与Ajax不同，WebSocket可以使服务端主动向客户发送响应，本案例就是基于WebSocket的一个在线聊天室，不过功能比较简单，只能满足文字交流。演示如下。
案例学习于b站up主，链接 。这位up主讲的非常清楚，值得去学习。本文属于记录自我学习过程的文章。
项目目录下app.js
//导入nodejs-websocket包
const { connect } = require('net')
const ws = require('nodejs-websocket')
const PORT = 3000
//创建一个server
const server = ws.createServer(connect => {
console.log('有用户连接上来了')
})
server.listen(PORT,() => {
console.log('websocket服务启动成功了，监听了端口'+PORT)
})项目目录下打开终端
npm install nodejs-websocket
下载成功后。
项目目录下index.html
去掉css。
app.js
//导入nodejs-websocket包
const { connect } = require('net')
const ws = require('nodejs-websocket')
const PORT = 3000
//连接的数量
let count = 0
//创建一个server
const server = ws.createServer(connect => {
console.log('新的连接')
count++
connect.userName = `用户${count}`
broadcast(`${connect.userName}进入了聊天室`)
//接收
connect.on('text',data => {
broadcast(data)
})
//关闭
connect.on('close',data => {
console.log('关闭连接')
count--
broadcast(`${connect.userName}离开了聊天室`)
})
//异常
connect.on('error',data => {
console.log('发生异常')
})
})
//广播
function broadcast(msg) {
server.connections.forEach(item => {
item.send(msg)
})
}
server.listen(PORT,() => {
console.log('websocket服务启动成功了，监听了端口'+PORT)
})index.html
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title></title>
<style>
</style>
</head>
<body>
<div></div>
<input type="text" placeholder="请输入你的内容"/>
<button>发送</button>
<script>
var input = document.querySelector('input')
var button = document.querySelector('button')
var div = document.querySelector('div')
//websocket的服务地址
var socket = new WebSocket('ws://localhost:3000')
//连接成功时
socket.addEventListener('open',function() {
div.innerHTML = '连接服务成功了'
})
//主动向服务器发消息
button.addEventListener('click',function() {
var value = input.value
socket.send(value)
})
//接受数据
socket.addEventListener('message',function(e) {
console.log(e.data)
var dv = document.createElement('div')
dv.innerText = e.data
div.appendChild(dv)
})
//断开连接
socket.addEventListener('close',function(e) {
div.innerHTML = '服务断开连接'
})
</script>
</body>
</html>浏览框1
浏览框2
稍微美化页面，增强一下逻辑。在浏览器内打开三个窗口，既有3个人参与到聊天室中，现在可以聊天了。
用户1
用户2
用户3
主要代码
请先安装node.js并已下载websocket的环境。
项目目录：
app.js
//导入nodejs-websocket包
const { connect } = require('net')
const ws = require('nodejs-websocket')
const PORT = 3000
const TYPE_ENTER = 0
const TYPE_LEAVE = 1
const TYPE_MSG = 2
//连接的数量
let count = 0
//创建一个server
const server = ws.createServer(connect => {
console.log('新的连接')
count++
connect.userName = `用户${count}`
broadcast({
type: TYPE_ENTER,
msg: `${connect.userName}进入了聊天室`,
time: new Date().toLocaleString('chinese',{hour12:false}).slice(2).replace(/-/g,'/')
})
//接收
connect.on('text',data => {
broadcast({
type: TYPE_MSG,
msg: connect.userName + ':' + data,
time: new Date().toLocaleString('chinese',{hour12:false}).slice(2).replace(/-/g,'/')
})
})
//关闭
connect.on('close',data => {
console.log('关闭连接')
count--
broadcast({
type: TYPE_LEAVE,
msg: `${connect.userName}离开了聊天室`,
time: new Date().toLocaleString('chinese',{hour12:false}).slice(2).replace(/-/g,'/')
})
})
//异常
connect.on('error',data => {
console.log('发生异常')
})
})
//广播
function broadcast(msg) {
server.connections.forEach(item => {
item.send(JSON.stringify(msg))
})
}
server.listen(PORT,() => {
console.log('websocket服务启动成功了，监听了端口'+PORT)
})index.html
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title></title>
<style>
* {
padding: 0;
margin: 0;
}
body {
background: #eff0fe;
font-family: '宋体';
}
#box {
padding: 20px;
}
input {
width: 600px;
height: 30px;
border: none;
outline: none;
color: gray;
}
#chat {
padding: 10px;
background: white;
width: 920px;
box-sizing: border-box;
height: 95vh;
}
#operation {
position: fixed;
top: 300px;
right: 20px;
}
#title {
font-size: 200px;
position: fixed;
top: 20px;
right: 80px;
color: gray;
opacity: 0.3;
font-family: '黑体';
}
button {
height: 30px;
width: 50px;
text-align: center;
line-height: 30px;
border: none;
color: gray;
}
button:hover {
cursor: pointer;
}
.middle {
width: 200px;
margin: 0 auto;
font-size: 3px;
color: gray;
margin-bottom: 5px;
}
.msg {
width: 900px;
word-break: break-all;
}
</style>
</head>
<body>
<div id="box">
<div id="chat"></div>
<div id="title">聊天室</div>
<div id="operation">
<input type="text" placeholder="请输入你的内容"/>
<button>发送</button>
</div>
</div>
<script>
const TYPE_ENTER = 0
const TYPE_LEAVE = 1
const TYPE_MSG = 2
var input = document.querySelector('input')
var button = document.querySelector('button')
var div = document.querySelector('#chat')
console.log(input)
//websocket的服务地址
var socket = new WebSocket('ws://localhost:3000')
//连接成功时
socket.addEventListener('open',function() {
div.innerHTML = '欢迎来到聊天室'
})
//主动向服务器发消息
button.addEventListener('click',function() {
var value = input.value
socket.send(value)
input.value = ''
})
//接受数据
socket.addEventListener('message',function(e) {
console.log(e.data)
var data = JSON.parse(e.data)
if(data.type === TYPE_MSG) {
var dv = document.createElement('div')
var time = document.createElement('div')
var msg = document.createElement('div')
time.className = 'middle'
msg.className = 'msg'
time.innerText = data.time
msg.innerText = data.msg
dv.appendChild(time)
dv.appendChild(msg)
} else {
var dv = document.createElement('div')
var msg = document.createElement('div')
var time = document.createElement('div')
msg.className = 'middle'
time.className = 'middle'
msg.innerText = data.msg
time.innerText = data.time
dv.appendChild(time)
dv.appendChild(msg)
}
div.appendChild(dv)
})
//断开连接
socket.addEventListener('close',function(e) {
div.innerHTML = '服务断开连接'
})
</script>
</body>
</html>
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