InventoryManagement declaration?

[Charles O'Leary]

Hi Ranchers,

16.11.2Application Assembler’s Responsibilities
The Application Assembler can use the persistence-unit-name element in the deployment descriptor to specify a reference to a persistence unit using the syntax described in section 16.10.2. In this manner, multiple persistence units with the same persistence unit name may be uniquely identified when persistence unit names cannot be changed.
For example,
...
<enterprise-beans>
<session>
...
<ejb-name>InventoryManagerBean</ejb-name>
<ejb-class>
com.wombat.empl.InventoryManagerBean
</ejb-class>
...
<persistence-context-ref>
<description>
Persistence context for the inventory management
application.
</description>
<persistence-context-ref-name>
persistence/InventoryAppMgr
</persistence-context-ref-name>
<persistence-unit-name>
../lib/inventory.jar#InventoryManagement
</persistence-unit-name>
</persistence-context-ref>
...
</session>
</enterprise-beans>
...
The Application Assembler uses the persistence-unit-name element to link the persistence unit name InventoryManagement declared in the InventoryManagerBean to the persistence unit named InventoryManagement defined in inventory.jar.

Where is (and/or how does) the persistence unit name InventoryManagement declared in the InventoryManagerBean (look)?

[Frits Walraven]

Where is (and/or how does) the persistence unit name InventoryManagement declared in the InventoryManagerBean (look)?

That would be in the persistence.xml located in META-INF directory of the inventory.jar file. (assuming it is a standard ejb-jar file)

[Charles O'Leary]

Thanks Frits.

@PersistenceContext(unitName=”InventoryManagement”)
@Stateless
public class InventoryManagerBean  {
...
}

InventoryManagement would appear declared as in the above first? Secondly, application assemblers can then use the deployment descriptor persistence-unit-name element (quoted in my initial question) to refer or link to the persistence unit specified in the persistence.xml located in META-INF directory of the inventory.jar file?

Both, in this case the bean-based and the persistence.xml-based, declarations along with the deployment descriptor persistence-unit-name element, which ties these together, are required for the link? Correct?

[Frits Walraven]

Yes, that is exactly how I understood it as well.

You would only need this if you have two persistence units with the same name in your application. This way you don't have to change your code, but only link the unit-names to different locations.

[Charles O'Leary]

Thanks Frits.