Implementing Data Transfer Objects

public record CreateOrderRequest(
    @NotNull UUID customerId,
    @NotEmpty @Valid List<LineRequest> lines,
    @Pattern(regexp="^[A-Z]{3}$") String currency
) {}

public record OrderResponse(
    String id,
    CustomerSummary customer,
    List<LineResponse> lines,
    MoneyResponse total) {
    public record CustomerSummary(String id, String name) {}
    public record LineResponse(String productId, int qty, MoneyResponse price) {}
    public record MoneyResponse(long cents, String currency) {}
}

public record PageResponse<T>(
    List<T> items,
    int page, int size,
    long totalElements, int totalPages,
    boolean hasNext, boolean hasPrev) {}

public record OrderFilter(
    @Nullable String status,
    @Nullable Instant placedAfter,
    @Nullable Instant placedBefore,
    @Nullable Long minTotalCents) {}