setlistadapter问题，我根本不知道它是如何工作的

public class PassScreen extends Activity {
TextView selection;
ArrayList<String> items = new ArrayList<String>();
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    requestWindowFeature(Window.FEATURE_NO_TITLE);
    setContentView(R.layout.passwordscreen);
    selection=(TextView)findViewById(R.id.selection);

    try { 
        InputStream in=getResources().openRawResource(R.raw.words);
        DocumentBuilder builder=DocumentBuilderFactory.newInstance().newDocumentBuilder();
        Document doc = builder.parse(in,null);
        NodeList words=doc.getElementsByTagName(\"word\");
        for (int i =0;i<words.getLength();i++){
            items.add(((Element)words.item(i)).getAttribute(\"value\"));
        }
        in.close();
    }
    catch (Throwable t){
        Toast.makeText(this, \"Exception: \" + t.toString(), 2000).show();
    }

            setListAdapter(new ArrayAdapter<String>(this,
            android.R.layout.simple_list_item_1,
            items));

}
public void onListItemClick(ListView parent, View v, int position, long id){
    selection.setText(items.get(position).toString());
}
}

<?xml version=\"1.0\" encoding=\"utf-8\"?>
<LinearLayout
xmlns:android=\"http://schemas.android.com/apk/res/android\"
android:layout_width=\"fill_parent\"
android:layout_height=\"fill_parent\">

<TextView
android:id=\"@+id/selection\"
android:layout_width=\"fill_parent\"
android:layout_height=\"wrap_content\"/>

<ListView
  android:id=\"@android:id/list\"
  android:layout_width=\"fill_parent\"
  android:layout_height=\"fill_parent\"
  android:drawSelectorOnTop=\"false\"/>

</LinearLayout>

<words>
<word value=\"lorem\"/>
<word value=\"ipsom\"/>
<word value=\"dolor\"/>
</words>