Calling method of Superclass from subclasses

Question

I have faced a question in an interview whether we can access the method display() of class ABC from EDC as given below

class ABC {
    public void display() {
       System.out.println("from ABC");
    }
}

class CBD extends ABC {
    public void display() {
       System.out.println("From CBD");
    }
}

class EDC extends CBD {
    public void display() {
        System.out.println("From EDC");
    }
}

I would like to know if we can access the method of ABC from class EDC other than an object creation of ABC. I know the answer is very straight and simple that we can access only the super class method of EDC i.e; display() of CBD through super.display(), but I am feeling whether I am missing any approach here to access the display() of ABC from EDC.

I think one of the possible approaches is as below

    class ABC {
public void display()
{
   System.out.println("from ABC");
}
public static  void main(String args[])
{
      ABC obj=new EDC();
      obj.display();

}
}
class CBD extends ABC {
public void display()
{
   super.display();
}
}
class EDC extends CBD {
public void display()
{
    super.display();
}
}

You already mentioned the `super.display()` therefore I don't get your doubt. — António Ribeiro, Feb 19 '16 at 20:42
@aribeiro `super` goes up one level in the hierachy. OP wants to go up two levels in the hierachy. — Turing85, Feb 19 '16 at 20:44
but I am clearing myself a doubt whether any way exists other than the above. If exists then I am missing a simple and a very important one — niks, Feb 19 '16 at 20:45
Without creating object, I don't think so. But I think it can be achieved by using reflection. http://www.mkyong.com/java/how-to-use-reflection-to-call-java-method-at-runtime/ — Aditya Peshave, Feb 19 '16 at 20:47
yes, I think there is no other straight forward approach. Reflection is one possible way i have in mind. — niks, Feb 19 '16 at 20:48
no, reflection doesn't work here, see the question this duplicates: http://stackoverflow.com/a/3456599/217324 — Nathan Hughes, Feb 19 '16 at 20:49
This might be a case flag ABC's display() can be called from EDC using super only if CBD doesn't override A's display(). — niks, Feb 19 '16 at 20:50

score 2 · Accepted Answer · answered Feb 19 '16 at 20:42

2

No, it is not possible. You can only go one level up with super.

answered Feb 19 '16 at 20:42

Sleiman Jneidi

22,907
14
56
77

score 1 · Answer 2 · answered Feb 19 '16 at 20:46

1

You could have a method that calls super() from CBD and call that method from EDC using super(), i.e. chain the calls.

answered Feb 19 '16 at 20:46

Dave

321
1
8

Calling method of Superclass from subclasses

2 Answers2