实现功能：客户端与服务器建立socket后，服务器接收到客户端消息后返回给除自己外的其他客户端信息

1.需提前安装express
npm install express -a

2.服务端

var app = require('express')()

 var server = require('http').Server(app)

 var WebSocket = require('ws')

 var wss = new WebSocket.Server({ port: 8080 })//

let arr =[] //建立数组存储所有接入client的信息

 wss.on('connection', function connection(ws) { 

 console.log('server: receive connection.'+ws._ultron.id)

 ws.on('message', function incoming(message) { //接收到消息

 // console.log('client:'+ws._ultron.id+"send Info", message)// ws._ultron.id 相当于clientID

arr.push({client:ws._ultron.id,msg:message})

 wss.clients.forEach(function(item){ //广播

 if(item._ultron.id==ws._ultron.id){return}

 // console.log(item._ultron) 

 item.send(JSON.stringify(arr)) 

     }) 

 })

 ws.on('pong', () => { console.log('server: received pong from client'); })//ws是通过ping/pong 心跳维护连接的

//ws.send('world');
 // setInterval(() => { // ws.ping('', false, true); // }, 2000); })

app.get('/', function (req, res) { res.sendfile(__dirname + '/index.html'); })

app.listen(3000)

3.web端
sendToServer var ws = new WebSocket('ws://localhost:8080')

 ws.onopen = function () { 

 document.getElementById("bt1").onclick=function(e){ 

 let info = document.getElementById("input1").value ws.send(info)

 } 

 console.log('client: ws connection is open') 

 ws.send('hello') } 

ws.onmessage = function (e) { console.log( e.data) }