[REFACTOR]Zzim리스트 조회 시, User,Place,Photo,PostCategory 관련 N+1 문제 해결

src/main/java/com/spoony/spoony_server/adapter/out/persistence/post/PostPersistenceAdapter.java

@@ -20,9 +20,9 @@
 import com.spoony.spoony_server.global.message.business.PostErrorMessage;
 import com.spoony.spoony_server.global.message.business.UserErrorMessage;
 import lombok.RequiredArgsConstructor;
-import org.springframework.stereotype.Repository;
 
 import java.util.List;
+import java.util.Map;
 import java.util.stream.Collectors;
 
 @Adapter
@@ -48,6 +48,11 @@ public List<Post> findUserByUserId(Long userId) {
                 .map(PostMapper::toDomain)
                 .collect(Collectors.toList());
     }
+    public Post findPostWithPhotosAndCategoriesByPostId(Long postId) {
+        return postRepository.findPostWithPhotosAndCategories(postId)
+                .map(PostMapper::toDomain)
+                .orElseThrow(() -> new BusinessException(PostErrorMessage.POST_NOT_FOUND));
+    }
 
     public Post findPostById(Long postId) {
         return postRepository.findById(postId)
@@ -60,6 +65,18 @@ public PostCategory findPostCategoryByPostId(Long postId) {
                 .map(PostCategoryMapper::toDomain)
                 .orElseThrow(() -> new BusinessException(CategoryErrorMessage.CATEGORY_NOT_FOUND));
     }
+    @Override
+    public Map<Long, PostCategory> findPostCategoriesByPostIds(List<Long> postIds) {
+        List<PostCategoryEntity> postCategoryEntities = postCategoryRepository.findPostCategoriesByPostIds(postIds);
+
+        return postCategoryEntities.stream()
+                .map(PostCategoryMapper::toDomain) // PostCategoryEntity -> PostCategory 변환
+                .collect(Collectors.toMap(
+                        postCategory -> postCategory.getPost().getPostId(),
+                        postCategory -> postCategory,
+                        (existing, replacement) -> existing // 중복 방지
+                ));
+    }
 
     public Category findCategoryById(Long categoryId) {
         return categoryRepository.findById(categoryId)

src/main/java/com/spoony/spoony_server/adapter/out/persistence/post/db/CategoryEntity.java

@@ -11,6 +11,7 @@
 @Getter
 @NoArgsConstructor(access = AccessLevel.PROTECTED)
 @Table(name = "category")
+
 public class CategoryEntity {
     @Id
     @GeneratedValue(strategy = GenerationType.IDENTITY)

src/main/java/com/spoony/spoony_server/adapter/out/persistence/post/db/PhotoEntity.java

@@ -5,11 +5,13 @@
 import lombok.Builder;
 import lombok.Getter;
 import lombok.NoArgsConstructor;
+import org.hibernate.annotations.BatchSize;
 
 @Entity
 @Getter
 @NoArgsConstructor(access = AccessLevel.PROTECTED)
 @Table(name = "photo")
+@BatchSize(size = 10)
 public class PhotoEntity {
     @Id
     @GeneratedValue(strategy = GenerationType.IDENTITY)

src/main/java/com/spoony/spoony_server/adapter/out/persistence/post/db/PhotoRepository.java

@@ -1,10 +1,17 @@
 package com.spoony.spoony_server.adapter.out.persistence.post.db;
 
+import org.springframework.data.jpa.repository.EntityGraph;
 import org.springframework.data.jpa.repository.JpaRepository;
+import org.springframework.data.jpa.repository.Query;
+import org.springframework.data.repository.query.Param;
 
 import java.util.List;
 import java.util.Optional;
 
 public interface PhotoRepository extends JpaRepository<PhotoEntity, Long> {
     Optional<List<PhotoEntity>> findByPost_PostId(Long postId);
+
+    @Query("SELECT p FROM PhotoEntity p WHERE p.post.postId IN :postIds GROUP BY p.post.postId")
+    List<PhotoEntity> findFirstPhotosByPostIds(@Param("postIds") List<Long> postIds);
+
 }

src/main/java/com/spoony/spoony_server/adapter/out/persistence/post/db/PostCategoryEntity.java

@@ -5,11 +5,13 @@
 import lombok.Builder;
 import lombok.Getter;
 import lombok.NoArgsConstructor;
+import org.hibernate.annotations.BatchSize;
 
 @Entity
 @Getter
 @NoArgsConstructor(access = AccessLevel.PROTECTED)
 @Table(name = "post_category")
+@BatchSize(size = 10)
 public class PostCategoryEntity {
 
