socket

<div id="room" class="panel panel-primary">
        <div class="panel-heading clearfix">
            聊天室
            <input id="nickname" placeholder="昵称，默认为新朋友" style="200px;" type="text" class="form-control pull-right">
        </div>
        <div class="panel-body">
            <div class="content">
                <ul class="list-group msgs"></ul>
            </div>
            <div class="control-box">
                <input id="word" type="text" class="form-control">
                <button id="send" class="btn btn-success">发送</button>
            </div>
        </div>

        <div class="numbers">
            <button class="btn btn-info online">
                在线人数：<span class="count"></span>
            </button>
            <ul class="list-group clients">
                  
            </ul>
        </div>

    </div>
    

    
   
</body>
<script src="https://cdn.bootcss.com/jquery/3.2.1/jquery.min.js"></script>
<script>
    //创建客户端的连接socket
//   var wsc = new WebSocket('ws://127.0.0.1:2345');
  var wsc = new WebSocket('ws://10.9.166.55:2345');

  wsc.onopen = function (e) {//当客户端连接上的时候就会触发
    //console.log('我已经连接上服务端了')
  };

  wsc.onmessage = function (e) {//当服务端返回消息的时候触发
        //  console.log(e.data);
        let info = JSON.parse(e.data)
        switch(info.type){
            case 'msg':
            handleMsg(info);break;
            case 'count':
            handleCount(info);break;
        }

        
         
  };

  function handleMsg(info) {
    let str = `
    <li class="list-group-item ${info.isMe?'me':'other'}">
        <span>${info.nickname}</span>
        <button class="btn btn-success">${info.msg}</button>                    
    </li>
    `
    let li = $(str)       
    $(".msgs").append(li)
    li[0].scrollIntoView()
  }

  function handleCount(info) {
      $(".count").html(info.count)
      var str = ''
      info.clients.forEach(item => {
          str+='<li class="list-group-item list-group-item-info text-center">'+item+'</li>'
      });
      $(".clients").html(str)
      //如果有人来或者有人走，需要报一个消息
      if(info.nickname&&info._type){
          $(".msgs").append('<p class="p-info text-center">'+info.nickname+(info._type==1?'加入聊天室':'离开聊天室')+'</p>')
      }
  }

  $("#send").click(function () {
      send()
  })
  $("#word").keyup(function (e) {
      if(e.keyCode==13){
          send()
      }
  })

    function send() {
        var nickname = $("#nickname").val() || '新朋友'
        var msg = $("#word").val()
        wsc.send(JSON.stringify({nickname:nickname,msg:msg}))
    }

  var canUse = true
  wsc.onclose = function (e) {//当服务端关闭的时候触发
        // alert('聊天服务已经关闭了')
        canUse = false
  };






  wsc.onerror = function (e) {//错误情况触发
    console.log(e)
  }


</script>

服务端：

const http = require('http')
const fs = require('fs')

var server = http.createServer((req,res)=>{
    res.writeHead(200,{'Content-Type':'text/html;charset=utf8'})
    
    res.end(fs.readFileSync('./index.html'))

})


//socket
const Server = require('ws').Server

//建立好了服务端
var wss = new Server({server})

//存放前端连接的socket
var clientMap = {}
var count = 0
var id = 0
//当客户端连接上的就会触发，回调会接收一个socket对象
wss.on("connection",function (socket) {
    count++
    id++
    socket.id = id
    clientMap[socket.id] = socket
    socket.nickname = '新朋友'
    console.log(`现在有${count}人连接了`)
    broadClients(socket.nickname,1)


    //当这个客户端发送数据的时候会触发
    socket.on("message",function (msg) {
        //console.log(`客户端${socket.id} 说：${msg}`)
        let info = JSON.parse(msg)
        if(socket.nickname!=info.nickname){
            socket.nickname = info.nickname
            broadClients()
        }
        socket.nickname = info.nickname
        broadcast(socket,info.msg)
    })

    //当客户端断开到时候触发
    socket.on("close",function () {
        //console.log(`客户端${socket.id} 说：${msg}`)
        count--
        let nickname = socket.nickname
        delete clientMap[socket.id]
        broadClients(nickname,2)
       
      
    })

    //当客户端连接出错的时候
    socket.on("error",function (err) {
        console.log(err)
    })

})

//广播函数，像所有的客户端发送某一个客户端说的话
function  broadcast(socket,msg) {
    let info = {nickname:socket.nickname,msg:msg,type:'msg'}
    for(var id in clientMap){
        info.isMe = socket.id==id?'true':false
        clientMap[id].send(JSON.stringify(info))
    }
}

function  broadClients(nickname,type) {
    let clients = []
    for(var id in clientMap){
        clients.push(clientMap[id].nickname)
    }
    for(var id in clientMap){
        clientMap[id].send(JSON.stringify({
            count,clients,
            type:'count',
            nickname,_type:type
        }))
    }
}



server.listen(2345)
// server.listen(2345,'127.0.0.1')