Inheritance - Protected Method

[Sasha Ruehmkorf]

Why am I not able to invoke a protected method from within a subclass?

package pack2;
 
public class Father {
protected void method(){
}
}

and

package pack1;
import pack2.*;
 
class Son extends Father{
public static void invokeFatherMethod(Father f){
f.method();//method is not visible...?
}
}

[ April 27, 2007: Message edited by: Sasha Ruehmkorf ]

[Sasha Ruehmkorf]

K&B:

But what does it mean for a subclass-outside-the-package to have access to a superclass (parent) member? It means the subclass inherits the member. It does not, however, mean the subclass-outside-the-package can access the member using a reference to an instance of the superclass. In other words, protected = inheritance. Protected does not mean that the subclass can treat the protected superclass member as though it were public.

Ok, got it :-)

[Campbell Ritchie]

You can invoke a superclass method from inside an instance of a subclass. Your static method does not form part of the instance.
Try:

public void invokeFatherMethod(){
super.method();
}

[Sasha Ruehmkorf]

Thanks for the hint.
Still some strange things occur with the protected-modifier but I think I understand enough to answer the questions regarding "protected" in the exam and that should do it for the moment.

public void invokeFatherMethod(){
super.method();             // OK, I know that [B]my[/B] Father has this method
        new Father().method();      // Nope, I am not sure if every Father has such a method
}

[Ilja Preuss]

Originally posted by Sasha Ruehmkorf:

        new Father().method();      // Nope, I am not sure if every Father has such a method

[/QB]

In fact, you can be sure that every Father has such a method. But you simply don't have access to it, other than through the "this" reference.