     @Id
@@ -31,4 +33,5 @@ public PostCategoryEntity(Long postCategoryId, PostEntity post, CategoryEntity c
         this.post = post;
         this.category = category;
     }
+
 }

src/main/java/com/spoony/spoony_server/adapter/out/persistence/post/db/PostCategoryRepository.java

@@ -1,12 +1,18 @@
 package com.spoony.spoony_server.adapter.out.persistence.post.db;
 
 import org.springframework.data.jpa.repository.JpaRepository;
+import org.springframework.data.jpa.repository.Query;
+import org.springframework.data.repository.query.Param;
 import org.springframework.stereotype.Repository;
 
+import java.util.List;
 import java.util.Optional;
 
 @Repository
 public interface PostCategoryRepository extends JpaRepository<PostCategoryEntity, Long> {
     Optional<PostCategoryEntity> findByPost_PostId(Long postID);
+
+    @Query("SELECT pc FROM PostCategoryEntity pc WHERE pc.post.postId IN :postIds")
+    List<PostCategoryEntity> findPostCategoriesByPostIds(@Param("postIds") List<Long> postIds);
 }
 

src/main/java/com/spoony/spoony_server/adapter/out/persistence/post/db/PostEntity.java

@@ -7,11 +7,13 @@
 import lombok.Builder;
 import lombok.Getter;
 import lombok.NoArgsConstructor;
+import org.hibernate.annotations.BatchSize;
 import org.springframework.data.annotation.CreatedDate;
 import org.springframework.data.annotation.LastModifiedDate;
 import org.springframework.data.jpa.domain.support.AuditingEntityListener;
 
 import java.time.LocalDateTime;
+import java.util.List;
 
 @Entity
 @Getter
@@ -41,6 +43,8 @@ public class PostEntity {
     @LastModifiedDate
     private LocalDateTime updatedAt;
 
+
+
     @Builder
     public PostEntity(Long postId, UserEntity user, PlaceEntity place, String title, String description) {
         this.postId = postId;

src/main/java/com/spoony/spoony_server/adapter/out/persistence/post/db/PostRepository.java

@@ -1,11 +1,21 @@
 package com.spoony.spoony_server.adapter.out.persistence.post.db;
 
+import org.springframework.data.jpa.repository.EntityGraph;
 import org.springframework.data.jpa.repository.JpaRepository;
+import org.springframework.data.jpa.repository.Query;
+import org.springframework.data.repository.query.Param;
 import org.springframework.stereotype.Repository;
 
 import java.util.List;
+import java.util.Optional;
 
 @Repository
 public interface PostRepository extends JpaRepository<PostEntity, Long> {
+
     List<PostEntity> findByUser_UserId(Long userId);
+
+    @EntityGraph(attributePaths = {"photos", "postCategories", "postCategories.category"})
+    @Query("SELECT p FROM PostEntity p WHERE p.postId = :postId")
+    Optional<PostEntity> findPostWithPhotosAndCategories(@Param("postId") Long postId);
+
 }

src/main/java/com/spoony/spoony_server/adapter/out/persistence/zzim/ZzimPersistenceAdapter.java

@@ -21,6 +21,8 @@
 import org.springframework.stereotype.Repository;
 
 import java.util.List;
+import java.util.Map;
+import java.util.stream.Collectors;
 
 @Repository
 @RequiredArgsConstructor
@@ -39,7 +41,20 @@ public Long countZzimByPostId(Long postId) {
     public boolean existsByUserIdAndPostId(Long userId, Long postId) {
         return zzimPostRepository.existsByUser_UserIdAndPost_PostId(userId, postId);
     }
+    @Override
+    public Map<Long, Photo> findFirstPhotosByPostIds(List<Long> postIds) {
+        List<Photo> photos = photoRepository.findFirstPhotosByPostIds(postIds)
+                .stream()
+                .map(PhotoMapper::toDomain)
+                .toList();
 
+        return photos.stream()
+                .collect(Collectors.toMap(
+                        photo -> photo.getPost().getPostId(),
+                        photo -> photo,
+                        (existing, replacement) -> existing // 중복 방지
+                ));
+    }
     @Override
     public List<ZzimPost> findUserByUserId(Long userId) {
         return zzimPostRepository.findByUser_UserId(userId)
@@ -63,13 +78,15 @@ public void saveZzimPost(User user, Post post) {
         zzimPostRepository.save(zzimPostEntity);
     }
 
