HTTP Network Protocol Learning Summary

One: HTTP protocol status Code

The status code is mainly used to describe the results when the client sends a request to the server, to mark whether the service side is working properly, to notify the error, and so on.

The status code is divided into five main categories:

1 The opening status code: Information class status Code, the main receiving request, indicating acceptance is being processed;

2 Initial status code: The request is successful status code, indicating that the request is processed properly;

3 Initial status code: Redirect Status code, indicating that additional action is required to complete the client request;

4 Initial Status code: Client error, on behalf of the server could not process the request;

5 Initial Status code: Server error, on behalf of the server processing the request error;

Common Status Codes

200 the request was successful. Generally used for Get and post requests;

204 no content. The server processed successfully, but the content was not returned. Ensure that the browser continues to display the current document without updating the page;

206 part content. The server successfully processed a partial GET request;

301 permanent movement. The requested resource has been permanently moved to the new URI, the return information will include the new URI, and the browser will automatically redirect to the new URI. Any new requests in the future should be replaced with new URIs;

302 Temporary movement. Similar to 301. But resources are only temporarily moved. The client should continue to use the original URI;

304 Not modified. The requested resource is not modified and no resources are returned when the server returns this status code. Clients typically cache accessed resources by providing a header indicating that the client wants to return only the resources modified after the specified date;

400 syntax error of client request, server cannot understand;

403 The server understands the request of the requesting client, but refuses to execute the request;

404 the server cannot find the resource (Web page) based on the client's request. Through this code, the website designer can set "the resource you requested cannot be found" personality page;

500 Server Internal error, unable to complete the request;

503 due to overloading or system maintenance, the server is temporarily unable to process client requests. The length of the delay can be included in the server's Retry-after header information

HTTP Network Protocol Learning Summary