Round8

apps/commerce-api/build.gradle.kts

@@ -2,6 +2,7 @@ dependencies {
     // add-ons
     implementation(project(":modules:jpa"))
     implementation(project(":modules:redis"))
+    implementation(project(":modules:kafka"))
     implementation(project(":supports:jackson"))
     implementation(project(":supports:logging"))
     implementation(project(":supports:monitoring"))

apps/commerce-api/src/main/java/com/loopers/application/event/listener/OrderStatusEventListener.java

@@ -50,6 +50,13 @@ public void handlePaymentCompleted(PaymentCompletedEvent event) {
                 order.getOrderNo(),
                 order.getMemberId(),
                 order.getTotalPrice(),
+                order.getItems().stream()
+                    .map(item -> new OrderCompletedEvent.OrderItemInfo(
+                        item.getProductId(),
+                        item.getQuantity(),
+                        item.getUnitPrice()
+                    ))
+                    .toList(),
                 java.time.LocalDateTime.now()
             ));
 

apps/commerce-api/src/main/java/com/loopers/application/event/order/OrderCompletedEvent.java

@@ -2,11 +2,18 @@
 
 import com.loopers.domain.common.vo.Money;
 import java.time.LocalDateTime;
+import java.util.List;
 
 public record OrderCompletedEvent(
     String orderNo,
     Long memberId,
     Money totalPrice,
+    List<OrderItemInfo> items,
     LocalDateTime completedAt
 ) {
+    public record OrderItemInfo(
+        Long productId,
+        int quantity,
+        Money price
+    ) {}
 }

apps/commerce-api/src/main/java/com/loopers/application/event/product/ProductViewedEvent.java

@@ -0,0 +1,11 @@
+package com.loopers.application.event.product;
+
+import java.time.LocalDateTime;
+
+public record ProductViewedEvent(
+    Long memberId,      // nullable (비로그인 사용자도 추적)
+    Long productId,
+    Long brandId,
+    LocalDateTime viewedAt
+) {
+}

apps/commerce-api/src/main/java/com/loopers/application/like/LikeFacade.java

@@ -3,9 +3,9 @@
 import com.loopers.application.event.like.ProductLikedEvent;
 import com.loopers.application.event.like.ProductUnlikedEvent;
 import com.loopers.application.event.tracking.UserActionEvent;
+import com.loopers.domain.like.repository.LikeRepository;
 import com.loopers.domain.like.service.LikeService;
 import com.loopers.domain.product.Product;
-import com.loopers.domain.product.repository.ProductRepository;
 import lombok.RequiredArgsConstructor;
 import lombok.extern.slf4j.Slf4j;
 import org.springframework.context.ApplicationEventPublisher;
@@ -22,11 +22,17 @@
 public class LikeFacade {
 
     private final LikeService likeService;
-    private final ProductRepository productRepository;
+    private final LikeRepository likeRepository;
     private final ApplicationEventPublisher eventPublisher;
 
     public void likeProduct(Long memberId, Long productId) {
-        // 1. DB에 좋아요 저장 (Redis 로직은 LikeService에서 제거됨)
+        // 멱등성: 이미 좋아요한 경우 early return (좋아요가 존재하면 상품도 존재함)
+        if (likeRepository.existsByMemberIdAndProductId(memberId, productId)) {
+            log.debug("[LikeFacade] 이미 좋아요한 상품 - memberId: {}, productId: {}", memberId, productId);
+            return;
+        }
+
+        // 1. DB에 좋아요 저장
         Product product = likeService.like(memberId, productId);
 
         // 2. 이벤트 발행 (Redis 업데이트는 비동기 리스너에서 처리)
@@ -49,7 +55,13 @@ public void likeProduct(Long memberId, Long productId) {
     }
 
     public void unlikeProduct(Long memberId, Long productId) {
-        // 1. DB에서 좋아요 삭제 (Redis 로직은 LikeService에서 제거됨)
+        // 멱등성: 좋아요하지 않은 경우 early return
+        if (!likeRepository.existsByMemberIdAndProductId(memberId, productId)) {
+            log.debug("[LikeFacade] 좋아요하지 않은 상품 - memberId: {}, productId: {}", memberId, productId);
+            return;
+        }
+
+        // 1. DB에서 좋아요 삭제
         Product product = likeService.unlike(memberId, productId);
 
