AsyncTask Result for use in Fragment

Question

I have a Question about AsyncTask I Use a AsyncTask for get a Json list of Names

Here my AsyncTask

class GetNameAsync extends AsyncTask<String, String, JSONObject> {

    JSONParser jsonParser = new JSONParser();
    private static final String API_URL = "urlhere :-)";
    private static final String TAG_NAMES = "names";
    private ProgressDialog pDialog;

    @Override
    protected void onPreExecute() {
        pDialog = new ProgressDialog(getActivity());
        pDialog.setMessage("Attempting loading...");
        pDialog.setIndeterminate(false);
        pDialog.setCancelable(true);
        pDialog.show();
    }

    @Override
    protected JSONObject doInBackground(String... args) {
        try {
            HashMap<String, String> params = new HashMap<>();
            params.put("access", KEY);
            params.put("lang", LANG);

            Log.e("request", "starting");
            JSONObject names_json = jsonParser.makeHttpRequest(API_URL, "GET", params);
            return names_json;
        } catch (Exception e) {
            e.printStackTrace();
        }
        return null;
    }
    @Override
    protected void onPostExecute(JSONObject names_json) {
        super.onPostExecute(names_json);
        if (pDialog != null && pDialog.isShowing()) {
            pDialog.dismiss();
        }
        String names_entry = "";
        String mAktienlisteAdapter1 = "";

        try {
            names_entry = names_json.getString(TAG_NAMES);
        } catch (JSONException e) {
            e.printStackTrace();
        }
    }
}

This Works great But what I did not get is what I get the result to the outside to continue to use

i have try this in onPostExecute

    getFinalResult(String.valueOf(names_entry));

and this in my Fragment

public static String RESULT = null;
public void getFinalResult(String string) {
    RESULT = string;
}

Then is the RESULT empty -,-

Have already looked here but found nothing which helps me. Would be glad if someone can help me with my problem.

Edit Here myFragment.class

public class ThirdFragment extends Fragment {
public static String LANG = null;
public static String KEY = null;
public static String RESULT = null;



class GetNameAsync extends AsyncTask<String, String, JSONObject> {

    JSONParser jsonParser = new JSONParser();
    private static final String API_URL = "urlhere :-)";
    private static final String TAG_NAMES = "names";
    private ProgressDialog pDialog;

    @Override
    protected void onPreExecute() {
        pDialog = new ProgressDialog(getActivity());
        pDialog.setMessage("Attempting loading...");
        pDialog.setIndeterminate(false);
        pDialog.setCancelable(true);
        pDialog.show();
    }

    @Override
    protected JSONObject doInBackground(String... args) {
        try {
            HashMap<String, String> params = new HashMap<>();
            params.put("access", KEY);
            params.put("lang", LANG);

            Log.e("request", "starting");
            JSONObject names_json = jsonParser.makeHttpRequest(API_URL, "GET", params);
            return names_json;
        } catch (Exception e) {
            e.printStackTrace();
        }
        return null;
    }
    @Override
    protected void onPostExecute(JSONObject names_json) {
        super.onPostExecute(names_json);
        if (pDialog != null && pDialog.isShowing()) {
            pDialog.dismiss();
        }
        String names_entry = "";
        String mAktienlisteAdapter1 = "";

        try {
            names_entry = names_json.getString(TAG_NAMES);
        } catch (JSONException e) {
            e.printStackTrace();
        }
        getFinalResult(String.valueOf(names_entry));

    }
}

public void getFinalResult(String string) {
    RESULT = string;
}
public void setLang(String string){
    LANG = string;
}

public void setKey(String string){
    API_KEY = string;
}

public ThirdFragment() {
    // Required empty public constructor
}

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
                         Bundle savedInstanceState) {
    setHasOptionsMenu(true);
    // Inflate the layout for this fragment
    return inflater.inflate(R.layout.fragment_third, container, false);
}
@Override
public void onViewCreated(View view, @Nullable Bundle savedInstanceState) {
    super.onViewCreated(view, savedInstanceState);
    FloatingActionButton fab = (FloatingActionButton) getActivity().findViewById(R.id.fab);
    fab.setVisibility(View.VISIBLE);

    GetNameAsync GetNames = new GetNameAsync();
    GetNames.execute();
    Log.e("RESULT-ASYNC", RESULT);


}

@Override
public void onCreateOptionsMenu(Menu menu, MenuInflater inflater) {
    menu.clear();
    inflater.inflate(R.menu.main1, menu);
}


@Override
public boolean onOptionsItemSelected(MenuItem item) {

    if (item.getItemId() == 1) {
        Toast.makeText(getActivity(), "Test 1", Toast.LENGTH_LONG).show();
        return true;
    } else if (item.getItemId() == 2) {
        Toast.makeText(getActivity(), "Test 2", Toast.LENGTH_LONG).show();
        return true;
    } else {
        return super.onOptionsItemSelected(item);
    }
}
}

