text: // npm install ws
  var WebSocketServer = require('ws').Server,
      wss = new WebSocketServer({ port: 8181 });//服务端口8181
  wss.on('connection', function (ws) {
      console.log('服务端：客户端已连接');
      ws.on('message', function (message) {
          //打印客户端监听的消息
          console.log(message.toString("utf-8"));
      });
  });