Java generics parameter bounding to any of a range of types

Question

Is there a syntax or workaround to constrain a generic type parameter to any of a range of types?

I am aware that you can constrain a type to be all

Answer 1

No. It wouldn't make any sense unless all the types had a non-empty union type, e.g. an interface they all implemented, or a base class they all extended, in which case you just specify the union type.