I am getting the below exception when I try to set the parent reference for a collection in the setter of the collection in Parent.

If I don't propagate the parent reference to the child objects, the parent is not set on the child objects and I get a null pointer exception.
Please advice.

public void setPersonalInformationInsurance(Set personalInformationInsurance) {
if(personalInformationInsurance != null){
propagateParentReferenceToInsurances(personalInformationInsurance.iterator());
}
this.personalInformationInsurance = personalInformationInsurance;
}

private void propagateParentReferenceToInsurances(Iterator personalInformationInsurances) {
while (personalInformationInsurances.hasNext()) {
PersonalInformationInsurance insurance = (PersonalInformationInsurance)personalInformationInsurances.next();
insurance.setPersonalInformation(this);
}
}
<set
name="personalInformationInsurance"
lazy="true"
inverse="true"
cascade="all,delete-orphan"
>
<key>
<column name="PERSONAL_INFORMATION_ID_SEQ" />
</key>
<one-to-many
class="gov.va.med.domain.model.PersonalInformationInsurance"
/>
</set>

////////////

<!-- bi-directional many-to-one association to PersonalInformation (Parent)-->
<many-to-one
name="personalInformation"
class="gov.va.med.domain.model.PersonalInformation"
not-null="true"
>
<column name="PERSONAL_INFORMATION_ID_SEQ" />
</many-to-one>

////Exception //////////////////////////////////////////////////////////////////////

org.hibernate.PropertyAccessException: Exception occurred inside setter of gov.va.med.domain.model.Cytology.cytologySpecimens
at org.hibernate.property.BasicPropertyAccessor$BasicSetter.set(BasicPropertyAccessor.java:51)
at org.hibernate.tuple.AbstractTuplizer.setPropertyValues(AbstractTuplizer.java:207)
at org.hibernate.tuple.PojoTuplizer.setPropertyValues(PojoTuplizer.java:176)
at org.hibernate.persister.entity.BasicEntityPersister.setPropertyValues(BasicEntityPersister.java:2919)
at org.hibernate.engine.TwoPhaseLoad.initializeEntity(TwoPhaseLoad.java:113)
at org.hibernate.loader.Loader.initializeEntitiesAndCollections(Loader.java:530)
at org.hibernate.loader.Loader.doQuery(Loader.java:436)
at org.hibernate.loader.Loader.doQueryAndInitializeNonLazyCollections(Loader.java:218)
at org.hibernate.loader.Loader.doList(Loader.java:1593)
at org.hibernate.loader.Loader.list(Loader.java:1577)
at org.hibernate.loader.hql.QueryLoader.list(QueryLoader.java:395)
at org.hibernate.hql.ast.QueryTranslatorImpl.list(QueryTranslatorImpl.java:271)
at org.hibernate.impl.SessionImpl.list(SessionImpl.java:844)
at org.hibernate.impl.QueryImpl.list(QueryImpl.java:74)
at gov.va.med.domain.persistence.util.HibernateTableLoader.getRows(HibernateTableLoader.java:119)
at org.springframework.aop.framework.Cglib2AopProxy$CglibMethodInvocation.invokeJoinpoint(Cglib2AopProxy.java:661)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:122)

Caused by: org.hibernate.LazyInitializationException: illegal access to loading collection
at org.hibernate.collection.AbstractPersistentCollection.initialize(AbstractPersistentCollection.java:172)
at org.hibernate.collection.AbstractPersistentCollection.read(AbstractPersistentCollection.java:48)
at org.hibernate.collection.PersistentSet.iterator(PersistentSet.java:134)
at gov.va.med.domain.model.Cytology.setCytologySpecimens(Cytology.java:151)
... 112 more

You are accessing a proxy outside its session.

It's hard to tell what is cousing this problem without further information. My guess is that either you have a problem with your session management, or your passing around unitialized proxies as transfer objects.

You can switch of proxys in you hbm.xml file or initialize them explicitely with

HTH
Ernst