[39] 주문 전 재고 체크 및 재고 감소

src/main/java/org/example/commerce_site/application/order/OrderFacade.java

@@ -5,6 +5,7 @@
 import org.example.commerce_site.application.address.AddressService;
 import org.example.commerce_site.application.order.dto.OrderDetailResponseDto;
 import org.example.commerce_site.application.order.dto.OrderRequestDto;
+import org.example.commerce_site.application.product.ProductService;
 import org.example.commerce_site.application.shipment.ShipmentService;
 import org.example.commerce_site.application.user.UserService;
 import org.example.commerce_site.domain.Address;
@@ -23,12 +24,13 @@ public class OrderFacade {
 	private final OrderDetailService orderDetailService;
 	private final ShipmentService shipmentService;
 	private final AddressService addressService;
+	private final ProductService productService;
 
 	@Transactional
 	public void create(OrderRequestDto.Create dto) {
-		User user = userService.getUser(dto.getUserId());
-		//TODO 상품의 수량이 없어서 또는 상태 변경으로 구매하지 못할 경우에 대한 검증이 필요함
-		Order order = orderService.createOrder(dto);
+		User user = userService.getUser(dto.getUserAuthId());
+		productService.updateStock(dto.getDetails());
+		Order order = orderService.createOrder(dto, user.getId());
 		orderDetailService.createOrderDetails(dto.getDetails(), order);
 		List<OrderDetailResponseDto.Get> orderDetails = orderDetailService.getOrderDetails(order.getId());
 		Address address = addressService.getAddress(dto.getAddressId(), user);

src/main/java/org/example/commerce_site/application/order/OrderService.java

@@ -16,8 +16,8 @@ public class OrderService {
 	private final OrderRepository orderRepository;
 
 	@Transactional
-	public Order createOrder(OrderRequestDto.Create dto) {
-		return orderRepository.save(OrderRequestDto.Create.toEntity(dto));
+	public Order createOrder(OrderRequestDto.Create dto, Long userId) {
+		return orderRepository.save(OrderRequestDto.Create.toEntity(dto, userId));
 	}
 
 	@Transactional(readOnly = true)

src/main/java/org/example/commerce_site/application/order/dto/OrderRequestDto.java

@@ -16,14 +16,14 @@ public class OrderRequestDto {
 	@Getter
 	@Builder
 	public static class Create {
-		private Long userId;
+		private String userAuthId;
 		private BigDecimal totalAmount;
 		private List<OrderRequestDto.CreateDetail> details;
 		private Long addressId;
 
-		public static Order toEntity(OrderRequestDto.Create dto) {
+		public static Order toEntity(OrderRequestDto.Create dto, Long userId) {
 			return Order.builder()
-				.userId(dto.getUserId())
+				.userId(userId)
 				.totalAmount(dto.getTotalAmount())
 				.status(OrderStatus.PENDING)
 				.build();

src/main/java/org/example/commerce_site/application/product/ProductService.java

@@ -1,5 +1,10 @@
 package org.example.commerce_site.application.product;
 
+import java.util.List;
+import java.util.Map;
+import java.util.stream.Collectors;
+
+import org.example.commerce_site.application.order.dto.OrderRequestDto;
 import org.example.commerce_site.application.product.dto.ProductRequestDto;
 import org.example.commerce_site.application.product.dto.ProductResponseDto;
 import org.example.commerce_site.common.exception.CustomException;
@@ -46,8 +51,39 @@ public void delete(Product product) {
 		productRepository.delete(product);
 	}
 
