Hibernate的一个帮助类----------感觉写得比较好，有参考价值，果断备份下来……

package cn.zj.qiao.utils;

import org.hibernate.HibernateException;
import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.hibernate.cfg.Configuration;
import org.hibernate.service.ServiceRegistry;
import org.hibernate.service.ServiceRegistryBuilder;

public class HibernateUtil {
    public static final SessionFactory sessionFactory ;
    public static final ThreadLocal<Session> session = new ThreadLocal<Session>();
    static{
        try{
            //create the sessionFactory from hibernate.cfg.xml
            Configuration cf = new Configuration().configure();
            ServiceRegistry sr = new ServiceRegistryBuilder().applySettings(cf.getProperties()).buildServiceRegistry();  
            sessionFactory = cf.buildSessionFactory(sr);
        }catch(Throwable e){
            System.err.println("inital SessionFactory creation failed. " + e);
            throw new ExceptionInInitializerError(e);
        }
    }
    
    public static Session currrentSession()throws HibernateException{
        Session s = (Session)session.get();
        if(s == null){
            s = sessionFactory.openSession();
            session.set(s);
        }
        
        return s;
    }
    
    public static void closeSession()throws HibernateException{
        Session s = (Session)session.get();
        if(s != null){
            s.close();
            session.set(null);
        }
    }
}