websocket
2021-06-28 12:05
                         标签:console   const   question   host   new   closed   library   div   安装    不错的介绍:https://www.zhihu.com/question/20215561 websocket是一种持久化的协议,实现了浏览器和服务端的全双工通信; 握手阶段与HTTP协议相同,返回状态码101(switching protocols); 握手阶段完成之后,按照websocket协议进行通信   应用场景: 浏览器与服务端需要实时通信的场景,以前的解决方式:ajax轮询、HTTP长连接、Flash等。   实现: 浏览器端     node端 首先需要安装library:  以ws为例:   websocket 标签:console   const   question   host   new   closed   library   div   安装    原文地址:http://www.cnblogs.com/zmiaozzz/p/7143602.html什么是websocket?
const ws = new WebSocket(‘ws://localhost:8080‘);
ws.onopen = function (evt) {
    console.log(‘connection open...‘);
    ws.send(‘hello websocket‘);
}
ws.onmessage = function (evt) {
    console.log(‘frontend received: ‘ + evt.data);
}
ws.onclose = function (evt) {
    console.log(‘connection closed...‘);
}

const WebSocket = require(‘ws‘);
const ws = new WebSocket.Server({port: 8080});
ws.on(‘connection‘, function (ws) {
    ws.on(‘message‘, function (msg) {
        console.log(‘backend received: ‘+ msg);
    })
    ws.send(‘something‘);
})