How to get class of generic type when there is no parameter of it?

Question

I just learned about this fine looking syntax

Collections.emptyList()

to get an empty List with elements which a

Answer 1

I find out that there is one solution for getting Class from T:

public class Action{
}

public Class getGenericType(Object action) throws ClassNotFoundException{
   Type type =
   ((ParameterizedType)action.getClass().getGenericSuperclass())
      .getActualTypeArguments()[0];
   String sType[] = type.toString().split(" ");

   if(sType.length != 2)
      throw new ClassNotFoundException();

   return Class.forName(sType[1]);
}

The usage of code above:

Action myAction = new Action();

getGenericType(myAction);

I did not tested this with primitive types (int, byte, boolean).

I think that it is not very fast, but you do not have to pass Class to constructor.

EDIT:

The usage above is not right, because generic superclass is not available for Action. Generic super class will be available only for inherited class like class ActionWithParam extends Action{}. This is reason why I changed my mind and now I suggest to pass class parameter to constructor, too. Thanks to newacct for correction.