public class TransTask extends AsyncTask<String,Void,String>{

        private StringBuilder sb;

        @Override
        protected void onPreExecute() {
            super.onPreExecute();
        }

        @Override
        protected String doInBackground(String... strings) {
            URL url = null;
            try {
                url = new URL(strings[0]);
                InputStream is = url.openStream();
                BufferedReader in = new BufferedReader(new InputStreamReader(is));
                sb = new StringBuilder();
                String line =in.readLine();
                while (line!=null){
                    sb.append(line);
                    line = in.readLine();
                }
            } catch (MalformedURLException e) {
                e.printStackTrace();
            } catch (IOException e) {
                e.printStackTrace();
            }
            return sb.toString();
        }

        @Override
        protected void onPostExecute(String s) {
            super.onPostExecute(s);
            Log.d(TAG, "onPostExecute: "+s);
        }
    }