深入掌握JMS（四）：实战Queue

        Queue实现的是点到点模型，在下面的例子中，启动2个消费者共同监听一个Queue，然后循环给这个Queue中发送多个消息，我们依然采用ActiveMQ。 

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.Queue;
import javax.jms.Session;
import javax.jms.TextMessage;

import org.apache.activemq.ActiveMQConnectionFactory;
import org.apache.activemq.command.ActiveMQQueue;

public class QueueTest {

	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Queue
		Queue queue = new ActiveMQQueue("testQueue");
		// 创建一个Session
		Session session = connection.createSession(false,Session.AUTO_ACKNOWLEDGE);

		// 注册消费者1
		MessageConsumer comsumer1 = session.createConsumer(queue);
		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(queue);
		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(queue);
		for (int i = 0; i < 10; i++) {
			producer.send(session.createTextMessage("Message:" + i));
		}
	}
}

        运行这个例子会得到下面的输出结果：

Consumer1 get Message:0
Consumer2 get Message:1
Consumer1 get Message:2
Consumer2 get Message:3
Consumer1 get Message:4
Consumer2 get Message:5
Consumer1 get Message:6
Consumer2 get Message:7
Consumer1 get Message:8
Consumer2 get Message:9

        可以看出每个消息直被消费了一次，但是如果有多个消费者同时监听一个Queue的话，无法确定一个消息最终会被哪一个消费者消费。

 

文章来源：http://www.cnblogs.com/guthing/archive/2010/06/12/1757152.html