SpringBoot使用RabbitMQ 详解SpringBoot中使用RabbitMQ的RPC功能
黑莹de希望 人气:0一、RabbitMQ的RPC简介
实际业务中,有的时候我们还需要等待消费者返回结果给我们,或者是说我们需要消费者上的一个功能、一个方法或是一个接口返回给我们相应的值,而往往大型的系统软件,生产者跟消费者之间都是相互独立的两个系统,部署在两个不同的电脑上,不能通过直接对象.方法的形式获取想要的结果,这时候我们就需要用到RPC(Remote Procedure Call)远程过程调用方式。
RabbitMQ实现RPC的方式很简单,生产者发送一条带有标签(消息ID(correlation_id)+回调队列名称)的消息到发送队列,消费者(也称RPC服务端)从发送队列获取消息并处理业务,解析标签的信息将业务结果发送到指定的回调队列,生产者从回调队列中根据标签的信息获取发送消息的返回结果。
如图,客户端C发送消息,指定消息的ID=rpc_id,回调响应的队列名称为rpc_resp,消息从C发送到rpc_request队列,服务端S获取消息业务处理之后,将correlation_id附加到响应的结果发送到指定的回调队列rpc_resp中,客户端从回调队列获取消息,匹配与发送消息的correlation_id相同的值为消息应答结果。
二、SpringBoot中使用RabbitMQ的RPC功能
注意:springboot中使用的时候,correlation_id为系统自动生成的,reply_to在加载AmqpTemplate实例的时候设置的。
实例:
说明:队列1为发送队列,队列2为返回队列
1.先配置rabbitmq
package com.ws.common; import org.springframework.amqp.core.Binding; import org.springframework.amqp.core.BindingBuilder; import org.springframework.amqp.core.Queue; import org.springframework.amqp.core.TopicExchange; import org.springframework.amqp.rabbit.connection.CachingConnectionFactory; import org.springframework.amqp.rabbit.connection.ConnectionFactory; import org.springframework.amqp.rabbit.core.RabbitTemplate; import org.springframework.amqp.rabbit.listener.SimpleMessageListenerContainer; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.beans.factory.annotation.Value; import org.springframework.context.annotation.Bean; import org.springframework.context.annotation.Configuration; /* * rabbitMQ配置类 */ @Configuration public class RabbitMQConfig { public static final String TOPIC_QUEUE1 = "topic.queue1"; public static final String TOPIC_QUEUE2 = "topic.queue2"; public static final String TOPIC_EXCHANGE = "topic.exchange"; @Value("${spring.rabbitmq.host}") private String host; @Value("${spring.rabbitmq.port}") private int port; @Value("${spring.rabbitmq.username}") private String username; @Value("${spring.rabbitmq.password}") private String password; @Autowired ConnectionFactory connectionFactory; @Bean(name = "connectionFactory") public ConnectionFactory connectionFactory() { CachingConnectionFactory connectionFactory = new CachingConnectionFactory(); connectionFactory.setHost(host); connectionFactory.setPort(port); connectionFactory.setUsername(username); connectionFactory.setPassword(password); connectionFactory.setVirtualHost("/"); return connectionFactory; } @Bean public RabbitTemplate rabbitTemplate() { RabbitTemplate rabbitTemplate = new RabbitTemplate(connectionFactory); //设置reply_to(返回队列,只能在这设置) rabbitTemplate.setReplyAddress(TOPIC_QUEUE2); rabbitTemplate.setReplyTimeout(60000); return rabbitTemplate; } //返回队列监听器(必须有) @Bean(name="replyMessageListenerContainer") public SimpleMessageListenerContainer createReplyListenerContainer() { SimpleMessageListenerContainer listenerContainer = new SimpleMessageListenerContainer(); listenerContainer.setConnectionFactory(connectionFactory); listenerContainer.setQueueNames(TOPIC_QUEUE2); listenerContainer.setMessageListener(rabbitTemplate()); return listenerContainer; } //创建队列 @Bean public Queue topicQueue1() { return new Queue(TOPIC_QUEUE1); } @Bean public Queue topicQueue2() { return new Queue(TOPIC_QUEUE2); } //创建交换机 @Bean public TopicExchange topicExchange() { return new TopicExchange(TOPIC_EXCHANGE); } //交换机与队列进行绑定 @Bean public Binding topicBinding1() { return BindingBuilder.bind(topicQueue1()).to(topicExchange()).with(TOPIC_QUEUE1); } @Bean public Binding topicBinding2() { return BindingBuilder.bind(topicQueue2()).to(topicExchange()).with(TOPIC_QUEUE2); } }
