Subversion Repositories general

package ak.hostadmiral.util;

import java.util.Collection;

import net.sf.hibernate.*;
import net.sf.hibernate.cfg.*;

public class HibernateUtil
{
        public static final int DATABASE_VERSION = 1;

        private static       Configuration  configuration;
        private static       SessionFactory sessionFactory;
        private static final ThreadLocal    hibernateBean = new ThreadLocal();
    private static       boolean        validated     = false;

    private static void validate()
                throws HibernateException, ModelException
    {
        synchronized(HibernateUtil.class) {
                if(validated) return;

                        Collection versions = currentSession().find("from DatabaseVersion");

            if(versions == null || versions.size() == 0)
                throw new ModelException("Database structure version not found");

            if(versions.size() > 1)
                throw new ModelException("Too much entries in database structure version table");

            int version = ((DatabaseVersion)versions.iterator().next()).getVersion();
            if(version != DATABASE_VERSION)
                throw new ModelException("Expected database structure version "
                        + DATABASE_VERSION + ", found " + version);

                validated = true;
        }
    }

        public static Configuration getConfiguration()
                throws HibernateException
        {
                if(configuration == null)
                        configuration = new Configuration();

                return configuration;
        }

        public static SessionFactory getSessionFactory()
                throws HibernateException
        {
                if(sessionFactory == null)
                        sessionFactory = getConfiguration().configure().buildSessionFactory();

                return sessionFactory;
        }

        private static HibernateBean currentBean()
                throws HibernateException
        {
                HibernateBean hb = (HibernateBean)hibernateBean.get();

                if(hb == null) {
                        hb = new HibernateBean();
                        hb.session = getSessionFactory().openSession();
                        hibernateBean.set(hb);
                }
                return hb;
        }

        public static Session currentSession()
                throws HibernateException
        {
                return currentBean().session;
        }

        public static void closeSession()
                throws HibernateException, ModelException
        {
                HibernateBean hb = (HibernateBean)hibernateBean.get();

                if(hb == null)
                        throw new ModelException("No session found for this thread");

                hibernateBean.set(null);
                hb.session.close();
        }

        public static void beginTransaction()
                throws HibernateException, ModelException
        {
                HibernateBean hb = (HibernateBean)hibernateBean.get();

                if(hb != null && hb.transaction != null)
                        throw new ModelException("Transaction is already open");

                currentBean().transaction = currentSession().beginTransaction();

                // validate database structure version
        if(!validated) // just try to speed up by avoiding synchronization
                        validate();
        }

        public static boolean isTransactionOpen()
                throws HibernateException, ModelException
        {
                HibernateBean hb = (HibernateBean)hibernateBean.get();

                return (hb != null) && (hb.transaction != null);
        }

        public static void commitTransaction()
                throws HibernateException, ModelException
        {
                HibernateBean hb = (HibernateBean)hibernateBean.get();

                if(hb == null || hb.transaction == null)
                        throw new ModelException("No open transaction");

                hb.transaction.commit();
                hb.transaction = null;
        }

        public static void rollbackTransaction()
                throws HibernateException, ModelException
        {
                HibernateBean hb = (HibernateBean)hibernateBean.get();

                if(hb == null || hb.transaction == null)
                        throw new ModelException("No open transaction");

                hb.transaction.rollback();
                hb.transaction = null;
        }

        static class HibernateBean
        {
                public Session     session;
                public Transaction transaction;
        }
}