Hello All,

I have a very basic question on Tomcat and Hibernate. I took a deep dive into the many tutorials and I'm confused... I don't really understand
if I need to close the sessions or not....

Assuming that I have the following session factory util class :
public class HibernateUtil {

private static final SessionFactory sessionFactory;

public static final String HIBERNATE_PROPERTIES_FILE = "hibernate.cfg.xml";
static {
try {

sessionFactory = new Configuration().configure(new File(file)).buildSessionFactory();;
} catch (Throwable ex) {
throw new ExceptionInInitializerError(ex);
}
}

public static SessionFactory getSessionFactory() {
return sessionFactory;
}

}


Every thread uses the getSessionFactory and runs the openSession() method.

1. Do I need to use session.close() after committing the transactions ?
2. Do I need to use one session per thread, meaning that every thread needs to close the session before the thread dies ? notice that I
use hibernate.current_session_context_class = thread.
3. Is it more reasonable to use sessionFactory.getCurrentSession() ?

I'm sure that this is very basic, but there are too many examples and I still didn't solve this one....

Thanks for any help,
Elad.

So you are using a web server (as opposed to a full "application server"). The fact that it be Tomcat is irrelevant.

You would need to create some sort data access utility that wraps every single one of your data access operations.
That utility should expose methods, say, create(), update(), delete() and executeQuery(), and all DAOs from your application shouls inherit from it.

Inside each method call, you would get a session (yes, using the HibernateUtil with ThreadLocal), then create a transaction, begin it, do wjat you have to do, then close the transaction, and yes, then close the session.

This approach is somewhat wasteful, because it creates a transaction every time.
A different approach would be to use some sort of framework able to take advantage on "contextual sessions" and the pattern known as "OSIV", which takes care of finding every time a right session from the environment.
These are also called "managed environments", and the most popular is Spring.

For a minimal example of setting up such environment, you can go here

http://hibernar.org/articulos_en/spring ... xample.php

Hi,

Thank you for your reply. I will dig into spring to validate. I prefer to work without it using plain hibernate but i will try.

Thanks again,
Elad.

Hi,

Thank you for your reply. I will dig into spring to validate. I prefer to work without it using plain hibernate but i will try.

Thanks again,
Elad.