与Queue不同的是,Topic实现的是发布/订阅模型,在下面的例子中,启动2个消费者共同监听一个Topic,然后循环给这个Topic中发送多个消息。
package com.bijian.study; import javax.jms.Connection; import javax.jms.JMSException; import javax.jms.Message; import javax.jms.MessageConsumer; import javax.jms.MessageListener; import javax.jms.MessageProducer; import javax.jms.Session; import javax.jms.TextMessage; import javax.jms.Topic; import org.apache.activemq.ActiveMQConnectionFactory; import org.apache.activemq.command.ActiveMQTopic; public class TopicTest { public static void main(String[] args) throws Exception { ActiveMQConnectionFactory factory = new ActiveMQConnectionFactory("tcp://localhost:61616"); Connection connection = factory.createConnection(); connection.start(); // 创建一个Topic Topic topic = new ActiveMQTopic("testTopic"); Session session = connection.createSession(false, Session.AUTO_ACKNOWLEDGE); // 注册消费者1 MessageConsumer comsumer1 = session.createConsumer(topic); comsumer1.setMessageListener(new MessageListener() { public void onMessage(Message m) { try { System.out.println("Consumer1 get " + ((TextMessage) m).getText()); } catch (JMSException e) { e.printStackTrace(); } } }); // 注册消费者2 MessageConsumer comsumer2 = session.createConsumer(topic); comsumer2.setMessageListener(new MessageListener() { public void onMessage(Message m) { try { System.out.println("Consumer2 get " + ((TextMessage) m).getText()); } catch (JMSException e) { e.printStackTrace(); } } }); // 创建一个生产者,然后发送多个消息。 MessageProducer producer = session.createProducer(topic); for (int i = 0; i < 10; i++) { producer.send(session.createTextMessage("Message:" + i)); } } }
运行后得到下面的输出结果:
Consumer1 get Message:0 Consumer2 get Message:0 Consumer1 get Message:1 Consumer2 get Message:1 Consumer1 get Message:2 Consumer2 get Message:2 Consumer1 get Message:3 Consumer2 get Message:3 Consumer1 get Message:4 Consumer2 get Message:4 Consumer1 get Message:5 Consumer2 get Message:5 Consumer1 get Message:6 Consumer2 get Message:6 Consumer1 get Message:7 Consumer2 get Message:7 Consumer1 get Message:8 Consumer2 get Message:8 Consumer1 get Message:9 Consumer2 get Message:9
说明每一个消息都会被所有的消费者消费。
文章来源:http://www.cnblogs.com/guthing/archive/2010/06/12/1757154.html