rabbitmq 高级特性死信队列(死信交换机)

概念

信息成为死信的3种情况

代码实现

实现死信队列需要一组正常队列和交换机以及死信队列和死信交换机
但是声明死信交换机和队列和正常声明一致
最关键的是在声明要被处理的正常队列给出两个参数(deadLetterExchange,deadLetterRoutingKey)来绑定关系

package com.jie.config;

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

@Configuration
public class RabbitMQConfig {
    public static final String EXCHANGE_NAME = "boot_topic_exchange";
    public static final String QUEUE_NAME = "boot_queue";

    public static final String DLX_EXCHANGE_NAME = "dlx_boot_topic_exchange";
    public static final String DLX_QUEUE_NAME = "dlx_boot_queue";
    //交换机
    @Bean("bootExchange")
    public Exchange bootExchange(){
        return ExchangeBuilder.topicExchange(EXCHANGE_NAME).durable(true).build();
    }
    //队列
    @Bean("bootQueue")
    public Queue bootQueue(){
        return QueueBuilder
                .durable(QUEUE_NAME)
                //绑定对应的死信交换机
                .deadLetterExchange(DLX_EXCHANGE_NAME)
                //死信交换机设置的key为dlx.# 这里我们任意给出一个能被匹配的
                .deadLetterRoutingKey("dlx.hh")
                //设置10秒过期时间
                .ttl(10000)
                .build();
    }
    //绑定关系
    @Bean
    public Binding bingQueueExchange(@Qualifier("bootQueue") Queue queue,@Qualifier("bootExchange") Exchange exchange){
        return BindingBuilder.bind(queue).to(exchange).with("boot.#").noargs();
    }

    //死信交换机
    @Bean("bootDlxExchange")
    public Exchange bootDlxExchange(){
        return ExchangeBuilder.topicExchange(DLX_EXCHANGE_NAME).durable(true).build();
    }
    //死信队列
    @Bean("bootDlxQueue")
    public Queue bootDlxQueue(){
        return QueueBuilder.durable(DLX_QUEUE_NAME).build();
    }
    //绑定死信队列和死信交换机关系
    @Bean
    public Binding commonDeadLetterExchange(@Qualifier("bootDlxQueue")Queue queue,@Qualifier("bootDlxExchange")Exchange exchange){
        return BindingBuilder.bind(queue).to(exchange).with("dlx.#").noargs();
    }
}

测试过期时间死信队列

在上面声明中我们已经吧正常队列定义为TTL队列过期时间为10秒我们发信息测试一下

    @Test void send(){
        for (int i = 0; i < 10; i++) {
            rabbitTemplate.convertAndSend(RabbitMQConfig.EXCHANGE_NAME,"boot.haha","10秒后我就死了呜呜呜 "+i);
        }
    }

信息未过期时信息在原先的队列

10秒后信息过期于是触发死信机制队列给绑定的死信交换机发送消息对应的路由key为dlx.hh(上面配置定义的)

而死信交换机和死信队列绑定的路由Key为dlx.# 于是被匹配到消息成功进到死信队列里面