/*
* Copyright 2009 Red Hat, Inc.
* Red Hat licenses this file to you under the Apache License, version
* 2.0 (the "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at
* http://www.apache.org/licenses/LICENSE-2.0
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
* implied. See the License for the specific language governing
* permissions and limitations under the License.
*/
package org.hornetq.jms.example;
import javax.jms.Connection;
import javax.jms.ConnectionFactory;
import javax.jms.Message;
import javax.jms.MessageConsumer;
import javax.jms.MessageProducer;
import javax.jms.Session;
import javax.jms.TextMessage;
import javax.jms.Topic;
import javax.naming.InitialContext;
import org.hornetq.api.jms.HornetQJMSClient;
import org.hornetq.common.example.HornetQExample;
/**
* This example demonstrates how a JMS TopicSubscriber can be created to subscribe to a wild-card Topic.
*
* For more information please see the readme.html
*
* @author <a href="tim.fox@jboss.com">Tim Fox</a>
*/
public class TopicHierarchyExample extends HornetQExample
{
public static void main(final String[] args)
{
new TopicHierarchyExample().run(args);
}
@Override
public boolean runExample() throws Exception
{
Connection connection = null;
InitialContext initialContext = null;
try
{
// Step 1. Create an initial context to perform the JNDI lookup.
initialContext = getContext(0);
// Step 3. Perform a lookup on the Connection Factory
ConnectionFactory cf = (ConnectionFactory)initialContext.lookup("/ConnectionFactory");
// Step 4. Create a JMS Connection
connection = cf.createConnection();
// Step 5. Create a JMS Session
Session session = connection.createSession(false, Session.AUTO_ACKNOWLEDGE);
// Step 6. Instantiate a topic representing the wildcard we're going to subscribe to
Topic topicSubscribe = HornetQJMSClient.createTopic("news.europe.#");
// Step 7. Create a consumer (topic subscriber) that will consume using that wildcard
// The consumer will receive any messages sent to any topic that starts with news.europe
MessageConsumer messageConsumer = session.createConsumer(topicSubscribe);
// Step 8. Create an anonymous producer
MessageProducer producer = session.createProducer(null);
// Step 9. Instantiate some more topic objects corresponding to the individual topics
// we're going to send messages to
Topic topicNewsUsaWrestling = HornetQJMSClient.createTopic("news.usa.wrestling");
Topic topicNewsEuropeSport = HornetQJMSClient.createTopic("news.europe.sport");
Topic topicNewsEuropeEntertainment = HornetQJMSClient.createTopic("news.europe.entertainment");
// Step 10. Send a message destined for the usa wrestling topic
TextMessage messageWrestlingNews = session.createTextMessage("Hulk Hogan starts ballet classes");
producer.send(topicNewsUsaWrestling, messageWrestlingNews);
// Step 11. Send a message destined for the europe sport topic
TextMessage messageEuropeSport = session.createTextMessage("Lewis Hamilton joins European synchronized swimming team");
producer.send(topicNewsEuropeSport, messageEuropeSport);
// Step 12. Send a message destined for the europe entertainment topic
TextMessage messageEuropeEntertainment = session.createTextMessage("John Lennon resurrected from dead");
producer.send(topicNewsEuropeEntertainment, messageEuropeEntertainment);
// Step 9. Start the connection
connection.start();
// Step 10. We don't receive the usa wrestling message since we subscribed to news.europe.# and
// that doesn't match news.usa.wrestling. However we do receive the Europe sport message, and the
// europe entertainment message, since these match the wildcard.
TextMessage messageReceived1 = (TextMessage)messageConsumer.receive(5000);
System.out.println("Received message: " + messageReceived1.getText());
TextMessage messageReceived2 = (TextMessage)messageConsumer.receive(5000);
System.out.println("Received message: " + messageReceived2.getText());
Message message = messageConsumer.receive(1000);
if (message != null)
{
return false;
}
System.out.println("Didn't received any more message: " + message);
return true;
}
finally
{
// Step 12. Be sure to close our resources!
if (initialContext != null)
{
initialContext.close();
}
if (connection != null)
{
connection.close();
}
}
}
}