Http Error Status 304
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sections of messages Error, Forward and redirection responses may be used to contain human-readable diagnostic information. Success 2xx These codes indicate success. The
Http Response Example
body section if present is the object returned by the request. It is http code 302 a MIME format object. It is in MIME format, and may only be in text/plain, text/html or one fo http 403 the formats specified as acceptable in the request. OK 200 The request was fulfilled. CREATED 201 Following a POST command, this indicates success, but the textual part of the response line
Http 404
indicates the URI by which the newly created document should be known. Accepted 202 The request has been accepted for processing, but the processing has not been completed. The request may or may not eventually be acted upon, as it may be disallowed when processing actually takes place. there is no facility for status returns from asynchronous operations such as this. Partial
Http 500
Information 203 When received in the response to a GET command, this indicates that the returned metainformation is not a definitive set of the object from a server with a copy of the object, but is from a private overlaid web. This may include annotation information about the object, for example. No Response 204 Server has received the request but there is no information to send back, and the client should stay in the same document view. This is mainly to allow input for scripts without changing the document at the same time. Error 4xx, 5xx The 4xx codes are intended for cases in which the client seems to have erred, and the 5xx codes for the cases in which the server is aware that the server has erred. It is impossible to distinguish these cases in general, so the difference is only informational. The body section may contain a document describing the error in human readable form. The document is in MIME format, and may only be in text/plain, text/html or one for the formats specified as acceptable in the request. Bad request 400 T
false. In other words, there is no need for the server to transfer a http 400 representation of the target resource because the request indicates that
Http 422
the client, which made the request conditional, already has a valid representation; the server is therefore http 502 redirecting the client to make use of that stored representation as if it were the payload of a 200 OK response. The server generating a https://www.w3.org/Protocols/HTTP/HTRESP.html 304 response MUST generate any of the following header fields that would have been sent in a 200 OK response to the same request: Cache-Control, Content-Location, Date, ETag, Expires, and Vary. Since the goal of a 304 response is to minimize information transfer when the recipient already has one or more cached https://httpstatuses.com/304 representations, a sender SHOULD NOT generate representation metadata other than the above listed fields unless said metadata exists for the purpose of guiding cache updates (e.g., Last-Modified might be useful if the response does not have an ETag field). Requirements on a cache that receives a 304 response are defined in Section 4.3.4 of RFC7234. If the conditional request originated with an outbound client, such as a user agent with its own cache sending a conditional GET to a shared proxy, then the proxy SHOULD forward the 304 response to that client. A 304 response cannot contain a message-body; it is always terminated by the first empty line after the header fields. Source: RFC7232 Section 4.1 304 Code References Rails HTTP Status Symbol :not_modified Go HTTP Status Constant http.StatusNotModified Symfony HTTP Status Constant Response::HTTP_NOT_MODIFIED Python2 HTTP Status Constant httplib.NOT_MODIFIED Python3+ HTTP Status Constant http.client.NOT_MODIFIED Python3.5+ HTTP Status Constant http.HTTPStatus.NOT_MODIFIED← Return to httpstatuses.com
here for a quick overview of the site Help Center Detailed answers to any questions you might have Meta Discuss http://stackoverflow.com/questions/20978189/how-304-not-modified-works the workings and policies of this site About Us Learn more about Stack Overflow the company Business Learn more about hiring developers or posting ads with us Stack Overflow http://www.telerik.com/blogs/understanding-http-304-responses Questions Jobs Documentation Tags Users Badges Ask Question x Dismiss Join the Stack Overflow Community Stack Overflow is a community of 4.7 million programmers, just like you, helping each http error other. Join them; it only takes a minute: Sign up How “304 Not Modified” works? up vote 83 down vote favorite 19 How "304 Not Modified" is generated? How does a browser determine whether the response to a http request is 304.? Is it set by the browser or sent from the server? If sent by server, how http error status does server know the data available in cache, also how does it set 304 to an image? My Guess, if generated by browser function is_modified() { return get_data_from_cache() === get_data_from_url(); }; function get_data_from_cache() { return some_hash_or_xxx_function(cache_data); } function get_data_from_url() { return some_hash_or_xxx_function(new_data); } function some_hash_or_xxx_function(data) { // do something with data // what is that algorithm.? return result; } console.log(is_modified()); I am relying on 3rd party API provider to get data, parse & push it to DB. The data may or may not change during every request, but the header always sends 200, I do not want to parse, check the last Unique ID in DB & so on.. to determine the change in data, nor compare the result directly rather I md5(), sha1() & crc32() HASHed the result & works fine, but wondering the algorithm to determine 304 I want to use same kind of algorithm to determine the change in data. http browser http-headers firebug http-status-code-304 share|improve this question edited Feb 10 '14 at 17:17 asked Jan 7 '14
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