AsyncTask always return 0

Question

private class notesdb extends AsyncTask<Void, Void, Integer> {

        @Override
           protected void onPreExecute() {
              super.onPreExecute();
              //displayProgressBar("Downloading...");
           }

           @Override
           protected Integer doInBackground(Void... params) {
               db.getCount();
               result = db.getCount();

              return result;
           }



           @Override
           protected void onPostExecute(Integer result) {
              super.onPostExecute(result);
              Log.e(result+"",result+"");
              if(result==null){
                  Log.e("db","empty")
              }else{
                  Log.e("db","not empty")
              }

              //dismissProgressBar();
           }
           }



int result = 0;
new notesdb().onPostExecute(result);


public int getCount() {

        String countQuery = "SELECT  * FROM " + TABLE_NOTES;
        SQLiteDatabase db = this.getReadableDatabase();
        Cursor cursor = db.rawQuery(countQuery, null);
        int count = cursor.getCount();

        cursor.close();

        return count;
    }

i have this aynctask that check database if null or not but when i run it always return the same value always empty what is wrong in this code?any idea

UPDATE:

private class notesdb extends AsyncTask<Void, Void, Integer> {

        @Override
           protected void onPreExecute() {
              //super.onPreExecute();
              //displayProgressBar("Downloading...");
           }

           @Override
           protected Integer doInBackground(Void... params) {
               db.getCount();
               int result = db.getCount();

              return result;
           }



           @Override
           protected void onPostExecute(Integer result) {
             // super.onPostExecute(result);
              Log.e(result+"",result+"");
              if(result==null){
                  Log.e("db","empty");
              }else{
                  Log.e("db","not empty");
              }

              //dismissProgressBar();
           }
           }

Button..setOnClickListener(new OnClickListener() {
            @Override
            public void onClick(View v) {
                new notesdb().execute();
            }
        });

int result = 0; new notesdb().onPostExecute(result); is only code i have i dont have execute i have this on Oncreate.. — Giant, Jun 27 '14 at 07:36
@HakHak put a log in getCount() method to see what you get from the database too. — Lazy Ninja, Jun 27 '14 at 07:59
@LazyNinja log cat did not show because of processWorkerExit(w, completedAbruptly); — Giant, Jun 27 '14 at 08:06

JDJ · Accepted Answer · 2014-06-27T08:17:16.210

1

Remove the call to super.onPreExecute();

Remove the call to super.onPostExecute(result);

Also remove these lines:

int result = 0;
new notesdb().onPostExecute(result);

Create a new notesdb AsyncTask like this:

new notesdb().execute();

If it's still returning 0, make sure that your database table is populated.

edited Jun 27 '14 at 08:17

answered Jun 27 '14 at 07:43

JDJ

4,298
3
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now i get the same error as before i get this processWorkerExit(w, completedAbruptly); error when i use .execute – Giant Jun 27 '14 at 07:54
Where are you making this call: `new notesdb().execute()` ? In `onCreate()`? – JDJ Jun 27 '14 at 08:01
Are you certain that the database table is populated? – JDJ Jun 27 '14 at 08:14
you are correct sir because of the processWorkerExit(w, completedAbruptly); i wasnt aware that i get null pointer on database thanks to Lazy Ninja i was able to determine that i get a null pointer you get the +1 sir – Giant Jun 27 '14 at 08:38
one more question in this same activity can i put another asynctask for different database? – Giant Jun 27 '14 at 08:39
1

Yes, you can have multiple AsyncTasks. – JDJ Jun 27 '14 at 08:43

score 1 · Answer 2 · answered Jun 27 '14 at 07:54

1

Start your async task with

new notesdb().execute();

instead of

new notesdb().onPostExecute(result);

answered Jun 27 '14 at 07:54

Lazy Ninja

22,342
9
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Just pointing where you are doing wrong! It is not the way to call an AsyncTask – Lazy Ninja Jun 27 '14 at 07:56
what is the cause why i get this error processWorkerExit(w, completedAbruptly);? – Giant Jun 27 '14 at 08:10
sir one question the thing i did on preference will it affect my sample program in anyway if i put it on real device?how can i fix that problem? – Giant Jun 27 '14 at 08:45
1

@HakHak I dont think it will cause a problem. – Lazy Ninja Jun 27 '14 at 08:48

AsyncTask always return 0

2 Answers2