doubt on use Hibernate with EJB and thread

belcore · **Joined:** Mon Sep 01, 2003 10:40 am **Posts:** 17

I use the below stateless ejb as facade.
I think that with it I haven't any problem with multithreading.
Is correct ?

Code:

//simple ejb facade
public class FacadeBean implements SessionBean 
{

 private SessionContext sessionContext;
  private SessionFactory sf=null;

  
  public void setSessionContext(SessionContext ctx)
  {
    this.sessionContext = ctx;
    getHibernateSessionFactory();
  }

  
  /**
  * Save a object
  */
  public void saveObject(Object obj, String action) throws HibernateException
    {
       Session se=null;
       Transaction trans=null;
       try{
             se=getHibernateSessionFactory().openSession(); //open session
             trans=se.beginTransaction();
             se.save(obj);
              trans.commit();
        }
        catch(Exception ej){trans.rollback(); ej.printStackTrace();}
        finally{se.close();}
  }
  
  /**
  * Return a SessionFactory
  */

   public SessionFactory getHibernateSessionFactory() {
    String sessionFactoryName = null;
    if(sf==null)
    {
          try{
               InitialContext ctx = new InitialContext();
               sf = (SessionFactory) ctx.lookup("hibernate/SessionFactory");
             }catch(Exception ex){ex.printStackTrace();}


    }
    return sf;
  }

drj · **Posted:** Wed Jan 28, 2004 8:12 am

Not 100% sure what you are asking.
The code that you have posted is completely single threaded so there shouldn't be any threading issues from your perspective.

l.masini · **Posted:** Wed Jan 28, 2004 8:17 am

I agree, the problem set field only in initializer, so perfectly compatible with your EJB container.
But why do you open and close a Session only to save one object ?
Ciao

nerotnt · **Joined:** Wed Oct 08, 2003 10:31 am **Posts:** 247

l.masini wrote:

I agree, the problem set field only in initializer, so perfectly compatible with your EJB container.
But why do you open and close a Session only to save one object ?
Ciao

How do you save a object without opening a session?

belcore · **Joined:** Mon Sep 01, 2003 10:40 am **Posts:** 17

Into any method I make a new Session so I haven't problems with multithreading.

When I use EJBs, the application server make a pool of ejbs, so when a client call a service, the application restore a ejb from the pool and call the method.
So I can't set a session as variable istance, like code below

Code:

public class FacadeBean implements SessionBean 
{ 

 private SessionContext sessionContext; 
 private SessionFactory sf=null; //perform only a session create
 private Session session;// <- possible sharing issue

drj · **Posted:** Thu Jan 29, 2004 1:03 am

SessionFactory is threadsafe. You can save this as an instance variable.
Don't save your Session as an instance variable. From the Session Javadocs:

Quote:

It is not intended that implementors be threadsafe. Instead each thread/transaction should obtain its own instance from a SessionFactory.

l.masini · **Posted:** Thu Jan 29, 2004 6:47 am

I mean that you should't use a session-per-update pattern !!!
Ciao.

emmanuel · **Posted:** Thu Jan 29, 2004 7:39 pm

l.masini meant http://www.hibernate.org/Documentation/SessionAndTransactionScope

This is a brand new and key page, so linking it isn't superfluous.

belcore · **Joined:** Mon Sep 01, 2003 10:40 am **Posts:** 17

Thanks for your hints.

But what you change into my code ?