*
     * @param c the character to check
     * @return {@code true} if the character is a valid URL character, {@code false} otherwise
     */
    public static boolean isUrlChar(final char c) {
        if (c >= 'a' && c <= 'z' //
                || c >= 'A' && c <= 'Z' //
                || c >= '0' && c <= '9' //
                || c == '.' //
                || c == '-' //

            return url;
        }

        final StringBuilder buf = new StringBuilder(url.length() + 100);
        for (final char c : url.toCharArray()) {
            if (CharUtil.isUrlChar(c)) {
                buf.append(c);
            } else {
                try {
                    buf.append(URLEncoder.encode(String.valueOf(c), enc));
                } catch (final UnsupportedEncodingException e) {