詳解SpringBoot中使用RabbitMQ的RPC功能

一、RabbitMQ的RPC簡介

實際業務中,有的時候我們還需要等待消費者返回結果給我們,或者是說我們需要消費者上的一個功能、一個方法或是一個接口返回給我們相應的值,而往往大型的系統軟件,生產者跟消費者之間都是相互獨立的兩個系統,部署在兩個不同的電腦上,不能通過直接對象.方法的形式獲取想要的結果,這時候我們就需要用到RPC(Remote Procedure Call)遠程過程調用方式。
RabbitMQ實現RPC的方式很簡單,生產者發送一條帶有標簽(消息ID(correlation_id)+回調隊列名稱)的消息到發送隊列,消費者(也稱RPC服務端)從發送隊列獲取消息並處理業務,解析標簽的信息將業務結果發送到指定的回調隊列,生產者從回調隊列中根據標簽的信息獲取發送消息的返回結果。

在這裡插入圖片描述

如圖,客戶端C發送消息,指定消息的ID=rpc_id,回調響應的隊列名稱為rpc_resp,消息從C發送到rpc_request隊列,服務端S獲取消息業務處理之後,將correlation_id附加到響應的結果發送到指定的回調隊列rpc_resp中,客戶端從回調隊列獲取消息,匹配與發送消息的correlation_id相同的值為消息應答結果。

二、SpringBoot中使用RabbitMQ的RPC功能

註意:springboot中使用的時候,correlation_id為系統自動生成的,reply_to在加載AmqpTemplate實例的時候設置的。

實例:
說明:隊列1為發送隊列,隊列2為返回隊列

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配置類
 */
@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);
    	//設置reply_to(返回隊列,隻能在這設置)
    	rabbitTemplate.setReplyAddress(TOPIC_QUEUE2);
    	rabbitTemplate.setReplyTimeout(60000);
    	return rabbitTemplate;
    }
    //返回隊列監聽器(必須有)
    @Bean(name="replyMessageListenerContainer")
    public SimpleMessageListenerContainer createReplyListenerContainer() {
         SimpleMessageListenerContainer listenerContainer = new SimpleMessageListenerContainer();
         listenerContainer.setConnectionFactory(connectionFactory);
         listenerContainer.setQueueNames(TOPIC_QUEUE2);
         listenerContainer.setMessageListener(rabbitTemplate());
         return listenerContainer;
    }
    

    
    //創建隊列
    @Bean
    public Queue topicQueue1() {
        return new Queue(TOPIC_QUEUE1);
    }
    @Bean
    public Queue topicQueue2() {
        return new Queue(TOPIC_QUEUE2);
    }
    
    //創建交換機
    @Bean
    public TopicExchange topicExchange() {
        return new TopicExchange(TOPIC_EXCHANGE);
    }
    
    //交換機與隊列進行綁定
    @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.發送消息並同步等待返回值

@Autowired
private RabbitTemplate rabbitTemplate;


//報文body
String sss = "報文的內容";
//封裝Message
Message msg = this.con(sss);
log.info("客戶端--------------------"+msg.toString());
//使用sendAndReceive方法完成rpc調用
Message message=rabbitTemplate.sendAndReceive(RabbitMQConfig.TOPIC_EXCHANGE, RabbitMQConfig.TOPIC_QUEUE1, msg);
//提取rpc回應內容body
String response = new String(message.getBody());
log.info("回應:" + 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");   加載AmqpTemplate時設置,這裡設置沒用
	//mp.setCorrelationId("2222");   系統生成,這裡設置沒用
	mp.setContentType("application/json");
	mp.setContentEncoding("UTF-8");
	mp.setContentLength((long)s.length());
	return new Message(src, mp);
} 

3.寫消費者

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("隊列1:"+msg.toString());
		String msgBody = new String(msg.getBody());
		//數據處理,返回的Message
		Message repMsg = con(msgBody+"返回瞭", msg.getMessageProperties().getCorrelationId());
		
		rabbitTemplate.send(RabbitMQConfig.TOPIC_EXCHANGE, RabbitMQConfig.TOPIC_QUEUE2, repMsg);
		
    }
	@RabbitListener(queues=RabbitMQConfig.TOPIC_QUEUE2)
	public void receiveTopic2(Message msg) {
		log.info("隊列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 – 客戶端——————–(Body:‘報文的內容’ 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 – 隊列1:(Body:‘報文的內容’ 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 – 回應:報文的內容返回瞭

2019-06-26 17:11:16.623 [http-nio-8080-exec-4] INFO com.ws.controller.UserController – rpc完成———————————————

到此這篇關於SpringBoot中使用RabbitMQ的RPC功能的文章就介紹到這瞭,更多相關SpringBoot使用RabbitMQ內容請搜索WalkonNet以前的文章或繼續瀏覽下面的相關文章希望大傢以後多多支持WalkonNet!

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