Rabbitmq之高级特性——实现消费端限流&NACK重回队列

　　如果是高并发下，rabbitmq服务器上收到成千上万条消息，那么当打开消费端时，这些消息必定喷涌而来，导致消费端消费不过来甚至挂掉都有可能。

在非自动确认的模式下，可以采用限流模式，rabbitmq 提供了服务质量保障qos机制来控制一次消费消息数量。

下面直接上代码：

生产端：

 1 package com.zxy.demo.rabbitmq;
 2 
 3 import java.io.IOException;
 4 import java.util.concurrent.TimeoutException;
 5 
 6 import com.rabbitmq.client.AMQP;
 7 import com.rabbitmq.client.Channel;
 8 import com.rabbitmq.client.ConfirmListener;
 9 import com.rabbitmq.client.Connection;
10 import com.rabbitmq.client.ConnectionFactory;
11 import com.rabbitmq.client.ReturnListener;
12 import com.rabbitmq.client.AMQP.BasicProperties;
13 
14 public class Producter {
15 
16     public static void main(String[] args) throws IOException, TimeoutException {
17         // TODO Auto-generated method stub
18         ConnectionFactory factory = new ConnectionFactory();
19         factory.setHost("192.168.10.110");
20         factory.setPort(5672);
21         factory.setUsername("guest");
22         factory.setPassword("guest");
23         factory.setVirtualHost("/");
24         Connection conn = factory.newConnection();
25         Channel channel = conn.createChannel();
26         String exchange001 = "exchange_001";
27         String queue001 = "queue_001";
28         String routingkey = "mq.topic";
29         String body = "hello rabbitmq!===============限流策略";
30 //        开启确认模式
31         channel.confirmSelect();
32 //        循环发送多条消息        
33         for(int i = 0 ;i<10;i++){
34         channel.basicPublish(exchange001, routingkey, null, body.getBytes());
35     }
36         
37 //        添加一个返回监听========消息返回模式重要添加
38         channel.addConfirmListener(new ConfirmListener() {
39             
40             @Override
41             public void handleNack(long deliveryTag, boolean multiple) throws IOException {
42                 System.out.println("===========NACK============");
43                 
44             }
45             
46             @Override
47             public void handleAck(long deliveryTag, boolean multiple) throws IOException {
48                 System.out.println("===========ACK============");
49                 
50             }
51         });
52     }
53 
54 }

 

消费端：

 1 package com.zxy.demo.rabbitmq;
 2 
 3 import java.io.IOException;
 4 import java.util.concurrent.TimeoutException;
 5 
 6 import com.rabbitmq.client.Channel;
 7 import com.rabbitmq.client.Connection;
 8 import com.rabbitmq.client.ConnectionFactory;
 9 
10 public class Receiver {
11 
12     public static void main(String[] args) throws IOException, TimeoutException, InterruptedException {
13         // TODO Auto-generated method stub
14         ConnectionFactory factory = new ConnectionFactory();
15         factory.setHost("192.168.10.110");
16         factory.setPort(5672);
17         factory.setUsername("guest");
18         factory.setPassword("guest");
19         factory.setVirtualHost("/");
20         Connection conn = factory.newConnection();
21         Channel channel = conn.createChannel();
22         String exchange001 = "exchange_001";
23         String queue001 = "queue_001";
24         String routingkey = "mq.*";
25         channel.exchangeDeclare(exchange001, "topic", true, false, null);
26         channel.queueDeclare(queue001, true, false, false, null);
27         channel.queueBind(queue001, exchange001, routingkey);
28 //        设置限流策略
29 //        channel.basicQos(获取消息最大数[0-无限制], 依次获取数量, 作用域[true作用于整个channel，false作用于具体消费者]);
30         channel.basicQos(0, 2, false);
31 //        自定义消费者
32         MyConsumer myConsumer = new MyConsumer(channel);
33 //        进行消费，签收模式一定要为手动签收
34         Thread.sleep(3000);
35         channel.basicConsume(queue001, false, myConsumer);
36     }
37 
38 }

 

自定义消费者：

 1 package com.zxy.demo.rabbitmq;
 2 
 3 import java.io.IOException;
 4 
 5 import com.rabbitmq.client.AMQP.BasicProperties;
 6 import com.rabbitmq.client.Channel;
 7 import com.rabbitmq.client.DefaultConsumer;
 8 import com.rabbitmq.client.Envelope;
 9 
10 /**
11  * 可以继承，可以实现，实现的话要覆写的方法比较多，所以这里用了继承
12  *
13  */
14 public class MyConsumer extends DefaultConsumer{
15     private Channel channel;
16     public MyConsumer(Channel channel) {
17         super(channel);
18         // TODO Auto-generated constructor stub
19         this.channel=channel;
20     }
21 
22     @Override
23     public void handleDelivery(String consumerTag, Envelope envelope, BasicProperties properties, byte[] body)
24             throws IOException {
25         System.out.println("消费标签："+consumerTag);
26         System.out.println("envelope.getDeliveryTag():==="+envelope.getDeliveryTag());
27         System.out.println("envelope.getExchange():==="+envelope.getExchange());
28         System.out.println("envelope.getRoutingKey():==="+envelope.getRoutingKey());
29         System.out.println("body:==="+new String(body));
30 //        手动签收，一定要有消费者签收,如果没有如下代码，则限流模式下，仅能打印出来channel.basicQos(0, 2, false);第二参数的2条信息
31         channel.basicAck(envelope.getDeliveryTag(), false);
32     }
33     
34 
35 }

