Refactor#67 중복 코드 리팩토링 및 N+1 문제 해결

back/src/main/java/com/back/domain/post/comment/dto/CommentAllResponse.java

@@ -16,7 +16,7 @@ public static CommentAllResponse from(PostComment comment) {
         CommentAllResponse response = new CommentAllResponse();
         response.setId(comment.getId());
         response.setContent(comment.getContent());
-        response.setAuthorName(comment.getMember().getName()); // Member에서 이름 가져오기
+        response.setAuthorName(comment.getAuthorName()); // Member에서 이름 가져오기
         response.setCreatedAt(comment.getCreateDate());
         return response;
     }

back/src/main/java/com/back/domain/post/comment/entity/PostComment.java

@@ -9,6 +9,8 @@
 import lombok.Getter;
 import lombok.Setter;
 
+import java.util.Objects;
+
 @Entity
 @Getter
 @Setter
@@ -23,4 +25,14 @@ public class PostComment extends BaseEntity {
 
     private String role;
 
+    public Boolean isAuthor( Member member) {
+        return Objects.equals(this.member.getId(), member.getId());
+    }
+
+    public String getAuthorName() {
+        return member.getName();
+    }
+
+
+
 }

back/src/main/java/com/back/domain/post/comment/repository/PostCommentRepository.java

@@ -2,8 +2,15 @@
 
 import com.back.domain.post.comment.entity.PostComment;
 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;
+
 @Repository
 public interface PostCommentRepository extends JpaRepository<PostComment, Long> {
+
+    @Query("SELECT c FROM PostComment c JOIN FETCH c.member WHERE c.post.id = :postId")
+    List<PostComment> findCommentsWithMemberByPostId(@Param("postId") Long postId);
 }

back/src/main/java/com/back/domain/post/comment/service/PostCommentService.java

@@ -39,21 +39,22 @@ public void createComment(Member member, Long postId, CommentCreateRequest comme
 
     }
 
+    @Transactional
     public List<CommentAllResponse> getAllPostCommentResponse(Long postId) {
-        Post post = postRepository.findById(postId).orElseThrow(() -> new ServiceException("400", "해당 Id의 게시글이 없습니다."));
-
-        List<PostComment> listPostComment = post.getComments();
+        validatePostExists(postId);
 
+        List<PostComment> listPostComment = postCommentRepository.findCommentsWithMemberByPostId(postId);
 
         return listPostComment.stream()
                 .map(CommentAllResponse::from)
                 .toList();
     }
 
+    @Transactional
     public void removePostComment(Long postId, CommentDeleteRequest commentDeleteRequest, Member member) {
-        Post post = postRepository.findById(postId).orElseThrow(() -> new ServiceException("400", "해당 Id의 게시글이 없습니다."));
+        validatePostExists(postId);
 
-        PostComment postComment = postCommentRepository.findById(commentDeleteRequest.getCommentId()).orElseThrow(() -> new ServiceException("400", "해당 Id의 댓글이 없습니다."));
+        PostComment postComment = getPostCommentById(commentDeleteRequest.getCommentId());
         Member author = postComment.getMember();
 
 
@@ -67,9 +68,9 @@ public void removePostComment(Long postId, CommentDeleteRequest commentDeleteReq
 
     @Transactional
     public void updatePostComment(Long postId, CommentModifyRequest commentModifyRequest, Member member) {
-        Post post = postRepository.findById(postId).orElseThrow(() -> new ServiceException("400", "해당 Id의 게시글이 없습니다."));
+        validatePostExists(postId);
 
-        PostComment postComment = postCommentRepository.findById(commentModifyRequest.getCommentId()).orElseThrow(() -> new ServiceException("400", "해당 Id의 댓글이 없습니다."));
+        PostComment postComment = getPostCommentById(commentModifyRequest.getCommentId());
         Member author = postComment.getMember();
 
