互联网全景消息(8)之RabbitMQ进阶介绍

一、RabbitMQ架构

可以看出RabbitMQ主要分为三个角色：

Pulisher：消息的发布者，将消息发布到RabbitMQ中Exchange;
RabbitMQ服务：Exchange接收Publisher的消息，并且根据Routes策略将消息转发到Queue中；
Consumer：消息的消费者，监听Queue中的消息并进行消费；

官方提供的架构图相对简洁，我们可以自己画一份相对完整一些的架构图：

可以看得出来Publisher和Consumer都是单独和RabbitMQ服务某一个Virtual Host建立Connection的客户端，后续通过Connection可以构建多个channel，用来发布、接收消息,一个Virtual Host中可以有多个Exchange和Queue，Exchange可以同时绑定多个Queue。

基于以上架构图再结合图形管理界面会更加清晰：

二、RabbitMQ通讯方式

RabbitMQ提供了很多中通讯方式，依然可以去官方查看：https://rabbitmq.com/getstarted.html

2.1 RabbitMQ提供的通讯方式

Hello World!：为了入门操作！
Work queues：一个队列被多个消费者消费
Publish/Subscribe：手动创建Exchange（FANOUT）
Routing：手动创建Exchange（DIRECT）
Topics：手动创建Exchange（TOPIC）
RPC：RPC方式
Publisher Confirms：保证消息可靠性

接下来我们通过代码的方式来分别演示一下，以上场景的使用方式。

2.2 构建获取RabbitMQ的Connection工具类

导入依赖：amqp-client，junit

XML 复制代码

<dependencies>
    <dependency>
        <groupId>com.rabbitmq</groupId>
        <artifactId>amqp-client</artifactId>
        <version>5.9.0</version>
    </dependency>
    <dependency>
        <groupId>junit</groupId>
        <artifactId>junit</artifactId>
        <version>4.12</version>
    </dependency>
</dependencies>

构建工具类：

java 复制代码

package com.mashibing.util;

import com.rabbitmq.client.Connection;
import com.rabbitmq.client.ConnectionFactory;

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

/**
 * @description
 */
public class RabbitMQConnectionUtil {

    public static final String RABBITMQ_HOST = "192.168.11.32";

    public static final int RABBITMQ_PORT = 5672;

    public static final String RABBITMQ_USERNAME = "guest";

    public static final String RABBITMQ_PASSWORD = "guest";

    public static final String RABBITMQ_VIRTUAL_HOST = "/";

    /**
     * 构建RabbitMQ的连接对象
     * @return
     */
    public static Connection getConnection() throws Exception {
        //1. 创建Connection工厂
        ConnectionFactory factory = new ConnectionFactory();

        //2. 设置RabbitMQ的连接信息
        factory.setHost(RABBITMQ_HOST);
        factory.setPort(RABBITMQ_PORT);
        factory.setUsername(RABBITMQ_USERNAME);
        factory.setPassword(RABBITMQ_PASSWORD);
        factory.setVirtualHost(RABBITMQ_VIRTUAL_HOST);

        //3. 返回连接对象
        Connection connection = factory.newConnection();
        return connection;
    }

}

2.3 hello world

生产者：

java 复制代码

package com.mashibing.helloworld;

import com.mashibing.util.RabbitMQConnectionUtil;
import com.rabbitmq.client.Channel;
import com.rabbitmq.client.Connection;
import org.junit.Test;

/**
 * @description
 * @date 2022/1/24 22:54
 */
public class Publisher {

    public static final String QUEUE_NAME = "hello";

    @Test
    public void publish() throws Exception {
        //1. 获取连接对象
        Connection connection = RabbitMQConnectionUtil.getConnection();

        //2. 构建Channel
        Channel channel = connection.createChannel();

        //3. 构建队列
        channel.queueDeclare(QUEUE_NAME,false,false,false,null);

        //4. 发布消息
        String message = "Hello World!";
        channel.basicPublish("",QUEUE_NAME,null,message.getBytes());
        System.out.println("消息发送成功！");
    }
}

消费者：

java 复制代码

package com.mashibing.helloworld;

import com.mashibing.util.RabbitMQConnectionUtil;
import com.rabbitmq.client.*;
import org.junit.Test;

import java.io.IOException;

/**
 * @description
 * @date 2022/1/24 23:02
 */
public class Consumer {

    @Test
    public void consume() throws Exception {
        //1. 获取连接对象
        Connection connection = RabbitMQConnectionUtil.getConnection();