 重回队列模式，是当投递消息失败时，让该消息重新回到队列的模式，该模式需要手动签收，并需要在消费者中进行判断，调用重回队列的确认模式

代码如下

生产端：

 1 package com.zxy.demo.rabbitmq;
 2 
 3 import java.io.IOException;
 4 import java.util.HashMap;
 5 import java.util.Map;
 6 import java.util.concurrent.TimeoutException;
 7 
 8 import org.springframework.amqp.core.Message;
 9 
10 import com.rabbitmq.client.AMQP.BasicProperties;
11 import com.rabbitmq.client.Channel;
12 import com.rabbitmq.client.ConfirmListener;
13 import com.rabbitmq.client.Connection;
14 import com.rabbitmq.client.ConnectionFactory;
15 import com.rabbitmq.client.ReturnListener;
16 
17 public class Producter {
18 
19     public static void main(String[] args) throws IOException, TimeoutException {
20         // TODO Auto-generated method stub
21         ConnectionFactory factory = new ConnectionFactory();
22         factory.setHost("192.168.10.110");
23         factory.setPort(5672);
24         factory.setUsername("guest");
25         factory.setPassword("guest");
26         factory.setVirtualHost("/");
27         Connection conn = factory.newConnection();
28         Channel channel = conn.createChannel();
29         String exchange001 = "exchange_001";
30         String queue001 = "queue_001";
31         String routingkey = "mq.topic";
32         
33 //        循环发送多条消息        
34         for(int i = 0 ;i<5;i++){
35             String body = "hello rabbitmq!===============ACK&重回队列,第"+i+"条";
36             Map head = new HashMap<>();
37             head.put("n", i);
38             BasicProperties properties = new BasicProperties(null, "utf-8", head, 2, 1, null, null, null, null, null, null, null, null, null);
39             
40         channel.basicPublish(exchange001, routingkey, properties, body.getBytes());
41     }
42         
43     }
44 
45 }

 

消费端：

 1 package com.zxy.demo.rabbitmq;
 2 
 3 import java.io.IOException;
 4 import java.util.concurrent.TimeoutException;
 5 
 6 import com.rabbitmq.client.Channel;
 7 import com.rabbitmq.client.Connection;
 8 import com.rabbitmq.client.ConnectionFactory;
 9 
10 public class Receiver {
11 
12     public static void main(String[] args) throws IOException, TimeoutException, InterruptedException {
13         // TODO Auto-generated method stub
14         ConnectionFactory factory = new ConnectionFactory();
15         factory.setHost("192.168.10.110");
16         factory.setPort(5672);
17         factory.setUsername("guest");
18         factory.setPassword("guest");
19         factory.setVirtualHost("/");
20         Connection conn = factory.newConnection();
21         Channel channel = conn.createChannel();
22         String exchange001 = "exchange_001";
23         String queue001 = "queue_001";
24         String routingkey = "mq.*";
25         channel.exchangeDeclare(exchange001, "topic", true, false, null);
26         channel.queueDeclare(queue001, true, false, false, null);
27         channel.queueBind(queue001, exchange001, routingkey);
28 //        自定义消费者
29         MyConsumer myConsumer = new MyConsumer(channel);
30 //        进行消费，签收模式一定要为手动签收
31         channel.basicConsume(queue001, false, myConsumer);
32     }
33 
34 }

 

