Re: [eclipselink-users] Duplicate Entities in GlassFish Persistence Cont

[James Sutherland <jamesssss@xxxxxxxxx>]

Within a JTA transaction the EntityManager must always return the same
instance (unless you call clear).

Are you sure it is a single transaction?  Or is it two different
transactions, or not in a JTA transaction context?  With a JTA managed
EntityManager a different instance must be return across each transaction
boundary.

Ensure you are in a single transaction and are not calling clear, perhaps
enable logging on finest.


bht wrote:
> 
> Hi,
> 
> I am getting duplicate managed Entities in EntityManager in a single
> transaction.
> 
> This happens only in GlassFish, not with a JUnit test that uses
> transaction-type="RESOURCE_LOCAL" in persistence.xml.
> 
> After retrieveal from an object query, the same entities are looked up
> again using EntityManager.find().
> 
> find() gets the duplicates. I spotted them because they "lost" some
> transient fields that were set prior to find(), and they have
> different Object hashcodes.
> 
> One could argue that there is no contract that stipulates that
> EntityManager must return identical entities for the same entity type
> and ID within the same transaction.
> 
> However, there is also no reason for such a waste of memory because if
> I can compare them, then I have the references to them and they cannot
> be garbage collected anyway.
> 
> Is this a bug? Should I report this?
> 
> The scenario is very difficult to deal with - it limits my programming
> options quite a bit. It is scary and frustrating.
> 
> Regards,
> 
> Bernard
> 
> 


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