        //2. 构建Channel
        Channel channel = connection.createChannel();

        //3. 构建队列
        channel.queueDeclare(Publisher.QUEUE_NAME,false,false,false,null);

        //4. 监听消息
        DefaultConsumer callback = new DefaultConsumer(channel){
            @Override
            public void handleDelivery(String consumerTag, Envelope envelope, AMQP.BasicProperties properties, byte[] body) throws IOException {
                System.out.println("消费者获取到消息：" + new String(body,"UTF-8"));
            }
        };
        channel.basicConsume(Publisher.QUEUE_NAME,true,callback);
        System.out.println("开始监听队列");

        System.in.read();
    }
}

2.4 Work Queues

生产者：生产者和Hello World的形式是一样的，都是将消息推送到默认交换机。
消费者：让消费者关闭自动ack，并且设置消息的流控，最终实现消费者可以尽可能去多消费消息

java 复制代码

package com.mashibing.workqueues;

import com.mashibing.util.RabbitMQConnectionUtil;
import com.rabbitmq.client.*;
import org.junit.Test;

import java.io.IOException;

/**
 * @description
 * @date 2022/1/25 19:52
 */
public class Consumer {

    @Test
    public void consume1() throws Exception {
        //1. 获取连接对象
        Connection connection = RabbitMQConnectionUtil.getConnection();

        //2. 构建Channel
        Channel channel = connection.createChannel();

        //3. 构建队列
        channel.queueDeclare(Publisher.QUEUE_NAME,false,false,false,null);

        //3.5 设置消息的流控
        channel.basicQos(3);

        //4. 监听消息
        DefaultConsumer callback = new DefaultConsumer(channel){
            @Override
            public void handleDelivery(String consumerTag, Envelope envelope, AMQP.BasicProperties properties, byte[] body) throws IOException {
                try {
                    Thread.sleep(100);
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
                System.out.println("消费者1号-获取到消息：" + new String(body,"UTF-8"));
                channel.basicAck(envelope.getDeliveryTag(),false);
            }
        };
        channel.basicConsume(Publisher.QUEUE_NAME,false,callback);
        System.out.println("开始监听队列");

        System.in.read();
    }

    @Test
    public void consume2() throws Exception {
        //1. 获取连接对象
        Connection connection = RabbitMQConnectionUtil.getConnection();

        //2. 构建Channel
        Channel channel = connection.createChannel();

        //3. 构建队列
        channel.queueDeclare(Publisher.QUEUE_NAME,false,false,false,null);

        channel.basicQos(3);

        //4. 监听消息
        DefaultConsumer callback = new DefaultConsumer(channel){
            @Override
            public void handleDelivery(String consumerTag, Envelope envelope, AMQP.BasicProperties properties, byte[] body) throws IOException {
                try {
                    Thread.sleep(1000);
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
                System.out.println("消费者2号-获取到消息：" + new String(body,"UTF-8"));
                channel.basicAck(envelope.getDeliveryTag(),false);
            }
        };
        channel.basicConsume(Publisher.QUEUE_NAME,false,callback);
        System.out.println("开始监听队列");

        System.in.read();
    }
}

对于Exchange 的类型，大家可以参考上一篇博客的内容。

生产者：自行构建Exchange并绑定指定队列（FANOUT类型）

java 复制代码

package com.mashibing.pubsub;

import com.mashibing.util.RabbitMQConnectionUtil;
import com.rabbitmq.client.BuiltinExchangeType;
import com.rabbitmq.client.Channel;
import com.rabbitmq.client.Connection;
import org.junit.Test;

/**
 * @description
 * @date 2022/1/25 20:08
 */
public class Publisher {

    public static final String EXCHANGE_NAME = "pubsub";
    public static final String QUEUE_NAME1 = "pubsub-one";
    public static final String QUEUE_NAME2 = "pubsub-two";
    @Test
    public void publish() throws Exception {
        //1. 获取连接对象
        Connection connection = RabbitMQConnectionUtil.getConnection();

        //2. 构建Channel
        Channel channel = connection.createChannel();

        //3. 构建交换机
        channel.exchangeDeclare(EXCHANGE_NAME, BuiltinExchangeType.FANOUT);

        //4. 构建队列
        channel.queueDeclare(QUEUE_NAME1,false,false,false,null);
        channel.queueDeclare(QUEUE_NAME2,false,false,false,null);

