java使用RabbitMQ实现延迟消息示例

package com.heima.stroke.configuration;

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;

@Configuration
public class RabbitConfig {
    // 延迟时间 单位：毫秒 (这里设为30秒)
    private static final long DELAY_TIME = 1000 * 30;

    // 行程超时队列
    public static final String STROKE_OVER_QUEUE = "STROKE_OVER_QUEUE";
    // 行程死信队列
    public static final String STROKE_DEAD_QUEUE = "STROKE_DEAD_QUEUE";

    // 行程超时队列交换机
    public static final String STROKE_OVER_QUEUE_EXCHANGE = "STROKE_OVER_QUEUE_EXCHANGE";
    // 行程死信队列交换机
    public static final String STROKE_DEAD_QUEUE_EXCHANGE = "STROKE_DEAD_QUEUE_EXCHANGE";

    // 行程超时交换机 Routing Key
    public static final String STROKE_OVER_KEY = "STROKE_OVER_KEY";
    // 行程死信交换机 Routing Key
    public static final String STROKE_DEAD_KEY = "STROKE_DEAD_KEY";

    /**
     * 声明行程超时队列，并设置其参数
     * x-dead-letter-exchange：绑定的死信交换机
     * x-dead-letter-routing-key：死信路由Key
     * x-message-ttl：消息的过期时间
     */
    @Bean
    public Queue strokeOverQueue() {
        Map<String, Object> args = new HashMap<>(3);
        args.put("x-dead-letter-exchange", STROKE_DEAD_QUEUE_EXCHANGE);
        args.put("x-dead-letter-routing-key", STROKE_DEAD_KEY);
        args.put("x-message-ttl", DELAY_TIME); // 设置TTL为30秒
        return QueueBuilder.durable(STROKE_OVER_QUEUE).withArguments(args).build();
    }

    @Bean
    public DirectExchange strokeOverQueueExchange() {
        return new DirectExchange(STROKE_OVER_QUEUE_EXCHANGE);
    }

    @Bean
    public Binding bindingStrokeOverDirect() {
        return BindingBuilder.bind(strokeOverQueue()).to(strokeOverQueueExchange()).with(STROKE_OVER_KEY);
    }
}

package com.heima.stroke.rabbitmq;

import com.alibaba.fastjson.JSON;
import com.heima.modules.vo.StrokeVO;
import com.heima.stroke.configuration.RabbitConfig;
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;

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

    @Autowired
    RabbitTemplate rabbitTemplate;

    /**
     * 发送延时消息到行程超时队列
     *
     * @param strokeVO 消息体
     */
    public void sendOver(StrokeVO strokeVO) {
        String mqMessage = JSON.toJSONString(strokeVO);
        logger.info("send timeout msg:{}", mqMessage);

        rabbitTemplate.convertAndSend(RabbitConfig.STROKE_OVER_QUEUE_EXCHANGE, RabbitConfig.STROKE_OVER_KEY, mqMessage);
    }
}

package com.heima.stroke.rabbitmq;

import com.alibaba.fastjson.JSON;
import com.heima.modules.vo.StrokeVO;
import com.heima.stroke.configuration.RabbitConfig;
import com.heima.stroke.handler.StrokeHandler;
import com.rabbitmq.client.Channel;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.amqp.rabbit.annotation.*;
import org.springframework.amqp.support.AmqpHeaders;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.messaging.handler.annotation.Header;
import org.springframework.stereotype.Component;

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

    @Autowired
    private StrokeHandler strokeHandler;

    /**
     * 监听死信队列
     *
     * @param message 消息体
     * @param channel RabbitMQ的Channel
     * @param tag 消息的Delivery Tag
     */
    @RabbitListener(
            bindings = {
                    @QueueBinding(
                            value = @Queue(value = RabbitConfig.STROKE_DEAD_QUEUE, durable = "true"),
                            exchange = @Exchange(value = RabbitConfig.STROKE_DEAD_QUEUE_EXCHANGE),
                            key = RabbitConfig.STROKE_DEAD_KEY)
            })
    @RabbitHandler
    public void processStroke(Message message, Channel channel, @Header(AmqpHeaders.DELIVERY_TAG) long tag) {
        StrokeVO strokeVO = JSON.parseObject(message.getBody(), StrokeVO.class);
        logger.info("get dead msg:{}", message.getBody());
        
        if (strokeVO == null) {
            return;
        }

        try {
            // 处理超时的行程消息
            strokeHandler.timeoutHandel(strokeVO);
            // 手动确认消息
            channel.basicAck(tag, false);
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}

public void timeoutHandel(StrokeVO strokeVO) {
    // 获取司机行程ID和乘客行程ID
    String inviterTripId = strokeVO.getInviterTripId();
    String inviteeTripId = strokeVO.getInviteeTripId();

    // 检查邀请状态是否为未确认
    String inviteeStatus = redisHelper.getHash(HtichConstants.STROKE_INVITE_PREFIX, inviteeTripId, inviterTripId);
    String inviterStatus = redisHelper.getHash(HtichConstants.STROKE_INVITE_PREFIX, inviterTripId, inviteeTripId);

    if (String.valueOf(InviteState.UNCONFIRMED.getCode()).equals(inviteeStatus) &&
        String.valueOf(InviteState.UNCONFIRMED.getCode()).equals(inviterStatus)) {
        // 更新为超时状态
        redisHelper.addHash(HtichConstants.STROKE_INVITE_PREFIX, inviteeTripId, inviterTripId, String.valueOf(InviteState.TIMEOUT.getCode()));
        redisHelper.addHash(HtichConstants.STROKE_INVITE_PREFIX, inviterTripId, inviteeTripId, String.valueOf(InviteState.TIMEOUT.getCode()));
    }
}