1.安装vue-cli
2.init 初始化项目
3.npm install ws(websocket)
4.文件夹中创建server.js

var userNum = 0 // 统计人数
var chatList = []// 记录聊天内容
var WebSocketServer = require('ws').Server// 引入 ws
// 端口对应
var wss = new WebSocketServer({ port: 8080 })
// 调用broadcast广播，实现数据互通和实时更新
wss.broadcast = function (msg) {
  wss.clients.forEach(function (item) {
    item.send(msg)
  })
}
// 监听连接
wss.on('connection', function (ws) {
  userNum++
  wss.broadcast(JSON.stringify({ funName: 'userCount', users: userNum, chat: chatList })) // 建立连接成功广播一次当前在线人数
  console.log('连接人数:', userNum)
  // 接受前端发来消息
  ws.on('message', function (e) {
    var resData = JSON.parse(e) // 消息处理 字符串转为对象
    console.log('接收到来自clent的消息：' + resData.msg)
    // 每次发送信息，都会把信息存起来，然后通过广播传递出去，这样此每次进来的用户就能看到之前的数据
    chatList.push({ userId: resData.userId, content: resData.msg })
    // 每次发送都相当于广播一次消息
    wss.broadcast(JSON.stringify({ userId: resData.userId, msg: resData.msg }))
  })
  ws.on('close', function (e) {
    userNum--
    // 建立连接关闭广播一次当前在线人数
    wss.broadcast(JSON.stringify({ funName: 'userCount', users: userNum, chat: chatList }))
    console.log('Connected clients:', userNum)
    console.log('长连接已关闭')
  })
})
console.log('服务器创建成功')

<template>
  <div class="chat-box">
    <div class="header">聊天室人数:{{count}}</div>
    <scroll class="message" ref="scorll" :data="list">
      <div>
        <div class="msg-box" ref="msgbox" v-for="(item,index) in list" :key="index">
          <span>{{item.content}}</span>
          <div class="header-avtor"></div>
        </div>
      </div>
    </scroll>
    <div class="bottom">
      <div class="down">
        <input type="text" ref="sendMsg" v-model="contentText" />
        <button ref="btn" @click="sendText">发送</button>
      </div>
    </div>
  </div>
</template>
<script>
import Scroll from 'base/scroll/scroll'
export default {
  data () {
    return {
      ws: null,
      count: 0,
      userId: null,
      list: [],
      contentText: '' // input输入的值
    }
  },
  created () {
    this.getUserId()
  },
  mounted () {
    this.initWebsocket()
    this.$refs.sendMsg.focus()
  },
  updated () {
  },
  methods: {
    getUserId () {
      let time = new Date().getTime()
      this.userId = time
    },
    // 滚动到底部
    scrollBottm () {
      let el = this.$refs.msgbox
      el.scrollTop = el.scrollHeight
      console.info(el.scrollHeight)
    },
    // 发送聊天消息
    sendText () {
      let _this = this
      _this.$refs.sendMsg.focus()
      if (!_this.contentText) {
        return false
      }
      let params = {
        userId: _this.userId,
        msg: _this.contentText
      }
      if (_this.ws.readyState == 1) {
        _this.ws.send(JSON.stringify(params)) // 调用WebSocket send()发送信息的方法
      }

      _this.contentText = ''
    },
    initWebsocket () {
      let _this = this
      // 判断页面有没有存在websocket连接
      if (window.WebSocket) {
        let ws = new WebSocket('ws://127.0.0.1:8080')
        _this.ws = ws
        console.log(ws)
        ws.onopen = function (e) {
          console.log('服务器连接成功')
        }
        ws.onclose = function () {
          console.log('服务器连接关闭')
        }
        ws.onerror = function () {
          console.log('服务器连接出错')
        }
        ws.onmessage = function (e) {
          // 接收服务器返回的数据
          let resData = JSON.parse(e.data)
          if (resData.funName === 'userCount') {
            _this.count = resData.users
            _this.list = resData.chat
            console.log(_this.list, '1234')
          } else {
            _this.list = [
              ..._this.list,
              { userId: resData.userId, content: resData.msg }
            ]
          }
        }
      }
    }
  },
  components: {
    Scroll
  },
  watch: {
    list () {
      this.$refs.scorll.refresh()
    }
  }
}
</script>
<style scoped>
.message {
  padding-top: 60px;
  margin-bottom: 60px;
  height: 100%;
  overflow: hidden;
}
.header {
  width: 100%;
  height: 50px;
  line-height: 50px;
  text-align: center;
  background: blue;
  color: #fff;
  font-size: 18px;
  position: fixed;
  top: 0;
  z-index: 2;
}
.bottom {
  position: fixed;
  bottom: 0;
  width: 100%;
  border-top: 1px solid #ccc;
}
.down {
  display: flex;
  align-items: center;
  padding: 5px;
  background: #fff;
}
.bottom input {
  flex: 1;
  height: 40px;
  font-display: 18px;
}
.bottom button {
  border: none;
  width: 70px;
  height: 44px;
  background: blue;
  color: #fff;
  line-height: 40px;
  text-align: center;
  border-radius: 5px;
  margin-left: 10px;
}
.msg-box {
  display: flex;
  align-items: center;
  justify-content: flex-end;
  width: 100%;
  margin: 20px 10px 0px 0px;
}

.avtive {
  display: inline-block;
  background: blue;
  color: #fff;
  padding: 10px;
  font-size: 16px;
  border-radius: 6px;
  margin-right: 10px;
  flex-wrap: wrap;
  word-break: break-all;
  max-width: 220px;
}
.header-avtor {
  width: 40px !important;
  height: 40px;
  border-radius: 50%;
  background: #ccc;
}
.avtive-left {
  justify-content: flex-start;
}
</style>

node server.js 启动服务端
运行npm run dev即可
参考文章：https://www.jianshu.com/p/6e52493c3bae