        //5. 绑定交换机和队列，使用的是FANOUT类型的交换机，绑定方式是直接绑定
        channel.queueBind(QUEUE_NAME1,EXCHANGE_NAME,"");
        channel.queueBind(QUEUE_NAME2,EXCHANGE_NAME,"");

        //6. 发消息到交换机
        channel.basicPublish(EXCHANGE_NAME,"45jk6h645jk",null,"publish/subscribe!".getBytes());
        System.out.println("消息成功发送！");
    }
}

2.6 Routing

生产者：在绑定Exchange和Queue时，需要指定好routingKey，同时在发送消息时，也指定routingKey，只有routingKey一致时，才会把指定的消息路由到指定的Queue中。

java 复制代码

package com.mashibing.routing;

import com.mashibing.util.RabbitMQConnectionUtil;
import com.rabbitmq.client.BuiltinExchangeType;
import com.rabbitmq.client.Channel;
import com.rabbitmq.client.Connection;
import org.junit.Test;

/**
 * @description
 * @date 2024/12/25 20:20
 */
public class Publisher {

    public static final String EXCHANGE_NAME = "routing";
    public static final String QUEUE_NAME1 = "routing-one";
    public static final String QUEUE_NAME2 = "routing-two";
    @Test
    public void publish() throws Exception {
        //1. 获取连接对象
        Connection connection = RabbitMQConnectionUtil.getConnection();

        //2. 构建Channel
        Channel channel = connection.createChannel();

        //3. 构建交换机
        channel.exchangeDeclare(EXCHANGE_NAME, BuiltinExchangeType.DIRECT);

        //4. 构建队列
        channel.queueDeclare(QUEUE_NAME1,false,false,false,null);
        channel.queueDeclare(QUEUE_NAME2,false,false,false,null);

        //5. 绑定交换机和队列
        channel.queueBind(QUEUE_NAME1,EXCHANGE_NAME,"ORANGE");
        channel.queueBind(QUEUE_NAME2,EXCHANGE_NAME,"BLACK");
        channel.queueBind(QUEUE_NAME2,EXCHANGE_NAME,"GREEN");

        //6. 发消息到交换机
        channel.basicPublish(EXCHANGE_NAME,"ORANGE",null,"大橙子！".getBytes());
        channel.basicPublish(EXCHANGE_NAME,"BLACK",null,"黑布林大狸子".getBytes());
        channel.basicPublish(EXCHANGE_NAME,"WHITE",null,"小白兔！".getBytes());
        System.out.println("消息成功发送！");


    }

}

2.7 Topic

生产者：TOPIC类型可以编写带有特殊意义的routingKey的绑定方式。

java 复制代码

package com.mashibing.topics;

import com.mashibing.util.RabbitMQConnectionUtil;
import com.rabbitmq.client.BuiltinExchangeType;
import com.rabbitmq.client.Channel;
import com.rabbitmq.client.Connection;
import org.junit.Test;

/**
 * @description
 * @date 2022/1/25 20:28
 */
public class Publisher {

    public static final String EXCHANGE_NAME = "topic";
    public static final String QUEUE_NAME1 = "topic-one";
    public static final String QUEUE_NAME2 = "topic-two";
    @Test
    public void publish() throws Exception {
        //1. 获取连接对象
        Connection connection = RabbitMQConnectionUtil.getConnection();

        //2. 构建Channel
        Channel channel = connection.createChannel();

        //3. 构建交换机
        channel.exchangeDeclare(EXCHANGE_NAME, BuiltinExchangeType.TOPIC);

        //4. 构建队列
        channel.queueDeclare(QUEUE_NAME1,false,false,false,null);
        channel.queueDeclare(QUEUE_NAME2,false,false,false,null);

        //5. 绑定交换机和队列，
        // TOPIC类型的交换机在和队列绑定时，需要以aaa.bbb.ccc..方式编写routingkey
        // 其中有两个特殊字符：*（相当于占位符），#（相当通配符）
        channel.queueBind(QUEUE_NAME1,EXCHANGE_NAME,"*.orange.*");
        channel.queueBind(QUEUE_NAME2,EXCHANGE_NAME,"*.*.rabbit");
        channel.queueBind(QUEUE_NAME2,EXCHANGE_NAME,"lazy.#");