+	@Transactional(readOnly = true)
 	public Page<ProductResponseDto.Get> getProductList(PageRequest of, String keyword, Long categoryId,
 		Long partnerId) {
 		return customProductRepository.getProducts(of, keyword, categoryId, partnerId);
 	}
+
+	@Transactional
+	public void updateStock(List<OrderRequestDto.CreateDetail> details) {
+		List<Long> productIds = details.stream()
+			.map(OrderRequestDto.CreateDetail::getProductId)
+			.toList();
+
+		List<Product> products = productRepository.findByIdInWithLock(productIds);
+
+		Map<Long, Product> productMap = products.stream()
+			.collect(Collectors.toMap(Product::getId, product -> product));
+
+		for (OrderRequestDto.CreateDetail detail : details) {
+			Product product = productMap.get(detail.getProductId());
+
+			if (product == null) {
+				throw new CustomException(ErrorCode.PRODUCT_NOT_FOUND);
+			}
+
+			long newStockQuantity = product.getStockQuantity() - detail.getQuantity();
+
+			if (newStockQuantity < 0) {
+				throw new CustomException(ErrorCode.PRODUCT_OUT_OF_STOCK);
+			}
+
+			product.updateQuantity(newStockQuantity);
+		}
+
+		productRepository.saveAll(products);
+	}
 }

src/main/java/org/example/commerce_site/common/exception/ErrorCode.java

@@ -37,6 +37,7 @@ public enum ErrorCode {
 	//product
 	PRODUCT_NOT_FOUND(HttpStatus.NOT_FOUND, 404, "상품 정보를 찾을 수 없습니다."),
 	PRODUCT_ACCESS_DENIED(HttpStatus.FORBIDDEN, 403, "상품 정보 수정에 대한 권한이 없습니다."),
+	PRODUCT_OUT_OF_STOCK(HttpStatus.CONFLICT, 409, "상품의 재고가 부족합니다"),
 
 	//category
 	CATEGORY_NOT_FOUND(HttpStatus.NOT_FOUND, 404, "카테고리 정보를 찾을 수 없습니다.");

src/main/java/org/example/commerce_site/domain/Product.java

@@ -54,4 +54,8 @@ public void update(ProductRequestDto.Put dto, Category category) {
 		this.isEnable = dto.getIsEnable() != null ? dto.getIsEnable() : this.isEnable;
 		this.category = category != null ? category : this.category;
 	}
+
+	public void updateQuantity(Long stockQuantity) {
+		this.stockQuantity = stockQuantity;
+	}
 }

src/main/java/org/example/commerce_site/infrastructure/product/ProductRepository.java

@@ -1,9 +1,18 @@
 package org.example.commerce_site.infrastructure.product;
 
+import java.util.List;
+
 import org.example.commerce_site.domain.Product;
 import org.springframework.data.jpa.repository.JpaRepository;
+import org.springframework.data.jpa.repository.Lock;
+import org.springframework.data.jpa.repository.Query;
 import org.springframework.stereotype.Repository;
 
+import jakarta.persistence.LockModeType;
+
 @Repository
 public interface ProductRepository extends JpaRepository<Product, Long> {
+	@Lock(LockModeType.PESSIMISTIC_WRITE)
+	@Query("SELECT p FROM Product p WHERE p.id IN :productIds")
+	List<Product> findByIdInWithLock(List<Long> productIds);
 }

src/main/java/org/example/commerce_site/representation/order/OrderController.java

@@ -5,6 +5,7 @@
 import org.example.commerce_site.representation.order.request.OrderRequest;
 import org.springframework.web.bind.annotation.PathVariable;
 import org.springframework.web.bind.annotation.PostMapping;
+import org.springframework.web.bind.annotation.RequestAttribute;
 import org.springframework.web.bind.annotation.RequestBody;
 import org.springframework.web.bind.annotation.RequestMapping;
 import org.springframework.web.bind.annotation.RestController;
@@ -17,11 +18,12 @@
 public class OrderController {
 	private final OrderFacade orderFacade;
 
-	@PostMapping("/{user_id}")
-	public ApiSuccessResponse createOrder(@PathVariable("user_id") long userId,
+	@PostMapping()
+	public ApiSuccessResponse createOrder(
+		@RequestAttribute("userId") String userAuthId,
 		@RequestBody OrderRequest.Create request
 	) {
-		orderFacade.create(OrderRequest.Create.toDto(request, userId));
+		orderFacade.create(OrderRequest.Create.toDto(request, userAuthId));
 		return ApiSuccessResponse.success();
 	}
 }

src/main/java/org/example/commerce_site/representation/order/request/OrderRequest.java

