场景

用户下单后，如果30min未支付，则删除该订单，这时候就要可以用延迟队列

准备

利用rabbitmq_delayed_message_exchange插件；

首先下载该插件：https://www.rabbitmq.com/community-plugins.html

然后把该插件放到rabbitmq安装目录plugins下；

进入到sbin目录下，执行"rabbitmq-plugins.bat enable rabbitmq_delayed_message_exchange";

关闭RabbitMQ服务，然后再启动（直接重启该插件可能会不生效）。

SpringBoot RabbitMQ代码

application.properties配置文件

spring.application.name=spring-boot-rabbitmq
spring.rabbitmq.host=localhost
spring.rabbitmq.port=5672
spring.rabbitmq.username=nut
spring.rabbitmq.password=nut

配置类

注意这里的"x-delayed-type"和"x-delayed-message"

/**
 * 延迟队列配置exchange
 */
@Configuration
public class DelayQueueConfig {

    public static final String DELAY_EXCHANGE = "DELAY_EXCHANGE";
    public static final String DELAY_QUEUE = "DELAY_QUEUE";
    public static final String DELAY_ROUTING_KEY = "DELAY_ROUTING_KEY";

    @Bean("delayExchange")
    public Exchange delayExchange() {
        Map<String, Object> args = new HashMap<>(1);
//       x-delayed-type    声明 延迟队列Exchange的类型
        args.put("x-delayed-type", "direct");
        return new CustomExchange(DELAY_EXCHANGE, "x-delayed-message",true, false,args);
    }

    @Bean("delayQueue")
    public Queue delayQueue() {
        return QueueBuilder.durable(DELAY_QUEUE).build();
    }

    /**
     * 将延迟队列通过routingKey绑定到延迟交换器
     *
     * @return
     */
    @Bean
    public Binding delayQueueBindExchange() {
        return new Binding(DELAY_QUEUE, Binding.DestinationType.QUEUE, DELAY_EXCHANGE, DELAY_ROUTING_KEY, null);
    }

}

生产者

发送消息时，指定延迟的毫秒

/**
 * 延迟队列发送者
 */
@Component
@Slf4j
public class DelayQueueSender {

    @Autowired
    private RabbitTemplate rabbitTemplate;

    public void sendDelayQueue(int number) {
        log.warn("延迟队列发送 : {} milliseconds", number);
        // 这里的Exchange可以是业务的Exchange，为了方便测试这里直接往死信Exchange里投递消息
        rabbitTemplate.convertAndSend(
                DelayQueueConfig.DELAY_EXCHANGE,
                DelayQueueConfig.DELAY_ROUTING_KEY,
                number, (message) -> {
                    // 设置延迟的毫秒数
                    message.getMessageProperties().setDelay(number);
                    log.info("Now : {}", ZonedDateTime.now());
                    return message;
                });
    }
}

消费者

/**
 * 延迟队列消费者
 */
@Component
@Slf4j
@RabbitListener(queues = DelayQueueConfig.DELAY_QUEUE)
public class DelayQueueConsumer {

    @RabbitHandler
    public void receiveDelayMessage(Integer milliseconds){
        log.warn("DelayQueueConsumer Time : {}， and the millis : {}", ZonedDateTime.now(), milliseconds);

    }

}

测试

先启动项目；

然后在测试类中发送消息；

@RunWith(SpringRunner.class)
@SpringBootTest
public class RabbitmqApplicationTests {

    @Autowired
    private DelayQueueSender delayQueueSender;


    @Test
    public void testDelayQueueSender(){
        delayQueueSender.sendDelayQueue(5000);
    }
}