On Sep 21, 2009, at 2:59 AM, Quintin Beukes wrote:
Hey,
I have 2 persistence units, one for each module in the system. The
first has an entity Employee, and the other has an Entity
LampAssignment. LampAssignment has a @OneToOne on a field:
private Employee employee;
The JAR containing Employee is KMS-Personnel-ejb-1.0.jar, and it's PU
is: KMS-Personnel-PU
The JAR containing LampAssignment is VDS-lamps-ejb, and it's PU is:
VDS-lamps-PU
When I try and run this OpenEJB give the following output:
[...]
ERROR - Application could not be deployed: classpath.ear
org.apache.openejb.OpenEJBException: Creating application failed:
classpath.ear: org.hibernate.AnnotationException: @OneToOne or
@ManyToOne on net.kunye.vds.lamps.LampAssignment.employee references
an unknown entity: net.kunye.personnel.Employee: @OneToOne or
@ManyToOne on net.kunye.vds.lamps.LampAssignment.employee references
an unknown entity: net.kunye.personnel.Employee
[...]
How can I get them to notice each other?
No real way to split them into two units like that. A persistence-
unit is really the definition of a database cache. Meaning it's a
whole view of an entire set of data. The entity manager instance is
really your way to pull and push data to and from that cache and by
definition it can't see data for tables (entities) it doesn't control.
A lot of people want to split up their "units" for build reasons and
have the entities divided into specific jar files, which is more than
valid. But at run time it has to be joined together and defined as
one persistence-unit if the entities are part of the same relational
scheme. You can use the persistence.xml <jar-file> element to pull in
other jars or use the <class> element to list the classes individually
and have them count as being in the same unit regardless of which jar
they may be in.
This doc isn't directly related to your question, but I do find it
demystifies JPA a bit:
http://openejb.apache.org/3.0/jpa-concepts.html
-David
