How to use WebSocket+SpringBoot+Vue to build a simple web chat room

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

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

/** 
* @Author：WSKH 
* @ClassName：WebSocketConfig 
* @ClassType：配置类 
* @Description：WebSocket配置类 
* @Date：2022/1/25/12:21 
* @Email：1187560563@qq.com 
* @Blog：https://blog.csdn.net/weixin_51545953?type=blog 
*/

@Configuration
public class WebSocketConfig {
    /** * 开启webSocket * @return */ 
    @Bean 
    public ServerEndpointExporter serverEndpointExporter() {
        return new ServerEndpointExporter(); 
    }
}

import com.wskh.chatroom.util.FastJsonUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.stereotype.Component;

import javax.websocket.*;
import javax.websocket.server.PathParam;
import javax.websocket.server.ServerEndpoint;
import java.io.EOFException;
import java.io.IOException;
import java.util.concurrent.ConcurrentHashMap;

@ServerEndpoint("/websocket/{sid}")
@Component
public class WebSocketServer {
    private static final Logger log = LoggerFactory.getLogger(WebSocketServer.class);

    private static int onlineCount = 0;

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

    private Session session;

    private String sid;


    @OnOpen
    public void onOpen(Session session, @PathParam("sid") String sid) {
        this.sid = sid;
        this.session = session;
        webSocketServerMap.put(sid, this);
        addOnlineCount();
        log.info("有新窗口开始监听:"+sid+",当前在线人数为" + getOnlineCount());
        try {
            sendInfo("openSuccess:"+webSocketServerMap.keySet());
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

    @OnClose
    public void onClose() {
        webSocketServerMap.remove(sid);
        subOnlineCount();
        log.info("有一连接关闭！当前在线人数为" + getOnlineCount());
        try {
            sendInfo("openSuccess:"+webSocketServerMap.keySet());
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

    @OnMessage
    public void onMessage(String message) throws IOException {
        if("ping".equals(message)) {
            sendInfo(sid, "pong");
        }
        if(message.contains(":")) {
            String[] split = message.split(":");
            sendInfo(split[0], "receivedMessage:"+sid+":"+split[1]);
        }
    }

    @OnError
    public void onError(Session session, Throwable error) {
        if(error instanceof EOFException) {
            return;
        }
        if(error instanceof IOException && error.getMessage().contains("已建立的连接")) {
            return;
        }
        log.error("发生错误", error);
    }

    /**
     * 实现服务器主动推送
     */
    public void sendMessage(String message) throws IOException {
        synchronized (session) {
            this.session.getBasicRemote().sendText(message);
        }
    }

    public static void sendObject(Object obj) throws IOException {
        sendInfo(FastJsonUtils.convertObjectToJSON(obj));
    }

    public static void sendInfo(String sid,String message) throws IOException {
        WebSocketServer socketServer = webSocketServerMap.get(sid);
        if(socketServer != null) {
            socketServer.sendMessage(message);
        }
    }

    public static void sendInfo(String message) throws IOException {
        for(String sid : webSocketServerMap.keySet()) {
            webSocketServerMap.get(sid).sendMessage(message);
        }
    }

    public static void sendInfoByUserId(Long userId,Object message) throws IOException {
        for(String sid : webSocketServerMap.keySet()) {
            String[] sids =  sid.split("id");
            if(sids.length == 2) {
                String id = sids[1];
                if(userId.equals(Long.parseLong(id))) {
                    webSocketServerMap.get(sid).sendMessage(FastJsonUtils.convertObjectToJSON(message));
                }
            }
        }
    }

    public static Session getWebSocketSession(String sid) {
        if(webSocketServerMap.containsKey(sid)) {
            return webSocketServerMap.get(sid).session;
        }
        return null;
    }

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

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

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

import org.springframework.context.annotation.Configuration;
import org.springframework.web.servlet.config.annotation.CorsRegistry;
import org.springframework.web.servlet.config.annotation.WebMvcConfigurerAdapter;

@Configuration
public class WebMvcConfig extends WebMvcConfigurerAdapter {

    @Override
    // 跨域配置
    public void addCorsMappings(CorsRegistry registry) {
        registry.addMapping("/**")
                .allowedOrigins("*")
                .allowedMethods("POST", "GET", "PUT", "OPTIONS", "DELETE")
                .maxAge(3600)
                .allowCredentials(true);
    }

}

/**
 * @Author：WSKH
 * @ClassName：MsgController
 * @ClassType：控制类
 * @Description：信息控制类
 * @Date：2022/1/25/12:47
 * @Email：1187560563@qq.com
 * @Blog：https://blog.csdn.net/weixin_51545953?type=blog
 */
@ApiModel("信息控制类")
@RestController
@RequestMapping("/chatroom/msg")
public class MsgController {
    @ApiOperation("发送信息方法")
    @PostMapping("/sendMsg")
    public R sendMsg(String msg) throws IOException {
        WebSocketServer.sendInfo(msg);
        return R.ok().message("发送成功");
    }
}

//websocket.js
import Vue from 'vue'

// 1、用于保存WebSocket 实例对象
export const WebSocketHandle = undefined

// 2、外部根据具体登录地址实例化WebSocket 然后回传保存WebSocket
export const WebsocketINI = function(websocketinstance) {
  this.WebSocketHandle = websocketinstance
  this.WebSocketHandle.onmessage = OnMessage
}

// 3、为实例化的WebSocket绑定消息接收事件：同时用于回调外部各个vue页面绑定的消息事件
// 主要使用WebSocket.WebSocketOnMsgEvent_CallBack才能访问  this.WebSocketOnMsgEvent_CallBack 无法访问很诡异
const OnMessage = function(msg) {
  // 1、消息打印
  // console.log('收到消息：', msg)

  // 2、如果外部回调函数未绑定 结束操作
  if (!WebSocket.WebSocketOnMsgEvent_CallBack) {
    console.log(WebSocket.WebSocketOnMsgEvent_CallBack)
    return
  }

  // 3、调用外部函数
  WebSocket.WebSocketOnMsgEvent_CallBack(msg)
}

// 4、全局存放外部页面绑定onmessage消息回调函数:注意使用的是var
export const WebSocketOnMsgEvent_CallBack = undefined

// 5、外部通过此绑定方法 来传入的onmessage消息回调函数
export const WebSocketBandMsgReceivedEvent = function(receiveevent) {
  WebSocket.WebSocketOnMsgEvent_CallBack = receiveevent
}

// 6、封装一个直接发送消息的方法：
export const Send = function(msg) {
  if (!this.WebSocketHandle || this.WebSocketHandle.readyState !== 1) {
    // 未创建连接 或者连接断开 无法发送消息
    return
  }
  this.WebSocketHandle.send(msg)// 发送消息
}

// 7、导出配置
const WebSocket = {
  WebSocketHandle,
  WebsocketINI,
  WebSocketBandMsgReceivedEvent,
  Send,
  WebSocketOnMsgEvent_CallBack
}

// 8、全局绑定WebSocket
Vue.prototype.$WebSocket = WebSocket