HTTP状态码
2XX成功
200 OK
204 No Content
206 Partial Content
3XX重定向
301 Moved Permanently
302 Found
303 See Other
304 Not Modified
307 Temporary Redirect
4XX 客户端错误
400 Bad Request
401 Unauthorized
403 Forbidden
404 Not Found
服务器错误
500 Internal Server Error
053 Service Unavailable
状态码和状态不一致这种情况经常遇到。