Problem to read bytes in NanoHttpd post with octet-stream (Android)

[brunogabriel]

Hello, I am using Nanohttpd in Android to create an app that receives bytes from other instance of the same app. In my case, my application works and send data normally to a web service, but when I tried to send data between two instance of this application, when I debugged I saw strange bytes like trash or for example different encoding. I tried to use InputStream from NanoHttpd.

My code send data with a java code:

import java.io.DataOutputStream;
import java.io.OutputStream;
import java.net.HttpURLConnection;
import java.net.URL;

public class MainTest {
    public static void main(String[] args) {
        try {
            URL url = new URL("http://192.168.0.215:8080");
            HttpURLConnection httpConnection = (HttpURLConnection) url.openConnection();
            httpConnection.setUseCaches(false);
            httpConnection.setDoInput(true);
            httpConnection.setDoOutput(true);
            httpConnection.setChunkedStreamingMode(4096);
            httpConnection.setConnectTimeout(1000 * 5);
            httpConnection.setReadTimeout(1000 * 5);
            httpConnection.setRequestMethod("POST");
            httpConnection.addRequestProperty("Content-Type", "application/octet-stream");
            httpConnection.addRequestProperty("Transfer-Encoding", "chunked");
            httpConnection.addRequestProperty("Connection", "close");
            OutputStream out = httpConnection.getOutputStream();

            DataOutputStream dataOutputStream = new DataOutputStream(out);
            dataOutputStream.writeInt(37);
            dataOutputStream.close();
            httpConnection.getResponseMessage();
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}

In Android, I want to read bytes from the last code, my code is:

@Override
        public Response serve(IHTTPSession session) {
            Method method = session.getMethod();
            try {
                if (Method.POST.equals(method)) {
                    DataInputStream in = new DataInputStream(session.getInputStream());
                    int value = in.readInt();
                    Log.d("nextValue: ", value); // expected 37
                } else {
                    return executeGet(session);
                }
            } catch (Exception ex) {
                return newFixedLengthResponse(Response.Status.INTERNAL_ERROR, NanoHTTPD.MIME_PLAINTEXT,
                        "SERVER MOBILE INTERNAL ERROR: : " + ex.getMessage());
            }
        }

Can you help me? I need to use main java sample to send bytes, sometimes I need to writeUtf etc., because I've an app that works the same.

Thanks

[brunogabriel]

Anyone could help? If I don't use ocstream, works correctly, but all my server was written using it.

[LordFokas]

You need to do a bit more homework, but I'll try to help here.
Follow these steps to debug it:

• log the whole outgoing and incoming packet in hexadecimal form.
• isolate the \r\n\r\n sequence (should be 0D0A0D0A or something like that, depending on the encoding)
• look at the following bytes and understand what you're looking at.
• check if you're misreading the packet or miswriting it.
• locate the problem
• fix it

You should be able to perform at least the first 3 steps. Whether or not you can fix it by yourself, share your findings with us.