使用@Transactional读取方法摆脱“没有Hibernate Session绑定到线程”和性能

Question

I've introduced HibernateTransactionManager in my project, because we need to use transactions for some service methods. I've also followed the best practice to inject the SessionFactory into the DAO layer instead of implementing the HibernateDaoSupport.

Now in some read methods that are not annotated with @Transactional I got the error:

No Hibernate Session bound to thread, and configuration does not allow creation of non-transactional one here

I know how to solve it, just add the @Transactional all over the place. But my colleagues are worried about performance. Should also read methods like:

        return sessionFactory.getCurrentSession().createCriteria(MyClass.class).add(Restrictions.eq("color", color)).addOrder(Order.asc("createDate")).list();

be annotated with @Transactional?

I've also read this post Some clarification about Spring @Transactional annotation on a method that discourage to use this annotation in DAO layer, so I don't see what is the best practice for getting rid of the issue AND have good performances on read methods .

Many thanks for helping!

Answer 1

When you use the Spring TransactionManager abstraction, you must always mark all Service methods with:

• @Transactional
• @Transaction(readOnly = true) for read-only methods

That's because Hibernate will no longer manage transaction, but instead it will delegate this responsibility to the Spring framework. Unless you mark each transaction-boundary method with the @Transactional annotation, Spring cannot associate the current Thread with a Hibernate Session and an associated JDBC Connection.

So, using @Transactional is not an option.