+    // postId별로 개별적인 조회가 발생하여 N+1 문제 발생!
     @Override
     public Photo findFistPhotoById(Long postId) {
         return photoRepository.findByPost_PostId(postId)
                 .map(list -> PhotoMapper.toDomain(list.get(0))) // 첫 번째 요소만 매핑
                 .orElseThrow(() -> new BusinessException(PostErrorMessage.PHOTO_NOT_FOUND));
     }
 
+
     @Override
     public List<Photo> findPhotoListById(Long postId) {
         return photoRepository.findByPost_PostId(postId)

src/main/java/com/spoony/spoony_server/adapter/out/persistence/zzim/db/ZzimPostEntity.java

@@ -7,6 +7,7 @@
 import lombok.Builder;
 import lombok.Getter;
 import lombok.NoArgsConstructor;
+import org.hibernate.annotations.BatchSize;
 
 @Entity
 @Getter

src/main/java/com/spoony/spoony_server/adapter/out/persistence/zzim/db/ZzimPostRepository.java

@@ -13,6 +13,8 @@
 public interface ZzimPostRepository extends JpaRepository<ZzimPostEntity, Long> {
     Long countByPost_PostId(Long postId);
     boolean existsByUser_UserIdAndPost_PostId(Long userId, Long postId);
+
+
     List<ZzimPostEntity> findByUser_UserId(Long userId);
     void deleteByUser_UserIdAndPost_PostId(Long userId, Long postId);
 }

src/main/java/com/spoony/spoony_server/application/port/out/post/PostPort.java

@@ -7,9 +7,11 @@
 import com.spoony.spoony_server.domain.user.User;
 
 import java.util.List;
+import java.util.Map;
 
 public interface PostPort {
     List<Post> findUserByUserId(Long userId);
+    Post findPostWithPhotosAndCategoriesByPostId(Long postId);
     boolean existsByUserIdAndPostId(Long userId, Long postId);
     Post findPostById(Long postId);
     List<Photo> findPhotoById(Long postId);
@@ -19,4 +21,5 @@ public interface PostPort {
     void saveMenu(Menu menu);
     void savePhoto(Photo photo);
     void saveScoopPost(User user, Post post);
+    Map<Long, PostCategory> findPostCategoriesByPostIds(List<Long> postIds);
 }

src/main/java/com/spoony/spoony_server/application/port/out/zzim/ZzimPostPort.java

@@ -6,6 +6,7 @@
 import com.spoony.spoony_server.domain.zzim.ZzimPost;
 
 import java.util.List;
+import java.util.Map;
 
 public interface ZzimPostPort {
     Long countZzimByPostId(Long postId);
@@ -15,4 +16,5 @@ public interface ZzimPostPort {
     List<ZzimPost> findUserByUserId(Long userId);
     void saveZzimPost(User user, Post post);
     void deleteByUserAndPost(User user, Post post);
+    Map<Long, Photo> findFirstPhotosByPostIds(List<Long> postIds); // 🔥 추가된 메서드
 }

src/main/java/com/spoony/spoony_server/application/service/post/PostService.java

@@ -62,7 +62,9 @@ public class PostService implements
     @Transactional
     public PostResponseDTO getPostById(PostGetCommand command) {
 
-        Post post = postPort.findPostById(command.getPostId());
+        //Post post = postPort.findPostById(command.getPostId());
+        Post post = postPort.findPostWithPhotosAndCategoriesByPostId(command.getPostId());
+
         User user = userPort.findUserById(command.getUserId());
 
         PostCategory postCategory = postCategoryPort.findPostCategoryByPostId(post.getPostId());

src/main/java/com/spoony/spoony_server/application/service/zzim/ZzimPostService.java

@@ -52,7 +52,6 @@ public void addZzimPost(ZzimAddCommand command) {
         zzimPostPort.saveZzimPost(user,post);
     }
 
-    //사용자 지도 리스트 조회
     public ZzimCardListResponseDTO getZzimCardList(ZzimGetCardCommand command) {
         List<ZzimPost> zzimPostList = zzimPostPort.findUserByUserId(command.getUserId());
 
@@ -70,12 +69,20 @@ public ZzimCardListResponseDTO getZzimCardList(ZzimGetCardCommand command) {
             }
         }
 
