnectionFactory.createQueueConnection();
QueueSession queueSession =
queueConnection.createQueueSession(false, Session.AUTO_ACKNOWLEDGE);
QueueSender queueSender = queueSession.createSender(queue);
TextMessage message = queueSession.createTextMessage();
message.setText("This is a TextMessage");
queueSender.send(message);
System.out.println("Message sent.");
}
catch (NamingException e) {
System.out.println("Naming Exception");
}
catch (JMSException e) {
System.out.println("JMS Exception");
}
finally {
if (queueConnection != null) {
try {
queueConnection.close();
}
catch (JMSException e) {}
}
}
}
}


MessageReceiver.java


/*
* MessageReceiver.java
*
* Created on April 18, 2007, 12:00 PM
*
* To change this template, choose Tools | Template Manager
* and open the template in the editor.
*/

/**
*
* @author 278085
*/

import javax.jms.*;
import javax.naming.*;
public class MessageReceiver {
public static void main(String[] args) {
QueueConnection queueConnection = null;
try {
Context context = new InitialContext();
QueueConnectionFactory queueConnectionFactory =
(QueueConnectionFactory) context.lookup("QueueConnectionFactory");
String queueName = "MyQueue";
Queue queue = (Queue) context.lookup(queueName);
queueConnection =
queueConnectionFactory.createQueueConnection();
QueueSession queueSession = queueConnection.createQueueSession(false,
Session.AUTO_ACKNOWLEDGE);
QueueReceiver queueReceiver = queueSession.createReceiver(queue);
queueConnection.start();
Message message = queueReceiver.receive(1);
if (message != null) {
if (message instanceof TextMessage) {
TextMessage textMessage = (TextMessage) message;
System.out.println(textMessage.getText());
}
}
}
catch (NamingException e) {
System.out.println("Naming Exception");
}
catch (JMSException e) {
System.out.println("JMS Exception");
}
finally {
if (queueConnection != null) {
try {
queueConnection.close();
}
catch (JMSException e) {}
}
}
}
}


i am getting Naming exception

[Cameron Wallace McKenzie]

Here's a collection of multimedia tutorials that deal with developing EJBs. Take a look at the tutorial on creating an MDB, and the section on setting up a message queue/topic.

Creating an MDB and a Session Bean to put a message on a queue.

  
 
package com.examscam.ejb;
 
import javax.jms.JMSException;
 
/**
* Bean implementation class for Enterprise Bean: MagicMDB
*/
public class MagicMDBBean implements javax.ejb.MessageDrivenBean,
javax.jms.MessageListener {
private javax.ejb.MessageDrivenContext fMessageDrivenCtx;
 
/**
* getMessageDrivenContext
*/
public javax.ejb.MessageDrivenContext getMessageDrivenContext() {
return fMessageDrivenCtx;
}
 
/**
* setMessageDrivenContext
*/
public void setMessageDrivenContext(javax.ejb.MessageDrivenContext ctx) {
fMessageDrivenCtx = ctx;
}
 
/**
* ejbCreate
*/
public void ejbCreate() {
}
 
public void onMessage(javax.jms.Message message) {
/* cast the generic message into a TextMessage */
javax.jms.TextMessage textMessage = (javax.jms.TextMessage) message;
try {
System.out.println("MDB has obtained the following message: "
+ textMessage.getText());
} catch (JMSException e) {
System.out.println(e.getClass() + e.getMessage());
}
 
}
 
/**
* ejbRemove
*/
public void ejbRemove() {
}
}
 

 

/**
* Bean implementation class for Enterprise Bean: MagicMessageMaker
*/
public class MagicMessageMakerBean implements javax.ejb.SessionBean {
 
public void dropOffMessage() throws Exception
{
try
{
String magicString = "The magic number is: " + System.currentTimeMillis()%100;
 
InitialContext context = new InitialContext();
ConnectionFactory cf = (ConnectionFactory)context.lookup("jms/examscamcf");
Connection conn = cf.createConnection();
Session jmsSession = conn.createSession(false,Session.AUTO_ACKNOWLEDGE);
 
Destination destination = (Destination)context.lookup("jms/examscamqueue");
 
//session requires the destination to create the producer
MessageProducer producer = jmsSession.createProducer(destination);
 
TextMessage message = jmsSession.createTextMessage();
message.setText(magicString);
producer.send(message);
 
producer.close();
jmsSession.close();
conn.close();
}
 
catch(Exception e)
{
System.out.println(e.getClass() + e.getMessage());
}
}