Why I get 411 Length required error?

Question

This is how I call a service with .NET:

var requestedURL = "https://accounts.google.com/o/oauth2/token?code=" + code + "&client_id=" + client_id + "&client_secret=" + client_secret + "&redirect_uri=" + redirect_uri + "&grant_type=authorization_code"; HttpWebRequest authRequest = (HttpWebRequest)WebRequest.Create(requestedURL); authRequest.ContentType = "application/x-www-form-urlencoded"; authRequest.Method = "POST"; WebResponse authResponseTwitter = authRequest.GetResponse(); 

but when this method is invoked, I get:

Exception Details: System.Net.WebException: The remote server returned an error: (411) Length Required.

what should I do?

Answer 1

When you're using HttpWebRequest and POST method, you have to set a content (or a body if you prefer) via the RequestStream. But, according to your code, using authRequest.Method = "GET" should be enough.

In case you're wondering about POST format, here's what you have to do :

ASCIIEncoding encoder = new ASCIIEncoding(); byte[] data = encoder.GetBytes(serializedObject); // a json object, or xml, whatever...  HttpWebRequest request = WebRequest.Create(url) as HttpWebRequest; request.Method = "POST"; request.ContentType = "application/json"; request.ContentLength = data.Length; request.Expect = "application/json";  request.GetRequestStream().Write(data, 0, data.Length);  HttpWebResponse response = request.GetResponse() as HttpWebResponse; 

Answer 2

you need to add Content-Length: 0 in your request header.

a very descriptive example of how to test is given here