【ActiveMQ入门-4】ActiveMQ学习-异步接收

总体说明：

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1. 一个生产者/发布者：可以向多个目的地发送消息；

2. 每个目的地（destination）可以有多个订阅者或消费者；

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如下图所示：

程序结构：

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1. Publisher.java  ：创建1个生产者和4个主题，遍历4个主题，生产者依次向4个主题中发送Message，共发送5次；

2.Consumer.java ：消费者，创建8个消费者，每两个消费者订阅一个相同的主题，采用异步接收方式；

3. Listener.java   ：异步监听

运行结果：

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生产者：

消费者：

程序代码：

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Publisher.java

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package com.ll.activemq;

import javax.jms.Connection;
import javax.jms.ConnectionFactory;
import javax.jms.Destination;
import javax.jms.JMSException;
import javax.jms.MapMessage;
import javax.jms.Message;
import javax.jms.MessageProducer;
import javax.jms.Session;

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

public class Publisher {

	private ConnectionFactory factory;
	private Connection connection = null;
	private Session session;
	private String brokerURL = "tcp://localhost:61616";
	private MessageProducer producer;
	private Destination[] destinations;

	/**
	 * 构造函数 创建连接、创建生产者
	 * 
	 * @throws JMSException
	 */
	public Publisher() throws JMSException {
		factory = new ActiveMQConnectionFactory(brokerURL);
		connection = factory.createConnection();
		try {
			connection.start();
		} catch (JMSException jmse) {
			connection.close();
			throw jmse;
		}
		session = connection.createSession(false, Session.AUTO_ACKNOWLEDGE);
		producer = session.createProducer(null);
	}

	/**
	 * 设置目的地
	 * 
	 * @param stocks
	 *            ：主题名列表
	 * @throws JMSException
	 */
	protected void setTopics(String[] stocks) throws JMSException {
		destinations = new Destination[stocks.length];
		for (int i = 0; i < stocks.length; i++) {
			destinations[i] = session.createTopic("STOCKS." + stocks[i]);
		}
	}

	/**
	 * 创建消息
	 * 
	 * @param stock
	 *            :主题名
	 * @param session
	 * @return
	 * @throws JMSException
	 */
	protected Message createStockMessage(String stock, Session session)
			throws JMSException {
		MapMessage message = session.createMapMessage();
		message.setString("stock", stock);
		message.setDouble("price", 1.00);
		message.setDouble("offer", 0.01);
		message.setBoolean("up", true);

		return message;
	}
	
	/**
	 * 发送消息
	 * 遍历所有主题（目的地），向每个目的地分别发送一个MapMessage
	 * @param stocks
	 *            ：主题名
	 * @throws JMSException
	 */
	protected void sendMessage(String[] stocks) throws JMSException {
		//遍历所有主题
		for (int i = 0; i < stocks.length; i++) {
			// 创建消息
			Message message = createStockMessage(stocks[i], session); 
			
			System.out.println("发送: "
					+ ((ActiveMQMapMessage) message).getContentMap()
					+ " on destination: " + destinations[i]);
			
			// 往目的地发送消息
			producer.send(destinations[i], message); 
		}
	}

	public void close() throws JMSException {
		try {
			if (null != connection)
				connection.close();
		} catch (Exception e) {
			e.printStackTrace();
		}
	}

	public static void main(String[] argss) throws JMSException {

		String[] topics = { "MyTopic1", "MyTopic2", "MyTopic3", "MyTopic4" };

		Publisher publisher = new Publisher();

		publisher.setTopics(topics);

		//每隔1s发送一次消息，共发送5次消息
		for (int i = 0; i < 5; i++) {
			System.out.println("发布者第：" + i + " 次发布消息...");
			publisher.sendMessage(topics);
			try {
				Thread.sleep(2000);
			} catch (InterruptedException e) {
				e.printStackTrace();
			}
		}
		publisher.close();
	}
}

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Consumer.java

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package com.ll.activemq;

import javax.jms.Connection;
import javax.jms.Destination;
import javax.jms.JMSException;
import javax.jms.MessageConsumer;
import javax.jms.Session;

import org.apache.activemq.ActiveMQConnectionFactory;

public class Consumer {

	private ActiveMQConnectionFactory factory;
	private String brokerURL = "tcp://localhost:61616";
	private Connection connection = null;
	private Session session;

	public Consumer() throws JMSException {
		factory = new ActiveMQConnectionFactory(brokerURL);
		connection = factory.createConnection();
		connection.start();
		session = connection.createSession(false, Session.AUTO_ACKNOWLEDGE);
	}

	public Session getSession() {
		return session;
	}

	public static void main(String[] args) throws JMSException {
		String[] topics = { "MyTopic1", "MyTopic2", "MyTopic3", "MyTopic4" };

		Consumer consumer = new Consumer();

		for (String stock : topics) {
			//创建目的地
			Destination destination = consumer.getSession().createTopic(
					"STOCKS." + stock);
			
			//创建消费者
			MessageConsumer messageConsumer = consumer.getSession()
					.createConsumer(destination);
			MessageConsumer messageConsumer2 = consumer.getSession()
					.createConsumer(destination);
			
			//设置监听器
			messageConsumer.setMessageListener(new Listener());
			messageConsumer2.setMessageListener(new Listener());
		}
	}

}

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Listener.java

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package com.ll.activemq;

import java.text.DecimalFormat;

import javax.jms.MapMessage;
import javax.jms.Message;
import javax.jms.MessageListener;

public class Listener implements MessageListener {  
	  
	/**
	 * 异步接收
	 * 当有消息时，就会触发该事件
	 */
    public void onMessage(Message message) {  
        try {  
            MapMessage map = (MapMessage)message;  
            String stock = map.getString("stock");  
            double price = map.getDouble("price");  
            double offer = map.getDouble("offer");  
            boolean up = map.getBoolean("up");  
      
            DecimalFormat df = new DecimalFormat( "#,###,###,##0.00" );  
            System.out.println("接收消息："+stock + "\t" + df.format(price) + "\t" + df.format(offer) + "\t" + (up?"up":"down"));  
        } catch (Exception e) {  
            e.printStackTrace();  
        }  
    }  
  
}  

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延伸：

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若是将上述程序中的 createTopic全部替换为createQueue，则运行结果如下：

生产者输出不变，这里就不截图了。

下面是消费者消费情况截图：

  

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