public String add(HttpServletRequest request, HttpServletResponse response)
      throws ServletException, IOException {
    Category category = CommonUtils.toBean(request.getParameterMap(), Category.class);
    category.setCid(CommonUtils.uuid());

    try {
      categoryService.add(category);
    } catch (CategoryException e) {
      String msg = e.getMessage();
      request.setAttribute("msg", msg);
      return "/adminjsps/admin/category/add.jsp";
    }
    request.setAttribute("msg", "添加分类成功!");
    return "/adminjsps/admin/msg.jsp";
  }