Walidacja dto, które jest w dto

public class OrderDto implements Serializable {

    @Null
    private Long id;
    @NotNull
    private CustomerDto customer;
    @NotNull
    private CartDto cart;
    private boolean isPaid;
    private boolean isDelivered;
    private String promotionCode;
}

public class CustomerDto implements Serializable {

    @Null
    Long id;

    @Size(min = 2, max = 40)
    private String firstName;

    @Size(min = 2, max = 40)
    private String lastName;

    @Email
    @Size(min = 1, max = 40)
    private String email;

    @Size(min = 9, max = 9)
    private String phoneNumber;

    @Size(min = 1, max = 40)
    private String zipCode;

    @Size(min = 1, max = 40)
    private String town;

    @Size(min = 1, max = 40)
    private String province;

    @Size(min = 1, max = 10)
    private String streetNumber;
}

    @PostMapping("/process")
    public void prodcessOrder(@Validated @RequestBody OrderDto orderDto){
        orderFacade.processOrder(orderDto);
    }