Kotlin for Enterprise Applications using Java EE

Persistence context

When we have multiple persistence units defined in the persistence.xml file, we need to inject the appropriate one to EntityManager using the @PersistenceContext annotation. We can point to a specific persistence unit using the PersistenceContext entity's unitName attribute.

Using @PersistenceContext on EntityManager, let's point to the integration unit:

@Statelessclass App {    @Inject    private lateinit var identityCreator: IdentityCreator    @PersistenceContext(unitName = "integration")    private lateinit var entityManager: EntityManager    fun createIdentity(inputData: InputData): Person {        val person = identityCreator.createPerson(inputData)        entityManager.persist(person)        return person    }    fun findAllPerson(): List<Identity> { return ...