Rabbitmq之高级特性——实现消费端限流&NACK重回队列

时间：2020-12-09 08:38:47

　　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：

 package com.zxy.demo.rabbitmq;

 import java.io.IOException;

 import java.util.concurrent.TimeoutException;

 import com.rabbitmq.client.AMQP;

 import com.rabbitmq.client.Channel;

 import com.rabbitmq.client.ConfirmListener;

 import com.rabbitmq.client.Connection;

 import com.rabbitmq.client.ConnectionFactory;

 import com.rabbitmq.client.ReturnListener;

 import com.rabbitmq.client.AMQP.BasicProperties;

 public class Producter {

     public static void main(String[] args) throws IOException, TimeoutException {

         // TODO Auto-generated method stub

         ConnectionFactory factory = new ConnectionFactory();

         factory.setHost("192.168.10.110");

         factory.setPort(5672);

         factory.setUsername("guest");

         factory.setPassword("guest");

         factory.setVirtualHost("/");

         Connection conn = factory.newConnection();

         Channel channel = conn.createChannel();

         String exchange001 = "exchange_001";

         String queue001 = "queue_001";

         String routingkey = "mq.topic";

         String body = "hello rabbitmq!===============限流策略";

 //        开启确认模式

         channel.confirmSelect();

 //        循环发送多条消息

         for(int i = 0 ;i<10;i++){

         channel.basicPublish(exchange001, routingkey, null, body.getBytes());

     }

 //        添加一个返回监听========消息返回模式重要添加

         channel.addConfirmListener(new ConfirmListener() {

             @Override

             public void handleNack(long deliveryTag, boolean multiple) throws IOException {

                 System.out.println("===========NACK============");

             }

             @Override

             public void handleAck(long deliveryTag, boolean multiple) throws IOException {

                 System.out.println("===========ACK============");

             }

         });

     }

 }

消费端：

 package com.zxy.demo.rabbitmq;

 import java.io.IOException;

 import java.util.concurrent.TimeoutException;

 import com.rabbitmq.client.Channel;

 import com.rabbitmq.client.Connection;

 import com.rabbitmq.client.ConnectionFactory;

 public class Receiver {

     public static void main(String[] args) throws IOException, TimeoutException, InterruptedException {

         // TODO Auto-generated method stub

         ConnectionFactory factory = new ConnectionFactory();

         factory.setHost("192.168.10.110");

         factory.setPort(5672);

         factory.setUsername("guest");

         factory.setPassword("guest");

         factory.setVirtualHost("/");

         Connection conn = factory.newConnection();

         Channel channel = conn.createChannel();

         String exchange001 = "exchange_001";

         String queue001 = "queue_001";

         String routingkey = "mq.*";

         channel.exchangeDeclare(exchange001, "topic", true, false, null);

         channel.queueDeclare(queue001, true, false, false, null);

         channel.queueBind(queue001, exchange001, routingkey);

 //        设置限流策略

 //        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]);

         channel.basicQos(0, 2, false);

 //        自定义消费者

         MyConsumer myConsumer = new MyConsumer(channel);

 //        进行消费，签收模式一定要为手动签收

         Thread.sleep(3000);

         channel.basicConsume(queue001, false, myConsumer);

     }

 }

自定义消费者：

 package com.zxy.demo.rabbitmq;

 import java.io.IOException;

 import com.rabbitmq.client.AMQP.BasicProperties;

 import com.rabbitmq.client.Channel;

 import com.rabbitmq.client.DefaultConsumer;

 import com.rabbitmq.client.Envelope;

 /**

  * 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

  *

  */

 public class MyConsumer extends DefaultConsumer{

     private Channel channel;

     public MyConsumer(Channel channel) {

         super(channel);

         // TODO Auto-generated constructor stub

         this.channel=channel;

     }

     @Override

     public void handleDelivery(String consumerTag, Envelope envelope, BasicProperties properties, byte[] body)

             throws IOException {

         System.out.println("消费标签："+consumerTag);

         System.out.println("envelope.getDeliveryTag():==="+envelope.getDeliveryTag());

