MQ的订阅模式

Posted 2020-10-27 曹军

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一：介绍

1.模式

2.使用场景

　　一个生产者，多个消费者

　　每一个消费者都有自己的队列

　　生产者没有直接把消息发送给队列，而是发送到了交换机

　　每一个队列都要绑定到交换机

　　可以实现一个消息被多个消费者消费。

二：程序

1.生产者

 1 package com.mq.PubSubFanout;
 2 
 3 import com.mq.utils.ConnectionUtil;
 4 import com.rabbitmq.client.Channel;
 5 import com.rabbitmq.client.Connection;
 6 
 7 public class FanoutSend {
 8     private static final String EXCHANGE_NAME="text_exchange_fanout";
 9     public static void main(String[] args) throws Exception {
10         //获取一个连接
11         Connection connection= ConnectionUtil.getConnection();
12         //从连接中获取一个通道
13         Channel channel=connection.createChannel();
14         //创建交换机
15         channel.exchangeDeclare(EXCHANGE_NAME,"fanout");
16 
17         //消息
18         String msg="hello pubsub";
19 
20         //发送
21         channel.basicPublish(EXCHANGE_NAME,"",null,msg.getBytes());
22 
23         System.out.println("send msg:"+msg);
24         //关闭连接
25         channel.close();
26         connection.close();
27     }
28 }

2.消费者一

 1 package com.mq.PubSubFanout;
 2 
 3 import com.mq.utils.ConnectionUtil;
 4 import com.rabbitmq.client.*;
 5 
 6 import java.io.IOException;
 7 
 8 public class FanoutReceive1 {
 9     private static final String EXCHANGE_NAME="text_exchange_fanout";
10     private static final String QUENE_NAME="test_fanout_queue_email";
11     public static void main(String[] args)throws Exception{
12         //获取一个连接
13         Connection connection = ConnectionUtil.getConnection();
14         //创建通道
15         final Channel channel = connection.createChannel();
16         //创建队列声明
17         channel.queueDeclare(QUENE_NAME,false,false,false,null);
18 
19         //绑定交换机
20         channel.queueBind(QUENE_NAME,EXCHANGE_NAME,"");
21 
22         //一次只能发送一个消息
23         channel.basicQos(1);
24 
25         //创建消费者
26         DefaultConsumer consumer=new DefaultConsumer(channel){
27             @Override
28             public void handleDelivery(String consumerTag, Envelope envelope, AMQP.BasicProperties properties, byte[] body) throws IOException {
29                 String msg=new String(body,"utf-8");
30                 System.out.println("[1]receive msg:"+msg);
31                 try {
32                     Thread.sleep(200);
33                 } catch (InterruptedException e) {
34                     e.printStackTrace();
35                 }finally {
36                     System.out.println("done");
37                     //手动应答
38                     channel.basicAck(envelope.getDeliveryTag(),false);
39                 }
40             }
41         };
42         //监听队列,不是自动应答
43         boolean autoAck=false;
44         channel.basicConsume(QUENE_NAME,autoAck,consumer);
45     }
46 }

3.消费者二

 1 package com.mq.PubSubFanout;
 2 
 3 import com.mq.utils.ConnectionUtil;
 4 import com.rabbitmq.client.*;
 5 
 6 import java.io.IOException;
 7 
 8 public class FanoutReceive2 {
 9     private static final String EXCHANGE_NAME="text_exchange_fanout";
10     private static final String QUENE_NAME="test_fanout_queue_ems";
11     public static void main(String[] args)throws Exception{
12         //获取一个连接
13         Connection connection = ConnectionUtil.getConnection();
14         //创建通道
15         final Channel channel = connection.createChannel();
16         //创建队列声明
17         channel.queueDeclare(QUENE_NAME,false,false,false,null);
18 
19         //绑定交换机
20         channel.queueBind(QUENE_NAME,EXCHANGE_NAME,"");
21 
22         //一次只能发送一个消息
23         channel.basicQos(1);
24 
25         //创建消费者
26         DefaultConsumer consumer=new DefaultConsumer(channel){
27             @Override
28             public void handleDelivery(String consumerTag, Envelope envelope, AMQP.BasicProperties properties, byte[] body) throws IOException {
29                 String msg=new String(body,"utf-8");
30                 System.out.println("[2]receive msg:"+msg);
31                 try {
32                     Thread.sleep(200);
33                 } catch (InterruptedException e) {
34                     e.printStackTrace();
35                 }finally {
36                     System.out.println("done");
37                     //手动应答
38                     channel.basicAck(envelope.getDeliveryTag(),false);
39                 }
40             }
41         };
42         //监听队列,不是自动应答
43         boolean autoAck=false;
44         channel.basicConsume(QUENE_NAME,autoAck,consumer);
45     }
46 }