Re: [eclipselink-users] Questions about Spring @Transactional annotatio

[Tim Hollosy <hollosyt@xxxxxxxxx>]

Thanks, that makes sense. I guess if I'm doing a set of operations on
multiple entities in a transaction it should probably be in it's own
DAO method just for business rules sake.

I'm wondering if I can mark my whole class as being inside a
transaction rather than a single method....

./tch



On Tue, Feb 10, 2009 at 8:37 AM, James Sutherland <jamesssss@xxxxxxxxx> wrote:
>
> I'm no Spring expert, but assuming it behaves the same way as SessionBeans,
> each transaction will have a new EntityManager.  So inside your delete, you
> will need to re-find the object by its id then delete it.
>
>
>
> tch wrote:
>>
>> Ok,
>> So I've finally gotten a few free seconds to start looking at Spring
>> and JPA/EclipseLink again, and have started to run into some curious
>> things.
>>
>> In this example I have a DAO that has 2 methods and an EM injected like
>> this:
>> @PersistenceContext
>> private EntityManager entityManager;
>>
>> @Transactional(readOnly=true)
>> find(..)
>>
>> @Transactional(propagation = Propagation.REQUIRED)
>> delete(Object entity)
>>
>>
>> So in my controller I inject the dao, then do something like this:
>>
>> Entity e = dao.find(..)
>> dao.delete(e);
>>
>> EclipseLink cries and says it can't delete an unmanaged entity :/
>>
>> So apparently I'm confused about what exactly is happening when I use
>> this @Transactional annotation. Admittedly I didn't read the docs too
>> thoroughly, so I'm not surprised. My options are to do the find/delete
>> in one @Transactional method or call a merge inside my dao's delete
>> method. But I don't understand why I'm getting a (different?) em even
>> though I'm using the same dao, in the same request. Does
>> @Transactional do something funky with the em? Does it not guarantee
>> the same one?
>>
>> Thanks and don't be afraid to reply with RTFM :)
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>>
>>
>
>
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