 
@@ -79,4 +80,19 @@ public void updatePostComment(Long postId, CommentModifyRequest commentModifyReq
 
         postComment.setContent(commentModifyRequest.getContent());
     }
+
+
+
+    private void validatePostExists(Long postId) {
+        if (!postRepository.existsById(postId)) {
+            throw new ServiceException("400", "해당 Id의 게시글이 없습니다.");
+        }
+    }
+
+    private PostComment getPostCommentById(Long commentId) {
+        return postCommentRepository.findById(commentId).orElseThrow(() -> new ServiceException("400", "해당 Id의 댓글이 없습니다."));
+    }
+
+
+
 }

back/src/main/java/com/back/domain/post/like/entity/PostLike.java

@@ -0,0 +1,66 @@
+package com.back.domain.post.like.entity;
+
+import com.back.domain.member.member.entity.Member;
+import com.back.domain.post.post.entity.Post;
+import com.back.global.jpa.BaseEntity;
+import jakarta.persistence.Entity;
+import jakarta.persistence.EnumType;
+import jakarta.persistence.Enumerated;
+import jakarta.persistence.FetchType;
+import jakarta.persistence.ManyToOne;
+import jakarta.persistence.Table;
+import jakarta.persistence.UniqueConstraint;
+import lombok.AccessLevel;
+import lombok.Builder;
+import lombok.Getter;
+import lombok.NoArgsConstructor;
+
+@Getter
+@Entity
+@Table(name = "post_like", uniqueConstraints = {
+        @UniqueConstraint(columnNames = {"member_id", "post_id"})
+})
+@NoArgsConstructor(access = AccessLevel.PROTECTED)
+public class PostLike extends BaseEntity {
+
+    @ManyToOne(fetch = FetchType.LAZY)
+    private Member member;
+
+    @ManyToOne(fetch = FetchType.LAZY)
+    private Post post;
+
+    @Enumerated(EnumType.STRING)
+    private LikeStatus status;
+
+    public enum LikeStatus {
+        LIKE, DISLIKE
+    }
+
+    @Builder(access = AccessLevel.PRIVATE)
+    private PostLike(Member member, Post post, LikeStatus status) {
+        this.member = member;
+        this.post = post;
+        this.status = status;
+    }
+
+    public static PostLike create(Member member, Post post, LikeStatus status) {
+        if (member == null) {
+            throw new IllegalArgumentException("Member cannot be null");
+        }
+        if (post == null) {
+            throw new IllegalArgumentException("Post cannot be null");
+        }
+        if (status == null) {
+            throw new IllegalArgumentException("Status cannot be null");
+        }
+        return PostLike.builder()
+                .member(member)
+                .post(post)
+                .status(status)
+                .build();
+    }
+
+    public void updateStatus(LikeStatus status) {
+        this.status = status;
+    }
+}

back/src/main/java/com/back/domain/post/like/repository/PostLikeRepository.java

@@ -0,0 +1,25 @@
+package com.back.domain.post.like.repository;
+
+import com.back.domain.member.member.entity.Member;
+import com.back.domain.post.like.entity.PostLike;
+import com.back.domain.post.post.entity.Post;
+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.Optional;
+
+@Repository
+public interface PostLikeRepository extends JpaRepository<PostLike, Long> {
+
+    Optional<PostLike> findByMemberAndPost(Member member, Post post);
+
+    @Query("SELECT COUNT(pl) FROM PostLike pl WHERE pl.post.id = :postId AND pl.status = 'LIKE'")
+    int countLikesByPostId(@Param("postId") Long postId);
+
+    @Query("SELECT COUNT(pl) FROM PostLike pl WHERE pl.post.id = :postId AND pl.status = 'DISLIKE'")
+    int countDislikesByPostId(@Param("postId") Long postId);
+
+    boolean existsByMemberAndPost(Member member, Post post);
+}