         // 2. 이벤트 발행 (Redis 업데이트는 비동기 리스너에서 처리)

apps/commerce-api/src/main/java/com/loopers/application/product/ProductFacade.java

@@ -1,18 +1,23 @@
 package com.loopers.application.product;
 
+import com.loopers.application.event.product.ProductViewedEvent;
 import com.loopers.domain.like.service.LikeReadService;
+import com.loopers.domain.product.Product;
+import com.loopers.domain.product.repository.ProductRepository;
 import com.loopers.domain.product.service.ProductReadService;
 import com.loopers.domain.product.command.ProductSearchFilter;
 import com.loopers.domain.product.enums.ProductSortCondition;
 import com.loopers.infrastructure.cache.ProductDetailCache;
 import com.loopers.infrastructure.cache.ProductListCache;
 import lombok.RequiredArgsConstructor;
+import org.springframework.context.ApplicationEventPublisher;
 import org.springframework.data.domain.Page;
 import org.springframework.data.domain.PageRequest;
 import org.springframework.data.domain.Pageable;
 import org.springframework.stereotype.Component;
 import org.springframework.transaction.annotation.Transactional;
 
+import java.time.LocalDateTime;
 import java.util.List;
 
 @RequiredArgsConstructor
@@ -24,6 +29,8 @@ public class ProductFacade {
     private final LikeReadService likeReadService;
     private final ProductDetailCache productDetailCache;
     private final ProductListCache productListCache;
+    private final ProductRepository productRepository;
+    private final ApplicationEventPublisher eventPublisher;
 
     @Transactional(readOnly = true)
     public Page<ProductSummaryInfo> getProducts(ProductSearchCommand command) {
@@ -93,16 +100,17 @@ public ProductDetailInfo getProductDetail(Long productId, Long memberIdOrNull) {
                     return result;
                 });
 
-        // 2. 로그인하지 않은 경우 바로 반환
-        if (memberIdOrNull == null) {
-            return cachedInfo;  // isLikedByMember=false 그대로
-        }
+        // 2. Product 엔티티 조회 (brandId 획득용)
+        Product product = productRepository.findById(productId)
+                .orElseThrow(() -> new com.loopers.support.error.CoreException(
+                        com.loopers.support.error.ErrorType.NOT_FOUND,
+                        "상품을 찾을 수 없습니다."));
 
-        // 3. isLikedByMember만 동적 계산
-        boolean isLiked = likeReadService.isLikedBy(memberIdOrNull, productId);
+        // 3. isLikedByMember 동적 계산
+        boolean isLiked = memberIdOrNull != null && likeReadService.isLikedBy(memberIdOrNull, productId);
 
         // 4. isLikedByMember 필드만 교체해서 반환
-        return ProductDetailInfo.builder()
+        ProductDetailInfo result = ProductDetailInfo.builder()
                 .id(cachedInfo.getId())
                 .name(cachedInfo.getName())
                 .description(cachedInfo.getDescription())
@@ -113,6 +121,16 @@ public ProductDetailInfo getProductDetail(Long productId, Long memberIdOrNull) {
                 .likeCount(cachedInfo.getLikeCount())
                 .isLikedByMember(isLiked)  // ⭐ 동적 계산
                 .build();
+
+        // 5. ProductViewedEvent 발행 (조회수 집계)
+        eventPublisher.publishEvent(new ProductViewedEvent(
+            memberIdOrNull,  // 비로그인 사용자는 null
+            productId,
+            product.getBrandId(),
+            LocalDateTime.now()
+        ));
+
+        return result;
     }
 
     @Transactional(readOnly = true)

apps/commerce-api/src/main/java/com/loopers/config/AsyncConfig.java

@@ -10,7 +10,6 @@
 import org.springframework.scheduling.annotation.Scheduled;
 import org.springframework.scheduling.concurrent.ThreadPoolTaskExecutor;
 
-import java.util.concurrent.Executor;
 import java.util.concurrent.ThreadPoolExecutor;
 
