Cookie

String add(HttpServletResponse res){
    token = Helper.randomString(32);
    Cookie cookie = new Cookie("token", token);
    cookie.setMaxAge(60 * 60 * 24 * 30);
    res.addCookie(cookie);
    return "home/add";
}

String index(@CookieValue(name = "token", defaultValue = "") String token){
    return "home/index";
}

public interface CartRepository extends CrudRepository<Cart, Integer> {
    @Modifying
    @Procedure
    void saveCart(String cartCode, long productId, short quantity);
    @Transactional
    @Modifying
    @Query(value = "UPDATE Cart SET Quantity = :quantity WHERE CartId = :id", nativeQuery = true)
    void edit(int id, short quantity);
}