Kár filozofálni, futtasd le és vond le a tanulságot:
import java.util.ArrayList;
import java.util.List;
public class Test {
private List<Object> list = new ArrayList<Object> ();
public <T> void addItem( T item )
{
list.add( item );
}
public <T> T getItem( int index, T dflt )
{
T resp = (T)list.get( index );
return (resp == null ) ? dflt : resp;
}
public static void main( String []args )
{
Test obj = new Test();
obj.addItem("Hello");
obj.addItem(23);
String str = obj.getItem(0,"");
Integer in = obj.getItem(1,0);
System.out.println(str);
System.out.println(in);
}
}