Configuring a managed persistence context is easy. In components.xml, we can write:

<core:managed-persistence-context name="bookingDatabase" 
                           auto-create="true"
            persistence-unit-jndi-name="java:/EntityManagerFactories/bookingData"/>

This configuration creates a conversation-scoped Seam component named bookingDatabase that manages the lifecycle of EntityManager instances for the persistence unit (EntityManagerFactory instance) with JNDI name java:/EntityManagerFactories/bookingData.

Of course, you need to make sure that you have bound the EntityManagerFactory into JNDI. In JBoss, you can do this by adding the following property setting to persistence.xml.

<property name="jboss.entity.manager.factory.jndi.name" 
          value="java:/EntityManagerFactories/bookingData"/>

Now we can have our EntityManager injected using:

@In EntityManager bookingDatabase;