Jpa-2.0 – execute @ postload_ after_ Eagerly extract?

Using JPA2 / Hibernate, I created an entity a with a one-way mapping to entity x (see below) In a, I also have a temporary member "t". I try to calculate it with @ postload method Computing requires access to disputed X:

@Entity  
public class A {  
    // ...
    @Transient
    int t;

    @OneToMany(orphanRemoval = false,fetch = FetchType.EAGER)  
    private List listOfX;  

    @PostLoad
    public void calculateT() {
        t = 0;
        for (X x : listOfX)
            t = t + x.someMethod();
    }
}

However, when I try to load this entity, I get an "org. Hibernate. Lazyinitializationexception: illegal access to the loaded collection" error

at org.hibernate.collection.AbstractPersistentCollection.initialize(AbstractPersistentCollection.java:363)
 at org.hibernate.collection.AbstractPersistentCollection.read(AbstractPersistentCollection.java:108)
 at org.hibernate.collection.PersistentBag.get(PersistentBag.java:445)
 at java.util.Collections$UnmodifiableList.get(Collections.java:1154)
 at mypackage.A.calculateT(A.java:32)

Looking at the hibernate code (abstractpersistentcollection. Java) during debugging, I found that:

1) my @PostLoad method has a clear check on the code that calls the 2] Hibernate before the "listOfX" member initializes, so as to prevent initialization of a hot collection within @PostLoad.

protected final void initialize(boolean writing) {
  if (!initialized) {
   if (initializing) {
    throw new LazyInitializationException("illegal access to loading collection");
   }
   throwLazyInitializationExceptionIfNotConnected();
   session.initializeCollection(this,writing);
  }
 }

The only way I want to solve this problem is to stop using @ postload, move the initialization code to the gett () accessor, and add a synchronization block But I want to avoid this

So, is there a method to perform snapping up before @ postload is called? I don't know what JPA facilities do, so I hope there are some things I don't know

In addition, perhaps hibernate's proprietary API can control this behavior?

Solution

This may be too late, but hibernate does not seem to support the default JPA fetchtype option

@OneToMany(orphanRemoval = false,fetch = FetchType.EAGER)

You must use a specific one of Hibernate:

@LazyCollection(LazyCollectionOption.FALSE)