RabbitMQ延迟消息（通过死信交换机实现）

延迟消息：生产者发送消息时指定一个时间，消费者不会立刻收到消息，而是在指定时间后才收到消息

通过DLX和TTL模拟出延迟队列的功能，即，消息发送以后，不让消费者拿到，而是等待过期时间，变成死信后，发送给死信交换机再路由到死信队列进行消费

1、声明延迟队列

package com.smart.wms.config.rabbitmq;import org.springframework.amqp.core.*;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;/*** 功能描述:* 配置交换机、队列、绑定关系* @Authoer: bgq* @Date:2024/6/4 17:33*/
@Configuration
public class MaterialStockExchangeConfig {public static final String MATERIAL_STOCK_EXCHANGE = "wms.material.exchange";public static final String MATERIAL_STOCK_QUEUE = "wms.material.queue";public static final String MATERIAL_DLX_DIRECT_EXCHANGE = "wms.dlx.exchange";public static final String MATERIAL_DLX_QUEUE = "wms.dlx.queue";public static final String MATERIAL_TTL__ROUTING_KEY = "ttl";public static final String MATERIAL_DLX_DELAYED_KEY = "dlx";@Beanpublic Queue ttlQueue() {return QueueBuilder.durable(MATERIAL_STOCK_QUEUE) // 指定队列的名称.ttl(10000) // 指定 TTL 为 10 秒,这里可设置过期时间也可以在发送消息时设置过期时间.deadLetterExchange(MATERIAL_DLX_DIRECT_EXCHANGE) // 指定死信交换机.deadLetterRoutingKey(MATERIAL_DLX_DELAYED_KEY) // 指定死信交换机的 RoutingKey.build();}/*** 声明TTl交换机*/@Beanpublic DirectExchange directExchange(){return new DirectExchange(MATERIAL_STOCK_EXCHANGE);}/*** 声明ttl交换机与队列的关联关系*/@Beanpublic Binding directBinding(){return BindingBuilder.bind(ttlQueue()).to(directExchange()).with(MATERIAL_TTL__ROUTING_KEY);}/*** 声明死信交换机*/@Beanpublic DirectExchange dlxDirect(){return new DirectExchange(MATERIAL_DLX_DIRECT_EXCHANGE);}/*** 声明死信队列*/@Beanpublic Queue dlxQueue(){return new Queue(MATERIAL_DLX_QUEUE);}/*** 声明死信交换机与队列关联关系*/@Beanpublic Binding tlxBinding(){return BindingBuilder.bind(dlxQueue()).to(dlxDirect()).with(MATERIAL_DLX_DELAYED_KEY);}}

2、监听死信队列消费

@RabbitListener(queues = MaterialStockExchangeConfig.MATERIAL_DLX_QUEUE)//监听的队列public void process(Message message, Channel channel) throws Exception {// 进入消息消费业务逻辑String body = new String(message.getBody());log.info("消息，参数：{}",body);JSONObject bodyJson = JSONUtil.parseObj(body);//业务逻辑TODOchannel.basicAck(message.getMessageProperties().getDeliveryTag(), false);
}

3、发送消息

@RequestMapping("/sendTTLMessage")
public void  sendTTLMessage(){JSONObject jsonObject = new JSONObject();jsonObject.putOpt("orderId",wmsSendOrder.getId());rabbitMQSendUtils.sendMessage(MaterialStockExchangeConfig.MATERIAL_STOCK_EXCHANGE,             MaterialStockExchangeConfig.MATERIAL_TTL__ROUTING_KEY, jsonObject, wmsSendOrder.getId().toString());log.info("消息发送成功！");
}