Question

What should happen, if both the entity class and its superclass implements methods annotated with javax.persistence.PostLoad? Which method must be called and which as first? Does it dependent on the visibility of the method (private, public)?

(Hibernate default session doesn’t calls such methods at all and I am about to implement a workaround using the Hibernate PostLoadEventListener.)

Answer 1

Let me copy some parts of the Java Persistence API 2.0 FR specification which I believe might answer your question.

3.5.1 Lifecycle Callback Methods

The callback methods can have public, private, protected, or package
level access, but must not be static or final.

3.5.4 Multiple Lifecycle Callback Methods for an Entity Lifecycle Event

If multiple classes in an inheritance
hierarchy—entity classes and/or mapped superclasses—define entity
listeners, the listeners defined for a superclass are invoked before
the listeners defined for its subclasses in this order.

(…)

If a lifecycle callback method for the same lifecycle event is also
specified on the entity class and/or one or more of its entity or
mapped superclasses, the callback methods on the entity class and/or
superclasses are invoked after the other lifecycle callback methods,
most general superclass first.

And following section brings a very detailed example which might solve your problem:

3.5.5 Example

There are several entity classes and listeners for animals:

@Entity
public class Animal {
    ....
    @PostPersist
    protected void postPersistAnimal() { .... }
}

@Entity
@EntityListeners(PetListener.class)
public class Pet extends Animal {
    ....
}

@Entity
@EntityListeners({CatListener.class, CatListener2.class})
public class Cat extends Pet {
    ....
}

public class PetListener {
    @PostPersist
    protected void postPersistPetListenerMethod(Object pet) { .... }
}

public class CatListener {
    @PostPersist
    protected void postPersistCatListenerMethod(Object cat) { .... }
}

public class CatListener2 {
    @PostPersist
    protected void postPersistCatListener2Method(Object cat) { .... }
}

If a PostPersist event occurs on an instance of Cat, the following
methods are called in order:
– postPersistPetListenerMethod
– postPersistCatListenerMethod
– postPersistCatListener2Method
– postPersistAnimal

Hope that helps!