springboot整合WebSocket

WebSocket通信过程

客户端构建一个websocket实例，并且为它绑定一个需要连接到的服务器地址，当客户端连接服务端的候，会向服务端发送一个http get报文，告诉服务端需要将通信协议切换到websocket，服务端收到http请求后将通信协议切换到websocket,同时发给客户端一个响应报文，返回的状态码为101，表示同意客户端协议转请求，并转换为websocket协议。以上过程都是利用http通信完成的，称之为websocket协议握手(websocket Protocol handshake)，经过握手之后，客户端和服务端就建立了websocket连接，以后的通信走的都是websocket协议了。

1.pom文件添加依赖

       
        
            org.springframework.boot
            spring-boot-starter-websocket

2.启用Springboot对WebSocket的支持

package com.lby.websocket.config;

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


@Configuration
public class WebSocketConfig {

    @Bean
    public ServerEndpointExporter serverEndpointExporter() {
        return new ServerEndpointExporter();
    }
}

3.核心配置：WebSocketServer

因为WebSocket是类似客户端服务端的形式(采用ws协议)，那么这里的WebSocketServer其实就相当于一个ws协议的Controller

@ ServerEndpoint 注解是一个类层次的注解，它的功能主要是将目前的类定义成一个websocket服务器端, 注解的值将被用于监听用户连接的终端访问URL地址,客户端可以通过这个URL来连接到WebSocket服务器端
新建一个ConcurrentHashMap webSocketMap 用于接收当前userId的WebSocket，方便传递之间对userId进行推送消息。

下面是具体业务代码：

package com.lby.websocket.component;

import org.apache.logging.log4j.LogManager;
import org.apache.logging.log4j.Logger;
import org.springframework.stereotype.Component;
import cn.hutool.core.util.StrUtil;
import javax.websocket.*;
import javax.websocket.server.PathParam;
import javax.websocket.server.ServerEndpoint;
import java.io.IOException;
import java.util.concurrent.ConcurrentHashMap;


@ServerEndpoint(value = "/websocket/{userId}")
@Component
public class WebSocket {
    private final static Logger logger = LogManager.getLogger(WebSocket.class);

    

    private static int onlineCount = 0;

    
    private static ConcurrentHashMap webSocketMap = new ConcurrentHashMap<>();

    

    private Session session;
    private String userId;


    
    @OnOpen
    public void onOpen(Session session, @PathParam("userId") String userId) {
        this.session = session;
        this.userId = userId;
        //加入map
        webSocketMap.put(userId, this);
        addOnlineCount();           //在线数加1
        logger.info("用户{}连接成功,当前在线人数为{}", userId, getOnlineCount());
        try {
            sendMessage(String.valueOf(this.session.getQueryString()));
        } catch (IOException e) {
            logger.error("IO异常");
        }
    }


    
    @OnClose
    public void onClose() {
        //从map中删除
        webSocketMap.remove(userId);
        subOnlineCount();           //在线数减1
        logger.info("用户{}关闭连接！当前在线人数为{}", userId, getOnlineCount());
    }

    
    @OnMessage
    public void onMessage(String message, Session session) {
        logger.info("来自客户端用户：{} 消息:{}",userId, message);

        //群发消息
        
    }

    
    @OnError
    public void onError(Session session, Throwable error) {
        logger.error("用户错误:" + this.userId + ",原因:" + error.getMessage());
        error.printStackTrace();
    }

    
    public void sendMessage(String message) throws IOException {
        this.session.getBasicRemote().sendText(message);
        //this.session.getAsyncRemote().sendText(message);
    }

    
    public void sendMessageByUserId(String userId, String message) throws IOException {
        logger.info("服务端发送消息到{},消息：{}",userId,message);
     if(StrUtil.isNotBlank(userId)&&webSocketMap.containsKey(userId)){
         webSocketMap.get(userId).sendMessage(message);
     }else{
         logger.error("用户{}不在线",userId);
     }

    }

    
    public static void sendInfo(String message) throws IOException {
        for (String item : webSocketMap.keySet()) {
            try {
                webSocketMap.get(item).sendMessage(message);
            } catch (IOException e) {
                continue;
            }
        }
    }

    public static synchronized int getOnlineCount() {
        return onlineCount;
    }

    public static synchronized void addOnlineCount() {
        WebSocket.onlineCount++;
    }

    public static synchronized void subOnlineCount() {
        WebSocket.onlineCount--;
    }

}

4.测试controller

package com.lby.websocket.controller;

import com.lby.websocket.component.WebSocket;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

import java.io.IOException;


@RestController
@RequestMapping("/webSocket")
public class WebSocketController {
    @Autowired
    private WebSocket webSocket;
    @PostMapping("/sentMessage")
    public void sentMessage(String userId,String message){
        try {
            webSocket.sendMessageByUserId(userId,message);
        } catch (IOException e) {
            e.printStackTrace();
        }

    }

}

5.webSocket网页客户端工具

http://websocket.jsonin.com/

复制三个tab

WebSocket地址分别输入后连接

ws://127.0.0.1:8092/websocket/1
ws://127.0.0.1.132:8092/websocket/2
ws://127.0.0.1.132:8092/websocket/3

6.通讯测试

1.往客户端发消息

127.0.0.1:8092/webSocket/sentMessage?userId=1&message=请进入视频会议
127.0.0.1:8092/webSocket/sentMessage?userId=2&message=请进入视频会议
127.0.0.1:8092/webSocket/sentMessage?userId=3&message=请进入视频会议

2.客户端收到消息回复“好的”

springboot整合WebSocket

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