基于RabbitMq的实现消息延时发送的优点以及其局限性；

#查看插件目录
rabbitmq-plugins list
#安装延迟队列插件 （rabbitmq-plugins enable 插件名）
rabbitmq-plugins enable rabbitmq_delayed_message_exchange

@Configuration
public class DelayedRabbitMQConfig {
  /**
     * 声明延时队列hangfire
     * 不设置TTL
     */
    @Bean("hDelayQueue")
    public Queue hangfireDelayQueue() {
        return new Queue(BaseDict.DELAY_QUEUE_NAME_H);
    }


    /**
     * 业务调用延迟队列
     *
     */
    @Bean("mDelayQueue")
    public Queue moduleDelayQueue() {
        return new Queue(BaseDict.DELAY_QUEUE_NAME_M);
    }


    /**
     * 延迟交换机
     *
     */
    @Bean(name = "delayExchange")
    public CustomExchange delayExchange() {
        Map<String, Object> args = new HashMap<>(2);
        args.put("x-delayed-type", "topic");
        return new CustomExchange(BaseDict.DELAY_EXCHANGE_DISPATCHER, "x-delayed-message", true, false, args);
    }


    @Bean
    public Binding hangfireBinding(@Qualifier("hDelayQueue") Queue queue,
                                   @Qualifier("delayExchange") CustomExchange customExchange) {
        return BindingBuilder.bind(queue).to(customExchange).with(BaseDict.DELAY_QUEUE_ROUTING_KEY_H).noargs();
    }


    @Bean
    public Binding moduleBinding(@Qualifier("mDelayQueue") Queue queue,
                                 @Qualifier("delayExchange") CustomExchange customExchange) {
        return BindingBuilder.bind(queue).to(customExchange).with(BaseDict.DELAY_QUEUE_ROUTING_KEY_M).noargs();
    }
}

    @PostMapping("addMsgToMDelayQueue")
    public void addMsgToMQueue(@RequestBody XXX request) {
        sendDelayMsg(BaseDict.DELAY_EXCHANGE_DISPATCHER,BaseDict.DELAY_QUEUE_ROUTING_KEY_M, JSONObject.toJSONString(request), 10*24*60*60*1000);
    }



    @PostMapping("addMsgToHDelay")
    public void addMsgToHQueue(@RequestBody List<AAA> request) {
        sendDelayMsg(BaseDict.DELAY_EXCHANGE_DISPATCHER,BaseDict.DELAY_QUEUE_ROUTING_KEY_H, JSONObject.toJSONString(request), 10*24*60*60*1000);
    }


    /**
     * 消息发送到延迟交换机上
     */
    public void sendDelayMsg(String exchange,String routingKey, String msg, Integer delayTime) {
        rabbitTemplate.convertAndSend(exchange, routingKey, msg, a -> {
            a.getMessageProperties().setDelay(delayTime);
            return a;
        });
    }

@RabbitListener(queues = BaseDict.DELAY_QUEUE_NAME_H, concurrency = "10-30")
    public void hangfireReceive(Message message, Channel channel) throws IOException {
        final List<AAA> sendDetails = JSONObject.parseArray(JSONObject.toJSONString(message.getBody()), AAA.class);
        Optional.ofNullable(sendDetails).ifPresent(item->item.forEach(System.out::println));
    }


    @RabbitListener(queues = BaseDict.DELAY_QUEUE_NAME_M, concurrency = "10-20")
    public void receiveQ(Message message, Channel channel) throws IOException {
        final XXX request = JSONObject.parseObject(message.getBody(), XXX.class);
        System.out.println("消费"+request.toString());
    }