Something

    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();            }        }