Escribir en un EditText tipo tarjeta de crédito

StringBuilder sb = new StringBuilder();
        for (int i = 0; i < ccNumber.length(); i++) {
            if (i % 4 == 0 && i != 0 && ccNumber.length() > 4) {
                sb.append(" ");
            }
            sb.append(ccNumber.charAt(i));
        }
        return sb.toString();