java generics, how to extend from two classes?

Question

I want to have a Class object, but I want to force whatever class it represents to extend class A and also class B. I can do

Answer 1

Java does not have multiple inheritance as a design decision, but you may implement multiple interfaces.

As of Java 8 these interfaces may have implementations.

To use multiple classes there are other patterns:

1. If the parent classes are purely intended for that child class, but handle entirely different aspects, and were therefore separated, place them in a single artificial hierarchy. I admit to doing this once.

2. Use delegation; duplicate the API and delegate.

3. Use a lookup/discovery mechanism for very dynamic behaviour.

   public T lookup(Class klazz);

   This would need an API change, but uncouples classes, and is dynamic.