Return消息机制

Return Listener 用于处理一些不可路由的消息

消息生产者通过制定一个Exchane和RoutingKey，把消息送达到某一个队列中去；消费者监听队列进行消费处理。

但是在某些情况下，发送消息的时候，当前Exchange不存在或制定的路由key不存在，这时我们需要监听这种不可达的消息。用到的就是Return Listener。

1.API中关键项配置

Mandatory:true 监听器会接收到路由不可达的消息，在进行后续处理；

                   false MQ服务端将自动删除该消息；

2.代码实现

package com.lfv.rabbitmq.api.returnlistener;

import java.io.IOException;
import java.util.concurrent.TimeoutException;

import com.rabbitmq.client.AMQP;
import com.rabbitmq.client.AMQP.BasicProperties;
import com.rabbitmq.client.Channel;
import com.rabbitmq.client.Connection;
import com.rabbitmq.client.ConnectionFactory;
import com.rabbitmq.client.ReturnListener;

public class Producer {

	public static void main(String[] args) throws IOException, TimeoutException {
		
		ConnectionFactory connectionFactory = new ConnectionFactory();
		connectionFactory.setHost("192.168.0.10");
		connectionFactory.setPort(5672);
		connectionFactory.setUsername("admin");
		connectionFactory.setPassword("admin");
		connectionFactory.setVirtualHost("/");
		
		
		//2获取Connection
		Connection connection = connectionFactory.newConnection();
		Channel channel = connection.createChannel();
		
		String exchange = "test_return_exchange";
		String routingKey = "return.save";
		String routingKeyError="abc.save";
		String sendmsg ="Hello RabbitMQ return Message";
		
		channel.addReturnListener(new ReturnListener() {

			@Override
			public void handleReturn(int replyCode, String replyText
					, String exchange, String routingKey
					, AMQP.BasicProperties properties, byte[] body)
					throws IOException {

				System.out.println("***************Handle  Return*********************");
				System.err.println("replyCode:"+replyCode);
				System.err.println("replyText:"+replyText);
				System.err.println("exchange:"+exchange);
				System.err.println("routingKey:"+routingKey);
				System.err.println("AMQP.BasicProperties:"+properties);
				System.err.println("body:"+new String(body));
			}
			
		});
		
		channel.basicPublish(exchange, routingKey, true, null, sendmsg.getBytes());
		
	}
}

package com.lfv.rabbitmq.api.returnlistener;

import com.rabbitmq.client.Channel;
import com.rabbitmq.client.Connection;
import com.rabbitmq.client.ConnectionFactory;
import com.rabbitmq.client.QueueingConsumer;
import com.rabbitmq.client.QueueingConsumer.Delivery;

public class Consumer {
	public static void main(String[] args) throws Exception{
	ConnectionFactory connectionFactory = new ConnectionFactory();
	connectionFactory.setHost("192.168.0.10");
	connectionFactory.setPort(5672);
	connectionFactory.setUsername("admin");
	connectionFactory.setPassword("admin");
	connectionFactory.setVirtualHost("/");
	
	Connection connection = connectionFactory.newConnection();
	Channel channel = connection.createChannel();
	
	
	String exchangeName = "test_return_exchange";
	String routingKey = "return.#";
	String queueName ="test_return_queue";
	
	channel.exchangeDeclare(exchangeName, "topic", true,false,null);
	channel.queueDeclareNoWait(queueName, true, false, false, null);
	channel.queueBind(queueName, exchangeName, routingKey);
	
	QueueingConsumer queueingConsume = new QueueingConsumer(channel);
	channel.basicConsume(queueName, true, queueingConsume);
	for(;;) {
		Delivery delivery = queueingConsume.nextDelivery();
		String msg = new String(delivery.getBody());
		System.out.println("------------- return 消費端---------------"+msg);
	}
	
	
	
	
	}
}

2.1消费端接收到正常的数据

 2.2生产端发送错误返回结果

设置一个不能投递的routingKey

String routingKeyError="abc.save";

消费端监听到的返回结果如下:

***************Handle  Return*********************
replyCode:312
replyText:NO_ROUTE
exchange:test_return_exchange
routingKey:abc.save
AMQP.BasicProperties:#contentHeader(content-type=null, content-encoding=null, headers=null, delivery-mode=null, priority=null, correlation-id=null, reply-to=null, expiration=null, message-id=null, timestamp=null, type=null, user-id=null, app-id=null, cluster-id=null)
body:Hello RabbitMQ return Message