How to handle many jpa entities in one request (OpenSessionInView)

we have classic Spring application with OpenSessionInView pattern.

Sometimes we want proces many (=unknown size) entities in one request. This is well-known OutOfMemory issue.

Long time ago, we create function(hack) to switch current hibernate session for particular method.

public void proceedOnePerson(int id) {
    recalculateVAT(id);
}

public void proceedAllPerson(int[] ids) {
    for(int id : ids) {
        switchToAnotherHibernateSesion();
        recalculateVAT(id); //OutOfMemory
        closeAnotherSessionAndSwitchBackToOriginSession();
    }
}

Is there standard solution to this in Spring, Spring Boot or Spring Data?

• Session.clear is not suitable, because has side effect on other entities from other methods.


• Session.evict is not suitable too, because developer of method recalculateVAT had no idea if this function will be used in batch. Error prone.


• Spring batch is too heavy. And we dont want to write one method for user and second method for batch.