HTTP Knowledge Popularity series: HTTP return status code

2. Status code
   1. 1XX an Informational status code accepted request is being processed
   2. 2XX Success Status code request normal processing completed
   3. 3XX REDIRECT Status code requires additional action to complete the request
   4. 4XX Client Error Status code server failed to process request
   5. 5XX server-side Error status Code server processing request Error
4. 2XX corresponding results indicate that the request was processed properly.
   1. A. OK indicates that the request from the client is handled properly on the server side;
   2. 204 No Content The status code indicates that the request received by the server has been successfully processed, but does not contain the body part of the entity in the returned response message. It is also not allowed to return the body of any entity.
   3. 206 Partial Content The status code indicates that the client made a scope request, and the server successfully performed the GET request for this part.
6. 3XX response results indicate that the browser needs to perform some special processing to properly process the request
   1. 301 Moved Permanently Permanent redirect
   2. 302 Found Temporary redirection
   3. 303 See other The status code indicates that the requested resource should be directed to the request by using the Get method because another URI exists for the resource that corresponds to the request.
   4. 304 not Modified The status code indicates that when a client sends a request with a condition, the server allows the request to access the resource, but returns 304.304 when the request is satisfied, and does not contain any body parts of the response.
   5. 307 temporary Redirect 307 will follow the browser standard and will not change from post to get.
8. When the 301, 302, 303 response status codes are returned, almost all browsers will change the post to get and delete the principal within the request message, and the request will be sent again automatically. 301, 302 Standard is to prohibit the post method into a Get method, but the actual use of people will do so.
10. The 4XX response results indicate that the client is the cause of the error.
    1. The status code indicates that there is a syntax error in the request message.
    2. 401 Unauthorized The status code indicates that the request sent requires authentication information that is authenticated by HTTP, and if 1 requests have been made before, the user authentication fails. The first time the browser receives a 401 response, the Authentication dialog window pops up.
    3. 403 Forbidden The status code indicates that access to the requested resource was rejected by the server.
    4. 404 Not Found This status code indicates that the requested resource cannot be found on the server, or it can be used when the server side denies the request and does not want to justify it.
12. 5XX response results indicate that the server itself has an error.
    1. Internal Server Error This status code indicates that the server side has encountered an error while executing the request.
    2. 503 Service Unavailable This status code indicates that the server is temporarily over-loaded or is undergoing downtime maintenance and is now unable to process the request.

HTTP Knowledge Popularity series: HTTP return status code