We are developing an Application Managed JPA application.
The structure of the application is
Business Components which have business logic.
Tool generated DAO layer (JPA Managers and JPA Entities)
The usage would be like
Note: JPA Managers do invoke any transaction related APIs.
1) Is this valid code? i.e. would the update happen in a single transaction even if the EntityManagers obtained by all the classes (BusinessComponent, JPAEntity2Mgr, JPAEntity1Mgr) are different?
2) Is there a need to invoke the em.joinTransaction() api in the JPA Managers?