         System.out.println("envelope.getExchange():==="+envelope.getExchange());

         System.out.println("envelope.getRoutingKey():==="+envelope.getRoutingKey());

         System.out.println("body:==="+new String(body));

 //        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

         channel.basicAck(envelope.getDeliveryTag(), false);

     }

 }

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：

 package com.zxy.demo.rabbitmq;

 import java.io.IOException;

 import java.util.HashMap;

 import java.util.Map;

 import java.util.concurrent.TimeoutException;

 import org.springframework.amqp.core.Message;

 import com.rabbitmq.client.AMQP.BasicProperties;

 import com.rabbitmq.client.Channel;

 import com.rabbitmq.client.ConfirmListener;

 import com.rabbitmq.client.Connection;

 import com.rabbitmq.client.ConnectionFactory;

 import com.rabbitmq.client.ReturnListener;

 public class Producter {

     public static void main(String[] args) throws IOException, TimeoutException {

         // TODO Auto-generated method stub

         ConnectionFactory factory = new ConnectionFactory();

         factory.setHost("192.168.10.110");

         factory.setPort(5672);

         factory.setUsername("guest");

         factory.setPassword("guest");

         factory.setVirtualHost("/");

         Connection conn = factory.newConnection();

         Channel channel = conn.createChannel();

         String exchange001 = "exchange_001";

         String queue001 = "queue_001";

         String routingkey = "mq.topic";

 //        循环发送多条消息

         for(int i = 0 ;i<5;i++){

             String body = "hello rabbitmq!===============ACK&重回队列,第"+i+"条";

             Map<String,Object> head = new HashMap<>();

             head.put("n", i);

             BasicProperties properties = new BasicProperties(null, "utf-8", head, 2, 1, null, null, null, null, null, null, null, null, null);

         channel.basicPublish(exchange001, routingkey, properties, body.getBytes());

     }

     }

 }

消费端：

 package com.zxy.demo.rabbitmq;

 import java.io.IOException;

 import java.util.concurrent.TimeoutException;

 import com.rabbitmq.client.Channel;

 import com.rabbitmq.client.Connection;

 import com.rabbitmq.client.ConnectionFactory;

 public class Receiver {

     public static void main(String[] args) throws IOException, TimeoutException, InterruptedException {

         // TODO Auto-generated method stub

         ConnectionFactory factory = new ConnectionFactory();

         factory.setHost("192.168.10.110");

         factory.setPort(5672);

         factory.setUsername("guest");

         factory.setPassword("guest");

         factory.setVirtualHost("/");

         Connection conn = factory.newConnection();

         Channel channel = conn.createChannel();

         String exchange001 = "exchange_001";

         String queue001 = "queue_001";

         String routingkey = "mq.*";

         channel.exchangeDeclare(exchange001, "topic", true, false, null);

         channel.queueDeclare(queue001, true, false, false, null);

         channel.queueBind(queue001, exchange001, routingkey);

 //        自定义消费者

         MyConsumer myConsumer = new MyConsumer(channel);

 //        进行消费，签收模式一定要为手动签收

         channel.basicConsume(queue001, false, myConsumer);

     }

 }

自定义消费者：

 package com.zxy.demo.rabbitmq;

 import java.io.IOException;

 import com.rabbitmq.client.AMQP.BasicProperties;

 import com.rabbitmq.client.Channel;

 import com.rabbitmq.client.DefaultConsumer;

 import com.rabbitmq.client.Envelope;

 /**

  * 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

  *

  */

 public class MyConsumer extends DefaultConsumer{

     private Channel channel;

     public MyConsumer(Channel channel) {

         super(channel);

         // TODO Auto-generated constructor stub

         this.channel=channel;

     }

     @Override

     public void handleDelivery(String consumerTag, Envelope envelope, BasicProperties properties, byte[] body)

             throws IOException {

         System.out.println("消费标签："+consumerTag);

         System.out.println("envelope.getDeliveryTag():==="+envelope.getDeliveryTag());

         System.out.println("envelope.getExchange():==="+envelope.getExchange());

         System.out.println("envelope.getRoutingKey():==="+envelope.getRoutingKey());

