[REFAC] 게시글 공감 기능 다중 선택 허용에 따른 목록 조회 성능 최적화

build.gradle

@@ -63,6 +63,9 @@ dependencies {
 
 	testImplementation 'org.springframework.boot:spring-boot-starter-test'
 	testRuntimeOnly 'org.junit.platform:junit-platform-launcher'
+
+	// AOP 사용을 위한 스타터 추가
+	implementation 'org.springframework.boot:spring-boot-starter-aop'
 }
 
 tasks.named('test') {

src/main/java/com/moongeul/backend/api/post/entity/Post.java

@@ -23,6 +23,7 @@ public class Post extends BaseTimeEntity {
     private LocalDate readDate; // 읽은날짜
     private Double rating; // 평점
     private Integer page; // 페이지 수
+    @Column(columnDefinition = "TEXT")
     private String content; // 감상평
 
     @Enumerated(EnumType.STRING)

src/main/java/com/moongeul/backend/api/post/repository/LikeRepository.java

@@ -11,6 +11,8 @@ public interface LikeRepository extends JpaRepository<Likes, Long> {
 
     List<Likes> findByPostIdAndMemberId(Long postId, Long memberId);
 
+    List<Likes> findAllByMemberEmailAndPostIdIn(String email, List<Long> postIds);
+
     Optional<Likes> findByPostIdAndMemberIdAndLikeType(Long postId, Long memberId, LikeType likeType);
 
     // 특정 게시글의 모든 공감 조회

src/main/java/com/moongeul/backend/api/post/repository/QuoteRepository.java

@@ -9,5 +9,7 @@ public interface QuoteRepository extends JpaRepository<Quote, Long> {
 
     List<Quote> findByPostId(Long postId);
 
+    List<Quote> findAllByPostIdIn(List<Long> postIds);
+
     void deleteAllByPostId(Long postId);
 }

src/main/java/com/moongeul/backend/api/post/service/PostService.java

@@ -16,6 +16,7 @@
 import com.moongeul.backend.api.post.repository.PostRepository;
 import com.moongeul.backend.api.post.repository.QuoteRepository;
 import com.moongeul.backend.api.post.util.WritingGuideGenerator;
+import com.moongeul.backend.common.annotation.Timer;
 import com.moongeul.backend.common.exception.NotFoundException;
 import com.moongeul.backend.common.exception.UnauthorizedException;
 import com.moongeul.backend.common.response.ErrorStatus;
@@ -31,10 +32,7 @@
 import java.time.LocalDate;
 import java.time.LocalDateTime;
 import java.time.temporal.TemporalAdjusters;
-import java.util.ArrayList;
-import java.util.List;
-import java.util.Optional;
-import java.util.Set;
+import java.util.*;
 import java.util.stream.Collectors;
 
 @Slf4j
@@ -116,6 +114,7 @@ public String writingGuide(){
     }
 
     /* 기록(게시글) 전체 조회 */
+    @Timer
     @Transactional
     public PostAllResponseDTO getPostAll(PostAllRequestDTO postAllRequestDTO, String email){
 
@@ -137,16 +136,55 @@ public PostAllResponseDTO getPostAll(PostAllRequestDTO postAllRequestDTO, String
             postPage = postRepository.findAllByFollower(email, pageable);
         }
 
-        List<PostDTO> postDTOList = new ArrayList<>();
-        if (!postPage.isEmpty()) {
-            for(Post post : postPage.getContent()){
-                postDTOList.add(getPostDetail(post.getId(), email));
-            }
+        if (postPage.isEmpty()) {
+            return PostAllResponseDTO.builder().data(new ArrayList<>()).build();
+        }
+
+        // Batch 준비: 현재 페이지의 게시글 ID 리스트 추출
+        List<Long> postIds = postPage.getContent().stream()
+                .map(Post::getId)
+                .toList();
+
+        // Batch 조회 & Map 매핑: 내가 누른 공감들 한꺼번에 가져오기
+        Map<Long, Set<LikeType>> myLikesMap;
+        if (!isAnonymous) {
+            List<Likes> allMyLikes = likeRepository.findAllByMemberEmailAndPostIdIn(email, postIds);
+            myLikesMap = allMyLikes.stream().collect(Collectors.groupingBy(
+                    like -> like.getPost().getId(),
+                    Collectors.mapping(Likes::getLikeType, Collectors.toSet())
+            ));
+        } else {
+            myLikesMap = new HashMap<>();
         }
 
