Multiple SessionFactory

sivajag · **Joined:** Mon Sep 20, 2004 10:27 am **Posts:** 7

Hibernate version:2.1.6

Hi Guys:

For my Stand alone application , I m trying to use Hibernate for persistence layer. Currently, the stand alone application is using direct JDBC for Data access. We are trying to change it to Hibernate. We are connecting to 4 different databases with different data modelling. I know that I need to configure multiple SessionFactory objects.

Is there a clean way of doing it.

Code:

public class FactoryDude {
         
        public static SessionFactory createDB1SessionFactory(){
                  ...
         }

         public static SessionFactory createDB2SessionFactory(){
                  ...
         }
}

In my DAO layer , instead of using SessionFactory could I use SessionManager interface .

Code:

public interface SessionManager {

       public Session getSession();

       public void removeSession();

}

The SessionManager implementation class will hold the Session in ThreadLocal.

This is where I am kind of stuck.

Lets Consider ,

UserDAO (needs to get data from DB1) and ItemDAO ( needs to get data from DB2). Both of them will having their own instance of SessionManager.

In this scenerio , how does ThreadLocal works. Will I be always getting DB1Session when called from UserDAO and DB2Session when called from ItemDAO?

I am sorry for this long message, I was trying to be as clear as possible.

Thank you,

ernst_pluess · **Posted:** Thu Sep 23, 2004 5:09 am

Case a)
In one thread only on DB (with is SessionFactory) is accessed: You need only one ThreadLocal.

Case b)
In one thread all DBs (with their respective SessionFactorys) are accessed: You need a ThreadLocal per SessionFactory.

A ThreadLocal is kind of a singleton per Thread.

HTH
Ernst

sivajag · **Joined:** Mon Sep 20, 2004 10:27 am **Posts:** 7

Thanks Ernst

It makes sense to me now.

kjsanchez · **Joined:** Thu May 20, 2004 3:40 pm **Posts:** 33

Hello!

We would also like to use Multiple Session Factories. I keep getting the following error:

Can you help?? What am I missing??

javax.naming.NoInitialContextException: Need to specify class name in environment or system property, or as an applet parameter, or in an application resource file: java.naming.factory.initial
at javax.naming.spi.NamingManager.getInitialContext(NamingManager.java:640)
at javax.naming.InitialContext.getDefaultInitCtx(InitialContext.java:243)
at javax.naming.InitialContext.getURLOrDefaultInitCtx(InitialContext.java:280)
at javax.naming.InitialContext.lookup(InitialContext.java:347)
at com.gs.aml.util.HibernateUtil.currentSession(HibernateUtil.java:78)
at com.gs.fw.gc.core.refs.DataSrcInstanceTB.main(DataSrcInstanceTB.java:115)

Here is the code:

Session s = (Session) session.get();
// Open a new Session, if this Thread has none yet

if (s == null)
{
SessionFactory sf = (SessionFactory) new InitialContext().lookup("KJSSessionFactory");
s = sf.openSession();

}
return s;

rollatwork · **Posted:** Wed Sep 29, 2004 2:02 am

This is a JDNI configuration issue. It occurs generally when the InitialContext doesn't have default properties configured and the JNDI server properties may not have been configured properly.

Check the J2EE and your app server docs for more info.

Cheers,
Roll