dir = new File(getFileName(url));
            for (int i = 0; i < num; ++i) {
                dir = dir.getParentFile();
            }
        } else {
            dir = new File(JarFileUtil.toJarFilePath(url));
        }
        return dir;
    }

    /**
     * Converts the resource URL to an external form.
     *
     * @param url
     *            The resource URL. Must not be {@literal null}.