[eclipselink-users] IndirectSet/IndirectList relationship may cause tran

[Patric Rufflar <Patric@xxxxxxxxxxx>]

Hi,

I am seeing a strange EclipseLink (2.3.2) behavior:

Imagine an entity class A which refers to an entity class B via 
OneToMany(cascade=PERSIST) relationship which itself refers to entity 
class C via ManyToOne(cascade=PERSIST) relationship.

Furthermore imagine the following steps:

1. find() entity B with entity manager 1 (which contains references to 
at least one entity C)
2. Detach this entity from entity manager 1 (optional step)
3. create a new instance of A
4. set a reference from A to the detached B
5. Persist A on entity manager 2

When tracing through the operations which EclipseLink does on 
persist(), the resolving of the relationship B->C which is done by 
IndirectSet.buildDelegate() seems to re-use the Session/UnitOfWork from 
entity manager 1!
In the best case this will lead to some exceptions (e.g. the connection 
from entity manager 1 has already been closed before), but in the worst 
this will silently lead to strange dirty read/data inconsistency 
situations.

At least with the optional step 2, the detachment, I would never expect 
that such an entity is still silently referencing and using the entity 
manager on which it was previously attached.
But even without the detachment this would be very questionable.
I thought that (at least detached) entities can be considered as simple 
beans and do not have any restrictions regarding share/re-usage.

Is this behavior expected?

(Related: 
http://stackoverflow.com/questions/11398527/jpa-entity-sharing-among-different-entity-managers 
)

Thank you and best regards,
Patric