How to create EntityManagerFactory?

avihaimar77 · **Joined:** Wed May 02, 2007 2:42 pm **Posts:** 101

Hey,

I want to create EntityManagerFactory in runtime.

Means, that i dont want to use the persistence.xml file, because i will know the schema name only in runtime.

Any one has a knowledge or an example how to create EntityManagerFactory in my code ?

Thank you.

emmanuel · **Posted:** Fri Aug 10, 2007 8:25 am

use Persistence.createEntityManagerFactory("name", properties)

put hibernate.default_schema in your properties and use persistence.xml for the rest.

avihaimar77 · **Joined:** Wed May 02, 2007 2:42 pm **Posts:** 101

In my DS i didnt set the schema.

When the server startup it create a factory based on this persistence unit:

Code:

<persistence>
  <persistence-unit name="BRL-Server">
    <jta-data-source>java:/InsiteDS</jta-data-source>
    <properties>
            <property name="hibernate.transaction.manager_lookup_class" value="org.hibernate.transaction.JBossTransactionManagerLookup"/>
            <property name="hibernate.ejb.naming_strategy" value="org.hibernate.cfg.DefaultComponentSafeNamingStrategy" />
    </properties>
  </persistence-unit>
</persistence>

In run time i create factories like the way you suggested
based on this factory with the schema as a parameter.

My questions are:
1. What is the meaning of the first factory? no schema was set for this factory.
2. How can i avoid from create the first facroty. I dont need it. Is there any API that i can craete a facroty in runtime without the need of base factory
3. the factoy that created is no ManagedFactory , so is used this code is this ok?

Code:

         ManagedEntityManagerFactory managedEntityManagerFactory = EntityManagerFactoryMap.getInstance().getManagedEntityManagerFactory(schemaName);
         em = new TransactionScopedEntityManager(managedEntityManagerFactory);

Thank you very much.

ps. i am working with JBoss 4.2

emmanuel · **Posted:** Wed Aug 15, 2007 9:47 pm

The first factory is created because the spec states so. if a persistence.xml if found the factory is deployed.
Of avoiding the deployment is not possible, and Jboss AS does not provide a proprietary way to do that either.

I don't know exactly what ManagedEntityManagerFactory is, but it seems you're messing up with internal JBoss AS classes, so no you can't do that.

emmanuel · **Posted:** Wed Aug 15, 2007 9:48 pm

I mean you can but at your own risk :)

avihaimar77 · **Joined:** Wed May 02, 2007 2:42 pm **Posts:** 101

Code:

em = managedEntityManagerFactory.getTransactionScopedEntityManager();

I look at the code and it seems to work.

It success to get the same entity manager in the transaction scope.[/quote]