"Computer network" HTTP status code

100-199 is used to specify certain actions that the client should be corresponding.
200-299 is used to indicate a successful request.
300-399 is used for files that have been moved and is often included in the locator header information to specify the new address information.
400-499 is used to indicate client-side errors.
500-599 is used to support server errors.

Common Status Codes:

The request was successful and the desired response header or data body will be returned with this response.

301 Moved Permanently The requested resource has been permanently moved to a new location, and any future references to this resource should use one of several URIs returned by this response.

302 Move Temporarily requests a resource temporarily in response to a request from a different URI. Because such redirects are temporary , the client should continue to send subsequent requests to the original address.

at 1, the semantics are incorrect and the current request cannot be understood by the server. Unless modified, the client should not submit the request repeatedly. 2, the request parameter is wrong.

401 Unauthorized The current request requires user authentication .

403 Forbidden The server has understood the request, but refuses to execute it. Unlike the 401 response, authentication does not provide any help, and the request should not be repeated.

404 Not Found The request failed and the requested resource was not found on the server. 404 This status code is widely used when the server does not want to reveal exactly why the request was rejected or if no other appropriate response is available.

Resources:

Http://www.cnblogs.com/lxinxuan/archive/2009/10/22/1588053.html

"Computer network" HTTP status code