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.List;
import java.util.Map;
import java.util.concurrent.CopyOnWriteArraySet;
@ServerEndpoint("/WebSocket/{myName}")
@Component
public class MyWebSocket {
    private static int onlineCount = 0;
    private static CopyOnWriteArraySet<MyWebSocket> webSocketSet = new CopyOnWriteArraySet<MyWebSocket>();
    //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;
    private String myName;
    /**
     * 连接建立成功调用的方法*/
    @OnOpen
    public void onOpen(Session session,@PathParam("myName")String myName) {
        System.out.println("Name is "+myName);
        this.myName = myName;
        this.session = session;
        webSocketSet.add(this);     //加入set中
        addOnlineCount();           //在线数加1
        System.out.println("有新连接加入！当前在线人数为" + getOnlineCount());
        try {
//            sendMessage(CommonConstant.CURRENT_WANGING_NUMBER.toString());
            sendMessage("Hello,如果我显示了说明你已经成功了！");
        } catch (IOException e) {
            System.out.println("IO异常");
        }
    }
    /**
     * 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
        System.out.println("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) {
        System.out.println("来自客户端的消息:" + message);
        System.out.println("session的ID为："+session.getId());
        //获取参数
        Map<String, List<String>> getRequestParameterMap = session.getRequestParameterMap();
        String toUserId = getRequestParameterMap.get("toUserId").get(0);
        // 单发信息
        for (MyWebSocket item : webSocketSet){
            try{
                if (toUserId.equals(item.myName)){
                        item.sendMessage("单人信息："+message);
                        break;
                }
            }catch (IOException e){
                continue;
            }
        }
        //群发消息
        for (MyWebSocket item : webSocketSet) {
            try {
                item.sendMessage("群发信息："+message);
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    }
    //发生错误时调用
     @OnError
     public void onError(Session session, Throwable error) {
     System.out.println("发生错误");
     error.printStackTrace();
     }
     public void sendMessage(String message) throws IOException {
     this.session.getBasicRemote().sendText(message);
     //this.session.getAsyncRemote().sendText(message);
     }
     /*
      * 群发自定义消息
      * */
    public static void sendInfo(String message) throws IOException {
        for (MyWebSocket item : webSocketSet) {
            try {
                item.sendMessage(message);
            } catch (IOException e) {
                continue;
            }
        }
    }
    public static synchronized int getOnlineCount() {
        return onlineCount;
    }
    public static synchronized void addOnlineCount() {
        MyWebSocket.onlineCount++;
    }
    public static synchronized void subOnlineCount() {
        MyWebSocket.onlineCount--;
    }
}

SpringMVC 集成 WebSocket

import org.springframework.http.server.ServerHttpRequest;
import org.springframework.http.server.ServerHttpResponse;
import org.springframework.http.server.ServletServerHttpRequest;
import org.springframework.web.socket.WebSocketHandler;
import org.springframework.web.socket.server.support.HttpSessionHandshakeInterceptor;
import javax.servlet.http.HttpServletRequest;
import java.util.Map;
/**
 * @author wsc
 * @description websocket的拦截器
 * @date 2019/9/4 12:12
 */
public class MyWebSocketInterceptor  extends HttpSessionHandshakeInterceptor {
    @Override
    public boolean beforeHandshake(ServerHttpRequest request, ServerHttpResponse response, WebSocketHandler wsHandler, Map<String, Object> attributes) throws Exception {
        System.out.println("启动了websocket的拦截器");
        HttpServletRequest servletRequest = ((ServletServerHttpRequest)request).getServletRequest();
        return super.beforeHandshake(request, response, wsHandler, attributes);
    }
}

import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.web.socket.WebSocketHandler;
import org.springframework.web.socket.config.annotation.EnableWebSocket;
import org.springframework.web.socket.config.annotation.WebSocketConfigurer;
import org.springframework.web.socket.config.annotation.WebSocketHandlerRegistry;
/**
 * @author wsc
 * @description  websocket配置类注解型
 * @date 2019/9/4 12:06
 */
@Configuration
@EnableWebSocket
public class WebSocketConfiguation implements WebSocketConfigurer {
    public void registerWebSocketHandlers(WebSocketHandlerRegistry registry) {
        System.out.println("开始注册");
         registry.addHandler(webSocketHandler(),"/connect/websocket").setAllowedOrigins("*").addInterceptors(new MyWebSocketInterceptor());
// 支持 socket.js
registry.addHandler(webSocketHandler(),"/connect/sockJS").setAllowedOrigins("*").addInterceptors(new MyWebSocketInterceptor()).withSockJS();
    }
    @Bean
    public WebSocketHandler webSocketHandler(){
        return  new MyWebSocketHandle();
    }
}

import org.springframework.web.socket.CloseStatus;
import org.springframework.web.socket.TextMessage;
import org.springframework.web.socket.WebSocketMessage;
import org.springframework.web.socket.WebSocketSession;
import org.springframework.web.socket.handler.TextWebSocketHandler;
import java.io.IOException;
/**
 * @author wsc
 * @description  websocket的各种事件
 * @date 2019/9/4 12:10
 */
public class MyWebSocketHandle extends TextWebSocketHandler {
    @Override
    public void afterConnectionEstablished(WebSocketSession session) throws Exception {
            System.out.println("开启连接");
    }
    @Override
    public void handleMessage(WebSocketSession session, WebSocketMessage<?> message) throws Exception {
        System.out.println("接收到前台发过来的信息:"+message.getPayload().toString());
    }
    @Override
    public void handleTransportError(WebSocketSession session, Throwable exception) throws Exception {
        System.out.println("抛出了异常");
    }
    @Override
    public void afterConnectionClosed(WebSocketSession session, CloseStatus status) throws Exception {
        System.out.println("关闭了连接");
    }
    private static void sendMsg(String message ,WebSocketSession session) throws IOException {
        TextMessage textMessage = new TextMessage(message);
        session.sendMessage(textMessage);
    }
}

<!DOCTYPE HTML>
<html>
<head>
<title>My WebSocket</title>
</head>
<body>
    <input id="text" type="text" />
    <button onclick="send()">Send</button>
    <button onclick="closeWebSocket()">Close</button>
    <div id="message"></div>
</body>
<script type="text/javascript">
    var websocket = null;
    //判断当前浏览器是否支持WebSocket, 主要此处要更换为自己的地址
    if ('WebSocket' in window) {
        //  https 协议 使用 wss
        websocket = new WebSocket("ws://localhost:18092/test/one");
    } else {
        alert('Not support websocket')
    }
    //连接发生错误的回调方法
    websocket.onerror = function() {
        setMessageInnerHTML("error");
    };
    //连接成功建立的回调方法
    websocket.onopen = function(event) {
        //setMessageInnerHTML("open");
    }
    //接收到消息的回调方法
    websocket.onmessage = function(event) {
        setMessageInnerHTML(event.data);
    }
    //连接关闭的回调方法
    websocket.onclose = function() {
        setMessageInnerHTML("close");
    }
    //监听窗口关闭事件，当窗口关闭时，主动去关闭websocket连接，防止连接还没断开就关闭窗口，server端会抛异常。
    window.onbeforeunload = function() {
        websocket.close();
    }
    //将消息显示在网页上
    function setMessageInnerHTML(innerHTML) {
        document.getElementById('message').innerHTML += innerHTML + '<br/>';
    }
    //关闭连接
    function closeWebSocket() {
        websocket.close();
    }
    //发送消息
    function send() {
        var message = document.getElementById('text').value;
        websocket.send(message);
    }
</script>
</html>