views:

623

answers:

1

When a web server responds to HttpWebRequest.GetResponse() with HTTP 304 (Not Modified), GetResponse() thows a WebException, which is so very weird to me. Is this by design or am I missing something obvious here?

+4  A: 

Ok, this seems to be a by-design behavior and a perfect example of a vexing exception. This can be solved with this:

public static HttpWebResponse GetHttpResponse(this HttpWebRequest request)
{
    try
    {
        return (HttpWebResponse) request.GetResponse();
    }
    catch (WebException ex)
    {
        if(ex.Response == null || ex.Status != WebExceptionStatus.ProtocolError)
            throw; 

        return (HttpWebResponse)ex.Response;
    }
}
Anton Gogolev
This works most of the cases, but some web servers could return a response body when returning a 404 error. In that case, the code above would treat a 404 as it treats a 304!
comshak