public static String escape(String s) {
        String newstr = "";
        for (char c : s.toCharArray()) {
            if (Character.isLetterOrDigit(c))
                newstr += c;
            else if (c == ' ')
                newstr += "+";
            else {
                String hex = Integer.toHexString(c);
                if (hex.length() == 1)
                    hex = "0" + hex;
                newstr += "%" + hex.toUpperCase();
            }
        }