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REST API PATCH request

I'm trying to send requests and get responses from MailChimp API . . so far, GET, POST and DELETE are working good however, PATCH always results to Bad Request can you identify the error in this code?
string data = "{\"name\": \"TestListTWOTWOTWO\"}";
HttpWebRequest request = (HttpWebRequest)HttpWebRequest.Create(uri);
request.Headers[HttpRequestHeader.Authorization] = accessToken;
request.Method = "PATCH";
request.ContentType = "text/plain;charset=utf-8";
System.Text.UTF8Encoding encoding = new System.Text.UTF8Encoding();
byte[] bytes = encoding.GetBytes(data);
request.ContentLength = bytes.Length;
using (Stream requestStream = request.GetRequestStream())
{
// Send the data.
requestStream.Write(bytes, 0, bytes.Length);
}
var response = (HttpWebResponse)request.GetResponse();
var responseString = new StreamReader(response.GetResponseStream()).ReadToEnd();
the error occus on the line with request.GetResponse();
it is an unhandled WebException saying The remote server returned an error: (400) Bad Request
after checking the error response, here's the what it says
"Your request doesn't appear to be valid JSON:
\nParse error on line 1:\nPATCH /3.0/lists/9bb\n^\n
Expected one of: 'STRING', 'NUMBER', 'NULL', 'TRUE', 'FALSE', '{', '['"

Many C# libraries seem to try to use the Expect: 100-Continue header, which MailChimp/Akamai has a problem with when combined with PATCH. You have two options.
Turn off Expect: 100-Continue in your HTTP library. In one C# library, you do that with a line of code like Client.DefaultRequestHeaders.ExpectContinue = False
Tunnel the PATCH request through HTTP POST using the X-Http-Method-Override header. Here's more details on that header.

Cause PATCH is a quite new RFC, so you would not expect that more then a few services support it at all. You'd better check that if the service supports it.
You send request using json format, but set content type to "text/plain" is that OK?

HttpWebRequest stops working suddenly, No response received after few requests

I’m working with a WPF .net 4.0 Application. I have a search bar. For each search token I need to do 8 http request to 8 separate URLs to get search results. I send 8 requests to server after 400 milliseconds once the user stops typing in search bar. Searching for 6 to 7 search-tokens results comes very nicely. But after that suddenly HttpWebRequest stops working silently. No exception was thrown, no response was received. I'm working with Windows 7, I disabled the firewall too. I don't know where the subsequent http requests are lost.
Can anyone show me lights to fix this issue?
Below is my code for HttpWebRequest call.
public static void SendReq(string url)
{
// Create a new HttpWebRequest object.
HttpWebRequest request = (HttpWebRequest)WebRequest.Create(url);
request.ContentType = "application/x-www-form-urlencoded";
request.Proxy = new WebProxy("192.168.1.1", 8000);
// Set the Method property to 'POST' to post data to the URI.
request.Method = "POST";
// start the asynchronous operation
request.BeginGetRequestStream(new AsyncCallback(GetRequestStreamCallback), request);
}
private static void GetRequestStreamCallback(IAsyncResult asynchronousResult)
{
HttpWebRequest request = (HttpWebRequest)asynchronousResult.AsyncState;
// End the operation
Stream postStream = request.EndGetRequestStream(asynchronousResult);
string postData = this.PostData;
// Convert the string into a byte array.
byte[] byteArray = Encoding.UTF8.GetBytes(postData);
// Write to the request stream.
postStream.Write(byteArray, 0, byteArray.Length);
postStream.Close();
// Start the asynchronous operation to get the response
request.BeginGetResponse(new AsyncCallback(GetResponseCallback), request);
}
private static void GetResponseCallback(IAsyncResult asynchronousResult)
{
HttpWebRequest request = (HttpWebRequest)asynchronousResult.AsyncState;
// End the operation
using(HttpWebResponse response = (HttpWebResponse)request.EndGetResponse(asynchronousResult))
{
using(Stream streamResponse = response.GetResponseStream())
{
using(StreamReader streamRead = new StreamReader(streamResponse))
{
string responseString = streamRead.ReadToEnd();
Debug.WriteLine(responseString);
}
}
}
}

I think i am very late, but i still want to answer your question, may be it can be helpful to others. By default HTTP Request you make are HTTP 1.1 requests. And HTTP 1.1 Request by default has Keep-Alive connection. so when you make too many request to same server .net framework only make x no. of request.
you should close all your response by response.Close()
you can also specify how many simultaneous requests you can make.
ServicePointManager.DefaultConnectionLimit = 20;
Note that you have to set DefaultConnectionLimit before the first request you make. you can find more information
here on msdn.

