private void getProductClass() {
    productClasses.clear();
    productClassAdapter.notifyDataSetChanged();
    SuningTask.getProductClass(
        getActivity(),
        new OnNetworkListener() {

          @Override
          public void onStart() {
            super.onStart();
            showLoading();
          }

          @Override
          public void onFinish() {
            super.onFinish();
            refreshScrollView.onRefreshComplete();
            hideLoading();
          }

          @Override
          protected void onFail(MissionMessage missionMessage) {
            super.onFail(missionMessage);
            loadingEmpty();
          }

          @Override
          public void onSuccess(NetworkMissionMessage message) {
            super.onSuccess(message);
            hideLoading();
            if (SuningManager.isSignatureOutOfDate(message.getResult())) {
              GetNewSignature getNewSignature =
                  new GetNewSignature() {
                    @Override
                    protected void onPreExecute() {
                      showLoading();
                    }

                    @Override
                    protected void onPostExecute(Boolean isSuccess) {
                      hideLoading();
                      if (isSuccess) {
                        getProductClass();
                      }
                    }
                  };
              getNewSignature.execute();
              return;
            }
            if (!TextUtils.isEmpty(message.getResult())) {
              try {
                JSONObject object = new JSONObject(message.getResult());
                if (object.optBoolean("isSuccess")) {
                  JSONArray array = object.optJSONArray("result");
                  if (array != null) {
                    for (int i = 0; i < array.length(); i++) {
                      productClasses.add(new ModelProductClass(array.optJSONObject(i)));
                    }
                    if (!productClasses.isEmpty()) {
                      select(productClasses.get(0));
                    }
                  }
                  return;
                }
                Notify.show(object.optString("returnMsg"));
              } catch (JSONException e) {
                e.printStackTrace();
              }
            }
          }
        });
  }
 private void select(ModelProductClass productClass) {
   selectedProductClass = productClass;
   productClassAdapter.notifyDataSetChanged();
   onClassSelected(selectedProductClass);
 }