JMS HelloWorld

[Ashwin Sridhar]

Hi,

I am new to JMS. i tried to run following program. But it throws Jndi exception. I am sure i am misssiong something on intialising JNDI.

import java.util.Properties;

import javax.jms.*;
import javax.naming.*;
public class TestMess {

	public static void main(String[] args){
	ConnectionFactory connF = null;
	Connection conn = null;
	Context ctx = null;
	Queue myQueue = null;
	QueueSession sess = null;
	QueueSender qSender = null;
	TextMessage mess = null;
	
	try{
		ctx = new InitialContext();
		connF = (ConnectionFactory) ctx.lookup("QueueConnectionFactory");
		myQueue = (Queue) ctx.lookup("Queue1");
		conn = connF.createConnection();
		sess = (QueueSession) conn.createSession(false, Session.AUTO_ACKNOWLEDGE);
		qSender = sess.createSender(myQueue);
		mess = sess.createTextMessage();
		mess.setText("Hi first message");
		System.out.println("Sending mess : "+mess.getText());
		qSender.send(mess);
		qSender.send(sess.createMessage());
	}
	catch(Exception e){
		e.printStackTrace();
	}
	
	}
	
}

And the Stack Trace is

javax.naming.NoInitialContextException: Need to specify class name in environment or system property, or as an applet parameter, or in an application resource file: java.naming.factory.initial
at javax.naming.spi.NamingManager.getInitialContext(NamingManager.java:645)
at javax.naming.InitialContext.getDefaultInitCtx(InitialContext.java:247)
at javax.naming.InitialContext.getURLOrDefaultInitCtx(InitialContext.java:284)
at javax.naming.InitialContext.lookup(InitialContext.java:351)
at TestMess.main(TestMess.java:20)

[Udara Amarasinghe]

HI Ashwin,

I think you may have miss to create those ConnectionFactory resource with JNDI name "QueueConnectionFactory" or Queue resource with JNDI name "Queue1" inside the server. Try to create them and try again. this document will help you http://download.oracle.com/docs/cd/E19957-01/816-5904-10/816-5904-10.pdf

[Ashwin Sridhar]

Hi udara,

I have missed that part. could please tell me how to create the connectionFactory resource. Couldn't find that part in the various tutorials

[Udara Amarasinghe]

They can create either with using your servers configuration tools or using your EJB applications configuration files

refer these tutorials :
http://help.sap.com/saphelp_nwmobile71/helpdata/en/46/11ff893ebe14dbe10000000a155369/content.htm
http://download.oracle.com/docs/cd/E13222_01/wls/docs90/jms_admin/deployjms.html

And also if you need to read those messages that sent by your client program you have to create MessageDrivenBean that have connected with that message Queue resource.

[Ashwin Sridhar]

Hi,

I had issues in creating Queue and ConnectionFactories. I solved them and now its working.

How to make Message Driven Bean listen to the queue.

[Udara Amarasinghe]

Try this:

import java.util.*;
import javax.annotation.*;
import javax.ejb*;
import javax.jms.*;

@MessageDriven(mappedName = "QUEUE_NAME" //this should be the JNDI name of the queue you want to connect and read messages
, activationConfig = {
    @ActivationConfigProperty(propertyName = "acknowledgeMode", propertyValue = "Auto-acknowledge") // set how to acknowledge when message received 
,   @ActivationConfigProperty(propertyName = "destinationType",
 propertyValue = "javax.jms.Queue") // set the message keeper resource type you can choose either "javax.jms.Queue" or "javax.jms.Topic" as your resource 
})
public class TestMessReader implements MessageListener {

    private static final Logger logger = Logger.getLogger("TestMessReader ");
    
    public void onMessage(Message message) {
        logger.log(Level.INFO, "Message arrived.");
        if (message instanceof TextMessage) {
            TextMessage tm = (TextMessage) message;
            try {
                logger.log(Level.INFO, "Text message arrived : {0}.",
                        tm.getText());
            } catch (JMSException jmsException) {
                logger.log(Level.WARNING, "An Exception occor on TextMessage "
                        + "getText : {0}.", jmsException.getMessage());
            }
        }
    }

    @PreDestroy
    public void preDestroy() {
        logger.log(Level.INFO, "TestMessReader is going to destroy.");
    }
}

This is a sample MessageDrivenBean and you may be have to make appropriate changes as your configurations. Deploy this into your server after wrap in a enterprise archive file(EAR).