Android HTTPS con.getResponseCode() throws EndOfFile exception on readUtf8LineStrict in big requests

问题

THE PROBLEM

I have a post request is causing an error only when data to recover are long (about 60Mb of data in json format).

The same request with less information does not cause any errors and it works perfectly.

The error message that is always appearing at exactly 2 minutes haver made the request, is the folowing:

java.io.EOFException
at com.android.okio.RealBufferedSource.readUtf8LineStrict(RealBufferedSource.java:98)
at com.android.okhttp.internal.http.HttpConnection.readResponse(HttpConnection.java:202)
at com.android.okhttp.internal.http.HttpTransport.readResponseHeaders(HttpTransport.java:119)
at com.android.okhttp.internal.http.HttpEngine.readResponse(HttpEngine.java:798)
at com.android.okhttp.internal.http.HttpURLConnectionImpl.execute(HttpURLConnectionImpl.java:405)
at com.android.okhttp.internal.http.HttpURLConnectionImpl.getResponse(HttpURLConnectionImpl.java:349)
at com.android.okhttp.internal.http.HttpURLConnectionImpl.getResponseCode(HttpURLConnectionImpl.java:517)
at com.android.okhttp.internal.http.DelegatingHttpsURLConnection.getResponseCode(DelegatingHttpsURLConnection.java:105)
at com.android.okhttp.internal.http.HttpsURLConnectionImpl.getResponseCode(HttpsURLConnectionImpl.java:25)
at com.myproject.mypackage.DataManagerService$ServiceHandler.sincronitzar_baixada_dades(DataManagerService.java:1406)
at com.myproject.mypackage.DataManagerService$ServiceHandler.handleMessage(DataManagerService.java:403)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:135)
at android.os.HandlerThread.run(HandlerThread.java:61)

On the server side, we found that the service is preparing the data still alive after the error occurs on my device.

A few days ago we increased the RAM on the server to avoid OOM errors in the same casuistry.

MORE CODE UPDATED 03/06/2016

also attached the code that makes the request and saves the response in a file on the device:

The request code:

HttpsURLConnection con = (HttpsURLConnection) Https_url.openConnection();
            if (android.os.Build.VERSION.SDK_INT >= android.os.Build.VERSION_CODES.JELLY_BEAN_MR1){
                con.setRequestProperty("Connection", "close");
            }
            con.setReadTimeout(DEFAULT_RESPONSE_TIMEOUT);
            con.setConnectTimeout(DEFAULT_RESPONSE_TIMEOUT);
            con.setRequestMethod("POST");
            con.setRequestProperty("Accept-Encoding","identity");
            con.setDoInput(true);
            con.setDoOutput(true);
            con.connect();
            int status = con.getResponseCode(); 
            if (status >= 400) {
                inputStreamPujada = con.getErrorStream();
            }
            else{
                inputStreamPujada = con.getInputStream();
            }

            if (inputStreamPujada != null){
                try {
                    OutputStream out = new FileOutputStream(file);
                    byte[] buf = new byte[1024];
                    int len;
                    while((len=in.read(buf))>0){ <--// THIS LINE IS THROWING EOFExceptiono error!
                        out.write(buf,0,len);
                    }
                    out.close();
                    in.close();
                }
                catch (Exception e) { e.printStackTrace(); }
            }

WHAT WE TRYED?

We tryed to format json outputs with no breaklines and also with pretty json format.
It seems that error is caused because the DataStream dosen't found an "\n" and throws an EndOfFile Exception
Also tryed to raise up the memory RAM in the server side with no more effect.
Also tryed edit the request property "Accept-Encoding" as this question

THE QUESTION

What is the cause of this EOFException? Why is working with low data and throwing this in big data? Ther are some extrange timeout or library limit with max time in 2 minutes?

Thanks in advance!