code: public Collection loadAllUploadFile(HttpServletRequest request) {
      Debug.logVerbose("[JdonFramework] load all upload files from session and remove them", module);
      Collection uploadList = null;
      try {
        HttpSession session = request.getSession();
        if (session != null) {
          uploadList = (Collection) session.getAttribute(PIC_NAME_PACKAGE);
          session.removeAttribute(PIC_NAME_PACKAGE);
        }
      } catch (Exception ex) {
        Debug.logError("[JdonFramework] not found the upload files in session" + ex, module);
      }
      return uploadList;
    }
docs: 一次性将之前保存的所有UploadFile集合取出，然后从Session中删除
  
  获得前一个步骤上传的数据
  
  文件上传是在专门页面操作，操作成功后，其它页面通过本方法获得数据。
  
  @param request
  @return UploadFile 集合