public void saveBusBriefs(ArrayList<BusLineBrief> busLineBriefs)
      throws JSONException, IOException {
    JSONArray array = new JSONArray();
    for (BusLineBrief b : busLineBriefs) {
      array.put(b.getJSONObject());
    }

    Writer writer = null;
    try {
      OutputStream out = mContext.openFileOutput(mFileName, Context.MODE_PRIVATE);
      writer = new OutputStreamWriter(out);
      writer.write(array.toString());
    } finally {
      if (writer != null) {
        writer.close();
      }
    }
  }
 @Override
 protected void onPostExecute(String s) {
   if (s != null) {
     Log.d(sTAG, s);
     BusLineBriefList.get(getActivity()).add(BusLineBrief.parse(s));
     if (BusLineBriefList.get(getActivity()).getBusLines().isEmpty()) {
       showToastInfo(R.string.bus_line_not_exist);
     }
     mAdapter.notifyDataSetChanged();
   } else {
     showToastInfo(R.string.query_failed);
   }
   mQueryBusLine.setEnabled(true);
 }