Three: http Status code meaning (from W3school):
Status code:
1XX: Information
Message: Description:
The Continue server only receives partial requests, but once the server does not reject the request, the client should continue to send the remaining requests.
101 Switching Protocols Server Conversion protocol: The server translates the client's request to a different protocol.
2XX: Success
Message: Description:
The OK request succeeds (followed by the answer document for the Get and post requests.) )
The 201 Created request is created and the new resource is created.
202 Accepted the request for processing has been accepted, but processing is not completed.
203 Non-authoritative Information The document has returned normally, but some of the answer headers may be incorrect because a copy of the document is being used.
204 No Content There are no new documents. The browser should continue to display the original document. This status code is useful if the user refreshes the page on a regular basis and the servlet can determine that the user's document is new enough.
205 Reset Content does not have a new document. But the browser should reset what it displays. Used to force the browser to clear the form input.
The 206 Partial Content client sends a GET request with a range header that the server has completed.
3XX: redirect
Message: Description:
Multiple Choices multiple options. A list of links. The user can select a link to reach the destination. A maximum of five addresses are allowed.
301 Moved Permanently The requested page has been transferred to the new URL.
302 Found The requested page has been temporarily transferred to the new URL.
303 see another page that is requested can be found under a different URL.
304 Not Modified The document was not modified as expected. The client has a buffered document and issues a conditional request (typically providing a if-modified-since header indicating that the customer only wants to update the document than the specified date). The server tells the customer that the original buffered document can continue to be used.
305 Use proxy The document requested by the client should be extracted from the agent server indicated by the location header.
306 Unused This code is used in the previous version. It is no longer used, but the code is still retained.
307 temporary Redirect The requested page has been temporarily moved to the new URL.
4XX: Client Error
Message: Description:
The requests server failed to understand the request.
401 Unauthorized The requested page requires a user name and password.
402 Payment Required This code is not yet available.
403 Forbidden access to the requested page is forbidden.
404 Not Found Server could not find the requested page.
405 Method Not allowed the methods specified in the request are not allowed.
The response generated by the 406 not acceptable server cannot be accepted by the client.
407 Proxy authentication Required The user must first authenticate with a proxy server so that the request is processed.
408 Request Timeout requests exceeded the server's wait time.
409 Conflict The request could not be completed due to a conflict.
410 Gone The requested page is not available.
411 Length Required "Content-length" is not defined. If there is no such content, the server will not accept the request.
412 Precondition Failed The prerequisites in the request are evaluated by the server as failed.
413 Request Entity Too Large The server will not accept requests because the requested entity is too large.
414 Request-url Too Long because the URL is too long, the server will not accept the request. This occurs when the POST request is converted to a GET request with very long query information.
415 unsupported media Type the server does not accept requests because the media types are not supported.
416 The server does not meet the range header specified by the customer in the request.
417 Expectation Failed
5XX: Server Error
Message: Description:
The Internal Server Error request was not completed. The server encountered unpredictable conditions.
501 Not implemented request was not completed. The requested functionality is not supported by the server.
502 Bad Gateway request was not completed. The server received an invalid response from the upstream server.
503 Service unavailable Request not completed. The server is temporarily overloaded or in a machine.
504 Gateway Timeout.
505 HTTP version not supported server does not support the HTTP protocol version indicated in the request.
Python interface Test (ii)