Christopher Gilmore

Hey Guys,

I am writing a small Netduino+2 application, which will communicate with the Phillips HUE light bridge controller. This should be a simple task, in that the all I am doing is sending simple Http requests to the bridge (which I can do sucessfully).

The problem however, is when I try to process/parse the responses. Right now, I am experiencing three strange issues using the HttpWebResponse and Stream objects.

1. HttpWebResponse.ContentLength is always equal to "-1", even thought there is always body content (application/json content).

2. HttpWebResponse.GetResponseStream() seems to be unstable, in that it will sometimes truncate the response for longer responses (~700 bytes +). Putting in a Thread.Sleep(500) right after seems to help this for some reason. I don't know why.

3. Stream.Read() seems to be unstable, in that it will truncate near the end of stream (return 0) for the larger response.

Below is my code. I need this to be able to process around 2KB responses at least. I am running the latest framework 4.3. Anyone have any ideas?

Thanks,

Chris

public static string Send(string uri, string method, string body, bool ignoreResponse = true)
        {
            try
            {
                using (HttpWebRequest req = (HttpWebRequest)WebRequest.Create(new Uri("http://" + bridgeIP + "/api/" + bridgeUser + "/" + uri)))
                {
                    req.Method = method;
                    req.ContentType = "text/plain;charset=UTF-8";
                    req.Timeout = 3000; //3s 
                    req.ReadWriteTimeout = 3000;
                    req.KeepAlive = false;
                    if (body != null && body != "")
                    {
                        byte[] buffer = Encoding.UTF8.GetBytes(body);
                        req.ContentLength = buffer.Length;
                        using (Stream PostData = req.GetRequestStream())
                        {
                            PostData.Write(buffer, 0, buffer.Length);
                            PostData.Close();
                        }
                    }
                    else
                    {
                        req.ContentLength = 0;
                    }

                    Debug.Print("Sending " + method + " request to: " + uri);
                    HttpWebResponse resp = (HttpWebResponse)req.GetResponse();

                    string responseString = "";
                    
                    int contentLength = (int)resp.ContentLength;
                    if (!ignoreResponse)// && contentLength > 0)
                    {
                        //Otherwise process response
                        using (Stream responseStream = resp.GetResponseStream())
                        {
                            System.Threading.Thread.Sleep(500); //This seems to help fix the following line (responseStream.Length)
                            int responseLength = (int)responseStream.Length;

                            Debug.Print("Response with length " + responseLength.ToString() + " received. Processing...");
                            if (responseLength <= 0) return null;

                            //write to responseString in chunks of 256 bytes 
                            byte[] c = null;
                            while (true)
                            {
                                c = new byte[256];
                                if (responseStream.Read(c, 0, c.Length) == 0) break;
                                responseString += new string(Encoding.UTF8.GetChars(c));
                            }
                        }
                    }
                    resp.Close();
                    resp.Dispose();
                    req.Dispose();
                    Debug.Print("Response Processed. Length of:" + responseString.Length.ToString());
                    return responseString == "" ? null : responseString;
                }
            }
            catch (Exception e)
            {
                Debug.Print(e.ToString());
            }
            
            return null;
        }