public void stopRecording() {
    arrowNext.setVisibility(View.INVISIBLE);
    progressNext.setVisibility(View.VISIBLE);
    cdTimer.cancel();
    RecorderStopAsync recorderStopAsync = new RecorderStopAsync();
    recorderStopAsync.execute(mediaRecorder);
}

class RecorderStopAsyncTask extends AsyncTask<MediaRecorder, Integer, String> {

    @Override
    protected String doInBackground(MediaRecorder... mediaRecorders) {
        if(mediaRecorders.length>0 && mediaRecorders[0]!=null){
            mediaRecorders[0].stop();
            return "Success";
        }
        return null;
    }

    @Override
    protected void onPostExecute(String s) {
        if(s!=null){
            onRecordingStoppedSuccessfully();
        }else{
            onRecordingStopFailed();
        }
    }
}