基本介绍

WebSocket 是 HTML5 开始提供的一种在单个 TCP 连接上进行全双工通讯的协议。
WebSocket 使得客户端和服务器之间的数据交换变得更加简单，允许服务端主动向客户端推送数据。在 WebSocket API 中，浏览器和服务器只需要完成一次握手，两者之间就直接可以创建持久性的连接，并进行双向数据传输。

简易聊天室实现

思路

前端实现

事件

open ：连接建立时触发
message：客户端接收服务端数据时触发
error：通信发生错误时触发
close：连接关闭时触发

步骤

目录文件
entry.html

<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta http-equiv="X-UA-Compatible" content="IE=edge">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Document</title>
</head>
<body>
  <div>
    用户名：  <input id="userName" type="text" placeholder="请输入用户名">
  </div>
  <div>
    密码：  <input id="passWord" type="text" placeholder="请输入密码">
  </div>
  <button id="btn">登入</button>
  <script src="./js/entry.js"></script>
  
</body>
</html>

entry.js

登录跳转

((doc, location) => {
  const useName = doc.querySelector('#userName')
  const passWord = doc.querySelector('#passWord')
  const btn = doc.querySelector('#btn')

  const init = () => {
    bindEvent()
  }

  function bindEvent() {
    btn.addEventListener('click', handClick, false)
  }

  function handClick () {
    // 输入用户名密码
   console.log('useName', useName, useName.value)
   console.log('passWord',passWord, passWord.value )
  //  跳转至聊天室
   if ( useName.value && passWord.value) {
    location.href = 'index.html?useName='+ useName.value + '&passWord='+ passWord.value
   }
  }
  init ()
})(document, location)

index.html

<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta http-equiv="X-UA-Compatible" content="IE=edge">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Document</title>
</head>
<body>
  <ul id="list"></ul>
  <input id="message" type="text" placeholder="请输入消息">
  <button id="send">发送</button>
  <script src="./js/index.js"></script>
</body>
</html>

index.js

绑定各种事件

((doc) => {
   const oList = doc.querySelector('#list')
   const oMsg = doc.querySelector('#message')
   const oSendbtn = doc.querySelector('#send')
   const ws = new WebSocket('ws:localhost:8000')
   let userName = ''
   let passWord = ''
   const init = () => {
    let url = location.search
    if (url.indexOf('?') !== -1) {
      let str = String(url).slice(0)
     let arr =  str.split('&')
     userName = arr[0].split('=')[1]
     passWord = arr[1].split('=')[1]
     console.log('userNamepassWord', userName, passWord)
    }
     bindEvent()
   }

  // 绑定事件处理函数
   function bindEvent() {
    oSendbtn.addEventListener('click', handSend, false)
    console.log('ws', ws)
    ws.addEventListener('open', handleOpen, false)
    ws.addEventListener('close', handleClose, false)
    ws.addEventListener('error', handleError, false)
    ws.addEventListener('message', handleMessage, false)
   }
   function handSend (e) {
     const msg = oMsg.value
     if (!msg.trim().length) {
       return
     }
    // 这里需传json字符串，二进制等
     ws.send(JSON.stringify({
       user: userName,
       passsword: passWord,
       msg,
       dateTime: new Date()
     }))
     console.log('send', e)
     oMsg.value = ''
   }
   function handleOpen (e) {
    console.log('open', e)
   }
   function handleClose (e) {
    console.log('close', e)
   }
   function handleError (e) {
    console.log('error', e)
   }
   function handleMessage (e) {
    console.log('message', e)
    const msgData = JSON.parse(e.data)
    console.log('msgData', msgData)
    oList.appendChild(createMsg(msgData))
   }
   function createMsg(data) {
    const {user, msg, dateTime} = data
    const oItem = doc.createElement('li')
    oItem.innerHTML = `
    <p>
    <span>${user}</span>
    <i>${dateTime}</i>
    </p>
    <p>消息：${msg}</p>
    `
    return oItem
   }
   init()
})(document)

后端实现

事件

open ：连接建立时触发
message：客户端接收服务端数据时触发
error：通信发生错误时触发
close：连接关闭时触发
connection：监测websocket连接

步骤

在这里插入图片描述

index.js

绑定事件开启服务

const Ws = require('ws').Server
;((Ws) => {
  // ws:localhost:8000
  const server = new Ws({
    port: 8000
  })
  const init = () => {
    bindEvent()
  }
  function bindEvent () {
    server.on('open', handleOpen)
    server.on('close', handleClose)
    server.on('error', handleError)
    server.on('connection', handleConnection)
  }

  function handleOpen (ws) {
    console.log('server open')
  }

  function handleClose (ws) {
    console.log('server close')
  }

  function handleError (ws) {
    console.log('server error')
  }

  function handleConnection (ws) {
    console.log('server connection')
    ws.on('message', handleMessag)
  }

  function handleMessag (msg) {
    console.log('msg', msg.toString())
    server.clients.forEach(c => {
      c.send(msg.toString())
    })
    console.log(server.clients)
  }
  init() 
})(Ws)