How do I access EntityManager from within Grails service (JPA + GAE)

I'm having trouble accessing the EntityManager from within a grails service:

My setup is as follows...

• Basic Grails application with the AppEngine and GORM-JPA plugins
• Default settings for pretty much everything. I haven't touched resources.groovy, persistence.xml etc.

Some things are good...

• I am able to access the EntityManager from within controllers by simply adding "def entityManager".

But...

• I have a service that I'm trying to access the EntityManager from, however, I get a "java.lang.IllegalStateException: EntityManager is already closed!" exception.

• Is a plugin closing the EntityManager somewhere? Do I need to change the scope of the EntityManager somehow? Is there some XML file I need to update to ensure proper injection?

  class GoogleCalendarService implements InitializingBean {
      void afterPropertiesSet() {
      }
  
  
     def entityManager
  
  
     public OAuthToken getAccessToken(User u) {
         //can't access entityManager from here
         entityManager.newQuery(...) //throws an IllegalStateException
     }
  
  
  }
  

One weird note: For some reason, if I re-save the service while Jetty is up and running the service is able to access the EntityManager just once. I开发者_JAVA技巧f I click reload (and have the controller access the service again) the service can no longer access the EntityManager...

---

I guess the right way to do this is use the EntityManagerFactory, like this:

import org.springframework.orm.jpa.EntityManagerFactoryUtils

class GoogleCalendarService implements InitializingBean {
    void afterPropertiesSet() {

    }

    def entityManagerFactory
    EntityManager em

    public OAuthToken getAccessToken(User u) {
        em = EntityManagerFactoryUtils.getTransactionalEntityManager(entityManagerFactory)
        //do stuff with em
    }
}