        //6. 发消息到交换机
        channel.basicPublish(EXCHANGE_NAME,"big.orange.rabbit",null,"大橙兔子！".getBytes());
        channel.basicPublish(EXCHANGE_NAME,"small.white.rabbit",null,"小白兔".getBytes());
        channel.basicPublish(EXCHANGE_NAME,"lazy.dog.dog.dog.dog.dog.dog",null,"懒狗狗狗狗狗狗".getBytes());
        System.out.println("消息成功发送！");

    }
}

三、SpringBoot操作RabbitMQ

3.1 SpringBoot声明信息

导入依赖：

XML 复制代码

<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-amqp</artifactId>
</dependency>

配置RabbitMQ信息

XML 复制代码

spring:
  rabbitmq:
    host: 192.168.11.32
    port: 5672
    username: guest
    password: guest
    virtual-host: /

声明交互机与队列：

java 复制代码

package com.mashibing.rabbitmqboot.config;

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

/**
 * @description
 * @date 2024/12/8 20:25
 */
@Configuration
public class RabbitMQConfig {

    public static final String EXCHANGE = "boot-exchange";
    public static final String QUEUE = "boot-queue";
    public static final String ROUTING_KEY = "*.black.*";

@Bean
  public Exchange bootExchange(){
      // channel.DeclareExchange
      return ExchangeBuilder.topicExchange(EXCHANGE).build();
  }

  @Bean
  public Queue bootQueue(){
      return QueueBuilder.durable(QUEUE).build();
  }

  @Bean
  public Binding bootBinding(Exchange bootExchange,Queue bootQueue){
      return BindingBuilder.bind(bootQueue).to(bootExchange).with(ROUTING_KEY).noargs();
  }
}

3.2 生产者

通过引入RabbitMQTemplate来发送消息。

java 复制代码

package com.mashibing.rabbitmqboot;

import com.mashibing.rabbitmqboot.config.RabbitMQConfig;
import org.junit.jupiter.api.Test;
import org.springframework.amqp.AmqpException;
import org.springframework.amqp.core.Message;
import org.springframework.amqp.core.MessagePostProcessor;
import org.springframework.amqp.rabbit.core.RabbitTemplate;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;

@SpringBootTest
public class PublisherTest {

    @Autowired
    public RabbitTemplate rabbitTemplate;

    @Test
    public void publish(){
        rabbitTemplate.convertAndSend(RabbitMQConfig.EXCHANGE,"big.black.dog","message");
        System.out.println("消息发送成功");
    }


    @Test
    public void publishWithProps(){
        rabbitTemplate.convertAndSend(RabbitMQConfig.EXCHANGE, "big.black.dog", "messageWithProps", new MessagePostProcessor() {
            @Override
            public Message postProcessMessage(Message message) throws AmqpException {
                message.getMessageProperties().setCorrelationId("123");
                return message;
            }
        });
        System.out.println("消息发送成功");
    }
}

3.3 消费者

java 复制代码

package com.mashibing.rabbitmqboot;

import com.mashibing.rabbitmqboot.config.RabbitMQConfig;
import com.rabbitmq.client.Channel;
import org.junit.jupiter.api.Test;
import org.springframework.amqp.core.Message;
import org.springframework.amqp.rabbit.annotation.RabbitListener;
import org.springframework.boot.test.context.SpringBootTest;
import org.springframework.context.annotation.Configuration;
import org.springframework.stereotype.Component;

import java.io.IOException;

@Component
public class ConsumeListener {

    @RabbitListener(queues = RabbitMQConfig.QUEUE)
    public void consume(String msg, Channel channel, Message message) throws IOException {
        System.out.println("队列的消息为：" + msg);
        String correlationId = message.getMessageProperties().getCorrelationId();
        System.out.println("唯一标识为：" + correlationId);
        channel.basicAck(message.getMessageProperties().getDeliveryTag(),false);
    }
}

四、RabbitMQ保证消息的可靠性

上一章节中我们也大体介绍了如果保证RabbitMQ消息的可靠性，在这一章节中我们主要结合代码来说明这一点。

总体来说需要保证RabbitMQ消息的可靠性，主要是：

保障消息一定送达到Exchange；
保障消息可以路由到Queue；
保障队列可以持久化消息；
保障消费者可以正常消费消息；

4.1 如果保障消息可以到达Exchange

Confirm机制：可以通过Confirm效果保证消息一定送达到Exchange，官方提供了三种方式，选择了对于效率影响最低的异步回调的效果。

java 复制代码

//4. 开启confirms
channel.confirmSelect();

