Re: [eclipselink-dev] Loading multiple persistence.xml files

[Tom Ware <tom.ware@xxxxxxxxxx>]

Hi Carl,

  What issues are you seeing when you specify several orm files within the same 
persistence unit definition in one persistence.xml file?

e.g.

<persistence xmlns="http://java.sun.com/xml/ns/persistence"; 
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"; 
xsi:schemaLocation="http://java.sun.com/xml/ns/persistence persistence_1_0.xsd" 
version="1.0">

    <persistence-unit name="default" transaction-type="RESOURCE_LOCAL">
        <provider>
            org.eclipse.persistence.jpa.PersistenceProvider
        </provider>

        <mapping-file>META-INF/advanced-entity-mappings.xml</mapping-file>
        <mapping-file>META-INF/inheritance-entity-mappings.xml</mapping-file-->
        <mapping-file>META-INF/inherited-entity-mappings.xml</mapping-file>
        <mapping-file>META-INF/relationships-entity-mappings.xml</mapping-file>


etc....


-Tom

Carl Hall wrote:
> Hi, Tom.
>
> You've nailed it.  Each persistence.xml is trying to create the same 
> persistence unit ("default").  Is there a nice way to load 1 persistence 
> unit from multiple orm.xml files?  I've seen some classloader tricks to 
> accomplish this but don't want to head down that rabbit hole unless 
> necessary.
>
> Thanks,
> Carl
>
>
> On Wed, Dec 17, 2008 at 10:55, Tom Ware <tom.ware@xxxxxxxxxx 
> <mailto:tom.ware@xxxxxxxxxx>> wrote:
>
>     Hi Carl,
>
>      Are you using separate EntityManagers for each persistence unit?
>
>      An EntityManager represents one persistence unit - when the
>     EntityManagerFactory is created, you get it by persistence unit
>     name.  Any EntityManager created by that factory will represent that
>     persistence unit.
>
>      The name of a persistence unit is specified in the persistence.xml
>     and only one persistence.xml may be used to define a given
>     persistence units.  It is an error to have multiple persistence.xml
>     that define the same persistence unit and the behavior is undefined
>     - I am not surprised that if you are doing this, you get the last
>     one loaded.
>
>      To access different persistence units, create an EntityManager for
>     each.
>
>     -Tom
>
>     Carl Hall wrote:
>
>         I have a setup where multiple project come into a shared
>         classloader.  Each project can have its own model files and
>         thusly its own persistence.xml and orm.xml files.  When I create
>         an EntityManager, I see in the logs that each persistence.xml
>         file is found (3) and each orm.xml file loads with the expected
>         entities.  When I try to query or persist using this
>         EntityManager, only the entities from the lastly loaded
>         persistence.xml is found.  Am I loading this correctly?  Am I
>         trying to access things incorrectly?
>
>
>         ------------------------------------------------------------------------
>
>         _______________________________________________
>         eclipselink-dev mailing list
>         eclipselink-dev@xxxxxxxxxxx <mailto:eclipselink-dev@xxxxxxxxxxx>
>         https://dev.eclipse.org/mailman/listinfo/eclipselink-dev
>
>     _______________________________________________
>     eclipselink-dev mailing list
>     eclipselink-dev@xxxxxxxxxxx <mailto:eclipselink-dev@xxxxxxxxxxx>
>     https://dev.eclipse.org/mailman/listinfo/eclipselink-dev
>
>
>
> ------------------------------------------------------------------------
>
> _______________________________________________
> eclipselink-dev mailing list
> eclipselink-dev@xxxxxxxxxxx
> https://dev.eclipse.org/mailman/listinfo/eclipselink-dev