hibernateutil.java

JSP+Struts+Hibernate进行网络开发的一个实例

package cn.com.zzb.eshopping.db;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.hibernate.HibernateException;
import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.hibernate.cfg.Configuration;

public class HibernateUtil {

	private static Log log = LogFactory.getLog(HibernateUtil.class); //定义一个日志Log对象
    private static final SessionFactory sessionFactory; //定义SessionFactory对象
		
	static{		
		try{
			//实例化一个SessionFactory对象
			sessionFactory = (new Configuration()).configure().buildSessionFactory();
		}
		catch(Throwable ex)
		{
			//把异常错误写入到日志中
			log.error("Initial SessionFactory creation failed.",ex);
			throw new ExceptionInInitializerError(ex);
		}
	}
	
	public static final ThreadLocal session = new ThreadLocal();
	
	public static Session currentSession() throws HibernateException
	{
		Session s = (Session)session.get();
		//当session为空或者已经关闭的时候，就新创建一个session对象。
		if(s == null||!s.isOpen())
		{
			s = sessionFactory.openSession();
			session.set(s);
		}
		return s;
	}	
	public static void closeSession() throws HibernateException
	{
		//关闭当前的session
		Session s = (Session)session.get();
		session.set(null);
		if(s!=null)
			s.close();
	}
}