MyEclipse+hibernate3开发，遇到java.lang.ExceptionInInitializerError的错误！

看了一下Java API，应该是初始化的时候，哪儿有问题，但是又查不出来。
 
  错误提示全文如下：
  java.lang.ExceptionInInitializerError
  all.HibUtil.(HibUtil.java:27)
  com.mytest.struts.action.AdduserAction.execute(AdduserAction.java:49)
  org.apache.struts.action.RequestProcessor.processActionPerform(RequestProcessor.java:419)
  org.apache.struts.action.RequestProcessor.process(RequestProcessor.java:224)
  org.apache.struts.action.ActionServlet.process(ActionServlet.java:1194)
  org.apache.struts.action.ActionServlet.doGet(ActionServlet.java:414)
  javax.servlet.http.HttpServlet.service(HttpServlet.java:743)
  javax.servlet.http.HttpServlet.service(HttpServlet.java:856)
 
 
  源代码如下：
  package all;
 
  import org.apache.commons.logging.Log;
  import org.apache.commons.logging.LogFactory;
 
  //import org.hibernate.*;
  //import org.hibernate.cfg.*;
  import org.hibernate.Session;
  import org.hibernate.cfg.Configuration;
 
  import org.hibernate.HibernateException;
  import org.hibernate.SessionFactory;
 
 
 
  public class HibUtil {
 
  private static Log log=LogFactory.getLog(HibUtil.class);
 
  private static final SessionFactory sessionFactory;
 
  static {
  try{
  sessionFactory = new Configuration().configure().buildSessionFactory();
  } catch (Throwable ex) {
  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();
  //Open a new Session, if this Thread has none yet
  if (s==null) {
  s=sessionFactory.openSession();
  session.set(s);
  }
  return s;
  }
 
  public static void closeSession() throws HibernateException {
  Session s=(Session) session.get();