Http error 406 when I try to access yahoo API - http

Question

I use yahoo oAuth1 and yahoo API to get contact list from yahoo server.
Here the code that I use to get contacts:
private void RetriveContacts()
{
OAuthBase oauth = new OAuthBase();
Uri uri = new Uri("https://social.yahooapis.com/v1/user/" + (string)Session["xoauth_yahoo_guid"] + "/contacts?format=XML");
string nonce = oauth.GenerateNonce();
string timeStamp = oauth.GenerateTimeStamp();
string normalizedUrl;
string normalizedRequestParameters;
string sig = oauth.GenerateSignature(uri, ConsumerKey, ConsumerSecret,
(string)Session["oauth_token"], (string)Session["oauth_token_secret"], "GET",
timeStamp, nonce, OAuthBase.SignatureTypes.HMACSHA1,
out normalizedUrl, out normalizedRequestParameters);
StringBuilder sbGetContacts = new StringBuilder(uri.ToString());
try
{
string returnStr = string.Empty;
HttpWebRequest req = (HttpWebRequest)WebRequest.Create(sbGetContacts.ToString());
req.Method = "GET";
string authHeader = "Authorization: OAuth " +
"realm=\"yahooapis.com\"" +
",oauth_consumer_key=\"" + ConsumerKey + "\"" +
",oauth_nonce=\"" + nonce + "\"" +
",oauth_signature_method=\"HMAC-SHA1\"" +
",oauth_timestamp=\"" + timeStamp + "\"" +
",oauth_token=\"" + (string)Session["oauth_token"] + "\"" +
",oauth_version=\"1.0\"" +
",oauth_signature=\"" + HttpUtility.UrlEncode(sig) + "\"";
req.Headers.Add(authHeader);
HttpWebResponse res = (HttpWebResponse)req.GetResponse();
StreamReader streamReader = new StreamReader(res.GetResponseStream());
returnStr = streamReader.ReadToEnd();
XmlDocument xmldoc = new XmlDocument();
xmldoc.LoadXml(returnStr);
XmlNodeList elemList = xmldoc.DocumentElement.GetElementsByTagName("fields");
List<string> emails = new List<string>();
for (int i = 0; i < elemList.Count; i++)
{
if (elemList[i].ChildNodes[1].InnerText == "email")
emails.Add(elemList[i].ChildNodes[2].InnerText);
//Response.Write(elemList[i].ChildNodes[2].InnerText + "<br/>");
}
}
catch (WebException ex)
{
//Response.Write(ex.Message);
Response.Write("<br/>" + ex.Message + "</br>xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx");
Response.Write("<br/>length: " + ex.Source.Length.ToString());
Response.Write("<br/>stack trace: " + ex.StackTrace);
Response.Write("<br/>status: " + ex.Status.ToString());
HttpWebResponse res = (HttpWebResponse)ex.Response;
int code = Convert.ToInt32(res.StatusCode);
Response.Write("<br/>Status Code: (" + code.ToString() + ") " + res.StatusCode.ToString());
Response.Write("<br/>Status Description: " + res.StatusDescription);
if (ex.InnerException != null)
{
Response.Write("<br/>innerexception: " + ex.InnerException.Message);
}
if (ex.Source.Length > 0)
Response.Write("<br/>source: " + ex.Source.ToString());
if (res != null)
{
for (int i = 0; i < res.Headers.Count; i++)
{
Response.Write("<br/>headers: " + i.ToString() + ": " + res.Headers[i]);
}
}
}
}
But in this row:
HttpWebResponse res = (HttpWebResponse)req.GetResponse();
I get this Error:
Any why I get this error and how to fix it?
Thank you in advance.

Answer 1

Try setting the Accept header in your HTTP request. Something like this:
Accept: text/html,*/*;q=0.9
HTTP 406 indicates that either this header is expected but missing, or that it was present but did not specify a Content-Type that is compatible with the resource (e.g. asking for Accept: text/html when requesting a JPEG image.)
See also the Accept-Charset, Accept-Encoding, and Accept-Language headers which can also trigger this status code.

Answer 2

My issue had to do with format=XML > changing it to format=json and changing both the accept and content type headers to appliocation/json, returns the emails which i was trying to GET
Get Yahoo Contact List in C# application