Is you async task in a separate class or internal in you Fragment — Omar HossamEldin, Nov 02 '16 at 00:41
Yes the _name_json_ value is {"names":["name1","name2","name3"]} and _name_entry_ is ["name1","name2","name3"] and the _name_entry_ is this was i need for next work outside from Async — Jesse Lukas, Nov 02 '16 at 01:00
And why do wrote `getFinalResult(String.valueOf(names_entry));` you can just write `getFinalResult(names_entry);` because *names_entry* is already a string — Omar HossamEldin, Nov 02 '16 at 01:05
GetNameAsync GetNames = new GetNameAsync(); GetNames.execute(); Log.e("RESULT-ASYNC", RESULT);, In this line you mean result is emtpy ? — Omar HossamEldin, Nov 02 '16 at 01:16
Yes this is the line i test before i write a full code what not working — Jesse Lukas, Nov 02 '16 at 01:21
Well this line is called before the Async task is even called, Because Async task works in background thread, and the line where you set the log in main thread which will not wait for background thread, you should move the log statement to the onPreExcute method on AsyncTask to print the correct data — Omar HossamEldin, Nov 02 '16 at 01:23
oh ok. How do I get it to do what the main thread wait for finish back thread — Jesse Lukas, Nov 02 '16 at 01:26
Call when you need in the 'onPostExcute' method, which is in main thread again. — Omar HossamEldin, Nov 02 '16 at 01:27

score 1 · Answer 1 · answered Nov 02 '16 at 01:35

1

The issue is your async task is not yet completed when you try to log the RESULT.

GetNameAsync GetNames = new GetNameAsync();
GetNames.execute();
Log.e("RESULT-ASYNC", RESULT); // At this point the task may not be complete.

The method onPostExecute of your GetNameAsync is running in your GUI thread and can access anything on your Fragment , for example text value of a label etc. So try to update your GUI (Fragment) from within your onPostExecute with the value you got for names_entry

answered Nov 02 '16 at 01:35

gipsy

3,859
1
13
21

You can access any ui elements on your Fragment layout by calling findViewById from onPostExecute. Then you can update that gui element using the values you have in names_entry – gipsy Nov 02 '16 at 02:39
i will use this _names_entry_ for create a menu in onCreateOptionsMenu and for this i need this outside from the async – Jesse Lukas Nov 02 '16 at 02:44

score 0 · Answer 2 · answered Nov 02 '16 at 01:40

class GetNameAsync extends AsyncTask<String, String, JSONObject> {

JSONParser jsonParser = new JSONParser();
private static final String API_URL = "urlhere :-)";
private static final String TAG_NAMES = "names";
private ProgressDialog pDialog;

@Override
protected void onPreExecute() {
    pDialog = new ProgressDialog(getActivity());
    pDialog.setMessage("Attempting loading...");
    pDialog.setIndeterminate(false);
    pDialog.setCancelable(true);
    pDialog.show();
}

@Override
protected JSONObject doInBackground(String... args) {
    try {
        HashMap<String, String> params = new HashMap<>();
        params.put("access", KEY);
        params.put("lang", LANG);

        Log.e("request", "starting");
        JSONObject names_json = jsonParser.makeHttpRequest(API_URL, "GET", params);
        return names_json;
    } catch (Exception e) {
        e.printStackTrace();
    }
    return null;
}
@Override
protected void onPostExecute(JSONObject names_json) {
    super.onPostExecute(names_json);
    if (pDialog != null && pDialog.isShowing()) {
        pDialog.dismiss();
    }
    String names_entry = "";
    String mAktienlisteAdapter1 = "";

    try {
        names_entry = names_json.getString(TAG_NAMES);
    } catch (JSONException e) {
        e.printStackTrace();
    }
    getFinalResult(String.valueOf(names_entry)); // Here the value has been updated and you can Call you next business depends on the results

}
}

You are printing the log can in a wrong place, which is after calling GetNames.execute(); and it is not preferrable to call the object with a name starts with Capital letter , Object should be getNames

So the call of Log.e("RESULT-ASYNC", RESULT); should be in onPostExecute when I wrote my comment.

In the place is all right but this helps me not to use the result outside the Async — Jesse Lukas, Nov 02 '16 at 01:48
You cannot use the result of the Async before it finishes, And to use it after finish, call a listener or whatever to call your login outside the Async. — Omar HossamEldin, Nov 02 '16 at 01:51
implements OnTaskCompleted in you fragment instead of the activity — Omar HossamEldin, Nov 02 '16 at 02:19
I have test it and then is OnTaskCompleted Red. when i use _ThirdFragment.OnTaskCompleted_ this error Class 'ThirdFragment' must either be declared abstract or implement abstract method 'onTaskCompleted()' in 'OnTaskCompleted' — Jesse Lukas, Nov 02 '16 at 02:20
Add this snippet of code to your fragment `public interface OnTaskCompleted{ void onTaskCompleted(); }` — Omar HossamEldin, Nov 02 '16 at 02:21

AsyncTask Result for use in Fragment

2 Answers2