//WebSocketClient连接
public class WebSocketConnect {//websocket建立连接         public void ClientConnect(String userInfo,HttpServletRequest request) {HttpSession session = request.getSession();try {WebSocketClient webSocketClient = new WebSocketClient(new URI("ws://服务器ip地址:8080/websocket"),new Draft_17()) { 　　　　　　　　　　　 //打开链接
                    @Override public void onOpen(ServerHandshake shake) { System.out.println("握手。。。"); } //这个方法自动接收服务器发过来的信息,直接在此处调用自己写的方法即可.本人将消息存入到session中，别处可以监听，然后取出再清空
                    @Override public void onMessage(String msgString) {System.out.println("websocket返回消息" + msgString); }//客户端发生错误,即将关闭!
                    @Override public void onError(Exception e) { System.out.println("发生错误已关闭"); } //关闭链接
                    @Override public void onClose(int arg0, String arg1, boolean arg2) { System.out.println("链接已关闭"); }}; webSocketClient.connect();System.out.println("建立websocket连接");//将用户websocket连接对象存入session中，别处用取出使用即可。session.setAttribute("webSocketClient", webSocketClient);} catch (URISyntaxException e) {e.printStackTrace();}}//关闭websocket连接public void closeWebSocket(HttpServletRequest request) {HttpSession session = request.getSession();WebSocketClient webSocketClient = (WebSocketClient) session.getAttribute("webSocketClient");
            webSocketClient.close();System.out.println("websocket主动关闭！");}
}

//实例化对象
WebSocketConnect webSocketConnect = new WebSocketConnect();
/*用户登录*/
@RequestMapping(value = "/login",method = RequestMethod.POST,produces="text/html;charset=UTF-8;")
@ResponseBody//此注解不能省略 否则ajax无法接受返回值
public void login(HttpServletRequest request,HttpServletResponse response) throws UnsupportedEncodingException{
//调用对象webSocketConnect中连接方法
    webSocketConnect.ClientConnect(request);
}

//从session中取出用户登录的连接对象，实现发送消息
WebSocketClient webSocketClient = (WebSocketClient) session.getAttribute("webSocketClient");String message= “狼来了”；webSocketClient.send(message);

//方式一：使用对象调用webSocketConnect类中写的closeWebSocket方法。
webSocketConnect.closeWebSocket(request);
//方式二：从session中取出连接对象，直接调用close()方法。
WebSocketClient webSocketClient = (WebSocketClient) session.getAttribute("webSocketClient");