Dynamic List Activity

public class TopActivity  extends ListActivity   
{
     private ArrayAdapter<String> adapter;
     private ArrayList<String> list;

     public void onCreate(Bundle savedInstanceState) 
     {
          super.onCreate(savedInstanceState);

          this.list = new ArrayList<String>();
          adapter = new ArrayAdapter<String>(this, R.layout.top, this.list);
          setListAdapter(adapter);

          //not for sure if I need the below.
          //ListView lv = getListView();
          //lv.setTextFilterEnabled(true);

          addItem();

     }

     public void addItem()
     {
          this.list.add("Two");
          adapter.notifyDataSetChanged();
     }
}