 /**
@@ -35,7 +34,7 @@ public class AsyncConfig implements AsyncConfigurer {
      */
     @Bean(name = "taskExecutor")
     @Override
-    public Executor getAsyncExecutor() {
+    public ThreadPoolTaskExecutor getAsyncExecutor() {
         ThreadPoolTaskExecutor executor = new ThreadPoolTaskExecutor();
         executor.setCorePoolSize(10);   // 5 → 10
         executor.setMaxPoolSize(20);    // 10 → 20

apps/commerce-api/src/main/java/com/loopers/domain/like/service/LikeService.java

@@ -28,22 +28,16 @@ public class LikeService {
      * - DB에는 Like 레코드만 저장
      * - 좋아요 카운트는 이벤트 리스너에서 Redis에 업데이트
      * - 스케줄러가 주기적으로 Redis → DB 동기화
+     * - 멱등성은 Facade에서 보장 (중복 체크는 Facade 책임)
      *
      * @return 좋아요한 상품 (이벤트 발행용 brandId 포함)
      */
     public Product like(Long memberId, Long productId) {
-        // 중복 좋아요 방지 (멱등성)
-        if (likeRepository.existsByMemberIdAndProductId(memberId, productId)) {
-            log.debug("[LikeService] 이미 좋아요한 상품 - memberId: {}, productId: {}", memberId, productId);
-            return productRepository.findById(productId)
-                    .orElseThrow(() -> new CoreException(ErrorType.NOT_FOUND, "상품을 찾을 수 없습니다."));
-        }
-
-        // 1. 상품 존재 확인 (비관적 락 제거)
+        // 1. 상품 존재 확인
         Product product = productRepository.findById(productId)
                 .orElseThrow(() -> new CoreException(ErrorType.NOT_FOUND, "상품을 찾을 수 없습니다."));
 
-        // 2. DB에 Like 레코드만 저장 (카운트는 Redis에서 관리)
+        // 2. DB에 Like 레코드 저장 (카운트는 Redis에서 관리)
         likeRepository.save(new Like(memberId, productId));
 
         log.info("[LikeService] 좋아요 저장 완료 - memberId: {}, productId: {}", memberId, productId);
@@ -56,22 +50,16 @@ public Product like(Long memberId, Long productId) {
      * - DB에서 Like 레코드만 삭제
      * - 좋아요 카운트는 이벤트 리스너에서 Redis에 업데이트
      * - 스케줄러가 주기적으로 Redis → DB 동기화
+     * - 멱등성은 Facade에서 보장 (존재 여부 체크는 Facade 책임)
      *
      * @return 좋아요 취소한 상품 (이벤트 발행용 brandId 포함)
      */
     public Product unlike(Long memberId, Long productId) {
-        // 좋아요 없으면 스킵 (멱등성)
-        if (!likeRepository.existsByMemberIdAndProductId(memberId, productId)) {
-            log.debug("[LikeService] 좋아요하지 않은 상품 - memberId: {}, productId: {}", memberId, productId);
-            return productRepository.findById(productId)
-                    .orElseThrow(() -> new CoreException(ErrorType.NOT_FOUND, "상품을 찾을 수 없습니다."));
-        }
-
-        // 1. 상품 존재 확인 (비관적 락 제거)
+        // 1. 상품 존재 확인
         Product product = productRepository.findById(productId)
                 .orElseThrow(() -> new CoreException(ErrorType.NOT_FOUND, "상품을 찾을 수 없습니다."));
 
-        // 2. DB에서 Like 레코드만 삭제 (카운트는 Redis에서 관리)
+        // 2. DB에서 Like 레코드 삭제 (카운트는 Redis에서 관리)
         likeRepository.deleteByMemberIdAndProductId(memberId, productId);
 
         log.info("[LikeService] 좋아요 취소 완료 - memberId: {}, productId: {}", memberId, productId);

apps/commerce-api/src/main/java/com/loopers/domain/order/service/OrderPlacementService.java

@@ -11,14 +11,17 @@
 import com.loopers.domain.order.repository.OrderRepository;
 import com.loopers.domain.product.Product;
 import com.loopers.domain.product.repository.ProductRepository;
+import com.loopers.infrastructure.cache.CacheInvalidationService;
 import com.loopers.support.error.CoreException;
 import com.loopers.support.error.ErrorType;
 import lombok.RequiredArgsConstructor;
+import lombok.extern.slf4j.Slf4j;
 import org.springframework.stereotype.Component;
 
 import java.util.ArrayList;
 import java.util.List;
 
