sessionfactorybuilder.java

基于j2ee的电子留言系统

package org.yeeku.factory;

import org.hibernate.*;
import org.hibernate.cfg.*;

import org.yeeku.exception.MessageException;

/**
 * @author  yeeku.H.lee [e-mail]
 * @version  1.0
 * <br>Copyright (C), 2005-2008, yeeku.H.Lee
 * <br>This program is protected by copyright laws.
 * <br>Program Name:
 * <br>Date: 
 */
public class SessionFactoryBuilder
{
	private SessionFactory sessionFactory;
	private static SessionFactoryBuilder sfb;

	private SessionFactoryBuilder()
	{
	}

    public static SessionFactoryBuilder instance()
    {
        if (sfb == null)
        {
            sfb = new SessionFactoryBuilder(); 
        }
        return sfb;
    }

	public SessionFactory getSessionFactory()throws MessageException
	{
		if (sessionFactory == null)
		{
			try
			{
				Configuration configuration = new Configuration().configure();
				sessionFactory = configuration.buildSessionFactory();
			}
			catch (Throwable ex)
			{
				System.out.println("初始化SessionFactory出现异常..." + ex);
				throw new MessageException("初始化SessionFactory出现异常...");
			}
		}
		return sessionFactory;
	}

}