         System.out.println("body:==="+new String(body));

         System.out.println("===================休眠以便查看===============");

         try {

             Thread.sleep(2000);

         } catch (InterruptedException e) {

             // TODO Auto-generated catch block

             e.printStackTrace();

         }

 //        手动签收

         Integer i = (Integer) properties.getHeaders().get("n");

         System.out.println("iiiiiiiiiiiiiiiii======================================================"+i);

         if(i==1) {

             channel.basicNack(envelope.getDeliveryTag(),false, true);//第三个参数为是否重返队列

         }else {

             channel.basicAck(envelope.getDeliveryTag(), false);

         }

     }

 }

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。

 消费标签：amq.ctag-eeeaa9jgrJ3tDhtQR2XReg

 envelope.getDeliveryTag():===1

 envelope.getExchange():===exchange_001

 envelope.getRoutingKey():===mq.topic

 body:===hello rabbitmq!===============ACK&重回队列,第0条

 ===================休眠以便查看===============

 iiiiiiiiiiiiiiiii======================================================0

 消费标签：amq.ctag-eeeaa9jgrJ3tDhtQR2XReg

 envelope.getDeliveryTag():===2

 envelope.getExchange():===exchange_001

 envelope.getRoutingKey():===mq.topic

 body:===hello rabbitmq!===============ACK&重回队列,第1条

 ===================休眠以便查看===============

 iiiiiiiiiiiiiiiii======================================================1

 消费标签：amq.ctag-eeeaa9jgrJ3tDhtQR2XReg

 envelope.getDeliveryTag():===3

 envelope.getExchange():===exchange_001

 envelope.getRoutingKey():===mq.topic

 body:===hello rabbitmq!===============ACK&重回队列,第2条

 ===================休眠以便查看===============

 iiiiiiiiiiiiiiiii======================================================2

 消费标签：amq.ctag-eeeaa9jgrJ3tDhtQR2XReg

 envelope.getDeliveryTag():===4

 envelope.getExchange():===exchange_001

 envelope.getRoutingKey():===mq.topic

 body:===hello rabbitmq!===============ACK&重回队列,第3条

 ===================休眠以便查看===============

 iiiiiiiiiiiiiiiii======================================================3

 消费标签：amq.ctag-eeeaa9jgrJ3tDhtQR2XReg

 envelope.getDeliveryTag():===5

 envelope.getExchange():===exchange_001

 envelope.getRoutingKey():===mq.topic

 body:===hello rabbitmq!===============ACK&重回队列,第4条

 ===================休眠以便查看===============

 iiiiiiiiiiiiiiiii======================================================4

 消费标签：amq.ctag-eeeaa9jgrJ3tDhtQR2XReg

 envelope.getDeliveryTag():===6

 envelope.getExchange():===exchange_001

 envelope.getRoutingKey():===mq.topic

 body:===hello rabbitmq!===============ACK&重回队列,第1条

 ===================休眠以便查看===============

 iiiiiiiiiiiiiiiii======================================================1

 消费标签：amq.ctag-eeeaa9jgrJ3tDhtQR2XReg

 envelope.getDeliveryTag():===7

 envelope.getExchange():===exchange_001

 envelope.getRoutingKey():===mq.topic

 body:===hello rabbitmq!===============ACK&重回队列,第1条

 ===================休眠以便查看===============

 iiiiiiiiiiiiiiiii======================================================1

 消费标签：amq.ctag-eeeaa9jgrJ3tDhtQR2XReg

 envelope.getDeliveryTag():===8

 envelope.getExchange():===exchange_001

 envelope.getRoutingKey():===mq.topic

 body:===hello rabbitmq!===============ACK&重回队列,第1条

 ===================休眠以便查看===============

 iiiiiiiiiiiiiiiii======================================================1

 消费标签：amq.ctag-eeeaa9jgrJ3tDhtQR2XReg

 envelope.getDeliveryTag():===9

 envelope.getExchange():===exchange_001

 envelope.getRoutingKey():===mq.topic

 body:===hello rabbitmq!===============ACK&重回队列,第1条

 ===================休眠以便查看===============

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