1.3. Java SE environments

In a Java SE environment only extended context application-managed entity managers are available. You can retrieve an entity manger using the EntityManagerFactory API. Only resource-local entity managers are available. In other words, JTA transactions and persistence context propagation are not supported in Java SE (you will have to propagate the persistence context yourself, e.g. using the thread local session pattern popular in the Hibernate community).

Extended context means that a persistence context is created when the entity manager is retrieved (using EntityManagerFactory.createEntityManager(...) ) and closed when the entity manager is closed. Many resource-local transaction share the same persistence context, in this case.