Escribir en un EditText con formato de tarjeta de crédito

public static void formatCreditCard(final EditText et) {
    et.addTextChangedListener(new TextWatcher() {
        private static final char space = ' ';
        @Override
        public void onTextChanged(CharSequence s, int start, int before, int count) {
        }
        @Override
        public void beforeTextChanged(CharSequence s, int start, int count, int after) {
        }
        @Override
        public void afterTextChanged(Editable s) {
            // Remove spacing char
            if (s.length() > 0 && (s.length() % 5) == 0) {
                final char c = s.charAt(s.length() - 1);
                if (space == c) {
                    s.delete(s.length() - 1, s.length());
                }
            }
            // Insert char where needed.
            if (s.length() > 0 && (s.length() % 5) == 0) {
                char c = s.charAt(s.length() - 1);
                // Only if its