static {
  Configuration cfg = new Configuration();
  // cfg.configure(); // ��ȡĬ�ϵ������ļ���hibernate.cfg.xml��
  // // cfg.configure("hibernate.cfg.xml"); // ��ȡָ��λ�õ������ļ�
  // sessionFactory = cfg.buildSessionFactory();
 
  // cfg.addResource("cn/itcast/a_helloworld/User.hbm.xml");
  // cfg.addClass(User.class); // ȥUser�����ڵİ��в������ΪUser����׺Ϊ.hbm.xml���ļ�
 
  // ��ʼ��SessionFactory
  sessionFactory = new Configuration()//
      .configure()//
      .buildSessionFactory();
   
}

  private static Properties props = null;
static{
  try {
    //獲取Property配置 并初始化 加載流到prop中
    InputStream inputStream=JdbcUtils.class.getClassLoader().getResourceAsStream("dbconfig.properties");
     
    props=new Properties();
   
    props.load(inputStream);
     
  } catch (IOException e) {
    throw new RuntimeException();
  }
  try {
    //加載驅動類
    Class.forName(props.getProperty("driverClassName"));
  } catch (ClassNotFoundException e) {
    throw new RuntimeException();
  } 
}