常见的请求头
| 消息头 | 描述 | 
|---|---|
| - | 常见 | 
| Authorization | 包含用服务器验证用户代理的凭证 | 
| Content-Type | 指示服务器文档的 MIME 类型 | 
| Set-Cookie | |
| Cookie | |
| - | CORS | 
| Access-Control-Allow-Origin | |
| Access-Control-Allow-Methods | |
| Access-Control-Allow-Headers | |
| Access-Control-Request-Method | |
| Access-Control-Request-Headers | |
| - | 缓存 | 
| Expires | |
| Cache-Control | |
| Last-Modified | |
| ETag | |
| If-Modified-Since | |
| If-None-Match |