public static String getUploadFileUrl(String identifier, String extendName) {
        SimpleDateFormat formater = new SimpleDateFormat("yyyyMMdd");
        String path = ROOT_PATH + "/" + formater.format(new Date()) + "/";
        File dir = new File(getStaticPath() + path);
        if (!dir.exists()) {
            boolean result = dir.mkdirs();
            if (!result) {
                throw new UFOPException("创建upload目录失败：目录路径：" + dir.getPath());
            }
        }

        path = path + identifier + "." + extendName;
        return path;
    }