JMS and Msg posting

This example shows how to set up the jms queue and send msg to the queues in java.

1.Setup XDoclet

Download XDoclet from here, and extract it.
In Eclipse->Window->preferences, select xdoclet and set the Xdoclet home to the appropriate directory.
Create the Message Driven Bean
Create an EJB project in Eclipse.
In the J2EE perspective, right-click on the Deployment descriptor and create a new Message Driven Bean. Eclipse generates the required classes and the ejb-jar.xml file with the new MDB definition in it. Modify the Bean to look like this
 
 public class MessagingExampleBean implements javax.ejb.MessageDrivenBean, javax.jms.MessageListener {
private javax.ejb.MessageDrivenContext messageContext = null;
public void setMessageDrivenContext(javax.ejb.MessageDrivenContext messageContext) throws javax.ejb.EJBException {
this.messageContext = messageContext;
}
public void ejbCreate() {}
public void ejbRemove() {
messageContext = null;
}
public MessagingExampleBean() {}
public void onMessage(javax.jms.Message message) {
System.out.println("Message Driven Bean got message " + message);
}
}

2. Add the following definitions to the ejb-jar.xml

MessagingExample


MessagingExampleMDB
 MessagingExampleMDB
 jms.MessagingExampleMdb
 Bean
 javax.jms.Queue


 

 MessagingExampleMDB


Required





3. Create a new file weblogic-ejb-jar.xml. This is required for Weblogic bindings.



MessagingExampleMDB


5
5

jms/testQueue
weblogic.jndi.WLInitialContextFactory
jms/connectionFactory
20


3600



 
4.Create the Client. For this example, I used a servlet that simply sends a "Hello" message to the MDB through the Queue. Here is the code for it
 
public class MessaginClientServlet extends javax.servlet.http.HttpServlet implements javax.servlet.Servlet {
public final static String JNDI_FACTORY = "weblogic.jndi.WLInitialContextFactory";
public final static String JMS_FACTORY = "weblogic.examples.jms.QueueConnectionFactory";
public final static String QUEUE = "weblogic.examples.jms.exampleQueue";public MessaginClientServlet() {
 super();
}
 
protected void service(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
 try {
 Context ctx = getInitialContext("t3://localhost:20001");
QueueConnectionFactory qconFactory;
 QueueConnection connection;
 QueueSession session;
 QueueSender sender;
 Queue queue;
 TextMessage msg;
 qconFactory = (QueueConnectionFactory) ctx.lookup("jms/connectionFactory");
 connection = qconFactory.createQueueConnection();
 session = connection.createQueueSession(false, Session.AUTO_ACKNOWLEDGE);
queue = (Queue) ctx.lookup("jms/testQueue");
 msg = session.createTextMessage();
sender = session.createSender(queue);
 msg.setText("Hello World");
 connection.start();
 sender.send(msg);
 session.close();
connection.close();
 }
 catch (Exception e) {
e.printStackTrace();
 }
}
 
private InitialContext getInitialContext(String url) throws NamingException {
Hashtable<//java.sun.com/xml/ns/j2ee:string, string=""> env = new Hashtable<//java.sun.com/xml/ns/j2ee:string, string="">(); <///java.sun.com/xml/ns/j2ee:string,><///java.sun.com/xml/ns/j2ee:string,>
env.put(Context.INITIAL_CONTEXT_FACTORY, JNDI_FACTORY);
env.put(Context.PROVIDER_URL, url); return new InitialContext(env);
}
}