RabbitMQ备份交换机

1. 备份交换机

备份交换机可以理解为 RabbitMQ 中交换机的“备胎”，当我们为某一个交换机声明一个对应的备份交换机时，就是为它创建一个备胎，当交换机接收到一条不可路由消息时，将会把这条消息转发到备份交换机中，由备份交换机来进行转发和处理，通常备份交换机的类型为 Fanout ，这样就能把所有消息都投递到与其绑定的队列中，然后我们在备份交换机下绑定一个队列，这样所有那些原交换机无法被路由的消息，就会都进 入这个队列了。当然，我们还可以建立一个报警队列，用独立的消费者来进行监测和报警。

2.修改配置类

    //备份交换机
    public static final String BACKUP_EXCHANGE_NAME = "backup.exchange";

    //备份队列
    public static final String BACKUP_QUEUE_NAME = "backup.queue";

    //告警队列
    public static final String WARNING_QUEUE_NAME = "warning.queue";
    
    @Bean("backupExchange")
    public FanoutExchange backupExchange() {
        return new FanoutExchange(BACKUP_EXCHANGE_NAME);
    }

    // 声明确认队列
    @Bean("backupQueue")
    public Queue backupQueue() {
        return QueueBuilder.durable(BACKUP_QUEUE_NAME).build();
    }

    @Bean("warningQueue")
    public Queue warningQueue() {
        return QueueBuilder.durable(WARNING_QUEUE_NAME).build();
    }

    @Bean
    public Binding backupQueueBindingBackupQueue(@Qualifier("backupQueue") Queue backupQueue,
                                @Qualifier("backupExchange") FanoutExchange backupExchange) {
        return BindingBuilder.bind(backupQueue).to(backupExchange);
    }

    @Bean
    public Binding warningQueueBindingBackupQueue(@Qualifier("warningQueue") Queue warningQueue,
                                                 @Qualifier("backupExchange") FanoutExchange backupExchange) {
        return BindingBuilder.bind(warningQueue).to(backupExchange);
    }

3. 告警消费者

package com.hong.springboot.rabbitmq.consumer;

import com.hong.springboot.rabbitmq.config.ConfirmConfig;
import lombok.extern.slf4j.Slf4j;
import org.springframework.amqp.core.Message;
import org.springframework.amqp.rabbit.annotation.RabbitListener;
import org.springframework.stereotype.Component;

import java.text.SimpleDateFormat;
import java.util.Date;

/**
 * @Description: 告警消费者
 * @Author: hong
 * @Date: 2024-03-10 17:54
 * @Version: 1.0
 **/
@Slf4j
@Component
public class WarningConsumer {
    //接收告警消息
    @RabbitListener(queues = ConfirmConfig.WARNING_QUEUE_NAME)
    public void receiveWarningMessage(Message message){
        String msg = new String(message.getBody());
        log.info("当前时间：{},备用交换机收到不可路由信息{}",new SimpleDateFormat("yyyy-MM-dd HH:mm:ss").format(new Date()) , msg);
    }
}

先删了confirm.exchange交换机(改了配置)再启动项目，发送http://localhost:8080/confirm/sendMsg/Hi,JAVA小生不才