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eclipselinklazy-loadingjpa-2.0

Eclipselink : Operation not supported: [instantiateForUnitOfWorkValueHolder]

I get the following error when I try to access Lazy loaded @oneToMany relationship attribute in a method present in Entity.

Error:

Caused by: Exception [EclipseLink-7097] (Eclipse Persistence Services - 2.6.3.v20160428-59c81c5): org.eclipse.persistence.exceptions.ValidationException
Exception Description: Operation not supported: [instantiateForUnitOfWorkValueHolder].
    at org.eclipse.persistence.exceptions.ValidationException.operationNotSupported(ValidationException.java:1496)
    at org.eclipse.persistence.internal.indirection.ProtectedValueHolder.instantiateForUnitOfWorkValueHolder(ProtectedValueHolder.java:61)
    at org.eclipse.persistence.internal.indirection.UnitOfWorkValueHolder.instantiateImpl(UnitOfWorkValueHolder.java:160)
    at org.eclipse.persistence.internal.indirection.UnitOfWorkValueHolder.instantiate(UnitOfWorkValueHolder.java:234)
    at org.eclipse.persistence.internal.indirection.DatabaseValueHolder.getValue(DatabaseValueHolder.java:89)
    at org.eclipse.persistence.indirection.IndirectList.buildDelegate(IndirectList.java:271)
    at org.eclipse.persistence.indirection.IndirectList.getDelegate(IndirectList.java:455)
    at org.eclipse.persistence.indirection.IndirectList$1.<init>(IndirectList.java:597)
    at org.eclipse.persistence.indirection.IndirectList.listIterator(IndirectList.java:596)
    at org.eclipse.persistence.indirection.IndirectList.iterator(IndirectList.java:555)
    at com.order.modelGroupBase.getStatus(GroupBase.java:205)

Entity:

@Entity
@Table(name="GROUP")
@Customizer(GroupBaseCustomizer.class)
@Inheritance(strategy=InheritanceType.SINGLE_TABLE)
@ClassExtractor(GroupClassExtractor.class)
@InstantiationCopyPolicy
@Cacheable
@Cache( alwaysRefresh=true,
refreshOnlyIfNewer=true,
expiry=300000,      
coordinationType = CacheCoordinationType.SEND_NEW_OBJECTS_WITH_CHANGES)
public class GroupBase {

@OneToMany(cascade=CascadeType.ALL, mappedBy="groupBase", targetEntity=Groups.class)
@PrivateOwned
private List groups = new ArrayList<>();

public OrderGroupStatus getStatus() {

//error is at this line when I try to iterate..
for (Iterator itr = getGroups().iterator(); itr.hasNext();) {
    Groups relationship = (Groups) itr.next();
    //some operation..

    }           


}

}

I've looked upon in eclipselink forum but they don't address this issue explicitly and some links say it's related to weaving.But in my application I haven't enabled weaving at all and I also don't intend to do.

This code works fine on Eclipselink 2.3.2 without JPA. Now I'm using Eclipselink 2.6.3 with JPA 2.0 and IBM Websphere 8.5.5.8.

Note: This issue occurs randomly not every time and also when ever a new object is created is what I have observed.

Solution

  • After many hit and trails and correcting my lazy loading settings, I've found out that using different fetchType on same entity in other entities can cause this issue in SHARED_CACHE mode.

    @OneToMany(cascade=CascadeType.ALL, mappedBy="groupBase", targetEntity=Groups.class)
@PrivateOwned
private List groups = new ArrayList<>();

    By default @OneToMany is lazily fetched but in another entity for the same entity 'Groups' I had configured fetchType as EAGER.

    When I made both fetch types to LAZY this error stopped occurring.