code: public static int getPageIndex() {
      String pageIndex = Params.get(PAGENO);
      int resultno = 1;
      if (Strings.isNotBlank(pageIndex)) resultno = Numbers.toInt(pageIndex.trim());
      if (resultno < 1) resultno = Page.DEFAULT_PAGE_NUM;
      return resultno;
    }
docs: 获得请求中的页码