RabbitMQ延迟队列实现

前言代码

依赖application.yml配置消费者写测试类

在电商项目中，当我们下单之后，一般需要 20 分钟之内或者 30 分钟之内付款，否则订单就会进入异常处理逻辑中，被取消，那么进入到异常处理逻辑中，就可以当成是一个延迟队列。很多场景下我们都需要延迟队列，本文我们就用RabbitMQ自带的延时和死信机制来实现延时队列。

        
            org.springframework.boot
            spring-boot-starter-amqp
        
        
            org.springframework.boot
            spring-boot-starter-web
        

server:
  port: 8021
spring:
  #给项目来个名字
  application:
    name: rabbitmq-provider
  #配置rabbitMq 服务器
  rabbitmq:
    host: 
    port: 5672
    username: guest
    password: guest

配置个普通队列和死信队列

import org.springframework.amqp.core.Binding;
import org.springframework.amqp.core.BindingBuilder;
import org.springframework.amqp.core.DirectExchange;
import org.springframework.amqp.core.Queue;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;

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

@Configuration
public class DDLQueueConfig {
    public static final String JAVABOY_QUEUE_NAME = "javaboy_queue_name";
    public static final String JAVABOY_EXCHANGE_NAME = "javaboy_exchange_name";
    public static final String JAVABOY_ROUTING_KEY = "javaboy_routing_key";
    public static final String DLX_QUEUE_NAME = "dlx_queue_name";
    public static final String DLX_EXCHANGE_NAME = "dlx_exchange_name";
    public static final String DLX_ROUTING_KEY = "dlx_routing_key";

    
    @Bean
    Queue dlxQueue() {
        return new Queue(DLX_QUEUE_NAME, true, false, false);
    }

    
    @Bean
    DirectExchange dlxExchange() {
        return new DirectExchange(DLX_EXCHANGE_NAME, true, false);
    }

    
    @Bean
    Binding dlxBinding() {
        return BindingBuilder.bind(dlxQueue()).to(dlxExchange())
                .with(DLX_ROUTING_KEY);
    }

    
    @Bean
    Queue javaboyQueue() {
        Map args = new HashMap<>();
        //设置消息过期时间
        args.put("x-message-ttl", 1000 * 10);
        //设置死信交换机
        args.put("x-dead-letter-exchange", DLX_EXCHANGE_NAME);
        //设置死信 routing_key
        args.put("x-dead-letter-routing-key", DLX_ROUTING_KEY);
        return new Queue(JAVABOY_QUEUE_NAME, true, false, false, args);
    }

    
    @Bean
    DirectExchange javaboyExchange() {
        return new DirectExchange(JAVABOY_EXCHANGE_NAME, true, false);
    }

    
    @Bean
    Binding javaboyBinding() {
        return BindingBuilder.bind(javaboyQueue())
                .to(javaboyExchange())
                .with(JAVABOY_ROUTING_KEY);
    }
}

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.amqp.rabbit.annotation.RabbitListener;
import org.springframework.stereotype.Component;

@Component
public class DlxConsumer {
    private static final Logger logger = LoggerFactory.getLogger(DlxConsumer.class);

    @RabbitListener(queues = DDLQueueConfig.DLX_QUEUE_NAME)
    public void handle(String msg) {
        logger.info(msg);
    }
}

然后启动

    @Autowired
    RabbitTemplate rabbitTemplate;

    @Test
    void contextLoads() {
        System.out.println(new Date());
        rabbitTemplate.convertAndSend(DDLQueueConfig.JAVABOY_EXCHANGE_NAME,
                DDLQueueConfig.JAVABOY_ROUTING_KEY, "hello javaboy!");
    }

这个就没啥好说的了，就是普通的消息发送，10 秒之后这条消息会在死信队列的消费者中被打印出来。