Java+Vue实现WebSocket

一、添加WebSocketConfig配置类

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


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

二、创建WebSocket服务处理类

import cn.hutool.log.Log;
import cn.hutool.log.LogFactory;
import com.alibaba.fastjson.JSONObject;
import com.elephant.framework.galaxy.travel.response.R;
import org.springframework.stereotype.Component;


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

/**
*  服务处理类
*  @author: xuyanqi
*/

@ServerEndpoint("/websocket/{sid}")
@Component
public class WebSocketServer {
    static Log log = LogFactory.get(WebSocketServer.class);
    //静态变量，用来记录当前在线连接数。应该把它设计成线程安全的。
    private static int onlineCount = 0;
    //concurrent包的线程安全Set，用来存放每个客户端对应的MyWebSocket对象。
    private static CopyOnWriteArraySet<WebSocketServer> webSocketSet = new CopyOnWriteArraySet<WebSocketServer>();


    //与某个客户端的连接会话，需要通过它来给客户端发送数据
    private Session session;


    //接收sid  用了标识哪个模块的通信
    private String sid="";
    /**
     * 连接建立成功调用的方法*/
    @OnOpen
    public void onOpen(Session session,@PathParam("sid") String sid) {
        this.session = session;
        webSocketSet.add(this);     //加入set中
        addOnlineCount();           //在线数加1
        log.info("有新窗口开始监听:"+sid+",当前在线人数为" + getOnlineCount());
        this.sid=sid;
        try {
            sendMessage("连接成功");
        } catch (IOException e) {
            log.error("websocket IO异常");
            e.printStackTrace();
        }
    }


    /**
     * 连接关闭调用的方法
     */
    @OnClose
    public void onClose() {
        webSocketSet.remove(this);  //从set中删除
        subOnlineCount();           //在线数减1
        log.info("有一连接关闭！当前在线人数为" + getOnlineCount());
    }


    /**
     * 收到客户端消息后调用的方法
     *
     * @param message 客户端发送过来的消息*/
    @OnMessage
    public void onMessage(String message, Session session) {
        log.info("收到来自窗口"+sid+"的信息:"+message);
        //群发消息
        for (WebSocketServer item : webSocketSet) {
            try {
                item.sendMessage(message);
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    }


    /**
     *
     * @param session
     * @param error
     */
    @OnError
    public void onError(Session session, Throwable error) {
        log.error("发生错误");
        error.printStackTrace();
    }
    /**
     * 实现服务器主动推送
     */
    public void sendMessage(Object obj) throws IOException {
        R r = new R(obj);
        this.session.getBasicRemote().sendText(JSONObject.toJSONString(r));
    }




    /**
     * 群发自定义消息
     * */
    public static void sendInfo(Object obj,@PathParam("sid") String sid) throws IOException {
        log.info("推送消息到窗口"+sid+"，推送内容:"+obj);
        for (WebSocketServer item : webSocketSet) {
            try {
                //这里可以设定只推送给这个sid的，为null则全部推送
                if(sid==null) {
                    item.sendMessage(obj);
                }else if(item.sid.equals(sid)){
                    item.sendMessage(obj);
                }
            } catch (IOException e) {
                continue;
            }
        }
    }


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


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


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

三、vue前端

在data中创建websock对象

/**
* 创建websocket
*/
initWebSocket(){
    console.log("创建WebSocket")
    this.websock = new WebSocket("ws://127.0.0.1:9998/websocket/ydsj")
    this.websock.onmessage = this.websocketonmessage
    this.websock.onerror = this.websocketonerror
    this.websock.onopen = this.websocketonopen
    this.websock.onclose = this.websocketclose

},
// 连接建立之后执行send方法发送数据
websocketonopen () {
   let data = {
     code: 0,
     msg: '这是client：初次连接'
   }
   this.websocketsend(data)
},
websocketonerror () {
  console.log( 'WebSocket连接失败')
},
// 数据接收
websocketonmessage (e) {
   console.log('数据接收' + e.data)
},
// 数据发送
websocketsend (Data) {
   this.websock.send(Data)
},
// 关闭
websocketclose (e) {
   console.log('已关闭连接', e)
}