NPE - Attempt to invoke interface method 'int android.database.Cursor.getCount()' on a null object reference while executing doInBackground

Question

1.MovieDetailsFragment

   @Override
public void onCreateOptionsMenu(Menu menu, MenuInflater inflater) {
    if (mMovie != null) {
        inflater.inflate(R.menu.menu_detail, menu);
        Log.d(LOG_TAG, "detail Menu created");

        final MenuItem action_fav = menu.findItem(R.id.action_fav);
        MenuItem action_share = menu.findItem(R.id.action_share);

        //set proper icon on toolbar for favored movies
        new AsyncTask<Void, Void, Integer>() {
            @Override
            protected Integer doInBackground(Void... params) {
                return Utility.isFavored(getActivity(), mMovie.getMovie_id());
            }

            @Override
            protected void onPostExecute(Integer isFavored) {
                action_fav.setIcon(isFavored == 1 ?
                        R.drawable.ic_favorite_black_24dp :
                        R.drawable.ic_favorite_border_black_24dp);
            }
        }.execute();
    }
}

2.Utility

    public class Utility {
//takes movie_id and tells whether or not that movie is favored
public static int isFavored(Context context, int id) {
    Cursor cursor = context.getContentResolver().query(
            MovieContract.FavEntry.CONTENT_URI,
            null,   // projection
            MovieContract.FavEntry.COLUMN_MOVIE_ID + " = ?", // selection
            new String[] { Integer.toString(id) },   // selectionArgs
            null    // sort order
    );
    int numRows = cursor.getCount();
    cursor.close();
    return numRows;
}

Caused by: java.lang.NullPointerException: Attempt to invoke interface method 'int android.database.Cursor.getCount()' on a null object reference at com.example.deepankmehta.popularmovies2.Utility.isFavored(Utility.java:20) at com.example.deepankmehta.popularmovies2.MovieDetailsFragment$1.doInBackground(MovieDetailsFragment.java:108) at com.example.deepankmehta.popularmovies2.MovieDetailsFragment$1.doInBackground(MovieDetailsFragment.java:105)

This message tells you, that your cursor instance returned by "Cursor cursor = context.getContentResolver()..." is null. And that's why "int numRows = cursor.getCount();" runs into a NPE. Why cursor is null you have to find out yourself. — , Mar 14 '18 at 18:55

NPE - Attempt to invoke interface method 'int android.database.Cursor.getCount()' on a null object reference while executing doInBackground

0 Answers0