Why hibernate create a new SessionFactory everytime?

Yashnoo · **Joined:** Wed Dec 17, 2003 4:24 am **Posts:** 188

hi everyone:

I want to know if hibernate create a new SessionFactory when I execute it like

Code:

from User as u

It is in the J2EE environment.(server :Tomcat).
Because building sessionFactory is take too much time. So I want to know if hibernate create a sessionFactory everytime when I invoke it. Thks

max · **Posted:** Wed Sep 01, 2004 1:46 am

Hibernate does NOT create SessionFactorie's - Users do.

Check your j2ee application for code that might construct the sessionfactory each time a bean (or servlet) is created...

Yashnoo · **Joined:** Wed Dec 17, 2003 4:24 am **Posts:** 188

Code:

Hibernate : 2.1.6
mysql      : 3.23.56
Tomcat    :5.16

The hibernate.cfg.xml is following:

Code:

   <hibernate-configuration>
   <session-factory>
      <property name="show_sql">true</property>
      <property name="dialect">net.sf.hibernate.dialect.MySQLDialect</property>
      <mapping resource="Trade.hbm.xml"/>
   </session-factory>
</hibernate-configuration>

The mapping file:

Code:

<hibernate-mapping>
<class name="lyo.test.bean.Trade" table="tradetest">
   <id name="trade_id" column="trade_id" type="int">
       <generator class="native"/>
   </id>
   <property name="trade_name" column="trade_name"/>
   <property name="trade_desc" column="trade_desc"/>
</class>
</hibernate-mapping>

I have a java helper class:

Code:

public class HibernateUtil {

    //private static Logger  log = LogFactory.getLog(HibernateUtil.class);

    private static final SessionFactory sessionFactory;

    static {
        try {
            // Create the SessionFactory
            sessionFactory = new Configuration().configure().buildSessionFactory();
        } catch (Throwable ex) {
      //      log.error("Initial SessionFactory creation failed.", ex);
            throw new ExceptionInInitializerError(ex);
        }
    }

    public static final ThreadLocal session = new ThreadLocal();

    public static Session currentSession() throws HibernateException {
        Session s = (Session) session.get();
        // Open a new Session, if this Thread has none yet
        if (s == null) {
            s = sessionFactory.openSession();
            session.set(s);
        }
        return s;
    }

    public static void closeSession() throws HibernateException {
        Session s = (Session) session.get();
        session.set(null);
        if (s != null)
            s.close();
    }
}

hibernate.properties File is:

Code:

#hibernate.connection.driver_class org.gjt.mm.mysql.Driver
#hibernate.connection.url jdbc:mysql://localhost:3306/poweracl
#hibernate.connection.username lyo
#hibernate.connection.password qijiashe

I use it in this way:

Code:

Session s=HibernateUtil.currentSession();
      Transaction t=s.beginTransaction();
List list=s.find("from Trade as trade");
      t.commit();
      HibernateUtil.closeSession();
return list;

Everytime I run it ,Tomcat console will output:

Code:

08:20:37,281  INFO TransactionManagerLookupFactory:33 - No TransactionManagerLoo
kup configured (in JTA environment, use of process level read-write cache is not
 recommended)
08:20:37,484  INFO SettingsFactory:103 - Use scrollable result sets: true
08:20:37,484  INFO SettingsFactory:106 - Use JDBC3 getGeneratedKeys(): false
08:20:37,484  INFO SettingsFactory:109 - Optimize cache for minimal puts: false
08:20:37,484  INFO SettingsFactory:115 - echoing all SQL to stdout
08:20:37,484  INFO SettingsFactory:118 - Query language substitutions: {no='N',
true=1, yes='Y', false=0}
.............................................................................................
........................................................................
....................................................................
08:20:37,515  INFO Configuration:1116 - instantiating and configuring caches
08:20:37,734  INFO SessionFactoryImpl:118 - building session factory
08:20:38,343  INFO SessionFactoryObjectFactory:82 - Not binding factory to JNDI,
 no JNDI name configured
08:20:38,359  INFO UpdateTimestampsCache:35 - starting update timestamps cache a
t region: net.sf.hibernate.cache.UpdateTimestampsCache
08:20:38,359  INFO StandardQueryCache:41 - starting query cache at region: net.s
f.hibernate.cache.StandardQueryCache
Hibernate: select trade0_.trade_id as trade_id, trade0_.trade_name as trade_name
, trade0_.trade_desc as trade_desc from tradetest trade0_

Is there any problem ?

max · **Posted:** Thu Sep 02, 2004 1:29 am

not apparently - but why don't you try to step through it with a debugger ?

Hibernate don't create SessionFactorie's - your code does somehow !