//5. 设置confirms的异步回调
channel.addConfirmListener(new ConfirmListener() {
    @Override
    public void handleAck(long deliveryTag, boolean multiple) throws IOException {
        System.out.println("消息成功的发送到Exchange！");
    }

    @Override
    public void handleNack(long deliveryTag, boolean multiple) throws IOException {
        System.out.println("消息没有发送到Exchange，尝试重试，或者保存到数据库做其他补偿操作！");
    }
});

4.2 保证消息可以路由到 Queue

Return机制：为了保证Exchange一定可以送达到Queue。

java 复制代码

//6. 设置Return回调，确认消息是否路由到了Queue
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("消息没有路由到指定队列，做其他的补偿措施！！");
    }
});
//7. 在发送消息时，将basicPublish方法参数中的mandatory设置为true，即可开启Return机制，当消息没有路由到队列中时，就会执行return回调

4.3 保证Queue可以持久化消息

DeliveryMode设置消息持久化， DeliveryMode设置为2代表持久化，如果设置为1，就代表不会持久化。

java 复制代码

//7. 设置消息持久化
AMQP.BasicProperties props = new AMQP.BasicProperties()
    .builder()
    .deliveryMode(2)
    .build();

//7. 发布消息
channel.basicPublish("","confirms",true,props,message.getBytes());

4.4 保证消费者可以正常消费消息

请查看上面的work queue模式。

4.5 Spring Boot实现RabbitMQ的消息可靠性

4.5.1Confirm

编写配置文件开启Confirm机制

XML 复制代码

spring:
  rabbitmq:
    publisher-confirm-type: correlated  # 新版本
    publisher-confirms: true  # 老版本

在发送消息时，配置RabbitMqTemplate

java 复制代码

@Test
public void publishWithConfirms() throws IOException {
    rabbitTemplate.setConfirmCallback(new RabbitTemplate.ConfirmCallback() {
        @Override
        public void confirm(CorrelationData correlationData, boolean ack, String cause) {
            if(ack){
                System.out.println("消息已经送达到交换机！！");
            }else{
                System.out.println("消息没有送达到Exchange，需要做一些补偿操作！！retry！！！");
            }
        }
    });
    rabbitTemplate.convertAndSend(RabbitMQConfig.EXCHANGE,"big.black.dog","message");
    System.out.println("消息发送成功");

    System.in.read();
}

4.5.2 Return机制

编写配置文件开启Return机制。

java 复制代码

spring:
  rabbitmq:
    publisher-returns: true # 开启Return机制

在发送消息时，配置RabbitMQTemplate

java 复制代码

@Test
public void publishWithReturn() throws IOException {
    // 新版本用 setReturnsCallback ，老版本用setReturnCallback
    rabbitTemplate.setReturnsCallback(new RabbitTemplate.ReturnsCallback() {
        @Override
        public void returnedMessage(ReturnedMessage returned) {
            String msg = new String(returned.getMessage().getBody());
            System.out.println("消息：" + msg + "路由队列失败！！做补救操作！！");
        }
    });
    rabbitTemplate.convertAndSend(RabbitMQConfig.EXCHANGE,"big.black.dog","message");
    System.out.println("消息发送成功");

    System.in.read();
}

4.5.3 消息持久化

java 复制代码

@Test
public void publishWithBasicProperties() throws IOException {
    rabbitTemplate.convertAndSend(RabbitMQConfig.EXCHANGE, "big.black.dog", "message", new MessagePostProcessor() {
        @Override
        public Message postProcessMessage(Message message) throws AmqpException {
            // 设置消息的持久化！
            message.getMessageProperties().setDeliveryMode(MessageDeliveryMode.PERSISTENT);
            return message;
        }
    });
    System.out.println("消息发送成功");
}

五、RabbitMQ死信队列&延迟交换机

5.1 什么是死信队列

死信队列的应用：

基于死信队列在队列消息已满的情况下，消息也不会丢失；
实现延迟消费的效果。比如：下订单时，有15分钟的付款时间。

5.2 实现死信队列

5.2.1 准备Exchange&Queue

java 复制代码

@Configuration
public class DeadLetterConfig {

    public static final String NORMAL_EXCHANGE = "normal-exchange";
    public static final String NORMAL_QUEUE = "normal-queue";
    public static final String NORMAL_ROUTING_KEY = "normal.#";

    public static final String DEAD_EXCHANGE = "dead-exchange";
    public static final String DEAD_QUEUE = "dead-queue";
    public static final String DEAD_ROUTING_KEY = "dead.#";