All i can see is that in GetRequestStreamCallback you should replace
postStream.Write(byteArray, 0, postData.Length);
by
postStream.Write(byteArray, 0, byteArray.Length);
since these length aren't necessarily equal.

#Somnath
I am not sure if you found this answer, but if anyone else stumbles across this post with the same issue that Somnath and I were having.
We all try to do our due diligence in keeping memory clean and clear, but with streams we always will save unexplained issues if we make sure to flush the stream before we close it.
Replace This :
postStream.Write(byteArray, 0, byteArray.Length);
postStream.Close();
With This :
postStream.Write(byteArray, 0, byteArray.Length);
postStream.Flush();
postStream.Close();

I followed all suggestion provide by all of you but couldn't stop the silent failure of HTTP request. But I found a workaround. Even myself could not reach to a final conclusion till now.
But my workaround is working well as off now without any failure.
In SendReq(string url) function i have added the following lines of code
System.Net.ServicePointManager.DefaultConnectionLimit = 100; // Just selected a random number for testing greater than 2
System.Net.ServicePointManager.SetTcpKeepAlive(true, 30, 30); // 30 is based on my server i'm hitting
System.Net.ServicePointManager.SecurityProtocol = SecurityProtocolType.Ssl3;
request.KeepAlive = true;

HttpWebOperation timing out. Why and what to check?

I'm calling web service (my web service) like this:
var request = WebRequest.Create(Options.ServerUri + Options.AccountId + "/integration/trip") as HttpWebRequest;
request.Timeout = 20000; // 20 seconds should be plenty, no need for 100 seconds
request.ContentType = "application/json";
request.Headers.Add(HttpRequestHeader.Authorization, "Basic " + Convert.ToBase64String(Encoding.UTF8.GetBytes(Options.LoginName + ":" + Options.Password)));
request.Method = "POST";
var serializedData = (new JavaScriptSerializer()).Serialize(trip);
var bytes = Encoding.UTF8.GetBytes(serializedData);
request.ContentLength = bytes.Length;
var os = request.GetRequestStream();
os.Write(bytes, 0, bytes.Length);
os.Close();
request.GetResponse();
LoggingAndNotifications.LogAndNotify(string.Format("Success uploading trip: {0}", trip.TripId), false);
return true;
This code called repeatedly to post new objects. After about 3 calls I start getting timeouts on reguest.GetReponse()
There is no errors on server side, nothing in Event Log. It feels like "something" stops me from repeatedly hitting service. What should I look for? Is it possible with company firewall? Or something wrong with my code?

I think the issue is that you are not closing the response. Try editing your code as follows:
var response = request.GetResponse() as HttpWebResponse;
response.Close();

You should close the response as per the example in the doco.
WebRequest myRequest = WebRequest.Create("http://www.contoso.com");
// Return the response.
WebResponse myResponse = myRequest.GetResponse();
// Code to use the WebResponse goes here.
// Close the response to free resources.
myResponse.Close();
Hmm. The doco also says
Any public static (Shared in Visual Basic) members of this type are
thread safe. Any instance members are not guaranteed to be thread
safe.
You should probably ask for a lock of some kind.

Are you sure this is not caused by server side bugs?
It seems strange, as far as I known, the webrequest on .net4 is based on IOCP in lower layer, maybe you can try release web request/response resources after each loop.
Since the GetResponse() will return a stream, if you don't read from it, the real data may not transfer from server to client side. (I found this when I am trying to parse a response that I used peek(), and it always return an invalid value until the read() is called.)
So, try to read it or just close it.

Failed To get oauth2 Token via request.GetResponse()

I'm Trying to access Google Data (Contact, Edit profile data, Calendar ... etc) by using GData and OAuth2.0 server side (Check this link), I finished the first step and got the first code, and when try to post a request to get the oauth2_token I always got the error "The remote server returned an error: (400) Bad Request."
Here is the code I use to POST the request that returns the OAuth2_token:
string clientToken = Request.QueryString["code"];
string post =
string.Format(
#"code={0}&client_id={1}&client_secret={2}&redirect_uri=http://localhost/default.aspx&grant_type=authorization_code",
clientToken, Settings.ClientId, Settings.ClientSecret);
WebRequest httpRequest = WebRequest.Create("https://accounts.google.com/o/oauth2/token");
httpRequest.Method = "POST";
httpRequest.ContentType = "application/x-www-form-urlencoded";
StreamWriter streamWriter = new StreamWriter(httpRequest.GetRequestStream());
streamWriter.Write(post);
streamWriter.Flush();
streamWriter.Close();
var ss = (HttpWebResponse)httpRequest.GetResponse();
Stream stream = ss.GetResponseStream();
Any help??? I spent 2 days till now trying to solve it but in vain :(

could it be that the redirect_uri needs to be URI encoded?
[https://groups.google.com/forum/#!topic/oauth2-dev/9xnn8nUIA2s]

