Im having an error responseCode returns -1

@Override
    protected String doInBackground(Object... arg0){

        int responseCode = -1;

        //PostActivity getBlogPostsTask = new PostActivity();
        try
        {
            URL blogFeedUrl = new URL("http://localhost/medapp/public/mobile/post");
            HttpURLConnection connection = (HttpURLConnection) blogFeedUrl.openConnection();
            connection.connect();

            responseCode = connection.getResponseCode();

            if (responseCode == 200)
            {
                InputStream inputStream = connection.getInputStream();
                Reader reader = new InputStreamReader(inputStream);
                int contentLength = connection.getContentLength();
                char[] charArray = new char[contentLength];
                reader.read(charArray);
                String responseData = new String(charArray);
                Log.v("TAG", responseData);

            }
            else
            {
                Log.i("TAG", "Unsuccessful HTTP Response Code: " + responseCode);
            }



        }
        catch (MalformedURLException e)
        {
            Log.e("TAG", "exception caught: ", e);
        }
        catch (IOException e)
        {
            Log.e("TAG", "exception caught: ", e);
        }
        catch (Exception e)
        {
            Log.e("TAG", "exception caught: ", e);
        }