2.发送消息并同步等待返回值
@Autowired private RabbitTemplate rabbitTemplate; //报文body String sss = "报文的内容"; //封装Message Message msg = this.con(sss); log.info("客户端--------------------"+msg.toString()); //使用sendAndReceive方法完成rpc调用 Message message=rabbitTemplate.sendAndReceive(RabbitMQConfig.TOPIC_EXCHANGE, RabbitMQConfig.TOPIC_QUEUE1, msg); //提取rpc回应内容body String response = new String(message.getBody()); log.info("回应:" + response); log.info("rpc完成---------------------------------------------"); public Message con(String s) { MessageProperties mp = new MessageProperties(); byte[] src = s.getBytes(Charset.forName("UTF-8")); //mp.setReplyTo("adsdas"); 加载AmqpTemplate时设置,这里设置没用 //mp.setCorrelationId("2222"); 系统生成,这里设置没用 mp.setContentType("application/json"); mp.setContentEncoding("UTF-8"); mp.setContentLength((long)s.length()); return new Message(src, mp); }
3.写消费者
package com.ws.listener.mq; import java.nio.charset.Charset; import org.springframework.amqp.core.Message; import org.springframework.amqp.core.MessageProperties; import org.springframework.amqp.rabbit.annotation.RabbitListener; import org.springframework.amqp.rabbit.core.RabbitTemplate; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.stereotype.Component; import com.ws.common.RabbitMQConfig; import lombok.extern.slf4j.Slf4j; @Slf4j @Component public class Receiver { @Autowired private RabbitTemplate rabbitTemplate; @RabbitListener(queues=RabbitMQConfig.TOPIC_QUEUE1) public void receiveTopic1(Message msg) { log.info("队列1:"+msg.toString()); String msgBody = new String(msg.getBody()); //数据处理,返回的Message Message repMsg = con(msgBody+"返回了", msg.getMessageProperties().getCorrelationId()); rabbitTemplate.send(RabbitMQConfig.TOPIC_EXCHANGE, RabbitMQConfig.TOPIC_QUEUE2, repMsg); } @RabbitListener(queues=RabbitMQConfig.TOPIC_QUEUE2) public void receiveTopic2(Message msg) { log.info("队列2:"+msg.toString()); } public Message con(String s, String id) { MessageProperties mp = new MessageProperties(); byte[] src = s.getBytes(Charset.forName("UTF-8")); mp.setContentType("application/json"); mp.setContentEncoding("UTF-8"); mp.setCorrelationId(id); return new Message(src, mp); } }
日志打印:
2019-06-26 17:11:16.607 [http-nio-8080-exec-4] INFO com.ws.controller.UserController - 客户端--------------------(Body:‘报文的内容' MessageProperties [headers={}, contentType=application/json, contentEncoding=UTF-8, contentLength=5, deliveryMode=PERSISTENT, priority=0, deliveryTag=0])
2019-06-26 17:11:16.618 [SimpleAsyncTaskExecutor-1] INFO com.ws.listener.mq.Receiver - 队列1:(Body:‘报文的内容' MessageProperties [headers={}, correlationId=1, replyTo=topic.queue2, contentType=application/json, contentEncoding=UTF-8, contentLength=0, receivedDeliveryMode=PERSISTENT, priority=0, redelivered=false, receivedExchange=topic.exchange, receivedRoutingKey=topic.queue1, deliveryTag=1, consumerTag=amq.ctag-8IzlhblYmTebqUYd-uferw, consumerQueue=topic.queue1])
2019-06-26 17:11:16.623 [http-nio-8080-exec-4] INFO com.ws.controller.UserController - 回应:报文的内容返回了
2019-06-26 17:11:16.623 [http-nio-8080-exec-4] INFO com.ws.controller.UserController - rpc完成---------------------------------------------
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