Question

In Fiddler, I can pass in a request and get a response 500. Fine by me, I want my .NET code to handle this AND analyze the response message. In the case below there is a meaningful message. Yet using HttpWebRequest and HttpWebResponse, I cannot get that information.

Here is the response from Fiddler:

HTTP/1.1 500 Internal Server Error
Date: Sun, 25 Mar 2012 15:50:31 GMT
Transfer-Encoding: chunked
Content-Type: text/xml; charset=ISO-8859-1
X-Powered-By: Servlet/2.5 JSP/2.1

010e
<soap:Envelope xmlns:soap="http://schemas.xmlsoap.org/soap/envelope/"><soap:Body><soap:Fault><faultcode>soap:Client</faultcode><faultstring>WSS header is missing from request. Can't do username token authentication.</faultstring></soap:Fault></soap:Body></soap:Envelope>
0000

Here is my code which tries to catch the exception:

        try
        {
            HttpWebResponse resp2 = (HttpWebResponse) req.GetResponse();
        }
        catch (WebException ex)
        {
            WebException we = (WebException) ex;
            HttpWebResponse respp = (HttpWebResponse) we.Response;
            log.Info((int)respp.StatusCode);
            log.Error(ex.ToString());
        }

I just cannot get anything more from the exception object. But I know the response should be readable. Hopefully there are lower-level http classes I can use that I just don’t know about now. I don’t want .NET protecting me from the real HTTP protocols.

Answer 1

It’s not clear what you’ve tried to do with respp. (I note that you’re not using resp2, either.) For example, what does this do:

catch (WebException ex)
{
    using (HttpWebResponse respp = (HttpWebResponse) ex.Response)
    {
        log.Info((int)respp.StatusCode);
        log.Error(ex.ToString());
        log.Error(new StreamReader(respp.GetResponseStream()).ReadToEnd());
    }
}

(It’s never been clear to me whether you really need to dispose of a WebResponse obtained in a WebException, but it’s probably a good idea. You might want to dispose of the response stream as well, although I believe disposing of the response is good enough.)