Question of multiple interface

Question

I have two interface as below:
public interface A{
void hello();
public interface B{
void hello();
I want a class named ABImpl to implements both A and B with different code.
How can deal with this? thanks.
My tester class is as below.
public class Tester{
public static void main(String[] args){
ABImpl ab = new ABImpl();
A a = ab;
B b = ab;
a.hello();
b.hello();
}

Answer 1

Implement two different classes. One implementing Interface A, and another one Implementing Inteface B.
Note: I know this is probably the baddest code, what can you do when there are two interfaces with the same signature? Do not ever use the interfaces, or clases as an instance variables rather use them as a generic definition of an object!!!
But I cannot modify the interface because these
interfaces is gived by other coporation. Probably you may want to ask the vendor the use of two interefaces with the same signaure?
>
I know C++ can do this by extends multiple class. but