@@ -18,9 +18,9 @@ public static class Create {
 		@NotNull
 		private Long addressId;
 
-		public static OrderRequestDto.Create toDto(OrderRequest.Create request, Long userId) {
+		public static OrderRequestDto.Create toDto(OrderRequest.Create request, String userId) {
 			return OrderRequestDto.Create.builder()
-				.userId(userId)
+				.userAuthId(userId)
 				.totalAmount(request.getTotalAmount())
 				.details(CreateDetail.toDtos(request.getDetails()))
 				.addressId(request.getAddressId())

src/test/java/org/example/commerce_site/application/order/OrderFacadeTest.java

@@ -8,6 +8,7 @@
 import org.example.commerce_site.application.address.AddressService;
 import org.example.commerce_site.application.order.dto.OrderDetailResponseDto;
 import org.example.commerce_site.application.order.dto.OrderRequestDto;
+import org.example.commerce_site.application.product.ProductService;
 import org.example.commerce_site.application.shipment.ShipmentService;
 import org.example.commerce_site.application.user.UserService;
 import org.example.commerce_site.domain.Address;
@@ -39,12 +40,15 @@ class OrderFacadeTest {
 	@Mock
 	private AddressService addressService;
 
+	@Mock
+	private ProductService productService;
+
 	@Test
 	public void create_ShouldCreateOrder() {
 		Long userId = 1L;
 		Long addressId = 1L;
 		OrderRequestDto.Create dto = OrderRequestDto.Create.builder()
-			.userId(userId)
+			.userAuthId("Test Auth")
 			.addressId(addressId)
 			.details(Collections.emptyList())
 			.build();
@@ -54,15 +58,16 @@ public void create_ShouldCreateOrder() {
 		Address address = Address.builder().id(addressId).build();
 		List<OrderDetailResponseDto.Get> orderDetails = Collections.emptyList();
 
-		when(userService.getUser(userId)).thenReturn(user);
-		when(orderService.createOrder(dto)).thenReturn(order);
+		when(userService.getUser(dto.getUserAuthId())).thenReturn(user);
+		when(orderService.createOrder(eq(dto), eq(userId))).thenReturn(order);
 		when(addressService.getAddress(addressId, user)).thenReturn(address);
 		when(orderDetailService.getOrderDetails(order.getId())).thenReturn(orderDetails);
 
 		orderFacade.create(dto);
 
-		verify(userService).getUser(userId);
-		verify(orderService).createOrder(dto);
+		verify(userService).getUser(dto.getUserAuthId());
+		verify(productService).updateStock(dto.getDetails());
+		verify(orderService).createOrder(eq(dto), eq(userId)); // 매처 사용
 		verify(orderDetailService).createOrderDetails(dto.getDetails(), order);
 		verify(orderDetailService).getOrderDetails(order.getId());
 		verify(addressService).getAddress(addressId, user);

src/test/java/org/example/commerce_site/application/order/OrderServiceTest.java

@@ -35,11 +35,11 @@ void create_ShouldCreateOrder() {
 		details.add(detailDto2);
 
 		OrderRequestDto.Create createDto = OrderRequestDto.Create.builder()
-			.userId(1L).addressId(1L).totalAmount(new BigDecimal(10000)).details(details).build();
+			.userAuthId("Test Auth").addressId(1L).totalAmount(new BigDecimal(10000)).details(details).build();
 
 		Order order = Order.builder().id(1L).userId(1L).build();
 		when(orderRepository.save(any(Order.class))).thenReturn(order);
-		orderService.createOrder(createDto);
+		orderService.createOrder(createDto, 1L);
 		verify(orderRepository).save(any(Order.class));
 	}