Java Generics - Compile time validation of type and implementing object

Question

I have a method to add implementing class' objects against interface class and I want to make this as a generic one. The implementing class also extends a class X

public abstract class X<T>{...}

public interface InterfaceA{...}

public class A extends X implements InterfaceA{...}

now, currently my method is:

public <S, <T extends X<S>> void add(Class<S> clazz, T object){...}

But I have no use of type parameter on X, it is just for the above method. Is there a way I could have X without type parameter and still have compile-time validation in method 'add' please?

Thanks

EDIT:

I think my question is not clear. Please look at the below example code:

public interface I {}

public abstract class X {}

public class A extends X implements I {}

public class B implements I {}

public class C extends X {}

public class Main {
    public static void main(String[] args) {
        add(I.class, new A());  // uses first method
        add(I.class, new B());  // uses second method
        add(I.class, new C());  // uses first method
    }

    public static <P, T extends P> void add(Class<P> c, T object) {}  //No

    public static <P, T extends X> void add(Class<P> c, T object) {}  //No

}

I need an 'add' method that just accepts A's instance and not B's not C's. Both the above method signature don't fulfill my requirement

Answer 1

If you don't care about the type parameter of X , just make it Object :

public class A extends X<Object> implements InterfaceA{...}

So the method will work with anything.

Answer 2

I believe you can remove the type on X and still get a compile-time error for add in the following manner. Now, of course, a little more context will be more helpful if this doesn't meet your requirement.

public abstract class X {
}

public class A<T> extends X implements InterfaceA {

      public <S, M extends X> void add(Class<S> clazz, M object){
      }

      public void abc() {
         Class<String> clazz = String.class;
         this.add(clazz, new B());//This should throw compilation error
      }

}

public class B implements InterfaceA {
}