No type-erasure for JpaRepository's generics?

Question

I use the data-repository like this:

interface HerbadgeRepository extends JpaRepository<Herbadge, Integer> {
}

At oracle they say:

To implement generics, the Java compiler applies type erasure ...

I am confused, the bytecode must be like this:

interface HerbadgeRepository extends JpaRepository<?, ?> {
}

So how do spring-data knows what entity must be returned?

Answer 1

Spring data analyze class signature with Reflection. You could obtian class types with code:

HerbadgeRepository.class.getGenericInterfaces()[0].getTypeName()