Java bounded wilcard type

Question

Hi,

I need to define a generic class, and the type parameter must be an enum. I think it should look something like

public class <T> MyClass<T extends Enum<T>> {

}

But I can't seem to figure out the exact syntax. I should mention that I need a way to refer to the type (within MyClass) that it is instantiated with.

Thanks!

Answer 1

public class MyClass<T extends Enum<T>> { }

Answer 2

While the approved answer looks syntactically correct, what's the scenario for such a declaration? Are you trying to write some class that can operate on any enum-defined type, like java.util.EnumSet or java.util.EnumMap? It's an unusual arrangement, so be sure you really need it in order to meet your requirements.