Need Help: Managing Hibernate Session at EJB layer

This is my architecture:
@Stateless EJB 3 Services --> Business Services (Spring) --> DAO via HibernateDaoSupport (Spring)

I am using CMT in an application server. I need the Hibernate session available to me in EJB layer for lazy loading/object conversion; unfortunately it only opens/closes at my Business Service layer because that's the boundaries of Spring's transactional support.

How can I push Spring's transactional support to the EJB 3 layer? I am looking to automatically open and close the Hibernate session there? This has been a problem plaguing me for months; haven't found any solution.

Configure everything correctly... YOu need a JTA transaction manager and you need a proper setup of hibernate to run in a JTA environment. Next to that also make sure your EJB is managing your transaction and not spring.

This is my plan, as of now:
1) XA database driver
2) Use <tx:jta-transaction-manager> in Spring
3) Inject a Spring TransactionTemplate into my EJB to wrap the delegation in a transaction; this will make one Hibernate Session available to my business objects ... but most importantly, I will be able to access the lazy-loaded properties that return from the service method

Example:

Code:

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@Stateless
@Interceptors(SpringBeanAutowiringInterceptor.class)
public class SampleEJB {

    @Autowired
    private SpringManagedService service;
    @Autowired
    private TransactionTemplate t;

    public void foo() {
        t.execute(new TransactionCallbackWithoutResult() {
            @Override
            doInTransactionWithoutResult(TransactionStatus status) {
                MyEntity entity = service.foo();
                entity.lazyCollection().iterator(); // access lazy properties; hibernate session still open
            }
        });
    }
}

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Two questions though:
A) Is #3 the right strategy? It's my version of OpenSessionInViewFilter for EJB
B) Should I set "hibernate.transaction.factory_class" and "hibernate.transaction.manager_lookup_class" in my SessionFactory properties? They are not set.

Thanks

BTW, for anyone browsing this thread, the topic has been discussed before with 2 possible solutions:
http://forum.springsource.org/showth...pation-problem

Quote:

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A) Is #3 the right strategy? It's my version of OpenSessionInViewFilter for EJB

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No... Configure hibernate/jta correctly..

Quote:

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B) Should I set "hibernate.transaction.factory_class" and "hibernate.transaction.manager_lookup_class" in my SessionFactory properties? They are not set.

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Yes (or no depending on your hibernate version if you use Hibernate 4+ configure the JtaPlatform instead).