Question

I came to situation :

public interface Intr {
    public void m1();
}

public abstract class Abs {
    public void m1() {
        System.out.println("Abs.m1()");
    }
    // public abstract void m1();
}

public class A extends Abs implements Intr {

    @Override
    public void m1() {
        // which method am I overriding, well it is Abs.m1() but why?
        // if method implemented is Abs.m1(), then why I am not getting error for Intr.m1() not implemented.
    }

}

Answer 1

You are satisfying both conditions at once; ie. the one implementation is at the same time fulfilling the abstract class requirements and the interface requirements.

As a note, unless you are using Intr in another inheritance chain, you don’t need it. Also, it might make sense to move the implements Intr up to the abstract class definition.