topic Re: Activiti JavaDelegate, JPA and JTA best practice in Alfresco Archive

Activiti JavaDelegate, JPA and JTA best practice

chris_joelly — Wed, 17 Aug 2011 22:30:16 GMT

Hello,i want to create/query entities using JPA in an JavaDelegateand i have Activiti configured to use JTA and a datasource from Glassfish 3.1.1.Within a JavaDelegate serviceTask I lookup the EntityManagerusing JNDI and use this entity manager for my entity. Then iset the entity as process variable

Re: Activiti JavaDelegate, JPA and JTA best practice

jbarrez — Fri, 26 Aug 2011 08:04:55 GMT

It should basically work, the way you describe it.
Is there any chance you could wrap it up in a simple unit test so I can test it myself?

Re: Activiti JavaDelegate, JPA and JTA best practice

chris_joelly — Sat, 03 Sep 2011 08:34:20 GMT

i am working on a unit test which deploys the ejb and war to a glassfish-embedded
and i hope i can simulate this behavior. but at the moment i have issues getting
glassfish-embedded to work. only test the Activiti will not be the same scenario.

Re: Activiti JavaDelegate, JPA and JTA best practice

chris_joelly — Sun, 04 Sep 2011 21:44:48 GMT

I think i found my problem. If i put a UserTransaction around the Activiti calls
then i can avoid these exceptions, the UserTransaction utx is injeced via
@Resource into the @ManagedBean:


    utx.begin();
    List<Task> tasks = activiti.getProcessEngine().getTaskService()
        .createTaskQuery()
        .taskAssignee(userSession.getUser().getUsername())
        .orderByTaskCreateTime().asc().list();
    utx.commit();

So: i need to start and end a transaction if i call Activiti services in an Bean
outside of an EJB and i dont need to do it if i use Activiti services within an EJB
if i use transactionsExternallyManaged = true. Btw. if i use transactionsExternallyManaged
set to false it works too.

But what i even dont understand is are the cfg options jpaPersistenceUnitName,
jpaHandleTransaction and jpaCloseEntityManager. When do i need these parameters?
Dont they interfer with a JTA setup?

Re: Activiti JavaDelegate, JPA and JTA best practice

frederikherema1 — Mon, 05 Sep 2011 07:09:49 GMT

The JPA-configurations you only need when you want to use JPA-entities as process-variables in your processes. If you're just using JPA alongside your process (calling your own services from the process for example), it's not needed.