I wrote a simple listener to the publisher from previous ActiveMQ post: activemq-topic-sender
The MessageListener callback class that’s receives notification when a topic message has received.
1: private class TextMessageListener implements MessageListener {
2: public void onMessage(Message message) {
3: try {
4: System.out.println("Got the Message TimeStamp: "
5: + message.getJMSTimestamp());
6: System.out.println("Got the Message JMS ID : "
7: + message.getJMSMessageID() );
8:
9: TextMessage theMsg = (TextMessage)message;
10: System.out.println("The message:" + theMsg.getText());
11:
12: } catch (JMSException e) {
13: e.printStackTrace();
14: }
15: }
16: }
The message consumer class :
Note:the connection must be started in order to receive notifications
1: public class MessageConsumer {
2:
3: private String topicName = "myTopic.Programming";
4: private String initialContextFactory = "org.apache.activemq"
5: +".jndi.ActiveMQInitialContextFactory";
6: private String connectionString = "tcp://localhost:61616";
7:
8: public void ListenWithTopicLookup() {
9: try {
10: Properties properties = new Properties();
11: TopicConnection topicConnection = null;
12: properties.put("java.naming.factory.initial", initialContextFactory);
13: properties.put("connectionfactory.QueueConnectionFactory",
14: connectionString);
15: properties.put("topic." + topicName, topicName);
16:
17:
18: // initialize
19: // the required connection factories
20: InitialContext ctx = new InitialContext(properties);
21: TopicConnectionFactory topicConnectionFactory = (TopicConnectionFactory) ctx
22: .lookup("QueueConnectionFactory");
23: topicConnection = topicConnectionFactory.createTopicConnection();
24:
25: TopicSession topicSession = topicConnection.createTopicSession(
26: false, Session.AUTO_ACKNOWLEDGE);
27: Topic topic = (Topic) ctx.lookup(topicName);
28:
29: TopicSubscriber theTopicSubscriber = topicSession.createSubscriber(topic);
30:
31: theTopicSubscriber.setMessageListener(new TextMessageListener());
32:
33: topicConnection.start();
34:
35: } catch (NamingException ex) {
36: Logger.getLogger(MessageProducer.class.getName()).log(Level.SEVERE, null, ex);
37: }
38: catch (JMSException e) {
39: throw new RuntimeException("Error in initial context lookup", e);
40: }
41: }
42: }
I change the main class in order to start 2 new message consumers :
1: public static void main( String[] args )
2: {
3: System.out.println( "Hello World!" );
4:
5: MessageConsumer theMessageConsumer= new MessageConsumer();
6:
7: theMessageConsumer.ListenWithTopicLookup();
8:
9: MessageConsumer OthertheMessageConsumer= new MessageConsumer();
10:
11: OthertheMessageConsumer.ListenWithTopicLookup();
12:
13: MessageProducer publisher = new MessageProducer();
14:
15: publisher.publishWithTopicLookup();
16: try {
17: Thread.sleep( 1000);
18: } catch (InterruptedException ex) {
19: Logger.getLogger(App.class.getName()).log(Level.SEVERE, null, ex);
20: }
The Result :
[exec:exec]
Hello World!
log4j:WARN No appenders could be found for logger (org.apache.activemq.thread.TaskRunnerFactory).
log4j:WARN Please initialize the log4j system properly.
log4j:WARN See http://logging.apache.org/log4j/1.2/faq.html#noconfig for more info.
Publishing message ActiveMQTextMessage {commandId = 0, responseRequired = false, messageId = ID:Zvika-PC-2639-1370199196674-5:1:1:1:1, originalDestination = null, originalTransactionId = null, producerId = null, destination = topic://myTopic.Programming, transactionId = null, expiration = 0, timestamp = 1370199196906, arrival = 0, brokerInTime = 0, brokerOutTime = 0, correlationId = null, replyTo = null, persistent = true, type = null, priority = 4, groupID = null, groupSequence = 0, targetConsumerId = null, compressed = false, userID = null, content = null, marshalledProperties = null, dataStructure = null, redeliveryCounter = 0, size = 0, properties = null, readOnlyProperties = false, readOnlyBody = false, droppable = false, text = This is a test message}
Got the Message TimeStamp: 1370199196906
Got the Message JMS ID : ID:Zvika-PC-2639-1370199196674-5:1:1:1:1
The message:This is a test message
Got the Message TimeStamp: 1370199196906
Got the Message JMS ID : ID:Zvika-PC-2639-1370199196674-5:1:1:1:1
The message:This is a test message
Each listener got notification about the message that was send .
