Internet Error Codes 304
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here for a quick overview of the site Help Center Detailed answers to any questions you might have Meta Discuss the workings and policies of this site About Us Learn more about Stack Overflow the company Business http status code 400 Learn more about hiring developers or posting ads with us Stack Overflow Questions Jobs Documentation http code 302 Tags Users Badges Ask Question x Dismiss Join the Stack Overflow Community Stack Overflow is a community of 4.7 million programmers, just like http code 403 you, helping each other. Join them; it only takes a minute: Sign up Why am I getting “(304) Not Modified” error on some links when using HttpWebRequest? up vote 18 down vote favorite 7 Any ideas why
Http Status Codes Cheat Sheet
on some links that I try to access using HttpWebRequest I am getting "The remote server returned an error: (304) Not Modified." in the code? The code I'm using is from Jeff's post here (the page seems to have disappeared, see an archive copy at the Wayback Machine). Note the concept of the code is a simple proxy server, so I'm pointing my browser at this locally running piece of code, which gets my browsers http response example request, and then proxies it on by creating a new HttpWebRequest, as you'll see in the code. It works great for most sites/links, but for some this error comes up. You will see one key bit in the code is where it seems to copy the http header settings from the browser request to it's request out to the site, and it copies in the header attributes. Not sure if the issue is something to do with how it mimics this aspect of the request and then what happens as the result comes back? case "If-Modified-Since": request.IfModifiedSince = DateTime.Parse(listenerContext.Request.Headers[key]); break; I get the issue for example from http://en.wikipedia.org/wiki/Main_Page PS. UPDATE HERE Still can't work this out. Basically I can identify 1 link which has an issue, and it seems to work fine, 2nd time it gets the error, 3rd time OK, 4th time gets the error, 5th time OK etc. As if there is some state not getting cleared or something in the code. I've tried to clean up the code a bit using "using" type statements etc. Here's the code. If anyone can spot why every 2nd time I browse to a link like http://newsimg.bbc.co.uk/css/screen/1_0_16/nol/v4/story.css (starting at the 2nd time, not the first) via this proxy code I get the error I'd love to hear. class Program { static void Main(string[] args) {
response. 10.1 Informational 1xx This class of status code indicates a provisional response, consisting only of the Status-Line and optional headers, and is terminated by an empty line. There are no required headers for this class of status code. Since HTTP/1.0 did 304 not modified cache not define any 1xx status codes, servers MUST NOT send a 1xx response to an
Http 404
HTTP/1.0 client except under experimental conditions. A client MUST be prepared to accept one or more 1xx status responses prior to a regular
Http 422
response, even if the client does not expect a 100 (Continue) status message. Unexpected 1xx status responses MAY be ignored by a user agent. Proxies MUST forward 1xx responses, unless the connection between the proxy and its client http://stackoverflow.com/questions/2603595/why-am-i-getting-304-not-modified-error-on-some-links-when-using-httpwebrequ has been closed, or unless the proxy itself requested the generation of the 1xx response. (For example, if a proxy adds a "Expect: 100-continue" field when it forwards a request, then it need not forward the corresponding 100 (Continue) response(s).) 10.1.1 100 Continue The client SHOULD continue with its request. This interim response is used to inform the client that the initial part of the request has been received and has not yet been rejected by the https://www.w3.org/Protocols/rfc2616/rfc2616-sec10.html server. The client SHOULD continue by sending the remainder of the request or, if the request has already been completed, ignore this response. The server MUST send a final response after the request has been completed. See section 8.2.3 for detailed discussion of the use and handling of this status code. 10.1.2 101 Switching Protocols The server understands and is willing to comply with the client's request, via the Upgrade message header field (section 14.42), for a change in the application protocol being used on this connection. The server will switch protocols to those defined by the response's Upgrade header field immediately after the empty line which terminates the 101 response. The protocol SHOULD be switched only when it is advantageous to do so. For example, switching to a newer version of HTTP is advantageous over older versions, and switching to a real-time, synchronous protocol might be advantageous when delivering resources that use such features. 10.2 Successful 2xx This class of status code indicates that the client's request was successfully received, understood, and accepted. 10.2.1 200 OK The request has succeeded. The information returned with the response is dependent on the method used in the request, for example: GET an entity corresponding to the requested resource is sent in the response; HEAD the entity-header fields corresponding to the requested resource are sent in the response without any m
here for a quick overview of the site Help Center Detailed answers to any questions you might have Meta Discuss the http://stackoverflow.com/questions/2603595/why-am-i-getting-304-not-modified-error-on-some-links-when-using-httpwebrequ 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 Questions Jobs http://100pulse.com/http-statuscode/304.jsp 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 other. Join http status them; it only takes a minute: Sign up Why am I getting “(304) Not Modified” error on some links when using HttpWebRequest? up vote 18 down vote favorite 7 Any ideas why on some links that I try to access using HttpWebRequest I am getting "The remote server returned an error: (304) Not Modified." in the code? The code I'm http status code using is from Jeff's post here (the page seems to have disappeared, see an archive copy at the Wayback Machine). Note the concept of the code is a simple proxy server, so I'm pointing my browser at this locally running piece of code, which gets my browsers request, and then proxies it on by creating a new HttpWebRequest, as you'll see in the code. It works great for most sites/links, but for some this error comes up. You will see one key bit in the code is where it seems to copy the http header settings from the browser request to it's request out to the site, and it copies in the header attributes. Not sure if the issue is something to do with how it mimics this aspect of the request and then what happens as the result comes back? case "If-Modified-Since": request.IfModifiedSince = DateTime.Parse(listenerContext.Request.Headers[key]); break; I get the issue for example from http://en.wikipedia.org/wiki/Main_Page PS. UPDATE HERE Still can't work this out. Basically I can identify 1 link which has an issue, and it seem
is sent in response to a request (for a document) that asked for the document only if it was newer than the one the client already had. Normally, when a document is cached, the date it was cached is stored. The next time the document is viewed, the client asks the server if the document has changed. If not, the client just reloads the document from the cache. Why it Occurs The HTTP status code 304 Not Modified occurs if the client has performed a conditional GET request and access is allowed, but the document has not been modified. The server SHOULD respond with this status code. The 304 response MUST NOT contain a message-body, and thus is always terminated by the first empty line after the header fields. Fixing 304 Error Code You should never see this error in your Web browser. It should simply present the Web page from its cache - because it believes the page has not changed since it was last cached. If your client is not a Web browser, then it should equally be able to present the page from a cache. If unable to do so, it is not using the If_Modified_Since or related headers correctly. If you monitor your website through 100 pulse, we will intimate you through mail or short message service whenever you encounter 304 status code. Features Website Monitoring Monitor DNS Server Mail Server Monitoring Mysql Server Monitoring FTP Monitoring Port Monitoring Alerts & Reports Instant Notification Web Server Monitoring Report Public Report Template Free Uptime Button Monitoring Tools Webpage Availability Checker Port checker DNS Checker IP Finder Server location Finder and more... Reseller Affiliate Program Pricing Latest Updates Feedback Write a testimonial About Us Contact Us Follow Us on Twitter Facebook Server Time : 19-Oct-2016 03:43:40 GMT All Rights reserved © 100pulse.com Terms | Privacy | Sitemap