Question

I am searching for an elegant solutions for the following problem:

//one interface
public interface MyInterface () {
}
//two implementations
public class ImplA implements MyInterface (){ 
}
public class ImplB implements MyInterface () {
}

In another class:

//one generic method
public void myMethod(Class<MyInterface>... myTypes) {
  for (Class<MyInterface> myType : myTypes) {
     System.err.println("my Type:" +myType);
  }
}

The issue is that you cannot simply invoke this method with:

myMethod(ImplA.class, ImplB.class);

This is just simply not accepted. Is it true that optional parameter and generics can’t be combined? I cannot find any example.

Answer 1

I would try

public void myMethod(Class<? extends MyInterface>... myTypes) {

Class<MyInterface> has to be MyInterface.class not a subclass.