+@Slf4j
 @RequiredArgsConstructor
 @Component
 public class OrderPlacementService {
@@ -27,6 +30,7 @@ public class OrderPlacementService {
     private final ProductRepository productRepository;
     private final MemberRepository memberRepository;
     private final MemberCouponRepository memberCouponRepository;
+    private final CacheInvalidationService cacheInvalidationService;
 
     public Order placeOrder(OrderPlacementCommand command) {
         validateMemberExists(command.getMemberId());
@@ -83,6 +87,13 @@ private List<OrderItem> processOrderLines(List<OrderLineCommand> orderLines) {
                 throw new CoreException(ErrorType.BAD_REQUEST, "재고가 부족합니다.");
             }
 
+            // 재고 소진 시 캐시 무효화
+            int remainingStock = productRepository.getStockQuantity(product.getId());
+            if (remainingStock == 0) {
+                log.info("[Order] Stock depleted for productId={}, invalidating cache", product.getId());
+                cacheInvalidationService.invalidateOnStockDepletion(product.getId());
+            }
+
             items.add(new OrderItem(product.getId(), line.getQuantity(), product.getPrice()));
         }
 

apps/commerce-api/src/main/java/com/loopers/domain/product/repository/ProductRepository.java

@@ -26,6 +26,8 @@ public interface ProductRepository {
 
     int increaseStock(Long productId, int quantity);
 
+    int getStockQuantity(Long productId);
+
     int incrementLikeCount(Long productId);
 
     int decrementLikeCount(Long productId);

apps/commerce-api/src/main/java/com/loopers/infrastructure/cache/CacheInvalidationService.java

@@ -35,4 +35,13 @@ public void invalidateOnProductUpdate(Long productId) {
         log.info("[CacheInvalidation] Invalidating cache for product update, productId={}", productId);
         productDetailCache.delete(productId);
     }
+
+    /**
+     * Invalidate cache when product stock is depleted
+     */
+    public void invalidateOnStockDepletion(Long productId) {
+        log.info("[CacheInvalidation] Invalidating cache for stock depletion, productId={}", productId);
+        productDetailCache.delete(productId);
+        // Note: Product list cache는 TTL(60초)에 의존하여 자동 무효화
+    }
 }

apps/commerce-api/src/main/java/com/loopers/infrastructure/cache/MemberLikesCache.java

@@ -79,9 +79,10 @@ public Set<Long> findLikedProductIds(Long memberId, List<Long> productIds) {
                 return Set.of();
             }
 
-            // productIds 중 좋아요한 것만 필터링
+            // productIds 중 좋아요한 것만 필터링 (변환 실패한 값은 제외)
             Set<Long> likedSet = allLiked.stream()
-                    .map(obj -> (Long) obj)
+                    .map(this::toLongOrNull)
+                    .filter(v -> v != null)
                     .collect(Collectors.toSet());
 
             return productIds.stream()
@@ -107,7 +108,8 @@ public Set<Long> findAll(Long memberId) {
             }
 
             return members.stream()
-                    .map(obj -> (Long) obj)
+                    .map(this::toLongOrNull)
+                    .filter(v -> v != null)
                     .collect(Collectors.toSet());
 
         } catch (Exception e) {
@@ -165,4 +167,29 @@ public void delete(Long memberId) {
             log.warn("[MemberLikesCache] delete failed, error={}", e.getMessage());
         }
     }
+
+    /**
+     * Redis 값을 Long으로 변환 (변환 실패 시 null 반환)
+     */
+    private Long toLongOrNull(Object value) {
+        if (value == null) {
+            return null;
+        }
+        if (value instanceof Long) {
+            return (Long) value;
+        }
+        if (value instanceof Integer) {
+            return ((Integer) value).longValue();
+        }
+        if (value instanceof String) {
+            try {
+                return Long.parseLong((String) value);
+            } catch (NumberFormatException e) {
+                log.warn("[MemberLikesCache] Failed to parse String to Long: {}", value);
+                return null;
+            }
+        }
+        log.warn("[MemberLikesCache] Unsupported value type: {}", value.getClass().getSimpleName());
+        return null;
+    }
 }