springboot使用RabbitMQ实现延时任务

延时队列顾名思义，即放置在该队列里面的消息是不须要当即消费的，而是等待一段时间以后取出消费。
那么，为何须要延迟消费呢？咱们来看如下的场景

订单业务： 在电商/点餐中，都有下单后 30 分钟内没有付款，就自动取消订单。
短信通知： 下单成功后 60s 以后给用户发送短信通知。
失败重试： 业务操做失败后，间隔必定的时间进行失败重试。

本文基于springboot，使用rabbitmq_delayed_message_exchange插件实现延时队列（RabbitMQ及其插件环境安装点此），具体实践以下：

application.properties

spring.rabbitmq.username=root
spring.rabbitmq.password=root
spring.rabbitmq.host=192.168.1.123
spring.rabbitmq.port=5672
spring.rabbitmq.virtual-host=test

XdelayConfig.java

import org.springframework.amqp.core.Binding;
import org.springframework.amqp.core.BindingBuilder;
import org.springframework.amqp.core.CustomExchange;
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 XdelayConfig {
 
    /**
     * 当即消费的队列名称
     */
    public static final String IMMEDIATE_QUEUE_XDELAY = "queue.xdelay.immediate";
    /**
     * 延时的exchange
     */
    public static final String DELAYED_EXCHANGE_XDELAY = "exchange.xdelay.delayed";
    public static final String DELAY_ROUTING_KEY_XDELAY = "routingkey.xdelay.delay";

    /**
     * 建立一个当即消费队列
     *
     * @return
     */
    @Bean
    public Queue immediateQueue() {
        // 第一个参数是建立的queue的名字，第二个参数是是否支持持久化
        return new Queue(IMMEDIATE_QUEUE_XDELAY, true);
    }

    @Bean
    public CustomExchange delayExchange() {
        Map<String, Object> args = new HashMap<String, Object>();
        args.put("x-delayed-type", "direct");
        return new CustomExchange(DELAYED_EXCHANGE_XDELAY, "x-delayed-message", true, false, args);
    }

    /**
     * 把当即消费的队列和延时消费的exchange绑定在一块儿
     *
     * @return
     */
    @Bean
    public Binding bindingNotify() {
        return BindingBuilder.bind(immediateQueue()).to(delayExchange()).with(DELAY_ROUTING_KEY_XDELAY).noargs();
    }
}

XdelaySender.java 生产者

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.amqp.rabbit.core.RabbitTemplate;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Component;

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

/**
 * 生产者
 */
@Component
public class XdelaySender {
    private final static Logger logger = LoggerFactory.getLogger(XdelaySender.class);
    @Autowired
    private RabbitTemplate rabbitTemplate;

    public void send(String msg, int delayTime) {
        logger.info("msg= " + msg + ".delayTime" + delayTime);
        SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
        this.rabbitTemplate.convertAndSend(XdelayConfig.DELAYED_EXCHANGE_XDELAY, XdelayConfig.DELAY_ROUTING_KEY_XDELAY, msg, message -> {
            message.getMessageProperties().setDelay(delayTime);
            System.out.println(sdf.format(new Date()) + " Delay sent.");
            return message;
        });
    }
}

XdelayReceiver.java 消费者

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

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

/**
 * 消费者
 */
@Component
@EnableRabbit
@Configuration
public class XdelayReceiver {
    private final static Logger logger = LoggerFactory.getLogger(XdelayReceiver.class);

    @RabbitListener(queues = com.example.antchat.rabbitmq.XdelayConfig.IMMEDIATE_QUEUE_XDELAY)
    public void get(String msg) {
        SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
        logger.info("收到延时消息时间：" + sdf.format(new Date()) + " Delay sent.");
        logger.info("收到延时消息:" + msg);
    }
}

测试

import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

@RestController
public class RabbitMQController {
    @Autowired
    XdelaySender xdelaySender;
    @RequestMapping("/testRabbit")
    public void testRabbit() {
        xdelaySender.send("我来发一个测试消息,10秒", 10000);//10秒
        xdelaySender.send("我来发一个测试消息，2秒", 2000);//2秒
        xdelaySender.send("我来发一个测试消息，1秒", 2000);//1秒
    }
}

参考博文：

微服务-springboot-rabbitmq:实现延时队列