GetRequestStream() is throwing time out exception

问题:

I'm calling an API hosted on Apache server to post data. I'm using HttpWebRequest to perform POST in C#.

API has both normal HTTP and secure layer (HTTPS) PORT on the server. When I call HTTP URL it works perfectly fine. However, when I call HTTPS it gives me time-out exception (at GetRequestStream() function). Any insights? I'm using VS 2010, .Net framework 3.5 and C#. Here is the code block:

string json_value = jsonSerializer.Serialize(data);


        HttpWebRequest request = (HttpWebRequest)System.Net.WebRequest.Create("https://server-url-xxxx.com");
        request.Method = "POST";
        request.ProtocolVersion = System.Net.HttpVersion.Version10;
        request.ContentType = "application/x-www-form-urlencoded";

        byte[] buffer = Encoding.ASCII.GetBytes(json_value);
        request.ContentLength = buffer.Length;
        System.IO.Stream reqStream = request.GetRequestStream();
        reqStream.Write(buffer, 0, buffer.Length);
        reqStream.Close();

EDIT: The console program suggested by Peter works fine. But when I add data (in JSON format) that needs to be posted to the API, it throws out operation timed out exception. Here is the code that I add to console based application and it throws error.

byte[] buffer = Encoding.ASCII.GetBytes(json_value);
request.ContentLength = buffer.Length;

回答1:

I don't know if this will help you with your specific problem but you should consider Disposing some of those objects when you are finished with them. I was doing something like this recently and wrapping stuff up in using statements seems to clean up a bunch of timeout exceptions for me.

            using (var reqStream = request.GetRequestStream())
            {
                if (reqStream == null)
                {
                    return;
                }

              //do whatever

            }

also check these things

• Is the server serving https in your local dev environment?
• Have you set up your bindings *.443 (https) properly?
• Do you need to set credentials on the request?
• Is it your application pool account accessing the https resources or is it your account being passed through?

• Have you thought about using WebClient instead?

  using (WebClient client = new WebClient())
      {               
          using (Stream stream = client.OpenRead("https://server-url-xxxx.com"))
          using (StreamReader reader = new StreamReader(stream))
          {
              MessageBox.Show(reader.ReadToEnd());
          }
      }
  

EDIT:

make a request from console.

internal class Program
{
    private static void Main(string[] args)
    {
        new Program().Run();
        Console.ReadLine();
    }

    public void Run()
    {

       var request = (HttpWebRequest)System.Net.WebRequest.Create("https://server-url-xxxx.com");
        request.Method = "POST";
        request.ProtocolVersion = System.Net.HttpVersion.Version10;
        request.ContentType = "application/x-www-form-urlencoded";

        using (var reqStream = request.GetRequestStream())
        {
            using(var response = new StreamReader(reqStream )
            {
              Console.WriteLine(response.ReadToEnd());
            }
        }
    }
}

回答2:

I ran into the same issue. It seems like it is solved for me. I went through all my code making sure to invoke webResponse.Close() and/or responseStream.Close() for all my HttpWebResponse objects. The documentation indicates that you can close the stream or the HttpWebResponse object. Calling both is not harmful, so I did. Not closing the responses may cause the application to run out of connections for reuse, and this seems to affect the HttpWebRequest.GetRequestStream as far as I can observe in my code.

回答3:

Try this:

    WebRequest req = WebRequest.Create("https://server-url-xxxx.com");
    req.Method = "POST";
    string json_value = jsonSerializer.Serialize(data); //Body data
    ServicePointManager.Expect100Continue = false;
    using (var streamWriter = new StreamWriter(req.GetRequestStream()))
    {
        streamWriter.Write(json_value);
        streamWriter.Flush();
        streamWriter.Close();
    }
    HttpWebResponse resp = req.GetResponse() as HttpWebResponse;
    Stream GETResponseStream = resp.GetResponseStream();
    StreamReader sr = new StreamReader(GETResponseStream);
    var response = sr.ReadToEnd(); //Response
    resp.Close(); //Close response
    sr.Close(); //Close StreamReader

And review the URI:

• Reserved characters. Send reserved characters by the URI can bring problems ! * ' ( ) ; : @ & = + $ , / ? # [ ]

• URI Length: You should not exceed 2000 characters

回答4:

You may want to set timeout property, check it here http://www.codeproject.com/Tips/69637/Setting-timeout-property-for-System-Net-WebClient