SpringCloud、RabbitMQ、Websocket集群搭建以及集群通信

最近遇到了一个难题，搭建websocket集群实现消息推送，在这之前基本没接触过websocket和集群问题，这次找了很多资料和博文，在经历了几天的研究和设计实现了websocket集群的搭建和集群的通信。

一、环境准备

软件方面：主要是Erlang+RabbitMQ得提前安装好。不知道如何安装的可以转到我的文章查看。Erlang及RabbitMQ下载安装

二、设计思路

①集群的实现我使用spring-cloud-gateway、Spring-cloud-alibaba等框架实现，设计基于微服务架构的集群。网关可以使用nacos配置中心实现负载均衡。

②集群方案解决了，接着便是集群通信了，在这之前我看了很多博文，因为websocket的session不支持序列化，导致不能使用Redis存储session二次利用，大佬们提供了许多解决集群通信的方式：比如提取公共服务创建Map对象来保存session进行调用，或者使用RabbitMQ中间件进行消息传递，实现集群消息共享，当然肯定不止以上两种方法，大家有好的建议欢迎留言，我也乐于尝试，我使用的是RabbitMQ中间件。

③实现流程：做的一个小案例，用户之间处于不同的服务器上，最终实现了指定用户发送消息和群体发送消息。

三、代码实现

1、父项目exam-web-net依赖

    
    
        exam-web-gateway
        exam-web-websocket
    
    
     1.16.18
     2.1.6.RELEASE
     2.1.0.RELEASE
     Greenwich.SR5
    
    
        
            
                org.springframework.boot
                spring-boot-dependencies
                ${spring-boot.version}
                pom
                import
            
            
                org.springframework.cloud
                spring-cloud-dependencies
                ${spring-cloud.version}
                pom
                import
            
            
                com.alibaba.cloud
                spring-cloud-alibaba-dependencies
                ${spring-cloud-alibaba.version}
                pom
                import
            
        
    

2、子项目

①exam-web-gateway 

    
        
        
            com.alibaba.cloud
            spring-cloud-alibaba-nacos-discovery
        
        
        
            com.alibaba.cloud
            spring-cloud-alibaba-nacos-config
        
        
        
            org.springframework.cloud
            spring-cloud-starter-gateway
            2.1.5.RELEASE
        
    

网关主要是用于统一管理集群入口，根据断言进行匹配转发至对应的集群服务器，比较重要的是yaml文件配置，同时创建一个启动类即可：

spring:
  application:
    name: gateway-server
  cloud:
    nacos:
      discovery:
        # 服务地址和端口
        server-addr: localhost:8812
        namespace: 05c28632-9826-4852-83ff-9315fb619084 #dev
      config:
        server-addr: localhost:8812
        namespace: 05c28632-9826-4852-83ff-9315fb619084 #dev
        file-extension: yaml
        group: DEV_GROUP #dev
    gateway:
      #路由规则
      routes:
        - id: setstatus_route # - 表示该数据为一个集合  存在多个
          # lb负载均衡 从注册中心读取服务进行使用
          uri: lb://websocket-server #websocket服务ID
          predicates:
            - Path=/demo/**

启动类

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;

/**
 * @author secondj
 * @Date 2021/10/26 14:17
 */
@SpringBootApplication
public class GateWayApplication {
    public static void main(String[] args) {
        SpringApplication.run(GateWayApplication.class,args);
    }
}

②exam-web-websocke

这里RabbitMQ配置用到了该博主的代码，在自己的需求下进行了改造

pom依赖

        
            org.springframework.boot
            spring-boot-starter-web
        
        
            com.alibaba.cloud
            spring-cloud-alibaba-nacos-discovery
        
        
            com.alibaba.cloud
            spring-cloud-alibaba-nacos-config
        
        
            org.projectlombok
            lombok
        
        
            org.springframework.boot
            spring-boot-starter-websocket
        
        
            org.springframework.boot
            spring-boot-starter-amqp
        
        
            com.alibaba
            fastjson
            1.2.9
        
    

websocket配置类

import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.web.socket.server.standard.ServerEndpointExporter;

