hibernateutils.java

用java三大框架和mysql开发的网上购物系统

package com.bookshop.util;


import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.hibernate.cfg.Configuration;

/**
 * 一个Hibernate相关的实用类，
 * 统一管理SessionFactory
 * @author Administrator
 *
 */
public class HibernateUtils {
	//静态最终变量，不能再改变
	private static final SessionFactory sf;
	
	//静态游离块，只初始化一次
	static{
		Configuration cfg = new Configuration().configure();
		sf = cfg.buildSessionFactory();
	}
	
	//返回唯一的SessionFactory
	public static SessionFactory getSessionFactory(){
		return sf;
	}
	
	
	//返回Session
	public static Session getHibernateSession(){
		return sf.openSession();
	}
	
	//关闭Session
	public static void closeHibernateSession(Session session){
		if(session!=null){
			if(session.isOpen()){
				session.close();
			}
		}
	}
}