SpringBoot整合RabbitMQ--死信队列/延迟队列--用法/实例

原文网址：SpringBoot整合RabbitMQ--死信队列/延迟队列--用法/实例_IT利刃出鞘的博客-CSDN博客

简介

说明

** **本文用示例介绍SpringBoot整合RabbitMQ时如何处理死信队列/延迟队列。

RabbitMQ消息简介

    RabbitMQ的消息默认不会超时。 

什么是死信队列？什么是延迟队列？

死信队列：

    DLX，全称为Dead-Letter-Exchange,可以称之为死信交换器，也有人称之为死信邮箱。当消息在一个队列中变成死信（dead message)之后，它能被重新被发送到另一个交换器中，这个交换器就是DLX，绑定DLX的队列就称之为死信队列。

以下几种情况会导致消息变成死信：

1. 消息被拒绝（Basic.Reject/Basic.Nack)，并且设置requeue参数为false;
2. 消息过期；
3. 队列达到最大长度。

延迟队列：

    延迟队列用来存放延迟消息。延迟消息：指当消息被发送以后，不想让消费者立刻拿到消息，而是等待特定时间后，消费者才能拿到这个消息进行消费。

相关网址

RabbitMQ--死信队列/延迟队列--使用/原理_IT利刃出鞘的博客-CSDN博客_死信队列原理

实例代码

路由配置

package com.example.config;

import org.springframework.amqp.core.*;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;

@Configuration
public class RabbitRouterConfig {
    public static final String EXCHANGE_TOPIC_WELCOME   = "[email protected]";
    public static final String EXCHANGE_FANOUT_UNROUTE  = "[email protected]";
    public static final String EXCHANGE_TOPIC_DELAY     = "[email protected]";

    public static final String ROUTINGKEY_HELLOS        = "hello.#";
    public static final String ROUTINGKEY_DELAY         = "delay.#";

    public static final String QUEUE_HELLO              = "Queue@hello";
    public static final String QUEUE_HI                 = "Queue@hi";
    public static final String QUEUE_UNROUTE            = "Queue@unroute";
    public static final String QUEUE_DELAY              = "Queue@delay";

    public static final Integer TTL_QUEUE_MESSAGE       = 5000;

    @Autowired
    AmqpAdmin amqpAdmin;

    @Bean
    Object initBindingTest() {
        amqpAdmin.declareExchange(ExchangeBuilder.fanoutExchange(EXCHANGE_FANOUT_UNROUTE).durable(true).autoDelete().build());
        amqpAdmin.declareExchange(ExchangeBuilder.topicExchange(EXCHANGE_TOPIC_DELAY).durable(true).autoDelete().build());
        amqpAdmin.declareExchange(ExchangeBuilder.topicExchange(EXCHANGE_TOPIC_WELCOME)
                .durable(true)
                .autoDelete()
                .withArgument("alternate-exchange", EXCHANGE_FANOUT_UNROUTE)

                .build());

        amqpAdmin.declareQueue(QueueBuilder.durable(QUEUE_HI).build());
        amqpAdmin.declareQueue(QueueBuilder.durable(QUEUE_HELLO)
                .withArgument("x-dead-letter-exchange", EXCHANGE_TOPIC_DELAY)
                .withArgument("x-dead-letter-routing-key", ROUTINGKEY_DELAY)
                .withArgument("x-message-ttl", TTL_QUEUE_MESSAGE)
                .build());
        amqpAdmin.declareQueue(QueueBuilder.durable(QUEUE_UNROUTE).build());
        amqpAdmin.declareQueue(QueueBuilder.durable(QUEUE_DELAY).build());

        amqpAdmin.declareBinding(new Binding(QUEUE_HELLO, Binding.DestinationType.QUEUE,
                EXCHANGE_TOPIC_WELCOME, ROUTINGKEY_HELLOS, null));
        amqpAdmin.declareBinding(new Binding(QUEUE_UNROUTE, Binding.DestinationType.QUEUE,
                EXCHANGE_FANOUT_UNROUTE, "", null));
        amqpAdmin.declareBinding(new Binding(QUEUE_DELAY, Binding.DestinationType.QUEUE,
                EXCHANGE_TOPIC_DELAY, ROUTINGKEY_DELAY, null));

        return new Object();
    }
}

控制器

package com.example.controller;

import com.example.config.RabbitRouterConfig;
import com.example.mq.Sender;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RestController;

import java.time.LocalDateTime;