    @Bean
    public Exchange normalExchange(){
        return ExchangeBuilder.topicExchange(NORMAL_EXCHANGE).build();
    }

    @Bean
    public Queue normalQueue(){
        return QueueBuilder.durable(NORMAL_QUEUE).deadLetterExchange(DEAD_EXCHANGE).deadLetterRoutingKey("dead.abc").build();
    }

    @Bean
    public Binding normalBinding(Queue normalQueue,Exchange normalExchange){
        return BindingBuilder.bind(normalQueue).to(normalExchange).with(NORMAL_ROUTING_KEY).noargs();
    }


    @Bean
    public Exchange deadExchange(){
        return ExchangeBuilder.topicExchange(DEAD_EXCHANGE).build();
    }

    @Bean
    public Queue deadQueue(){
        return QueueBuilder.durable(DEAD_QUEUE).build();
    }

    @Bean
    public Binding deadBinding(Queue deadQueue,Exchange deadExchange){
        return BindingBuilder.bind(deadQueue).to(deadExchange).with(DEAD_ROUTING_KEY).noargs();
    }

}

5.2.2 实现效果

基于消费进行reject或者nack实现死信效果

java 复制代码

import com.mashibing.rabbitmqboot.config.DeadLetterConfig;
import com.rabbitmq.client.Channel;
import org.springframework.amqp.core.Message;
import org.springframework.amqp.rabbit.annotation.RabbitListener;
import org.springframework.stereotype.Component;

import java.io.IOException;


@Component
public class DeadListener {

    @RabbitListener(queues = DeadLetterConfig.NORMAL_QUEUE)
    public void consume(String msg, Channel channel, Message message) throws IOException {
        System.out.println("接收到normal队列的消息：" + msg);
        channel.basicReject(message.getMessageProperties().getDeliveryTag(),false);
        channel.basicNack(message.getMessageProperties().getDeliveryTag(),false,false);
    }
}

基于消息的生存时间：1、给消息设置生存时间。

java 复制代码

@Test
public void publishExpire(){
    String msg = "dead letter expire";
    rabbitTemplate.convertAndSend(DeadLetterConfig.NORMAL_EXCHANGE, "normal.abc", msg, new MessagePostProcessor() {
        @Override
        public Message postProcessMessage(Message message) throws AmqpException {
            message.getMessageProperties().setExpiration("5000");
            return message;
        }
    });
}

给队列设置生存时间。

java 复制代码

@Bean
public Queue normalQueue(){
    return QueueBuilder.durable(NORMAL_QUEUE)
            .deadLetterExchange(DEAD_EXCHANGE)
            .deadLetterRoutingKey("dead.abc")
            .ttl(10000)
            .build();
}

基于设置Queue中的消息最大长度。

java 复制代码

@Bean
public Queue normalQueue(){
    return QueueBuilder.durable(NORMAL_QUEUE)
            .deadLetterExchange(DEAD_EXCHANGE)
            .deadLetterRoutingKey("dead.abc")
            .maxLength(1)
            .build();
}

5.3 延迟交换机

下载地址：https://github.com/rabbitmq/rabbitmq-delayed-message-exchange/releases/tag/3.8.9 ；

死信队列实现延迟消费时，如果延迟时间比较复杂，比较多，直接使用死信队列时，需要创建大量的队列还对应不同的时间，可以采用延迟交换机来解决这个问题。

构建延迟交换机

java 复制代码

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

import java.util.HashMap;
import java.util.Map;

/**
 * @author zjw
 * @description
 */
@Configuration
public class DelayedConfig {

    public static final String DELAYED_EXCHANGE = "delayed-exchange";
    public static final String DELAYED_QUEUE = "delayed-queue";
    public static final String DELAYED_ROUTING_KEY = "delayed.#";

    @Bean
    public Exchange delayedExchange(){
        Map<String, Object> arguments = new HashMap<>();
        arguments.put("x-delayed-type","topic");
        Exchange exchange = new CustomExchange(DELAYED_EXCHANGE,"x-delayed-message",true,false,arguments);
        return exchange;
    }

    @Bean
    public Queue delayedQueue(){
        return QueueBuilder.durable(DELAYED_QUEUE).build();
    }

