Question

I need to make a POST request with an xml data.

String xml = "";
byte[] data = System.Text.Encoding.UTF8.GetBytes(xml);
HttpClient.post(url, data, "text/xml")

Then I call the POST function:

public static String post(String url, byte[] data, String contentType){
        String body = "";
        body = getResponse("POST", url, data, contentType, 80);
        return body;
    }

Now I call this function to make the request / get the response:

public static String getResponse(String method, String url, byte[] data, String contentType, int serverPort)
    {
        String result = null;
        HttpWebRequest request = sendRequest(method, url, data, contentType, serverPort);
        HttpWebResponse response = null;
        try
        {
            response = (HttpWebResponse)request.GetResponse();
            if (response != null){
                // Get the stream associated with the response
                Stream receiveStream = response.GetResponseStream ();
                // Pipes the stream to a higher level stream reader
                StreamReader readStream = new StreamReader (receiveStream, System.Text.Encoding.UTF8);
                result = readStream.ReadToEnd ();
            }
        }
        catch(WebException ex)
        {
            if (ex.Status == WebExceptionStatus.ProtocolError){
                throw new HttpClientException("HTTP response error. ", (int)(((HttpWebResponse)ex.Response).StatusCode), ((HttpWebResponse)ex.Response).StatusDescription);
            }
            else{
                throw new HttpClientException("HTTP response error with status: " + ex.Status.ToString());
            }
        }
}

and

public static HttpWebRequest sendRequest(String method, String url, byte[] data, String contentType, int serverPort){
        HttpWebRequest request = null;
        try
        {
            UriBuilder requestUri = new UriBuilder(url);
            requestUri.Port = serverPort;
            request = (HttpWebRequest)WebRequest.Create(requestUri.Uri);
            request.Method = method;
            //
            if ((method == "POST") && (data != null) && (data.Length > 0)){
                request.ContentLength = data.Length;
                request.ContentType = ((String.IsNullOrEmpty(contentType))?"application/x-www-form-urlencoded":contentType);
                Stream dataStream = request.GetRequestStream ();
                dataStream.Write (data, 0, data.Length);
                // Close the Stream object.
                dataStream.Close ();
            }
        }
        catch(WebException ex)
        {
            if (ex.Status == WebExceptionStatus.ProtocolError){
                throw new HttpClientException("HTTP request error. ", (int)(((HttpWebResponse)ex.Response).StatusCode), ((HttpWebResponse)ex.Response).StatusDescription);
            }
            else{
                throw new HttpClientException("HTTP request error with status: " + ex.Status.ToString());
            }
        }
}

It always give me an HttpCliendException:

video_api.HttpClientException: HttpClient exception :HTTP response error.  with `code: 400` and `status: Bad Request`

But when I tried it with Firefox addon HTTP Resource Test, it ran fine and get 202 Accepted status with the same XML doc.

I consoled the content-type and data.length before the post request was called, the content-type was text/xml and the data.length is 143.

Answer 1

I have known some websites to be picky about request headers and return different results solely based on those values. Compare the request headers of the HTTP request in FireFox, and your request, and if you mimic the headers in the FireFox Resource Test, it will most likely work (Request.AddHeader("name", "value")). The other difference to note might be the user-agent which again can be picky for web servers.