Question

Can I use geCurrentSession() instead of using HibernateCallback to get the session?. If both sessions are managed by Spring, why do I need a Callback ? Is there any performance advantage associated with this ?

Answer 1

In a well-configured Spring application, both are equivalent except in one case: when there is no current transaction context. In this case, getCurrentSession() won’t work, whereas using a HibernateCallback will open a session and a Hibernate transaction for you and close them at the end.

Note that the documentation of HibernateTemplate mentions that getCurrentSession() should be preferred:

NOTE: As of Hibernate 3.0.1, transactional Hibernate access code can
also be coded in plain Hibernate style. Hence, for newly started
projects, consider adopting the standard Hibernate3 style of coding
data access objects instead, based on
SessionFactory.getCurrentSession().

It also says:

Note that HibernateTemplate will perform its own Session management,
not participating in a custom Hibernate CurrentSessionContext unless
you explicitly switch “allowCreate” to “false”.

Mixing both ways of doing is thus not a good idea.

My preference is to avoid HibernateTemplate, use the Hibernate Session API directly, and use Spring-managed declarative transactions.