Using a non-mapped superclass breaks my entity listener

Support
#1

Sorry about the somewhat vague title; this is easier to illustrate in code. I had a BeforeInsertEntityListener which creates a new access group when a specific entity type is created, which worked just fine until I changed the entity type to extend a non-mapped superclass.

Firstly, here’s the code which works:

(All of my entites were created using Studio, so there’s no custom code involved except in the listener.)

ConcreteEntity

@Listeners("app_ConcreteEntityListener")
@Table(name = "APP_CONCRETE_ENTITY")
@Entity(name = "app$ConcreteEntity")
public class ConcreteEntity extends BaseLongIdEntity {
    // lots of POD properties
}

EntityAccessGroup

@Entity(name = "app$EntityAccessGroup")
public class EntityAccessGroup extends Group {
    @OnDeleteInverse(DeletePolicy.CASCADE)
    @OneToOne(fetch = FetchType.LAZY)
    @JoinColumn(name = "CONCRETE_ENTITY_ID")
    private ConcreteEntity concreteEntity;

    // getters, setters
}

ConcreteEntityListener

@Component("app_ConcreteEntityListener")
public class ConcreteEntityListener implements BeforeInsertEntityListener<ConcreteEntity> {
    @Inject private Metadata metadata;

    @Override
    public void onBeforeInsert(ConcreteEntity entity, EntityManager entityManager) {
        Group parentGroup = entityManager
              .createQuery("SELECT g FROM sec$Group g WHERE g.name = :name", Group.class)
              .setParameter("name", "parentAccessGroupName")
              .getFirstResult();

        if (parentGroup == null) {
            throw new IllegalStateException("Parent access group missing!");
        }

        EntityAccessGroup accessGroup = metadata.create(EntityAccessGroup.class);
        accessGroup.setParent(parentGroup);
        accessGroup.setConcreteEntity(entity);
        accessGroup.setName(generateAccessGroupName(entity)); // returns a string based on entity.getName()
        entityManager.persist(accessGroup);

        SessionAttribute attr = metadata.create(SessionAttribute.class);
        attr.setGroup(accessGroup);
        attr.setName("concreteEntityId");
        attr.setDatatype("long");
        attr.setStringValue(entity.getId().toString());
        entityManager.persist(attr);
    }
}

So when I create a new ConcreteEntity, I also get a new EntityAccessGroup set up which puts the ConcreteEntity ID into the session.

However, if I introduce a superclass to pull out some of the implementation of ConcreteEntity, things no longer work correctly. For example, if I add:

MyBaseEntity

@DiscriminatorColumn(name = "DTYPE", discriminatorType = DiscriminatorType.STRING)
@Inheritance(strategy = InheritanceType.JOINED)
@Table(name = "APP_MY_BASE_ENTITY")
@Entity(name = "app$MyBaseEntity")
public class MyBaseEntity extends BaseLongIdEntity implements SoftDelete, Updatable, Creatable {
    // some common stuff
}

Then change ConcreteEntity thus:

@PrimaryKeyJoinColumn(name = "ID", referencedColumnName = "ID")
@Listeners("app_ConcreteEntityListener")
@Table(name = "APP_CONCRETE_ENTITY")
@Entity(name = "app$ConcreteEntity")
public class ConcreteEntity extends MyBaseEntity {
    // Some concrete class-specific stuff
}

Now I get the following SQLException when I try to insert a new ConcreteEntity (caused by the underlying INSERT INTO SEC_GROUP … query):

SQLException: The INSERT statement conflicted with the FOREIGN KEY constraint “FK_SEC_GROUP_CONCRETE_ENTITY”. The conflict occurred in database “mydbname”, table “dbo.AAP_CONCRETE_ENTITY”, column ‘ID’.

#2

I’ve found a solution: If I add a call to entityManager.flush(); before I create the EntityAccessGroup instance, it works.

I’m still curious whether this is the “correct” way of going about things, or whether there are other possible solutions.

#3

Hi David,

Thank you for reporting the problem.
The cause of the problem is that EclipseLink ORM doesn’t order inserts properly for this case: it first inserts MyBaseEntity, then EntityAccessGroup, which has a reference to ConcreteEntity that is not inserted yet.

A similar problem is described in Cascade Insert problem - CUBA.Platform

Workaround: create the reference to MyBaseEntity in EntityAccessGroup.

We have created a YouTrack issue, see the link on the right.

1 Like
#4

:ticket: See the following issue in our bug tracker:

https://youtrack.cuba-platform.com/issue/PL-8135