/**
 * @author secondj
 * @Date 2021/10/26 9:18
 */
@Configuration
public class WebSocketConfig {
    /**
     * serverEndpointExporter作用
     * 这个bean会自动注册使用@serverEndpoint注解声明的websocket， endpoint
     * @return
     */
    @Bean
    public ServerEndpointExporter serverEndpointExporter(){
        return new ServerEndpointExporter();
    }
}

websocket服务

import *.*.*.websocket.result.MessageResult;
import *.*.*.websocket.service.WebSocketService;
import com.alibaba.fastjson.JSONObject;
import lombok.extern.slf4j.Slf4j;
import org.springframework.context.ApplicationContext;
import org.springframework.stereotype.Component;
import javax.websocket.*;
import javax.websocket.server.PathParam;
import javax.websocket.server.ServerEndpoint;
import java.util.Map;
import java.util.Set;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.atomic.AtomicInteger;

/**
 * @author secondj
 * @Date 2021/10/26 9:20
 */
//encoder为自定义解码器，因为websocket返回对象默认只能为String,byte[]和可序列化的对象，可实现自定义类实现序列化接口并编写该接口的解码器
@ServerEndpoint(value = "/webSocket/{sid}",encoders = {EncoderServer.class})
@Component
@Slf4j
public class WebSocketServer {

    public static ConcurrentHashMap electricSocketMap = new ConcurrentHashMap();
    /**
     * 此处是解决无法注入的关键
     */
    private static ApplicationContext applicationContext;

    private AtomicInteger ati = new AtomicInteger();

    public static void setApplicationContext(ApplicationContext applicationContext) {
       WebSocketServer.applicationContext = applicationContext;
    }

    @OnOpen
    public void open(@PathParam("sid")String sid,Session session){
        electricSocketMap.put(sid,session);
        Set> entries = electricSocketMap.entrySet();
        for (Map.Entry entry : entries) {
            System.out.println(entry.getKey()+"的session值为"+entry.getValue());
        }
        System.out.println("websocket连接成功,用户编号为"+sid);

    }

    @OnClose
    public void close(@PathParam("sid")String sid,Session session){
        Set> entries = electricSocketMap.entrySet();
        for (Map.Entry entry : entries) {
            int value = ati.getAndIncrement();
            System.out.println(value+"号为"+entry.getValue()+"Key为"+entry.getKey());
        }
        if(electricSocketMap.containsKey(sid)){
            electricSocketMap.remove(sid);
            System.out.println(String.format("--{%s}{%s}---",sid,"已断开链接"));
        }
    }

    /**
     * message:{toUserId,msgInfo,msgType}
     * 如果发送状态为1:表示单独返送
     * 如果发送状态为2:表示群体发送
     * @param message
     * @param session
     */
    @OnMessage
    public void onMessage(@PathParam("sid")String sid, String message, Session session) {
        WebSocketService websocketService = applicationContext.getBean(WebSocketService.class);
        System.out.println("websocket received message:"+message);
        MessageResult messageResult = JSONObject.parseObject(message,MessageResult.class);

        if(messageResult.getToUserId() != null){
            sid = messageResult.getToUserId();
        }

        if(electricSocketMap.containsKey(sid)){
            if(messageResult.getMsgType() == 1){
                session = electricSocketMap.get(sid);
                sendMsg(session,messageResult);
            }else {
                Set> entries = electricSocketMap.entrySet();
                for (Map.Entry entry : entries) {
                    sendMsg(entry.getValue(),messageResult);
                }
            }
        }
        else{
            if(messageResult.getMsgType() == 1){
                websocketService.send(sid,messageResult);
            }else{
                websocketService.sendAll(electricSocketMap,messageResult);
            }
        }
    }

    @OnError
    public void onError(Session session, Throwable error) {
        error.printStackTrace();
        System.out.println("发生错误");
    }

    /**
     *
     * @param session
     * @param message 消息结果集
     */
    public static void sendMsg(Session session, MessageResult message) {
        try {
            session.getBasicRemote().sendObject(message);
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    /**
     * 群发消息
     * @param message 消息内容
     */
    private void sendAll(MessageResult message) {
        WebSocketService websocketService = applicationContext.getBean(WebSocketService.class);
        websocketService.sendAll(electricSocketMap,message);
    }
}

