Left Join Fetch on Embeddable ElementColection fails & NamedQuery wit…

[kalinchan]

credit to @Pandrex247 and @Cousjava

Left Join Fetch

The error occurs when the Entities are compared to see if there is any change done and thus an update needs to be done to the database.

[2020-09-01T12:05:10.724+0200] [Payara 5.201] [WARNING] [] [javax.enterprise.web] [tid: _ThreadID=107 _ThreadName=http-thread-pool::http-listener-1(4)] [timeMillis: 1598954710724] [levelValue: 900] [[ StandardWrapperValve[be.rubus.payara.support.ticket1455.ApplicationConfig]: Servlet.service() for servlet be.rubus.payara.support.ticket1455.ApplicationConfig threw exception java.lang.NullPointerException at org.eclipse.persistence.internal.descriptors.InstanceVariableAttributeAccessor.getAttributeValueFromObject(InstanceVariableAttributeAccessor.java:83) at org.eclipse.persistence.mappings.DatabaseMapping.getAttributeValueFromObject(DatabaseMapping.java:691) at org.eclipse.persistence.mappings.foundation.AbstractDirectMapping.compareObjects(AbstractDirectMapping.java:412) at org.eclipse.persistence.mappings.foundation.AbstractDirectMapping.compareForChange(AbstractDirectMapping.java:386) at org.eclipse.persistence.descriptors.changetracking.DeferredChangeDetectionPolicy.createObjectChangeSetThroughComparison(DeferredChangeDetectionPolicy.java:192) at org.eclipse.persistence.descriptors.changetracking.DeferredChangeDetectionPolicy.createObjectChangeSet(DeferredChangeDetectionPolicy.java:152) at org.eclipse.persistence.descriptors.changetracking.DeferredChangeDetectionPolicy.calculateChanges(DeferredChangeDetectionPolicy.java:95) at org.eclipse.persistence.descriptors.changetracking.DeferredChangeDetectionPolicy.calculateChangesForExistingObject(DeferredChangeDetectionPolicy.java:61) at org.eclipse.persistence.internal.sessions.UnitOfWorkImpl.calculateChanges(UnitOfWorkImpl.java:713) at org.eclipse.persistence.internal.sessions.UnitOfWorkImpl.commitToDatabaseWithChangeSet(UnitOfWorkImpl.java:1568) at org.eclipse.persistence.internal.sessions.UnitOfWorkImpl.issueSQLbeforeCompletion(UnitOfWorkImpl.java:3258) at org.eclipse.persistence.internal.sessions.RepeatableWriteUnitOfWork.issueSQLbeforeCompletion(RepeatableWriteUnitOfWork.java:357) at org.eclipse.persistence.transaction.AbstractSynchronizationListener.beforeCompletion(AbstractSynchronizationListener.java:160) at org.eclipse.persistence.transaction.JTASynchronizationListener.beforeCompletion(JTASynchronizationListener.java:70) at com.sun.enterprise.transaction.JavaEETransactionImpl.commit(JavaEETransactionImpl.java:480)

When not using Left Join Fetch, no error occurs.

Named Query

When defining a NamedQuery that has EclipseLink hints, the query fails with an exception

Exception [EclipseLink-7081] (Eclipse Persistence Services - 2.7.6.payara-p1): org.eclipse.persistence.exceptions.ValidationException Exception Description: The aggregate object [class be.rubus.payara.support.ticket1455.model.Tag] cannot be directly registered in the UnitOfWork. It must be associated with the source (owner) object. at org.eclipse.persistence.exceptions.ValidationException.cannotRegisterAggregateObjectInUnitOfWork(ValidationException.java:622)

The offending NamedQuery, org.eclipse.persistence.config.QueryHints

@NamedQuery(
        name = "getAllBlogPosts_fail",
        query = "SELECT i FROM BlogPost i",
        hints = {
                @QueryHint(
                        name = QueryHints.REFRESH,
                        value = HintValues.TRUE
                ),
                @QueryHint(
                        name = QueryHints.LEFT_FETCH,
                        value = "i.tags"
                )
        }
)