+        // Batch 조회 & Map 매핑: 인상 깊은 구절들 한꺼번에 가져오기
+        List<Quote> allQuotes = quoteRepository.findAllByPostIdIn(postIds);
+        Map<Long, List<Quote>> quotesMap = allQuotes.stream()
+                .collect(Collectors.groupingBy(quote -> quote.getPost().getId()));
+
+        // 메모리 매핑: 루프를 돌며 Map에서 데이터를 꺼내 DTO 조립 (getPostDetail 호출 안 함 X)
+        List<PostDTO> postDTOList = postPage.getContent().stream().map(post -> {
+
+            // 해당 게시글의 공감/구절 데이터를 Map에서 즉시 꺼냄 (DB 조회 0번)
+            Set<LikeType> myTypes = myLikesMap.getOrDefault(post.getId(), Collections.emptySet());
+            List<Quote> postQuotes = quotesMap.getOrDefault(post.getId(), Collections.emptyList());
+
+            // MyLikesStatus 객체 조립
+            PostDTO.MyLikesStatus myLikesStatus = PostDTO.MyLikesStatus.builder()
+                    .relatableCount(myTypes.contains(LikeType.RELATABLE))
+                    .sameTasteCount(myTypes.contains(LikeType.SAME_TASTE))
+                    .impressiveExpressionCount(myTypes.contains(LikeType.IMPRESSIVE_EXPRESSION))
+                    .wantToReadCount(myTypes.contains(LikeType.WANT_TO_READ))
+                    .helpfulCount(myTypes.contains(LikeType.HELPFUL))
+                    .build();
+
+            // 최종 PostDTO 조립 (기존 getPostDetail에 있던 변환 로직만 활용)
+            return convertToPostDTO(post, myLikesStatus, postQuotes);
+        }).toList();
+
         return PostAllResponseDTO.builder()
                 .total(postPage.getTotalElements())
-                .page(postPage.getNumber() + 1) // 페이지 1부터 시작(임의 지정)
+                .page(postPage.getNumber() + 1)
                 .size(postPage.getSize())
                 .totalPages(postPage.getTotalPages())
                 .isLast(postPage.isLast())
@@ -155,68 +193,60 @@ public PostAllResponseDTO getPostAll(PostAllRequestDTO postAllRequestDTO, String
     }
 
     /* 기록(게시글) 상세 조회 */
-    @Transactional
-    public PostDTO getPostDetail(Long postId, String email){
+    @Transactional(readOnly = true)
+    public PostDTO getPostDetail(Long postId, String email) {
 
         Post post = getPost(postId);
-        Book book = getBook(post.getBook().getIsbn());
-
-        // 멤버 정보(필요 정보만) DTO
-        PostDTO.MemberInfo memberInfo = PostDTO.MemberInfo.builder()
-                .memberId(post.getMember().getId())
-                .nickname(post.getMember().getNickname())
-                .profileImage(post.getMember().getProfileImage())
-                .readingTasteType(post.getMember().getReadingTasteType())
-                .build();
+        List<Quote> quotes = quoteRepository.findByPostId(postId);
 
-        // 책 정보(필요 정보만) DTO
-        PostDTO.BookInfo bookInfo = PostDTO.BookInfo.builder()
-                .isbn(book.getIsbn())
-                .bookImage(book.getBookImage())
-                .title(book.getTitle())
-                .author(book.getAuthor())
-                .publisher(book.getPublisher())
-                .pubdate(book.getPubdate())
-                .ratingAverage(book.getRatingAverage())
-                .build();
-
-        // 인상깊은구절 조회
-        List<Quote> quotes = quoteRepository.findByPostId(postId); // 리스트 반환이기에 `orElseThrow()` 사용 x
-        List<PostDTO.QuoteDTO> quoteDTOList = new ArrayList<>();
-        for(Quote quote : quotes){
-            PostDTO.QuoteDTO quoteDTO = PostDTO.QuoteDTO.builder()
-                    .quoteContent(quote.getQuoteContent())
-                    .pageNumber(quote.getPageNumber())
-                    .build();
-            quoteDTOList.add(quoteDTO);
-        }
-
-        // 공감 개수 DTO
-        PostDTO.LikesCnt likesCnt = PostDTO.LikesCnt.builder()
-                .relatableCount(post.getRelatableCount())
-                .sameTasteCount(post.getSameTasteCount())
-                .impressiveExpressionCount(post.getImpressiveExpressionCount())
-                .wantToReadCount(post.getWantToReadCount())
-                .helpfulCount(post.getHelpfulCount())
-                .build();
-
-        /* 내가 누른 공감 유형 정보 DTO */
         boolean isAnonymous = (email == null || "anonymousUser".equals(email));
         PostDTO.MyLikesStatus myLikesStatus = isAnonymous
                 ? PostDTO.MyLikesStatus.empty()
                 : convertToMyLikesStatus(email, postId);
 