+        // 🔥 N+1 문제 해결: 한 번에 모든 postId의 첫 번째 사진을 조회
+        List<Long> postIds = uniquePlacePostMap.values().stream()
+                .map(zzimPost -> zzimPost.getPost().getPostId())
+                .toList();
+
+        Map<Long, Photo> firstPhotos = zzimPostPort.findFirstPhotosByPostIds(postIds);
+        Map<Long, PostCategory> postCategories = postPort.findPostCategoriesByPostIds(postIds);
         List<ZzimCardResponseDTO> zzimCardResponses = uniquePlacePostMap.values().stream()
                 .map(zzimPost -> {
                     Post post = zzimPost.getPost();
                     Place place = post.getPlace();
-                    Photo photo = zzimPostPort.findFistPhotoById(post.getPostId());
-                    PostCategory postCategory = postCategoryPort.findPostCategoryByPostId(post.getPostId());
+                    Photo photo = firstPhotos.get(post.getPostId()); // 🔥 Batch 조회된 결과 사용
+                    PostCategory postCategory = postCategories.get(post.getPostId());
+                    //PostCategory postCategory = postCategoryPort.findPostCategoryByPostId(post.getPostId());
 
                     CategoryColorResponseDTO categoryColorResponse = new CategoryColorResponseDTO(
                             postCategory.getCategory().getCategoryId(),
@@ -84,13 +91,12 @@ public ZzimCardListResponseDTO getZzimCardList(ZzimGetCardCommand command) {
                             postCategory.getCategory().getTextColor(),
                             postCategory.getCategory().getBackgroundColor());
 
-
                     return new ZzimCardResponseDTO(
-                            place.getPlaceId(),  // placeId 추가
+                            place.getPlaceId(),
                             place.getPlaceName(),
                             place.getPlaceAddress(),
                             post.getTitle(),
-                            photo.getPhotoUrl(),
+                            photo != null ? photo.getPhotoUrl() : null, // 사진이 없을 경우 null 처리
                             place.getLatitude(),
                             place.getLongitude(),
                             categoryColorResponse
@@ -101,6 +107,56 @@ public ZzimCardListResponseDTO getZzimCardList(ZzimGetCardCommand command) {
         return new ZzimCardListResponseDTO(zzimCardResponses.size(), zzimCardResponses);
     }
 
+
+//    //사용자 지도 리스트 조회
+//    public ZzimCardListResponseDTO getZzimCardList(ZzimGetCardCommand command) {
+//        List<ZzimPost> zzimPostList = zzimPostPort.findUserByUserId(command.getUserId());
+//
+//        Map<Long, ZzimPost> uniquePlacePostMap = new LinkedHashMap<>();
+//
+//        for (ZzimPost zzimPost : zzimPostList) {
+//            Place place = zzimPost.getPost().getPlace();
+//            if (place == null) {
+//                throw new BusinessException(PlaceErrorMessage.PLACE_NOT_FOUND);
+//            }
+//
+//            Long placeId = place.getPlaceId();
+//            if (!uniquePlacePostMap.containsKey(placeId)) {
+//                uniquePlacePostMap.put(placeId, zzimPost);
+//            }
+//        }
+//
+//        List<ZzimCardResponseDTO> zzimCardResponses = uniquePlacePostMap.values().stream()
+//                .map(zzimPost -> {
+//                    Post post = zzimPost.getPost();
+//                    Place place = post.getPlace();
+//                    Photo photo = zzimPostPort.findFistPhotoById(post.getPostId());
+//                    PostCategory postCategory = postCategoryPort.findPostCategoryByPostId(post.getPostId());
+//
+//                    CategoryColorResponseDTO categoryColorResponse = new CategoryColorResponseDTO(
+//                            postCategory.getCategory().getCategoryId(),
+//                            postCategory.getCategory().getCategoryName(),
+//                            postCategory.getCategory().getIconUrlColor(),
+//                            postCategory.getCategory().getTextColor(),
+//                            postCategory.getCategory().getBackgroundColor());
+//
+//
+//                    return new ZzimCardResponseDTO(
+//                            place.getPlaceId(),  // placeId 추가
+//                            place.getPlaceName(),
+//                            place.getPlaceAddress(),
+//                            post.getTitle(),
+//                            photo.getPhotoUrl(),
+//                            place.getLatitude(),
+//                            place.getLongitude(),
+//                            categoryColorResponse
+//                    );
+//                })
+//                .collect(Collectors.toList());
+//
+//        return new ZzimCardListResponseDTO(zzimCardResponses.size(), zzimCardResponses);
+//    }
+
     public ZzimFocusListResponseDTO getZzimFocusList(ZzimGetFocusCommand command) {
         User user = userPort.findUserById(command.getUserId());
         List<ZzimPost> zzimPostList = zzimPostPort.findUserByUserId(user.getUserId());