public ActionForward execute(
    ActionMapping mapping,
    ActionForm form,
    HttpServletRequest request,
    HttpServletResponse response) {
    RegForm regForm = (RegForm) form;

    Session session=HibernateSessionFactory.currentSession();
    Transaction ts=session.beginTransaction();   
 
    String name=regForm.getUsername(); //从jsp页面得到用户名和密码
    String pas=regForm.getPassword();  

    String str="from MyUsers where userName=?"; //查找用户是不是存在
    Query query=session.createQuery(str);
    query.setString(0,name);
    List list=(ArrayList) query.list();

    if(list.size()<=0){                            //不存在的话就写入数据库
      MyUsers users=new MyUsers();
      users.setNames(name);
      users.setPassWord(pas);
      session.save(users);    
      ts.commit();  
      return mapping.findForward("success1");    //跳转到注册好的页面
    }else{
        return mapping.findForward("defeat");
    }
  }