MessageResult实体类

import lombok.Data;
import java.io.Serializable;

/**
 * @author secondj
 * @Date 2021/11/3 9:32
 */
@Data
public class MessageResult implements Serializable {
    private static final long serialVersionUID = 7849057146501910808L;
    private String toUserId;
    private String msgInfo;
    private int msgType;
    public MessageResult(){

    }
    public MessageResult(String toUserId,String msgInfo,int msgType){
        this.toUserId = toUserId;
        this.msgInfo = msgInfo;
        this.msgType = msgType;
    }
}

EncoderServer解码器

import *.*.*.websocket.result.MessageResult;
import net.sf.json.JSONObject;

import javax.websocket.EncodeException;
import javax.websocket.Encoder;
import javax.websocket.EndpointConfig;

/**
 * @author secondj
 * @Date 2021/11/3 11:04
 */
public class EncoderServer implements Encoder.Text {
    @Override
    public String encode(MessageResult messageResult) throws EncodeException {
        JSONObject jsonObject = JSONObject.fromObject(messageResult);
        return jsonObject.toString();
    }

    @Override
    public void init(EndpointConfig endpointConfig) {

    }

    @Override
    public void destroy() {

    }
}

WebSocketService

import *.*.*.websocket.result.MessageResult;
import *.*.*.websocket.sender.FanoutSender;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

import javax.websocket.Session;
import java.util.HashMap;
import java.util.Map;

/**
 * @author secondj
 * @Date 2021/11/3 9:28
 */
@Service
public class WebSocketService {
    @Autowired
    private FanoutSender fanoutSender;

    public  void send(String id, MessageResult message) {
        Map map=new HashMap<>();
        map.put(id,message);
        fanoutSender.sendMessage(map);
    }

    public void sendAll(Map electricSocketMap, MessageResult message) {
        Map map=new HashMap<>();
        for (Map.Entry sessionEntry : electricSocketMap.entrySet()) {
            map.put(sessionEntry.getKey(),message);
        }
        fanoutSender.sendMessage(map);
    }
}

ExchangeConfiguration创建交换机和队列

import *.*.*.websocket.config.ServerConfig;
import *.*.*.websocket.entity.Constants;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.amqp.core.Binding;
import org.springframework.amqp.core.BindingBuilder;
import org.springframework.amqp.core.FanoutExchange;
import org.springframework.amqp.core.Queue;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;

/**
 * @author secondj
 * @Date 2021/11/3 9:35
 */
@Configuration
public class ExchangeConfiguration {

    private static Logger logger = LoggerFactory.getLogger(ExchangeConfiguration.class);

    @Autowired
    private ServerConfig serverConfig;

    @Bean
    public FanoutExchange fanoutExchange() {
        logger.info("【【【交换机实例创建成功】】】");
        return new FanoutExchange(Constants.FANOUT_EXCHANGE_NAME);
    }

    @Bean
    public Queue queue() {
        logger.info("【【【队列实例创建成功】】】");
        //动态名称
        return new Queue(Constants.TEST_QUEUE1_NAME+"——"+serverConfig.getUrl());
    }

    @Bean
    public Binding bingQueue1ToExchange() {
        logger.info("【【【绑定队列到交换机成功】】】");
        return BindingBuilder.bind(queue()).to(fanoutExchange());
    }

}

Constants常量

package *.*.*.websocket.entity;

/**
 * @author secondj
 * @Date 2021/11/3 9:36
 */
public class Constants {
    /**
     * 交换机名称
     */
    public static final String FANOUT_EXCHANGE_NAME = "fanout.exchange.name";

    /**
     * 测试队列名称
     */
    public static final String TEST_QUEUE1_NAME = "test.queue1.name";
}

FanoutSender发布消息

package *.*.*.websocket.sender;

import *.*.*.websocket.entity.Constants;
import *.*.*.websocket.result.MessageResult;
import net.sf.json.JSONObject;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.amqp.rabbit.core.RabbitTemplate;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Component;

import java.util.Map;

/**
 * rabbitMQ提供者
 * @author secondj
 * @Date 2021/11/3 9:46
 */
@Component
public class FanoutSender {

    private static Logger logger = LoggerFactory.getLogger(FanoutSender.class);