+        return convertToPostDTO(post, myLikesStatus, quotes);
+    }
+
+    // 메서드: PostDTO 조립 전용 Helper 메서드
+    private PostDTO convertToPostDTO(Post post, PostDTO.MyLikesStatus myLikesStatus, List<Quote> quotes) {
+
+        List<PostDTO.QuoteDTO> quoteDTOList = quotes.stream()
+                .map(q -> PostDTO.QuoteDTO.builder()
+                        .quoteContent(q.getQuoteContent())
+                        .pageNumber(q.getPageNumber())
+                        .build())
+                .toList();
+
         return PostDTO.builder()
-                .postId(postId)
-                .memberInfo(memberInfo)
+                .postId(post.getId())
+                .memberInfo(PostDTO.MemberInfo.builder()
+                        .memberId(post.getMember().getId())
+                        .nickname(post.getMember().getNickname())
+                        .profileImage(post.getMember().getProfileImage())
+                        .readingTasteType(post.getMember().getReadingTasteType())
+                        .build())
+                .bookInfo(PostDTO.BookInfo.builder()
+                        .isbn(post.getBook().getIsbn())
+                        .bookImage(post.getBook().getBookImage())
+                        .title(post.getBook().getTitle())
+                        .author(post.getBook().getAuthor())
+                        .publisher(post.getBook().getPublisher())
+                        .pubdate(post.getBook().getPubdate())
+                        .ratingAverage(post.getBook().getRatingAverage())
+                        .build())
                 .created(post.getCreatedAt())
-                .bookInfo(bookInfo)
                 .rating(post.getRating())
                 .content(post.getContent())
                 .readDate(post.getReadDate())
                 .quotesCnt(quoteDTOList.size())
                 .quotes(quoteDTOList)
-                .likesCnt(likesCnt)
+                .likesCnt(PostDTO.LikesCnt.builder()
+                        .relatableCount(post.getRelatableCount())
+                        .sameTasteCount(post.getSameTasteCount())
+                        .impressiveExpressionCount(post.getImpressiveExpressionCount())
+                        .wantToReadCount(post.getWantToReadCount())
+                        .helpfulCount(post.getHelpfulCount())
+                        .build())
                 .myLikesStatus(myLikesStatus)
                 .build();
     }
@@ -335,6 +365,7 @@ private void saveQuotes(PostRequestDTO postRequestDTO, Post post){
      */
 
     /* 공감 토글 */
+    @Timer
     @Transactional
     public void likePost(Long postId, String email, LikeDTO likeDTO){
 

src/main/java/com/moongeul/backend/api/setting/service/NoticeSettingService.java

@@ -3,7 +3,6 @@
 import com.moongeul.backend.api.member.entity.Member;
 import com.moongeul.backend.api.member.entity.Role;
 import com.moongeul.backend.api.member.repository.MemberRepository;
-import com.moongeul.backend.api.setting.dto.NoticeAllRequestDTO;
 import com.moongeul.backend.api.setting.dto.NoticeAllResponseDTO;
 import com.moongeul.backend.api.setting.dto.NoticeDTO;
 import com.moongeul.backend.api.setting.dto.NoticeRequestDTO;

src/main/java/com/moongeul/backend/common/annotation/Timer.java

@@ -0,0 +1,11 @@
+package com.moongeul.backend.common.annotation;
+
+import java.lang.annotation.ElementType;
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+import java.lang.annotation.Target;
+
+@Target({ElementType.METHOD})
+@Retention(RetentionPolicy.RUNTIME)
+public @interface Timer {
+}

src/main/java/com/moongeul/backend/common/aspect/TimerAspect.java

@@ -0,0 +1,29 @@
+package com.moongeul.backend.common.aspect;
+
+import lombok.extern.slf4j.Slf4j;
+import org.aspectj.lang.ProceedingJoinPoint;
+import org.aspectj.lang.annotation.Around;
+import org.aspectj.lang.annotation.Aspect;
+import org.springframework.stereotype.Component;
+import org.springframework.util.StopWatch;
+
+@Aspect
+@Component
+@Slf4j
+public class TimerAspect {
+
+    @Around("@annotation(com.moongeul.backend.common.annotation.Timer)")
+    public Object measureTime(ProceedingJoinPoint joinPoint) throws Throwable {
+        StopWatch stopWatch = new StopWatch();
+
+        try {
+            stopWatch.start();
+            return joinPoint.proceed();
+        } finally {
+            stopWatch.stop();
+            log.info("메서드 실행 시간 [{}]: {}ms",
+                    joinPoint.getSignature().getName(),
+                    stopWatch.getTotalTimeMillis());
+        }
+    }
+}