A.java

public class A {

    private final MyIntf myDelegate = new MyIntf();

    public Intf getMyDelegate() {
        return myDelegate;
    }

    public void method1() {
        myDelegate.method1();
    }

    private class MyIntf implements Intf {
        public void method1 () {
            System.out.println("1");
        }

        public void method2 () {
            System.out.println("2");
        }
    }
}