I've been battling some crazy ASP.NET 1.1 code the past couple of days. First, I was calling some web services with entirely hand written SOAP protocol management. That's always fun. While tedious and too low of a level to be mucking around, it was the fastest means to an end with a crotchity ol' Apache/AXIS web service. Even though I'm fresh off the WCF training regimen; that new stuff wouldn't have helped me here. Perhaps just having the new stuff in my head pushed me in the right direction to tackle this challenge - a man can dream, can't he?
Then, just to rub it in a little, the HTTPWebRequest object decided to give me a swift kick in the shorts. You see, in .Net 1.1, there's a tiny little unknown (unanswered) bug.
I have two instance methods and each make a single call over HTTP with their own HTTPWebRequest object, there's no sharing here. Every time, the second request would hang and throw a "System.Net.WebException : The operation has timed-out." error. The same code runs great in .Net 2.0 so I figure its a framework bug.
I call one method and return a string which is used as an input argument for the second method. Both calls go to the same top level domain, but call to different end points on the domain.
After much thought, trial and error, as well as reading about the same problem other folks were having, I finally figured out the workaround.
It turns out that calling the Abort() method on the HTTPRequest instance after completing the request is sufficient to break up the clog that is preventing subsequent calls. The following code block shows the working helper method. If I comment out the calll to Abort(), it no worky.
private string ExecuteHttpWebRequest(
string url, RequestMethod method, string message)
{
HttpWebRequest request =
(HttpWebRequest)HttpWebRequest.Create(url);
request.Timeout = 30000;
request.KeepAlive = false;
request.Headers.Add("Cache-Control", "no-cache");
request.Headers.Add("Pragma", "no-cache");
switch( method )
{
case RequestMethod.Get :
request.Method = "GET";
break;
case RequestMethod.Post :
request.ContentType
= "application/x-www-form-urlencoded";
request.Method = "POST";
request.ContentLength = message.Length;
StreamWriter sw =
new StreamWriter(request.GetRequestStream());
sw.Write(message);
sw.Flush();
break;
}
string html = null;
using( HttpWebResponse response
= (HttpWebResponse)request.GetResponse() )
{
Stream rs = response.GetResponseStream();
StreamReader sr = new StreamReader(rs);
html = sr.ReadToEnd();
response.Close();
// subsequent calls fail without this abort in .Net v1.1
request.Abort();
}
return html;
}