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I am learning java and I am trying to recreate a scenario where A class is extending an abstract class and also implementing an interface. Each abstract class and interface have a same method defined in them. Now from the class which is extending and implementing, I want to call the implementations of both the parents. I tried to recreate this scenario as below but it gave me the error: not an enclosing class: A

interface C {
  default void m1(){
      System.out.println("C");
  }
}

abstract class A{
  abstract void display();
  void m1(){
      System.out.println("A");
  }
}

class B extends A implements C{
    public void m1(){
    }
    void display() {
        C.super.m1();
        A.super.m1(); // error: not an enclosing class: A
    }
}

public class Main {
  public static void main(String[] args) {
    A obj = new B();
    obj.display();
  }
}
Tejas Nakhate
  • 11
  • 3

1 Answers1

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You don't need to explicitly name a superclass to invoke its methods, because a Java class can only extend one superclass, so MyClass.super.method() is unambiguous. In fact, you needn't even name the child class at all: super.method() is also unambiguous due to Java's single inheritance model.

You do need to explicitly name a super-interface to invoke its methods, because a Java class can implement multiple interfaces, so MyInterface.super.method() is necessary to identify which interface is being invoked.

interface MyInterface {
    default void m1(){
        System.out.println("MyInterface");
    }
}

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

public class MyClass extends MyAbstractClass implements MyInterface {
    @Override
    public void m1() {
        super.m1();             // MyAbstractClass
        MyClass.super.m1();     // MyAbstractClass
        MyInterface.super.m1(); // MyInterface
    }

    public static void main(String... args) {
        new MyClass().m1();
    }
}
jaco0646
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