eclipselink loading n+1 associations even though they are marked as FetchType.LAZY

Question

Given a mapped super class like this.

My query is resulting in each of the mapped classes getting loaded by JPA as soon as getResultsList() is executed.

I am not accessing any of the properties associated with the Order or Vehicle, but they are all being lazy loaded immediately?

@MappedSuperclass
public abstract class PimaOrderComponentORM implements Serializable, EntityWithPK<Long> {
    @ManyToOne(fetch = FetchType.LAZY)
    @JoinColumns(@JoinColumn(name="PIMA_ORDER_ID", referencedColumnName="ID"))
    private PimaOrderBE pimaOrder;
}

@MappedSuperclass
public abstract class PimaOrderORM implements Serializable, EntityWithPK<Long> {
    @Id
    @GeneratedValue(generator="SQ_PIMA_ORDER")
    @SequenceGenerator(name="SQ_PIMA_ORDER", sequenceName="SQ_PIMA_ORDER", allocationSize=20)
    @Column(name = "ID")
    private Long id;

    @ManyToOne(fetch = FetchType.LAZY)
    @JoinColumns(@JoinColumn(name="VEHICLE_ID", referencedColumnName="ID"))
    private VehicleBE vehicle;
}

Each class has a concrete implementation.

When executing this query using JPA

        String esql = "SELECT p FROM PimaOrderComponentBE p WHERE p.pimaOrder.vehicle.id in :vehicles";
        Query query = em
                .createQuery(esql)
                .setHint(QueryHints.JDBC_FETCH_SIZE, 1000)
                .setParameter("vehicles", ids);
        List<PimaOrderComponentBE> results = query.getResultList();

At this point 20-30 queries are all executed fetching all the lazy values? I have put breakpoints on all the necesary classes, and cannot figure it out.

Answer 1

Weaving is required for some lazy relationships such as OneToMany and ManyToOne, and enabling other performance enhancements such as fetch groups and change tracking, as described at https://www.eclipse.org/eclipselink/documentation/2.5/concepts/app_dev007.htm

Weaving generally automatic occurs within EE 7 containers, but will require extra steps to function outside of the container or in non-EE7 containers.