public static String fullWidthToHalfWidth(String s) {
        if (isEmpty(s)) {
            return s;
        }

        char[] source = s.toCharArray();
        for (int i = 0; i < source.length; i++) {
            if (source[i] == 12288) {
                source[i] = ' ';
                // } else if (source[i] == 12290) {
                // source[i] = '.';
            } else if (source[i] >= 65281 && source[i] <= 65374) {
                source[i] = (char)(source[i] - 65248);
            } else {
                source[i] = source[i];
            }
        }
        return new String(source);
    }