    @Bean
    public Binding delayedBinding(Queue delayedQueue,Exchange delayedExchange){
        return BindingBuilder.bind(delayedQueue).to(delayedExchange).with(DELAYED_ROUTING_KEY).noargs();
    }
}

发送消息；

java 复制代码

import com.mashibing.rabbitmqboot.config.DelayedConfig;
import org.junit.jupiter.api.Test;
import org.springframework.amqp.AmqpException;
import org.springframework.amqp.core.Message;
import org.springframework.amqp.core.MessagePostProcessor;
import org.springframework.amqp.rabbit.core.RabbitTemplate;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;

@SpringBootTest
public class DelayedPublisherTest {

    @Autowired
    private RabbitTemplate rabbitTemplate;

    @Test
    public void publish(){
        rabbitTemplate.convertAndSend(DelayedConfig.DELAYED_EXCHANGE, "delayed.abc", "xxxx", new MessagePostProcessor() {
            @Override
            public Message postProcessMessage(Message message) throws AmqpException {
                message.getMessageProperties().setDelay(30000);
                return message;
            }
        });
    }
}

六、RabbitMQ集群

RabbitMQ的镜像模式。

6.1 搭建RabbitMQ集群

准备两台虚拟机（克隆）
准备RabbitMQ的yml文件

分别编写RabbitMQ的docker-compose文件。

XML 复制代码

version: '3.1'
services:
  rabbitmq1:
    image: rabbitmq:3.8.5-management-alpine
    container_name: rabbitmq1
    hostname: rabbitmq1
    extra_hosts:
      - "rabbitmq1:192.168.11.32"
      - "rabbitmq2:192.168.11.33"
    environment: 
      - RABBITMQ_ERLANG_COOKIE=SDJHFGDFFS
    ports:
      - 5672:5672
      - 15672:15672
      - 4369:4369
      - 25672:25672

rabbitmq2：

XML 复制代码

version: '3.1'
services:
  rabbitmq2:
    image: rabbitmq:3.8.5-management-alpine
    container_name: rabbitmq2
    hostname: rabbitmq2
    extra_hosts:
      - "rabbitmq1:192.168.11.32"
      - "rabbitmq2:192.168.11.33"
    environment: 
      - RABBITMQ_ERLANG_COOKIE=SDJHFGDFFS
    ports:
      - 5672:5672
      - 15672:15672
      - 4369:4369
      - 25672:25672

准备完毕之后，启动两台RabbitMQ。

让RabbitMQ服务实现join操作，需要再rabbitmq2执行4个命令，让rabbitmq2加入到rabbitmq1中。

XML 复制代码

rabbitmqctl stop_app
rabbitmqctl reset 
rabbitmqctl join_cluster rabbit@rabbitmq1
rabbitmqctl start_app

执行成功后：

镜像队列通过在RabbitMQ集群中的多个节点上复制队列的内容，确保即使某个节点发生故障，队列及其消息仍然可以从其他节点恢复。这种机制基于主从复制模式，其中一个节点作为领导者（Leader，或主节点Master），负责处理所有的写入操作和部分读取操作，而其余的节点作为跟随者（Followers，或副节点Slave），从领导者那里同步消息。

设置镜像模式：在指定的RabbitMQ服务中设置好镜像策略即可。

互联网全景消息(8)之RabbitMQ进阶介绍

一、RabbitMQ架构

二、RabbitMQ通讯方式

2.1 RabbitMQ提供的通讯方式

2.2 构建获取RabbitMQ的Connection工具类

2.3 hello world

2.4 Work Queues

2.5 Publish/Subscribe

2.6 Routing

2.7 Topic

三、SpringBoot操作RabbitMQ

3.1 SpringBoot声明信息

3.2 生产者

3.3 消费者

四、RabbitMQ保证消息的可靠性

4.1 如果保障消息可以到达Exchange

4.2 保证消息可以路由到 Queue

4.3 保证Queue可以持久化消息

4.4 保证消费者可以正常消费消息

4.5 Spring Boot实现RabbitMQ的消息可靠性

4.5.1Confirm

4.5.2 Return机制

4.5.3 消息持久化

五、RabbitMQ死信队列&延迟交换机

5.1 什么是死信队列

5.2 实现死信队列

5.2.1 准备Exchange&Queue

5.2.2 实现效果

5.3 延迟交换机

六、RabbitMQ集群

6.1 搭建RabbitMQ集群