为什么我收到警告：类是原始类型。对泛型类型 Class<T> 的引用应该参数化“？

我在我的.我收到的警告如下所示ListActivity

• Class is a raw type. References to generic type Class<T> should be parameterized

它不会产生任何问题，但我想知道为什么我会收到此警告以及如何抑制它。请参阅写在星号内的行。

public class Menu extends ListActivity {

    String classes[]={"Second","example1","example2","example3","example4"}; 
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        // TODO Auto-generated method stub
        super.onCreate(savedInstanceState);
        setListAdapter(new ArrayAdapter<String>(Menu.this,android.R.layout.simple_list_item_1,classes));
    }

    @Override
    protected void onListItemClick(ListView l, View v, int position, long id) {
        // TODO Auto-generated method stub
        super.onListItemClick(l, v, position, id);
        String cheese=classes[position];
        try{
        **Class ourclass= Class.forName("com.app1."+cheese);**
        Intent ourintent= new Intent(Menu.this,ourclass);
        startActivity(ourintent);
        }catch(ClassNotFoundException e){
            e.printStackTrace();
        }
    }
}