Determine class type of Generic Parameter (not via getGenericSuperclass()!)

Question

I need to know the class type of a generic Parameter. Please imagine this class:
class MyGenericClass<T>
}In cases where other classes derived from MyClass and defined the generic parameter (like MyDerivedClass extends MyGenericClass<String>),
this snippets works just fine:
(Class<T>) ((ParameterizedType) getClass().getGenericSuperclass()).getActualTypeArguments()[0];But now I have no inheritance but the definition of the type parameter via instantiation:
MyGenericClass<String> entity = new MyGenericClass<String>();The method "getGenericSuperclass()" does not suit my needs because it does not target the actual class. Nor can "getTypeParameters() " help me...
After countless trying to retrieved the type information, I still have no clue how to determine for that case that (in my example) the type parameter
is a 'String'.
Does anyone know the solution?

Answer 1

Serethos_0 wrote:
Sure I could pass the class type itself as parameter to be stored in 'exportClassType'. But I only tried to adapt the idea used e.g. in Generic DAOs
as descibed here: [http://community.jboss.org/wiki/GenericDataAccessObjects]. The big difference is, that in the Generic DAO example the typed
information is available within the class definition ..
Besides that I am open for any other suggestion!I would recommend passing around the Class object as you say.
Some might suggest that you make MyGenericClass abstract, forcing any instantiation to be like this:
MyGenericClass<String> entity = new MyGenericClass<String>() {};That would indeed cause the String type parameter to be available at runtime, since you're creating an anonymous inner class. But it leads to a convoluted and extremely statically expensive instantiation pattern. Using the class object is a better solution IMO.