    @Autowired
    private RabbitTemplate rabbitTemplate;

    public void sendMessage(Map rabbitMessageList) {
        logger.info("【消息发送者】发送消息到fanout交换机，");
        rabbitTemplate.convertAndSend(Constants.FANOUT_EXCHANGE_NAME, "", JSONObject.fromObject(rabbitMessageList).toString());
    }

}

FanoutReceiver订阅消息

package *.*.*.websocket.receiver;

import *.*.*.websocket.result.MessageResult;
import *.*.*.websocket.server.WebSocketServer;

import com.alibaba.fastjson.JSONObject;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.amqp.rabbit.annotation.RabbitHandler;
import org.springframework.amqp.rabbit.annotation.RabbitListener;
import org.springframework.stereotype.Component;
import javax.websocket.Session;
import java.util.Map;
import java.util.Set;

/**
 * @author secondj
 * @Date 2021/11/3 9:55
 */
@Component
public class FanoutReceiver {
    private static Logger logger = LoggerFactory.getLogger(FanoutReceiver.class);

    @RabbitHandler
    @RabbitListener(queues = "#{queue.name}")//动态绑定
    public void receiveMessage(String jsonObject) {
        Map map = JSONObject.parseObject(jsonObject,Map.class);
        Set> entries = map.entrySet();
        for (Map.Entry entry : entries) {
            logger.info("消息接收者接收到来自【队列一】的消息，消息内容: "+jsonObject);
            Map electricSocketMap = WebSocketServer.electricSocketMap;
            if(electricSocketMap.containsKey(entry.getKey())){
                Object obj = map.get(entry.getKey());
                MessageResult result = (MessageResult) JSONObject.parseObject(obj.toString(),MessageResult.class);
                System.out.println(entry.getKey()+"的值为"+entry.getValue());
                WebSocketServer.sendMsg(electricSocketMap.get(entry.getKey()),result);
            }
        }
    }
}

html代码

    
    



hello socket
【userId】：

【toUserId】：

【msgType】：

【msgInfo】：

【操作】:
开启socket
【操作】：
发送消息

四、出现的问题及解决方案

1、websocketServer中无法注入WebSocketService的实例。

可以在主启动类中对sebsocketServer的静态变量websocketService进行手动赋值，把websocketService实例手动存放到容器中去，再在容器中根据类名进行引用即可。

主启动类：

import *.*.*.websocket.server.WebSocketServer;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.context.ConfigurableApplicationContext;

/**
 * @author secondj
 * @Date 2021/10/26 14:06
 */
@SpringBootApplication
public class WebSocketApplication {
    public static void main(String[] args) {
        SpringApplication springApplication = new SpringApplication(WebSocketApplication.class);
        ConfigurableApplicationContext configurableApplicationContext = springApplication.run(args);
        //解决websocket无法注入问题
        WebSocketServer.setApplicationContext(configurableApplicationContext);
    }
}

2、fastJson转换VO对象失败

原因是fastJson转换后的对象与原对象的toString方法冲突，导致fastJson提示cantconvert错误，可以先把fastJson转换后的对象先转为Object类，再使用根据类强制转换的方法:JSONObjecet.parseObject(String text,Class clazz)进行转换。

public void receiveMessage(String jsonObject) {
        Map map = JSONObject.parseObject(jsonObject,Map.class);
        Set> entries = map.entrySet();
        for (Map.Entry entry : entries) {
            logger.info("消息接收者接收到来自【队列一】的消息，消息内容: "+jsonObject);
            Map electricSocketMap = WebSocketServer.electricSocketMap;
            if(electricSocketMap.containsKey(entry.getKey())){
                Object obj = map.get(entry.getKey());
                MessageResult result = (MessageResult) JSONObject.parseObject(obj.toString(),MessageResult.class);
                System.out.println(entry.getKey()+"的值为"+entry.getValue());
                WebSocketServer.sendMsg(electricSocketMap.get(entry.getKey()),result);
            }
        }
    }

以上就是简单集群通信的准备和实现，作为一个学习记录。

下一篇中添加了接收websocket消息的另一种方式以及websocket拦截器的使用。

实现Websocket集群及通信的第二种方式（含拦截器）