Asynctask结果显示重新创建片段后

Question

在我的应用程序中，我从用户在fragment获取数据并使用输入的数据通过JSON使用AsyncTask获得结果然后将其保存到database然后在另一个fragment中显示。

问题是当我执行asyncTask并打开fragment数据不显示，除非我旋转设备（强制片段重新创建）。

我的第一个片段代码：

...
SecondFragment secondFragment = new SecondFragment();
new SecondFragment.GetTask("s").execute(URL);
FragmentTransaction ft =getActivity().getSupportFragmentManager().beginTransaction();
ft.setCustomAnimations(R.anim.slide_in_up, R.anim.slide_in_up);
ft.add(R.id.s_con, secondFragment).addToBackStack("back").commit();
...

第二个片段代码：

...
recyclerView.setAdapter(new SAdapter(getContext(),R.layout.group_header));
...

public static class GetTask extends AsyncTask<String, String, Void> {

    String arrayname;


    GetTask(String arrayname) {
        this.arrayname = arrayname;
    }


    }

    @Override
    protected Void doInBackground(String... params) {
        HttpURLConnection connection = null;
        BufferedReader reader = null;

        try {
            URL url = new URL(params[0]);
            connection = (HttpURLConnection) url.openConnection();
            connection.connect();

            InputStream stream = connection.getInputStream();

            reader = new BufferedReader(new InputStreamReader(stream));
            StringBuffer buffer = new StringBuffer();

            String line = "";
            while ((line = reader.readLine()) != null) {
                buffer.append(line);
            }

            String finalJson = buffer.toString();

            JSONObject parentObject = new JSONObject(finalJson);
            JSONObject secondParentObject = parentObject.getJSONObject("data");


            //json getter and adder to database
            JSONArray Array = secondParentObject.getJSONArray(arrayname);
            for (int i = 0; i < Array.length(); i++) {
                JSONObject finalObject = Array.getJSONObject(i);
                switch (arrayname) {
                    case "s":
                        db.SAddJson(finalObject);
                        break;
                }
            }


        } catch (MalformedURLException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        } catch (JSONException e) {
            e.printStackTrace();
        } finally {
            if (connection != null) {
                connection.disconnect();
            }
            try {
                if (reader != null) {
                    reader.close();
                }
            } catch (IOException e) {
                e.printStackTrace();
            }
        }

        return null;
    }

    @Override
    protected void onPostExecute(Void aVoid) {
        super.onPostExecute(aVoid);
    }
}