Http状态码含义

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The following is a list of HTTP response status codes and standard associated phrases, intended to give a short textual description of the status. These status codes are specified by RFC 2616, along with additional codes (RFC 2518, RFC 2817, RFC 2295, RFC 2774, RFC 4918), some from the Distributed Authoring (WebD***) extension. Others are unstandardised but commonly used.

The first digit of the status code specifies one of five classes of response.

Contents

1 1xx Informational

2 2xx Success

3 3xx Redirection

4 4xx Client Error

5 5xx Server Error

6 See also

7 References

8 External links

1xx Informational

Request received, continuing process.

100 Continue This means that the server has received the request headers, and that the client should proceed to send the request body (in the case of a request for which a body needs to be sent; for example, a POST request). If the request body is large, sending it to a server when a request has already been rejected based upon inappropriate headers is inefficient. To have a server check if the request could be accepted based on the request's headers alone, a client must send

Expect: 100-continue

as a header in its initial request (see RFC 2616 §14.20: Expect header) and check if a

100 Continue

status code is received in response before continuing (or receive

417 Expectation Failed

and not continue).[1] 101 Switching Protocols 102 Processing (WebD***) (RFC 2518)

2xx Success

The action was successfully received, understood, and accepted.

200 OK Standard response for HTTP successful requests. 201 Created 202 Accepted 203 Non-Authoritative Information (since HTTP/1.1) 204 No Content 205 Reset Content 206 Partial Content Notice that a file has been partially downloaded. This is used by tools like wget to enable resuming of interrupted downloads, or split a download into multiple simultaneous streams. 207 Multi-Status (WebD***) The message body that follows is an XML message and can contain a number of separate response codes, depending on how many sub-requests were made.

3xx Redirection

The client must take additional action to complete the request.

300 Multiple Choices Indicates multiple options for the URI that the client may follow. It, for instance, could be used to present different format options for video, list files with different extensions, or word sense disambiguation. 301 Moved Permanently This and all future requests should be directed to the given URI. 302 Found This is the most popular redirect code, but also an example of industrial practice contradicting the standard. HTTP/1.0 specification (RFC 1945) required the client to perform a temporary redirect (the original describing phrase was "Moved Temporarily"), but popular browsers implemented it as a 303 See Other. Therefore, HTTP/1.1 added status codes 303 and 307 to disambiguate between the two behaviors. However, the majority of Web applications and frameworks still use the 302 status code as if it were the 303. 303 See Other (since HTTP/1.1) The response to the request can be found under another URI using a GET method. 304 Not Modified Indicates the request URL has not been modified since last requested. Typically, the HTTP client provides a header like the If-Modified-Since header to provide a time with which to compare against. Utilizing this saves bandwidth and reprocessing on both the server and client. 305 Use Proxy (since HTTP/1.1) Many HTTP clients (such as Mozilla [1] and Internet Explorer) don't correctly handle responses with this status code, primarily for security reasons. 306 Switch Proxy No longer used. 307 Temporary Redirect (since HTTP/1.1) In this occasion, the request should be repeated with another URI, but future requests can still be directed to the original URI. In contrast to 303, the request method should not be changed when reissuing the original request. For instance, a POST request must be repeated using another POST request.

4xx Client Error

400 Bad Request The request contains bad syntax or cannot be fulfilled. 401 Unauthorized Similar to 403 Forbidden, but specifically for use when authentication is possible but has failed or not yet been provided. See Basic access authentication and Digest access authentication. 402 Payment Required The original intention was that this code might be used as part of some form of digital cash or micropayment scheme, but that has not happened, and this code has never been used. 403 Forbidden The request was a legal request, but the server is refusing to respond to it. Unlike a 401 Unauthorized response, authenticating will make no difference. 404 Not Found 405 Method Not Allowed A request was made to a URL using a request method not supported by that URL; for example, using GET on a form which requires data to be presented via POST, or using PUT on a read-only resource 406 Not Acceptable 407 Proxy Authentication Required 408 Request Timeout 409 Conflict 410 Gone Indicates that the resource requested is no longer available and will not be available again. This should be used when a resource has been intentionally removed; however, in practice, a 404 Not Found is often issued instead. 411 Length Required 412 Precondition Failed 413 Request Entity Too Large 414 Request-URI Too Long 415 Unsupported Media Type 416 Requested Range Not Satisfiable 417 Expectation Failed 422 Unprocessable Entity (WebD***) (RFC 4918) The request was well-formed but was unable to be followed due to semantic errors. 423 Locked (WebD***) (RFC 4918) The resource that is being accessed is locked 424 Failed Dependency (WebD***) (RFC 4918) The request failed due to failure of a previous request (e.g. a PROPPATCH). 425 Unordered Collection Defined in drafts of WebDav Advanced Collections, but not present in "Web Distributed Authoring and Versioning (WebD***) Ordered Collections Protocol" (RFC 3648). 426 Upgrade Required (RFC 2817) The client should switch to TLS/1.0. 449 Retry With A Microsoft extension: The request should be retried after doing the appropriate action.

5xx Server Error

The server failed to fulfill an apparently valid request.

500 Internal Server Error 501 Not Implemented 502 Bad Gateway 503 Service Temporarily Unavailable 504 Gateway Timeout 505 HTTP Version Not Supported 506 Variant Also Negotiates (RFC 2295) 507 Insufficient Storage (WebD***) (RFC 4918) 509 Bandwidth Limit Exceeded This status code, while used by many servers, is not an official HTTP status code. 510 Not Extended (RFC 2774)