search

zonglang / code

平时写的代码练习
1 stars 0 forks source link

websocket #46

Open zonglang opened 5 years ago

zonglang commented 5 years ago

websocket实现了全双工实时通信 本身tcp协议就是可以全双工实时通信的，但是http协议的请求-应答机制限制了全双工通信； 首先通过http的get请求，进行协议升级，前端和服务端商量着绕过http协议；

// 请求头
GET ws://localhost:3000/ws/chat HTTP/1.1
Host: localhost
Upgrade: websocket
Connection: Upgrade
Origin: http://localhost:3000
Sec-WebSocket-Key: client-random-string
Sec-WebSocket-Version: 13
// 响应头
HTTP/1.1 101 Switching Protocols
Upgrade: websocket
Connection: Upgrade
Sec-WebSocket-Accept: server-random-string