http_status_bad_request (400) 
the request could not be processed by the server due to invalid syntax. 
因为语法不能被服务器处理 
http_status_denied (401) 
the requested resource requires user authentication. 
请求资源命令必须被验证（拒绝访问） 
http_status_payment_req (402) 
not currently implemented in the http protocol. 
没有完全实现http协议 
http_status_forbidden (403) 
the server understood the request, but is refusing to fulfill it. 
服务器理解了请求，但是拒绝完成他 
http_status_not_found (404) 
the server has not found anything matching the requested uri (uniform resource identifier). 
没有找到任何被指定的uri 

http_status_bad_method (405) 
the http verb used is not allowed. 
http动作不被允许 
http_status_none_acceptable (406) 
no resp acceptable to the client were found. 
应答没有被客户接受 
http_status_proxy_auth_req (407) 
proxy authentication required. 
代理必须被验证 
http_status_request_timeout (408) 
the server timed out waiting for the request. 
服务器在等待请求时中止了 
http_status_conflict (409) 
the request could not be completed due to a c with the current state of the resource. the user should resubmit with more information. 
请求不能被完成，问题是资源冲突。用户应该进行调整 
http_status_gone (410) 
the requested resource is no l available at the server, and no forwarding address is known. 
请求的资源在服务器上不再可用，而且没有转发地址 
http_status_length_required (411) 
the server refuses to accept the request without a defined c length. 
服务器拒绝接受没有定义目录大小的请求 
http_status_precond_failed (412) 
the prec given in or more of the request header fields evaluated to false when it was tested on the server. 
当在服务器上测试请求头文件放弃一个或者多个请求的条件 
http_status_request_too_large (413) 
the server is refusing to process a request because the request entity is larger than the server is willing or able to process. 
服务器拒绝处理请求，原因是请求的大小超过服务器能够处理的大小 
http_status_uri_too_long (414) 
the server is refusing to service the request because the request uri (uniform resource identifier) is l than the server is willing to interpret. 
服务器拒绝服务，原因是请求的uri超过了服务器能够揭示的长度 
http_status_unsupported_media (415) 
the server is refusing to service the request because the entity of the request is in a format not supported by the requested resource for the requested method. 
服务器拒绝服务，原因是请求格式不被支持