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From Craig L Russell <Craig.Russ...@Sun.COM>
Subject Re: [DISCUSS] Named PMF proposal (JDOHelper enhancements)
Date Thu, 01 Mar 2007 06:06:03 GMT

On Feb 28, 2007, at 8:38 AM, Matthew Adams wrote:

> Inline...
>
>>> Call it what you want -- I only proposed these names.  I
>> wouldn't call
>>> it persistence.xml, as the contents are not the same as the
>>> JPA-specified content.  If the persistence.xml is found, its  
>>> contents
>>> are of course interpretable by the JDO implementation
>> according to our
>>> JPA alignment verbage defined in JDO 2.1.
>>
>> ok. So a JDO2.1 impl has to understand both "persistence.xml"
>> (JPA format) and
>> this "jdo.xml" ? No problem if that is the case but just want
>> to understand
>> what we're specifying here since not everyone was on this conf call.
>>
> Yes, this is correct.  I guess since JPA, which uses the base  
> namespace
> "javax.persistence" and calls the file "persistence.xml", then we  
> should
> probably call JDO bootstrap file "jdo.xml".  Done.

I like it.

>
>>>> We could use the
>>>> same boot idea as JPA and have a
>> META-INF/services/javax.jdo.XXX file
>>>> defining the PMF(s) available, and it takes the one that
>>>> claims it supports
>>>> the required "persistence-unit" (or PMF)
>>>
>>> I like this suggestion!  I assume the following would be
>> true -- please
>>> correct where I've got it wrong.
>>>
>>> * The name of this file is
>>> "META-INF/services/javax.jdo.PersistenceManagerFactory"
>>> 	* This is a text file
>>> 	* The contents of the file would be the name of the provider's
>>> implementation class of javax.jdo.PersistenceManagerFactory
>>
>> Yes. See a mail by Erik to the lists on 19/01/2007 called
>> "Proposal for
>> Service Discovery". JDOHelper would then have the job of
>> finding all services
>> files of this name ("javax.jdo.PersistenceManagerFactory"),
>> and from the
>> contents finding the relevant PMF to instantiate for a
>> particular PMF name.

Ok.
>>
>>
>> Since this appears to be an extension to JDO and not the
>> simple mapping across
>> of terminology JDO-JPA (being able to read a
>> "persistence.xml"), I'd ask are
>> we just confusing users by having "persistenceUnitName" and
>> "transactionType"
>> for when a JDO impl reads a "persistence.xml", yet here we
>> also have a PMF
>> name (which is the same as a persistence-unit name) for when
>> we use this
>> file.
>>
> This was brought up on the conference call.  A "persistence unit"  
> is the
> same thing as a "named PMF".

Yes.

> We decided that we won't use the term
> "named PMF" in the specification -- we'll just go with "persistence
> unit".  There will be a JPA flavor (already specified) and a
> corresponding JDO flavor (adding a name to a PMF, the getName()  
> method).
>
> As far as transaction type, I think they're the same.

There is nothing in JDO 2.0 that corresponds to JPA TransactionType.  
We're adding it to JDO 2.1. So there is no ambiguity and no reason I  
can think of to create a different name.

Craig

> Craig, can you
> please comment on transaction type?
>
> -matthew

Craig Russell
Architect, Sun Java Enterprise System http://java.sun.com/products/jdo
408 276-5638 mailto:Craig.Russell@sun.com
P.S. A good JDO? O, Gasp!


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