How could this happen? about hibernate and spring and SessionFactory

How could this happen? about hibernate and spring and SessionFactory

I have a bean in spring's config, which is
<bean id="sessionFactory"
class="org.springframework.orm.hibernate4.LocalSessionFactoryBean">
and in my MVC controller, I use:
@autowired
SessionFactory sf;
and spring can inject hibernate's SessionFactory (not just the
bean:LocalSessionFactoryBean)
how could this happen, SessionFactory is just a property of
LocalSessionFactoryBean.