Untitled

AsyncTask:onPostExecute
_artist = (AutoCompleteTextView)findViewById(R.id.artist);
  _artist.addTextChangedListener(new TextWatcher()
    {
        public void afterTextChanged(Editable s)
        {
            _artist.setAdapter(null);
            _fetcher = new AutoCompleteFetcher(_artist);
            _fetcher.execute();
        }
    }

    public class AutoCompleteFetcher extends AsyncTask<Void, Void, Void>
    {
        private AutoCompleteTextView _textView;
        private String[] _matches;

        public AutoCompleteFetcher(AutoCompleteTextView v)
        {
            super();
            _textView = v;
        }

        protected Void doInBackground(Void... v)
        {
            _matches = _getMatches();
            return null;
        }

        private String[] _getMatches()
        {
            // fill the list....... code removed here
            // returns populated String[]
        }

        @Override
        protected void onPostExecute(Void result)
        {
            ArrayAdapter<String> adapter =
                    new ArrayAdapter<String>(_textView.getContext(),
                        android.R.layout.simple_list_item_1,_matches);
            _textView.setAdapter(adapter);
        }
}

public class AutoCompleteFetcher extends AsyncTask<Void, Void, String[]>
{
    private AutoCompleteTextView _textView;

    public AutoCompleteFetcher(AutoCompleteTextView v)
    {
        super();
        _textView = v;
    }

    @Override
    protected String[] doInBackground(Void... v)
    {
        return _getMatches();
    }

    private String[] _getMatches()
    {
        // fill the list....... code removed here
        // returns populated String[]
        // TODO: it seems like this method should really just be moved into
        //  doInBackground().  That said, I don't think this is your problem.
    }

    @Override
    protected void onPostExecute(String[] result)
    {
        ArrayAdapter<String> adapter =
                new ArrayAdapter<String>(_textView.getContext(),
                    android.R.layout.simple_list_item_1, result);
        _textView.setAdapter(adapter);
    }
}