The document discusses JMS (Java Message Service) focusing on two messaging domains: point-to-point and publisher/subscriber. It details the setup for both the publisher and subscriber applications using JMS, including code examples for creating connections, sessions, and message listeners. References to supplementary resources, such as a YouTube playlist and GitHub repository, are also provided.

1. Distributed Systems
Lecture -8-
Created by :
Eng. Ghadeer Al Hasan
JMS
Java Message Service

2. Messaging Domains 1
There are two types of messaging domains in JMS :
• Point-to-PointMessaging Domain
• Publisher/Subscriber Messaging Domain

3. Publisher/Subscriber (Pub/Sub) Messaging Domain 2
• In Pub/Sub model, one message is delivered to all the subscribers. It is like broadcasting.
• Topicis used as a messageorientedmiddleware that is responsible to hold and deliver messages.
• In PTP model, there is timing dependency between publisher and subscriber.

4. JMS Programming Model 3

5. JMS Queue Example

6. 1st Create connection factory 5

7. 2nd Create destination resource 6

8. 3rd Create Sender application 7
InitialContext ctx = new InitialContext();
TopicConnectionFactory f = (TopicConnectionFactory) ctx.lookup("myTopicConnectionFactory");
TopicConnection con = f.createTopicConnection ();
con.start();
TopicSession session = con.createTopicSession(false, Session.AUTO_ACKNOWLEDGE);
Topic topic =(Topic) ctx.lookup("myTopic");
TopicPublisher publisher = session. createPublisher(topic);
TextMessage msg = session.createTextMessage();

9. 3rd Create Sender application… 8
BufferedReader reader = new BufferedReader(new InputStreamReader(System.in));
while(true) {
log("Enter Msg, end to terminate:");
String line = reader.readLine();
if (line.equals("end"))
break;
msg.setText(line);
publisher.publish(msg);
log("Message successfully sent.");
}

10. 4th Create Receiver application 8
public class MsgListener implements MessageListener {
@Override
public void onMessage(Message m) {
try {
TextMessage msg = (TextMessage) m;
log("following message is received:" + msg.getText());
} catch (JMSException e) {
log(e);
}
}
}

11. 4th Create Receiver application… 9
InitialContext ctx = new InitialContext();
TopicConnectionFactory f = (TopicConnectionFactory) ctx.lookup(" myTopicConnectionFactory");
TopicConnection con = f.createTopicConnection();
con.start();
TopicSession session = con.createTopicSession(false, Session.AUTO_ACKNOWLEDGE);
Topic topic = (Topic) ctx.lookup("myTopic");
TopicSubscriber receiver = session.createSubscriber(topic);
MsgListener listener = new MsgListener();
receiver.setMessageListener(listener);
Log("Subscriber is ready, waiting for messages... “);
while(true){
try {
Thread.sleep(1000);
} catch (InterruptedException ex) {
log(ex.getMessage());
}
}

12. References 10
- YouTube link
https://www.youtube.com/playlist?list=PLtDIUAtyP4lhV7CsYfLuIx26UeG4J-ujZ
- GitHub
https://github.com/Ghadeerof

13. End Lecture