LocalSessionFactoryBean is not a sessionfactory instance

[Erin Lee]

Hi,
I'm integrating Hibernate to Spring based on plain Hibernate3 and I have a understanding problem with DI.

public class ProductDaoImpl implements ProductDao {
private SessionFactory sessionFactory;
public void setSessionFactory(SessionFactory sessionFactory) {
this.sessionFactory = sessionFactory;
}
................
}
---------------------------------------------------------------
<beans>
 
<bean id="mySessionFactory"
class="org.springframework.orm.hibernate3.LocalSessionFactoryBean">
<property name="configLocation">
<value>file:src/hibernate.cfg.xml</value>
</property>
</bean>
 

<bean id="myProductDao" class="product.ProductDaoImpl">
<property name="sessionFactory" ref="mySessionFactory"/>
</bean>
 
</beans>
    

My question is:
The method setSessionFactory has an argument of SessionFactory and what we are injecting as setter DI, is an instance of LocalSessionFactoryBean which is surely not implemeting org.hibernate.SessionFactory interface.
How things are working here?

I'll appreciate the help on that.

Thanks

[Mark Spritzler]

Quite simple here. the LocalSessionFactoryBean implements FactoryBean, which is a special interface for Spring. Spring sees that the type of that class is a FactoryBean, so instead of creating the instance of LocalSessionFactoryBean, it calls the special public Object getObject() method, and the object that that returns is what is given out. It is the Factory pattern at work.

So LocalSessionFactoryBean's getObject() method returns a SessionFactory object.

Mark

[Erin Lee]

Thanks Mark, It was helpful.
[ December 28, 2008: Message edited by: Erin Lee ]