Hi Alex,
We actually do have to do quite a bit of linking and other work to
support JPA, so you definitely came to the right list. I'm ripping
that code up right now in fact.
While you do have to have a persistence.xml file for your application,
*some* of the values in a persistence.xml can be supplied via system
properties and left out of your persistence.xml.
Namely the following:
javax.persistence.provider
javax.persistence.transactionType
javax.persistence.jtaDataSource
javax.persistence.nonJtaDataSource
Note that the javax.persistence.provider will default to OpenJPA (i.e.
org.apache.openjpa.persistence.PersistenceProviderImpl). While that's
nice, it doesn't allow you to pass the vendor specific properties,
namely the truly amazing "openjpa.jdbc.SynchronizeMappings" that will
basically allow you to squeak by not having to create or drop tables.
We don't yet have the ability to fully define persistence units at the
openejb.xml level, but that definitely is a feature I've thought of
adding.
Along the lines of hooking your application up to persistence units
defined in a persistence.xml, I added some great code for the upcoming
beta 2 that performs some pretty bullet proof validation of your app.
Some sample validation messages you might see in beta 2 are:
Mistaken use of @PersistenceUnit on an EntityManager reference. Use
@PersistenceContext for ref "org.superbiz.injection.jpa.MoviesImpl/
entityManager"
Mistaken use of @Resource on an EntityManager reference. Use
@PersistenceContext for ref "org.superbiz.injection.jpa.MoviesImpl/
entityManager"
Persistence unit not found for
@PersistenceContext(name="entityManager", unitName="movie-unnit").
Available units [movie-unit]
We also have a new example for showing dependency injection of JPA
EntityManagers. It's fun to run it and attempt to break the app by
adding, changing, or removing persistence units or references to them.
If you find a way that we don't check for, I'll by you a book on
amazon. And as usual, all validation come in all-at-once "compiler"
format, so it should be possible to spot all your mistakes in one go
avoiding countless "small fix, compile, redeploy, fail, repeat" cycles.
The new example:
http://svn.apache.org/repos/asf/openejb/trunk/openejb3/examples/injection-of-entitymanager/
-David
On Dec 12, 2007, at 7:29 PM, Alexander Saint Croix wrote:
Hello,
I'm working on an application that at the moment includes a single
(proof-of-concept) entity bean in my main web application WAR, and
also
large number of entity beans which are JAR'd in the WEB-INF/lib.
Knowing that the persistence management is all outboard and not
contained
inside of OpenEJB, perhaps you guys could help me with a matter of
configuration anyway.
I wonder whether there is any way for me to NOT include the
<provider> and
<properties> elements defining the persistence provider
implementation,
connection URL, connection driver name, username and password in the
persistence.xml file for my entity/POJO jar (the one inside of WEB-
INF/lib),
but rather configure that specific portion of the persistence.xml file
inside of the context of the application that is using these beans?
It
doesn't seem to be any of the POJO JAR's business what type of
persistence
provider is being used to persist its contents.
I've attached an example of the <provider> and <properties> elements
I wish
to exclude below. I want to define classes but not persistence
provider
information in the entity JARs, and define the persistence provider
for
these persistence-units once at the container level. Is this
possible, and
if so, how might I accomplish that separation with OpenEJB?
Regards,
--
Alexander R. Saint Croix
<persistence xmlns="http://java.sun.com/xml/ns/persistence";
version="1.0">
<persistence-unit name="example" transaction-type="RESOURCE_LOCAL">
<provider>
org.apache.openjpa.persistence.PersistenceProviderImpl
</provider>
<class>org.eremite.SomeBeanInThisJar</class>
<properties>
<property name="openjpa.jdbc.SynchronizeMappings"
value="buildSchema"/>
<property name="openjpa.ConnectionURL"
value="jdbc:mysql://localhost/corm"/>
<property name="openjpa.ConnectionDriverName"
value="com.mysql.jdbc.Driver"/>
<property name="openjpa.ConnectionUserName"
value="username"/>
<property name="openjpa.ConnectionPassword"
value="password"/>
</properties>
</persistence-unit>
</persistence>
