Instantiate Java anonymous inner class with generic using Class in variable

Question

Is it possible in Java 7 to instantiate an anonymous inner class with a generic type using a Class object that I have in hand?

Here's the simplified version of the generic class I'm trying to instantiate:

abstract class DomainBuilder<E> {

    private final Class<E> entityClass

    public DomainBuilder() {
        this.entityClass = (Class<E>) ((ParameterizedType) getClass().getGenericSuperclass()).getActualTypeArguments()[0];
    }

    ...
}

Creating an anonymous inner class when I specify the class I want to build at compile time works fine:

DomainBuilder builder = new DomainBuilder<MyDomainClass>() {}

I'd like to be able to make it so that I can use a Class variable that I've determined at run-time like this, but haven't figured out how to yet:

Class clazz = MyDomainClass.class
...
DomainBuilder builder = new DomainBuilder<clazz>() {}

I've also tried creating methods along these lines without luck:

Class clazz = MyDomainClass.class
DomainBuilder builder = builderFor(clazz)

public static DomainBuilder<T> builderFor(Class<T> t) {
    return new DomainBuilder<T>(entityManager){}
}

Is something like this possible?

Answer 1

You'll have to create an entirely separate constructor for when the Class object is being passed in directly. You can't infer it again the way you're trying to.

Answer 2

I'd like to be able to make it so that I can use a Class variable that I've determined at run-time like this, but haven't figured out how to yet:

 Class clazz = MyDomainClass.class ... DomainBuilder 
 builder = new  DomainBuilder<clazz>() {}

we can't actually do it this way. Because by doing so, we are not defining a class Type in the diagonal <>, rather passing an object claszz of type Class.