自定义消费者：

 1 package com.zxy.demo.rabbitmq;
 2 
 3 import java.io.IOException;
 4 
 5 import com.rabbitmq.client.AMQP.BasicProperties;
 6 import com.rabbitmq.client.Channel;
 7 import com.rabbitmq.client.DefaultConsumer;
 8 import com.rabbitmq.client.Envelope;
 9 
10 /**
11  * 可以继承，可以实现，实现的话要覆写的方法比较多，所以这里用了继承
12  *
13  */
14 public class MyConsumer extends DefaultConsumer{
15     private Channel channel;
16     public MyConsumer(Channel channel) {
17         super(channel);
18         // TODO Auto-generated constructor stub
19         this.channel=channel;
20     }
21 
22     @Override
23     public void handleDelivery(String consumerTag, Envelope envelope, BasicProperties properties, byte[] body)
24             throws IOException {
25         System.out.println("消费标签："+consumerTag);
26         System.out.println("envelope.getDeliveryTag():==="+envelope.getDeliveryTag());
27         System.out.println("envelope.getExchange():==="+envelope.getExchange());
28         System.out.println("envelope.getRoutingKey():==="+envelope.getRoutingKey());
29         System.out.println("body:==="+new String(body));
30         System.out.println("===================休眠以便查看===============");
31         try {
32             Thread.sleep(2000);
33         } catch (InterruptedException e) {
34             // TODO Auto-generated catch block
35             e.printStackTrace();
36         }
37 //        手动签收
38         Integer i = (Integer) properties.getHeaders().get("n");
39         System.out.println("iiiiiiiiiiiiiiiii======================================================"+i);
40         if(i==1) {
41             channel.basicNack(envelope.getDeliveryTag(),false, true);//第三个参数为是否重返队列
42         }else {
43             channel.basicAck(envelope.getDeliveryTag(), false);    
44         }
45     }
46     
47 
48 }

下面是重回队列执行结果，可以看到当消费完后第一条不断的被扔回队列然后消费再扔回。

 1 消费标签：amq.ctag-eeeaa9jgrJ3tDhtQR2XReg
 2 envelope.getDeliveryTag():===1
 3 envelope.getExchange():===exchange_001
 4 envelope.getRoutingKey():===mq.topic
 5 body:===hello rabbitmq!===============ACK&重回队列,第0条
 6 ===================休眠以便查看===============
 7 iiiiiiiiiiiiiiiii======================================================0
 8 消费标签：amq.ctag-eeeaa9jgrJ3tDhtQR2XReg
 9 envelope.getDeliveryTag():===2
10 envelope.getExchange():===exchange_001
11 envelope.getRoutingKey():===mq.topic
12 body:===hello rabbitmq!===============ACK&重回队列,第1条
13 ===================休眠以便查看===============
14 iiiiiiiiiiiiiiiii======================================================1
15 消费标签：amq.ctag-eeeaa9jgrJ3tDhtQR2XReg
16 envelope.getDeliveryTag():===3
17 envelope.getExchange():===exchange_001
18 envelope.getRoutingKey():===mq.topic
19 body:===hello rabbitmq!===============ACK&重回队列,第2条
20 ===================休眠以便查看===============
21 iiiiiiiiiiiiiiiii======================================================2
22 消费标签：amq.ctag-eeeaa9jgrJ3tDhtQR2XReg
23 envelope.getDeliveryTag():===4
24 envelope.getExchange():===exchange_001
25 envelope.getRoutingKey():===mq.topic
26 body:===hello rabbitmq!===============ACK&重回队列,第3条
27 ===================休眠以便查看===============
28 iiiiiiiiiiiiiiiii======================================================3
29 消费标签：amq.ctag-eeeaa9jgrJ3tDhtQR2XReg
30 envelope.getDeliveryTag():===5
31 envelope.getExchange():===exchange_001
32 envelope.getRoutingKey():===mq.topic
33 body:===hello rabbitmq!===============ACK&重回队列,第4条
34 ===================休眠以便查看===============
35 iiiiiiiiiiiiiiiii======================================================4
36 消费标签：amq.ctag-eeeaa9jgrJ3tDhtQR2XReg
37 envelope.getDeliveryTag():===6
38 envelope.getExchange():===exchange_001
39 envelope.getRoutingKey():===mq.topic
40 body:===hello rabbitmq!===============ACK&重回队列,第1条
41 ===================休眠以便查看===============
42 iiiiiiiiiiiiiiiii======================================================1
43 消费标签：amq.ctag-eeeaa9jgrJ3tDhtQR2XReg
44 envelope.getDeliveryTag():===7
45 envelope.getExchange():===exchange_001
46 envelope.getRoutingKey():===mq.topic
47 body:===hello rabbitmq!===============ACK&重回队列,第1条
48 ===================休眠以便查看===============
49 iiiiiiiiiiiiiiiii======================================================1
50 消费标签：amq.ctag-eeeaa9jgrJ3tDhtQR2XReg
51 envelope.getDeliveryTag():===8
52 envelope.getExchange():===exchange_001
53 envelope.getRoutingKey():===mq.topic
54 body:===hello rabbitmq!===============ACK&重回队列,第1条
55 ===================休眠以便查看===============
56 iiiiiiiiiiiiiiiii======================================================1
57 消费标签：amq.ctag-eeeaa9jgrJ3tDhtQR2XReg
58 envelope.getDeliveryTag():===9
59 envelope.getExchange():===exchange_001
60 envelope.getRoutingKey():===mq.topic
61 body:===hello rabbitmq!===============ACK&重回队列,第1条
62 ===================休眠以便查看===============

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