Java Programming

Hello everyone,

Assume the following :

public class A { }

public class B extends A { }
public class C extends A { }

Now I have interface and base impl

public interface IFacade {
  public void method(A a);
}

public class FacadeBaseImpl implements IFacade {
  public void method(A a) {
    return;
}

Further down I have a concrete classes that know how to deal with B, C:

public class FacadeBImpl extends FacadeBaseImpl {
...

here I would like to implement method in such a way that I would be able to pass to it only B and subclasses of B.

I've tried to do this with Generic methods and it does work, I tried to use lower bounds of generics (extends) on the interface and in FacadeBImpl to define the method with the final class and it does work either. I know I can simply cast inside my method to B, and it works. I would on the other hand prefer something that could catch the error at compile time.

Anyone has any ideas? I would appreciate a tip or two.

Thank you,
Maxim.