MainActivity.java

private CoNaObiadDbHelper dbHelper;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        dbHelper = new CoNaObiadDbHelper(this);
        dbHelper.cleanData();
        dbHelper.initializeMealTable();

        List<String> preparedRows = DinnerListHelper.getPreparedRows(new Date(), dbHelper.getAllMeals());

        ArrayAdapter<String> adapter = new ArrayAdapter<String>(this, android.R.layout.simple_list_item_1, preparedRows);

        ListView listView = (ListView) findViewById(R.id.listview);
        listView.setAdapter(adapter);
    }