-
질문 & 답변
카테고리
-
세부 분야
백엔드
-
해결 여부
해결됨
mapping 사용법
22.04.03 21:31 작성 조회수 145
0
사용 에디터: VSCode
V6 Flat 버전을 할 때에 mapping에서 toList()가 먹지를 않습니다.
정확한 에러는 toList() 메소드가 없다고 메소드를 만들어 달라고 합니다.
mapping 사용법에는
Map<City, Set<String>> lastNamesByCity
= people.stream().collect(
groupingBy(Person::getCity,
mapping(Person::getLastName,
toSet())));
위와 같이 to타입()으로 쓰는 것 같은데 왜 toList() 타입이 적용 안되는지 모르겠습니다.
OrderApiController
@GetMapping("/api/v6/orders")
public List<OrderQueryDto> ordersV6() {
List<OrderFlatDto> flats = orderQueryRepository.findAllByDto_flat();
return flats.stream()
.collect(Collectors.groupingBy(o -> new OrderQueryDto(o.getOrderId(), o.getName(), o.getOrderDate(), o.getOrderStatus(), o.getAddress()),
Collectors.mapping(o -> new OrderItemQueryDto(o.getOrderId(), o.getItemName(), o.getOrderPrice(), o.getCount()), toList()))).entrySet().stream()
.map(e -> new OrderQueryDto(e.getKey().getOrderId(), e.getKey().getName(), e.getKey().getOrderDate(), e.getKey().getOrderStatus(), e.getKey().getAddress(), e.getValue()))
.collect(Collectors.toList());
}
OrderFlatDto
package jpabook.jpashop.repository.order.query;
import java.time.LocalDateTime;
import jpabook.jpashop.domain.Address;
import jpabook.jpashop.domain.OrderStatus;
import lombok.Data;
@Data
public class OrderFlatDto {
private Long orderId;
private String name;
private LocalDateTime orderDate;
private OrderStatus orderStatus;
private Address address;
private String itemName;
private int orderPrice;
private int count;
public OrderFlatDto(Long orderId, String name, LocalDateTime orderDate, OrderStatus orderStatus, Address address, String itemName, int orderPrice, int count) {
this.orderId = orderId;
this.name = name;
this.orderDate = orderDate;
this.orderStatus = orderStatus;
this.address = address;
this.itemName = itemName;
this.orderPrice = orderPrice;
this.count = count;
}
}
OrderQueryDto
package jpabook.jpashop.repository.order.query;
import java.time.LocalDateTime;
import java.util.List;
import jpabook.jpashop.domain.Address;
import jpabook.jpashop.domain.OrderStatus;
import lombok.Data;
import lombok.EqualsAndHashCode;
@Data
@EqualsAndHashCode(of = "orderId")
public class OrderQueryDto {
private Long orderId;
private String name;
private LocalDateTime orderDate;
private OrderStatus orderStatus;
private Address address;
private List<OrderItemQueryDto> orderItems;
public OrderQueryDto(Long orderId, String name, LocalDateTime orderDate, OrderStatus orderStatus, Address address) {
this.orderId = orderId;
this.name = name;
this.orderDate = orderDate;
this.orderStatus = orderStatus;
this.address = address;
}
public OrderQueryDto(Long orderId, String name, LocalDateTime orderDate, OrderStatus orderStatus, Address address, List<OrderItemQueryDto> orderItems) {
this.orderId = orderId;
this.name = name;
this.orderDate = orderDate;
this.orderStatus = orderStatus;
this.address = address;
this.orderItems = orderItems;
}
}
OrderQueryRepository
public List<OrderFlatDto> findAllByDto_flat() {
return em.createQuery("select new jpabook.jpashop.repository.order.query.OrderFlatDto(o.id, m.name, o.orderDate, o.status, d.address, i.name, oi.orderPrice, oi.count)" +
" from Order o" +
" join o.member m" +
" join o.delivery d" +
" join o.orderItems oi" +
" join oi.item i", OrderFlatDto.class)
.getResultList();
}
답변을 작성해보세요.
2
Dw Lee
2022.04.06
혹시 도움이 될까해서 올려봅니다.
Collectors.toList()으로 적용해 주시거나
import static java.util.stream.Collectors.*;위와같이 import static으로 해주시면 됩니다.
그리고 참고로 강의 중간에 보시면 import static으로 변환하는 과정이 있습니다.
답변 1