I think you should encode the redirect_uri parameter using HttpUtility.UrlEncode.
also, you should encode the request body using Utf8 encoding:
byte[] encoded = Encoding.UTF8.GetBytes(post);
httpRequest.ContentLength = encoded.Length
hope this helps.

getting this error: "The remote server returned an error: (422) Unprocessable Entity." when doing post from C# to RoR

This code is for an outlook plugin. We're trying to POST to a page and are getting this error:
The remote server returned an error: (422) Unprocessable Entity.
The C# code is here:
webClient.Headers.Add("Content-Type", "application/x-www-form-urlencoded");
ASCIIEncoding asciiEncoding = new System.Text.ASCIIEncoding();
Byte[] postData = asciiEncoding.GetBytes("email=e2#email.com&password=hunter2");
char[] resultHTML = asciiEncoding.GetChars(webClient.UploadData("http://url", "POST", postData));
string convertedResultHTML = new string(resultHTML);
Any idea what could be causing this?

POST data must be encoded prior to be sent out on the wire as ASCII, if you are sending character not in the ASCII range. You should try something like:
Byte[] postData = asciiEncoding.GetBytes(HttpUtility.UrlEncode("email=e2#email.com&password=hunter2"));

Because of its limited functionality, I avoid using WebClient and use WebRequest instead. The code below:
does not expect an HTTP 100 status code to be returned,
creates a CookieContainer to store any cookies we pick up,
sets the Content Length header, and
UrlEncodes each value in the post data.
Give the following a try and see if it works for you.
System.Net.ServicePointManager.Expect100Continue = false;
System.Net.CookieContainer cookies = new System.Net.CookieContainer();
// this first request just ensures we have a session cookie, if one exists
System.Net.WebRequest req = System.Net.WebRequest.Create("http://localhost/test.aspx");
((System.Net.HttpWebRequest)req).CookieContainer = cookies;
req.GetResponse().Close();
// this request submits the data to the server
req = System.Net.WebRequest.Create("http://localhost/test.aspx");
req.ContentType = "application/x-www-form-urlencoded";
req.Method = "POST";
((System.Net.HttpWebRequest)req).CookieContainer = cookies;
string parms = string.Format("email={0}&password={1}",
System.Web.HttpUtility.UrlEncode("e2#email.com"),
System.Web.HttpUtility.UrlEncode("hunter2"));
byte[] bytes = System.Text.Encoding.ASCII.GetBytes(parms);
req.ContentLength = bytes.Length;
// perform the POST
using (System.IO.Stream os = req.GetRequestStream())
{
os.Write(bytes, 0, bytes.Length);
}
// read the response
string response;
using (System.Net.WebResponse resp = req.GetResponse())
{
if (resp == null) return;
using (System.IO.StreamReader sr = new System.IO.StreamReader(resp.GetResponseStream()))
{
response = sr.ReadToEnd().Trim();
}
}
// the variable response holds the results of the request...
Credits: Hanselman, Simon (SO Question)

This is the RoR application telling you that you have not formed a request that it can handle; the destination script exists (otherwise you'd see a 404), the request is being handled (otherwise you'd get a 400 error) and it's been encoded correctly (or you'd get a 415 error) but the actual instruction can't be carried out.
Looking at it, you seem to be loading some email information. The RoR application could be telling you that the username and password is wrong, or that the user doesn't exist, or something else. It's up to the RoR application itself.
I think the code itself is good; it's just that the app at the other end isn't happy about doing what you ask it. Are you missing something else in the request information, like a command? (eg command=getnetemails&email=e2#email.com&password=hunter2) Are you sure the email/password combination you are passing is good?
see here for more on the 422 error.

Add the below line above your code.
System.Net.ServicePointManager.Expect100Continue = false;
Are you trying to access an authentication required page?

it was solved by returning xml instead of just unstructured text on the RoR side