public class A {

public A() { m(); }

public void m() {
    System.out.println(“m aus A“); }
}

public class B extends A {
A a;
    public B() {
        a = new A();
        m(); }

public void m() {
    a.m();
    System.out.println(“m aus B“); }

public static void main(String[] args)
{ new B(); }
}