Spring TopLink support outside container

Question

I'm setting up an internal workshop at our company to teach and demo TopLink. I'm aiming to focus on TopLink, so I figured I would keep it as simple as possible.
I still want to demo transaction spanning several DAO calls though, and thought I could use the TopLink support in Spring for that. Easier said than done when I'm only running from a simple class' main method...
First I try starting a transaction with Spring, as I thought it would be able to fallback/handle it with a ThreadLocal even though it's not inside a container:
TransactionDefinition transDef = new DefaultTransactionDefinition(
TransactionDefinition.PROPAGATION_REQUIRED); TransactionStatus
TransactionStatus transStatus = transManager.getTransaction(transDef);
Which gives:
java.lang.UnsupportedOperationException: SingleSessionFactory does not support managed client Sessions
So I figure, alright, fair enough. All I have to do then is initialise a UoW through spring instead of starting a transaction, and then that will be injected into the TopLinkCallback I'm using in my DAO:
SessionFactory sessionFactory = (SessionFactory) appContext.getBean("sessionFactory");
Session currentSession = SessionFactoryUtils.getSession(sessionFactory, true);
UnitOfWork uow = currentSession.getActiveUnitOfWork();
But nope. The getActiveUnitOfWork() in my TopLinkCallback just returns null. Anyone know how to do this best outside a container? How do I initialise a UoW that Spring will hold on to for me?
Anders,

Answer 1

Hi Anders,
SessionFactory sessionFactory = (SessionFactory)
appContext.getBean("sessionFactory");
Session currentSession =
SessionFactoryUtils.getSession(sessionFactory,
true);
UnitOfWork uow =
currentSession.getActiveUnitOfWork();
But nope. The getActiveUnitOfWork() in my
TopLinkCallback just returns null. Anyone know how to
do this best outside a container? How do I initialise
a UoW that Spring will hold on to for me?
Anders,You're getting the expected behavior. getActiveUnitOfWork returns null outside of a transaction. It won't start one for you--you're going to have to do that before you call it.
If you put your code inside a transaction callback like the following you get an active unit of work.
final ClassPathXmlApplicationContext ctx = new ClassPathXmlApplicationContext("applicationContext-toplink.xml");
PlatformTransactionManager txManager = (PlatformTransactionManager) ctx.getBean("transactionManager");
TransactionTemplate template = new TransactionTemplate(txManager);
template.setPropagationBehavior(TransactionDefinition.PROPAGATION_REQUIRED);
TransactionCallbackWithoutResult callback =     new TransactionCallbackWithoutResult() {
     protected void doInTransactionWithoutResult(TransactionStatus transactionStatus) {
          SessionFactory sessionFactory = (SessionFactory) ctx.getBean("sessionFactory");
          Session currentSession = SessionFactoryUtils.getSession(sessionFactory, true);
          UnitOfWork uow = currentSession.getActiveUnitOfWork();
          // uow is not null
          // your code goes here
// execute your code in a tx
template.execute(callback);This code runs out of container no problem. I tested it with the petclinic example. Hope this helps.
--Shaun