Hibernate出错java.lang.ExceptionInInitializerError

HibernateUtil照搬网上的，映射文件和类文件是用hibernate-extensions-2.1.3生成的，按书上的一步步作，最后总是   java.lang.ExceptionInInitializerError，位置在Session session = HibernateUtil.currentSession();
  不知何原因
 
  注意是NoClassDefFoundError，而不是NoClassDefFoundError: net/sf/hibernate/HibernateException。
  （我手工把hibernate必须库加到lib里面了，否则就是NoClassDefFoundError: net/sf/hibernate/HibernateException，这个是毫无疑问的classpath问题）
  第一次和之后运行时错误有一点不同，第一次是ExceptionInInitializerError，之后就是NoClassDefFoundError
 
  第一次运行时错误：
 
  javax.servlet.ServletException
  org.apache.jasper.runtime.PageContextImpl.doHandlePageException(PageContextImpl.java:848)
  org.apache.jasper.runtime.PageContextImpl.handlePageException(PageContextImpl.java:781)
  org.apache.jsp.hibernateTest_jsp._jspService(org.apache.jsp.hibernateTest_jsp:83)
  org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:97)
  javax.servlet.http.HttpServlet.service(HttpServlet.java:802)
  org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:322)
  org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:314)
  org.apache.jasper.servlet.JspServlet.service(JspServlet.java:264)
  javax.servlet.http.HttpServlet.service(HttpServlet.java:802)
 
  root cause
 
  java.lang.ExceptionInInitializerError
  org.zzd.listBean.getList(listBean.java:31)
  org.apache.jsp.hibernateTest_jsp._jspService(org.apache.jsp.hibernateTest_jsp:60)
  org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:97)
  javax.servlet.http.HttpServlet.service(HttpServlet.java:802)
  org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:322)
  org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:314)
  org.apache.jasper.servlet.JspServlet.service(JspServlet.java:264)
  javax.servlet.http.HttpServlet.service(HttpServlet.java:802)
 
 
  之后运行时错误：
 
  javax.servlet.ServletException
  org.apache.jasper.runtime.PageContextImpl.doHandlePageException(PageContextImpl.java:848)
  org.apache.jasper.runtime.PageContextImpl.handlePageException(PageContextImpl.java:781)
  org.apache.jsp.hibernateTest_jsp._jspService(org.apache.jsp.hibernateTest_jsp:83)
  org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:97)
  javax.servlet.http.HttpServlet.service(HttpServlet.java:802)
  org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:322)
  org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:314)
  org.apache.jasper.servlet.JspServlet.service(JspServlet.java:264)
  javax.servlet.http.HttpServlet.service(HttpServlet.java:802)