package com.netease.wireless.groupsms.hbnt.util;
import net.sf.hibernate.HibernateException;
import net.sf.hibernate.Session;
import net.sf.hibernate.cfg.Configuration;

/**//**
* Configures and provides access to Hibernate sessions, tied to the
* current thread of execution. Follows the Thread Local Session
* pattern, see {@link http://hibernate.org/42.html}.
*/
public class HibernateUtil ...{

/**//**
* Location of hibernate.cfg.xml file.
* NOTICE: Location should be on the classpath as Hibernate uses
* #resourceAsStream style lookup for its configuration file. That
* is place the config file in a Java package - the default location
* is the default Java package.<br><br>
* Examples: <br>
* <code>CONFIG_FILE_LOCATION = "/hibernate.conf.xml".
* CONFIG_FILE_LOCATION = "/com/foo/bar/myhiberstuff.conf.xml".</code>
*/
private static String CONFIG_FILE_LOCATION = "/hibernate.cfg.xml";//hibernate.cfg.xml 

/**//** Holds a single instance of Session */
private static final ThreadLocal threadLocal = new ThreadLocal();

/**//** The single instance of hibernate configuration */
private static final Configuration cfg = new Configuration();

/**//** The single instance of hibernate SessionFactory */
private static net.sf.hibernate.SessionFactory sessionFactory;

/**//**
* Returns the ThreadLocal Session instance. Lazy initialize
* the <code>SessionFactory</code> if needed.
*
* @return Session
* @throws HibernateException
*/
public static Session currentSession() throws HibernateException ...{
Session session = (Session) threadLocal.get();

if (session == null) ...{
if (sessionFactory == null) ...{
try ...{
cfg.configure(CONFIG_FILE_LOCATION);
//cfg.configure(); 
sessionFactory = cfg.buildSessionFactory();
}
catch (Exception e) ...{
System.err.println("%%%% Error Creating SessionFactory %%%%");
System.err.println("|||||||||||||" + e.getMessage());
e.printStackTrace();
}
}
session = sessionFactory.openSession();
threadLocal.set(session);
}

return session;
}

/**//**
* Close the single hibernate session instance.
*
* @throws HibernateException
*/
public static void closeSession() throws HibernateException ...{
Session session = (Session) threadLocal.get();
threadLocal.set(null);

if (session != null) ...{
session.close();
}
}

/**//**
* Default constructor.
*/
private HibernateUtil() ...{
}

}