Issues with collection association in two open sessions

sobemurray · **Joined:** Thu Jun 03, 2004 10:29 am **Posts:** 13

Hibernate version: 2.1.6

I seem to be constantly running into issues with Illegal attempt to associate a collection in two open sessions. I almost exclusivly use criteria queries. After every session call I make I implicitly call

session.close();
session = null;

This had solved some issue that I have had in the past. I don't know what I can do to stop these errors.

I'm now at a loss and don't know what else I can do.

anthony · **Posted:** Fri Sep 17, 2004 12:55 pm

how are you managing your sessions?

sobemurray · **Joined:** Thu Jun 03, 2004 10:29 am **Posts:** 13

This is the code snippit from a class called ConnectionFactory:

Code:

private static void buildSessionFactory()
    {
        try
        {
            Configuration hibernateConfig = new Configuration();
            try
            {
                hibernateConfig.configure();
            }
            catch (HibernateException ex)
            {
                ResourceBundle bundle = PropertyResourceBundle.getBundle("J2EE");
                hibernateConfig.addFile((String)bundle.getObject("sobetech.hibernate.config")
                        + "/" + configFileName);
            }

            factory = hibernateConfig.buildSessionFactory();
        }
        catch (HibernateException ex)
        {
            factory = null;
        }
    }

    public static Session getSession() throws HibernateException
    {
        if(factory == null)
        {
            buildSessionFactory();
        }
        return factory.openSession();
    }

So when I want a session I call:

Code:

Session session = ConnectionFactory.getSession();

I get the session Object

This is an offending method that is causing my errors:

Code:

    public Cart updateCart(Cart cart) throws EAOException
    {
        try
        {
            session = ConnectionFactory.getSession();
            session.update(cart);
            session.flush();
            session.close();
            session = null;
            return cart;
        }
        catch (HibernateException ex)
        {
            throw new EAOException(ex);
        }
    }

These are the settings that I have in the hibernate.cfg.xml:

Code:

<!DOCTYPE hibernate-configuration PUBLIC "-//Hibernate/Hibernate Configuration DTD 2.0//EN"
 "http://hibernate.sourceforge.net/hibernate-configuration-2.0.dtd">
<hibernate-configuration>
   <session-factory>
      <property name="hibernate.query.substitutions">true 'T', false 'F', yes 'Y', no 'N'</property>
      <property name="hibernate.connection.datasource">sobetech.jdbc.datasource.smoke</property>
      <property name="hibernate.connection.pool_size">1</property>
      <property name="hibernate.transaction.factory_class">net.sf.hibernate.transaction.JTATransactionFactory</property>
      <property name="hibernate.transaction.manager_lookup_class">net.sf.hibernate.transaction.WeblogicTransactionManagerLookup</property>
      <property name="hibernate.show_sql">false</property>
      <property name="hibernate.jdbc.batch_size">0</property>
      <property name="hibernate.jdbc.use_streams_for_binary">true</property>
      <property name="hibernate.jndi.url">t3://localhost:7001</property>
      <property name="hibernate.jndi.class">weblogic.jndi.WLInitialContextFactory</property>
      <property name="hibernate.max_fetch_depth">1</property>
      <property name="hibernate.cache.region_prefix">hibernate.test</property>
      <property name="hibernate.cache.use_query_cache">true</property>
      <property name="hibernate.cache.provider_class">net.sf.ehcache.hibernate.Provider</property>
      <property name="hibernate.dialect">net.sf.hibernate.dialect.OracleDialect</property>
       

[i]mappings....[/i]

   </session-factory>
</hibernate-configuration>

anthony · **Posted:** Fri Sep 17, 2004 2:55 pm

it's better to use threadlocal pattern...

sobemurray · **Joined:** Thu Jun 03, 2004 10:29 am **Posts:** 13

I think I have found a solution, but would like a bit of confirmation.

I had the Session object scoped as a class member. When I moved the scope to the method level, it seems to have fixed my current issue.

Does this make sense?

michael · **Posted:** Fri Sep 17, 2004 3:28 pm

A lot of sense - especially in a multithreaded environment like for example a servlet.

Still recommending ThreadLocal pattern.