/** 网络提取图片到本地 */
 public static File fetchImg(String url) {
   return FileUtil.download(url);
 }
 /** @param url 图片上传组件返回的nginx地址 */
 public static String upload(String tenantId, MediaType type, String url, boolean isForever) {
   File file = FileUtil.download(url);
   return upload(tenantId, type, file, isForever);
 }