RabbitMQ消息的延迟队列详解

    /**
     * 普通交换机绑定普通交换机
     *
     * @return
     */
    @Bean
    public Queue queueA() {
        //信息配置
        Map<String, Object> map = new HashMap<>();
        //message在该队列queue的存活时间最大为15秒
        map.put("x-message-ttl", 15000);
        //x-dead-letter-exchange参数是设置该队列的死信交换器（DLX）
        map.put("x-dead-letter-exchange", "exchangeB");
        //x-dead-letter-routing-key参数是给这个DLX指定路由键
        map.put("x-dead-letter-routing-key", "queueB");
        return new Queue("queueA", true, false, false, map);
    }
    @Bean
    public DirectExchange exchangeA() {
        return new DirectExchange("exchangeA");
    }
    @Bean
    public Binding bindingA() {
        return BindingBuilder
                .bind(queueA())
                .to(exchangeA()).with("queueA");
    }
    /**
     * 死信交换机绑定死信交换机
     *
     * @return
     */
    @Bean
    public Queue queueB() {
        return new Queue("queueB");
    }
    @Bean
    public DirectExchange exchangeB() {
        return new DirectExchange("exchangeB");
    }
    @Bean
    public Binding bindingB() {
        return BindingBuilder
                .bind(queueB())
                .to(exchangeB()).with("queueB");
    }

    @RequestMapping("/send6")
    public String sendSix() throws JsonProcessingException {
        rabbitTemplate.convertAndSend("exchangeA", "queueA", "检查订单是否过期");
        return "🫶";
    }

package com.ycxw.consumer.demos;
import com.rabbitmq.client.Channel;
import org.springframework.amqp.rabbit.annotation.RabbitHandler;
import org.springframework.amqp.rabbit.annotation.RabbitListener;
import org.springframework.amqp.support.AmqpHeaders;
import org.springframework.messaging.handler.annotation.Header;
import org.springframework.stereotype.Component;
import java.io.IOException;
@Component
public class DLXReceiver {
    @RabbitListener(queues = {"queueA"})
    @RabbitHandler
    public void handlerA(String msg, Channel channel, @Header(AmqpHeaders.DELIVERY_TAG) long tag) throws IOException {
        System.out.println("已接受到队列queueA传递过来的消息：" + msg);
        channel.basicReject(tag, false);// 拒接消息，如果为true则拒绝后又从新回到队列被接受（循环），除非消息过期。
        //channel.basicAck(tag, true); 确认消息（）一次性全接受，如果为false则接受一次
    }
    /**
     * 接受死信消息
     *
     * @param msg
     */
    @RabbitListener(queues = {"queueB"})
    @RabbitHandler
    public void handlerB(String msg) {
        /**
         * ...接受到信息，去数据库处理
         */
        System.out.println("已接受到队列queueB传递过来的消息：" + msg);
    }
}