@RestController
public class HelloController {
    @Autowired
    private Sender sender;

    @PostMapping("/hi")
    public void hi() {
        sender.send(RabbitRouterConfig.QUEUE_HI, "hi1 message:" + LocalDateTime.now());
    }

    @PostMapping("/hello1")
    public void hello1() {
        sender.send("hello.a", "hello1 message:" + LocalDateTime.now());
    }

    @PostMapping("/hello2")
    public void hello2() {
        sender.send(RabbitRouterConfig.EXCHANGE_TOPIC_WELCOME, "hello.b", "hello2 message:" + LocalDateTime.now());
    }

    @PostMapping("/ae")
    public void aeTest() {
        sender.send(RabbitRouterConfig.EXCHANGE_TOPIC_WELCOME, "nonono", "ae message:" + LocalDateTime.now());
    }
}

发送器

package com.example.mq;

import org.springframework.amqp.core.AmqpTemplate;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Component;

import java.util.Date;

@Component
public class Sender {
    @Autowired
    private AmqpTemplate rabbitTemplate;

    public void send(String routingKey, String message) {
        this.rabbitTemplate.convertAndSend(routingKey, message);
    }

    public void send(String exchange, String routingKey, String message) {
        this.rabbitTemplate.convertAndSend(exchange, routingKey, message);
    }
}

接收器

package com.example.mq;

import com.example.config.RabbitRouterConfig;
import org.springframework.amqp.rabbit.annotation.RabbitListener;
import org.springframework.stereotype.Component;

@Component
public class Receiver {
    @RabbitListener(queues = RabbitRouterConfig.QUEUE_HI)
    public void hi(String payload) {
        System.out.println ("Receiver(hi) : "  + payload);
    }

    // @RabbitListener(queues = RabbitRouterConfig.QUEUE_HELLO)
    // public void hello(String hello) throws InterruptedException {
    //     System.out.println ("Receiver(hello) : "  + hello);
    //     Thread.sleep(5 * 1000);
    //     System.out.println("(hello):sleep over");
    // }
    //
    // @RabbitListener(queues = RabbitRouterConfig.QUEUE_UNROUTE)
    // public void unroute(String hello) throws InterruptedException {
    //     System.out.println ("Receiver(unroute) : "  + hello);
    //     Thread.sleep(5 * 1000);
    //     System.out.println("(unroute):sleep over");
    // }

    @RabbitListener(queues = RabbitRouterConfig.QUEUE_DELAY)
    public void delay(String hello) throws InterruptedException {
        System.out.println ("Receiver(delay) : "  + hello);
        Thread.sleep(5 * 1000);
        System.out.println("(delay):sleep over");
    }
}

application.yml

server:
#  port: 9100
  port: 9101
spring:
  application:
#    name: demo-rabbitmq-sender
    name: demo-rabbitmq-receiver
  rabbitmq:
    host: localhost
    port: 5672
    username: admin
    password: 123456
#    virtualHost: /
    publisher-confirms: true
    publisher-returns: true
#    listener:
#      simple:
#        acknowledge-mode: manual
#      direct:
#        acknowledge-mode: manual

实例测试

分别启动发送者和接收者。

访问：Node Exporter

五秒钟后输出：

Receiver(delay) : hello2 message:2020-11-27T09:30:51.548
(delay):sleep over

其他网址

《RabbitMQ实战指南》=> 第4章 RabbitMQ进阶