back/src/main/java/com/back/domain/post/like/service/PostLikeService.java

@@ -0,0 +1,80 @@
+package com.back.domain.post.like.service;
+
+import com.back.domain.member.member.entity.Member;
+import com.back.domain.post.like.entity.PostLike;
+import com.back.domain.post.like.repository.PostLikeRepository;
+import com.back.domain.post.post.entity.Post;
+import com.back.domain.post.post.service.PostService;
+import com.back.global.rq.Rq;
+import jakarta.transaction.Transactional;
+import lombok.RequiredArgsConstructor;
+import org.springframework.stereotype.Service;
+
+import java.util.Optional;
+@Service
+@RequiredArgsConstructor
+public class PostLikeService {
+    private final Rq rq;
+    private final PostLikeRepository postLikeRepository;
+    private final PostService postService;
+
+
+    @Transactional
+    public void likePost(long postId) {
+        Member member = rq.getActor();
+        Post post = postService.findById(postId);
+
+        // 기존 좋아요/싫어요 기록 조회
+        Optional<PostLike> existingLike = postLikeRepository.findByMemberAndPost(member, post);
+
+        if (existingLike.isPresent()) {
+            PostLike postLike = existingLike.get();
+
+            if (postLike.getStatus() == PostLike.LikeStatus.LIKE) {
+                // 이미 좋아요 상태 -> 좋아요 취소
+                postLikeRepository.delete(postLike);
+            } else {
+                // 싫어요 상태 -> 좋아요로 변경
+                postLike.updateStatus(PostLike.LikeStatus.LIKE);
+            }
+        } else {
+            // 처음 좋아요
+            PostLike newLike = PostLike.create(member, post, PostLike.LikeStatus.LIKE);
+            postLikeRepository.save(newLike);
+
+        }
+    }
+
+    @Transactional
+    public void disLikePost(long postId) {
+        Member member = rq.getActor();
+        Post post = postService.findById(postId);
+
+        // 기존 좋아요/싫어요 기록 조회
+        Optional<PostLike> existingLike = postLikeRepository.findByMemberAndPost(member, post);
+
+        if (existingLike.isPresent()) {
+            PostLike postLike = existingLike.get();
+
+            if (postLike.getStatus() == PostLike.LikeStatus.DISLIKE) {
+                // 이미 싫어요 상태 -> 싫어요 취소
+                postLikeRepository.delete(postLike);
+            } else {
+                // 좋아요 상태 -> 싫어요로 변경
+                postLike.updateStatus(PostLike.LikeStatus.DISLIKE);
+            }
+        } else {
+            // 처음 싫어요
+            PostLike newDislike = PostLike.create(member, post, PostLike.LikeStatus.DISLIKE);
+            postLikeRepository.save(newDislike);
+        }
+    }
+
+    public int showDisLikeCount(Long postId) {
+        return postLikeRepository.countDislikesByPostId(postId);
+    }
+
+    public int showLikeCount(Long postId) {
+        return postLikeRepository.countLikesByPostId(postId);
+    }
+}

back/src/main/java/com/back/domain/post/post/controller/InformationPostController.java

@@ -1,6 +1,7 @@
 package com.back.domain.post.post.controller;
 
 import com.back.domain.member.member.entity.Member;
+import com.back.domain.post.like.service.PostLikeService;
 import com.back.domain.post.post.dto.*;
 import com.back.domain.post.post.entity.Post;
 import com.back.domain.post.post.service.PostService;
@@ -22,6 +23,7 @@
 @RequestMapping("post/infor")
 @RequiredArgsConstructor
 public class InformationPostController {
+    private final PostLikeService postLikeService;
     private final PostService postService;
     private final Rq rq;
 
@@ -90,27 +92,36 @@ public RsData<Void> updatePost(@PathVariable Long post_id
         return new RsData<>("200", "게시글 수정 성공", null);
     }
 
-    @Operation(summary = "게시글 좋아요 + ")
+    @Operation(summary = "게시글 좋아요")
     @PostMapping("/{post_id}/liked")
     public RsData<Void> likePost(@PathVariable Long post_id) {
-        postService.likePost(post_id);
+        postLikeService.likePost(post_id);
 
         return new RsData<>("200", "게시글 좋아요 성공", null);
     }
 
     @Operation(summary = "게시글 좋아요 (Show)")
     @GetMapping("/{post_id}/liked")
-    public RsData<PostLikedResponse> getlike(@PathVariable Long post_id) {
-        int likeCount = postService.showLikeCount(post_id);
+    public RsData<PostLikedResponse> getLike(@PathVariable Long post_id) {
+        int likeCount = postLikeService.showLikeCount(post_id);
         PostLikedResponse postLikedResponse = new PostLikedResponse(likeCount);
 
         return new RsData<>("200", "게시글 좋아요 조회 성공", postLikedResponse);
     }
 
+    @Operation(summary = "게시글 싫어요 (Show)")
+    @GetMapping("/{post_id}/Disliked")
+    public RsData<PostLikedResponse> getDisLike(@PathVariable Long post_id) {
+        int likeCount = postLikeService.showDisLikeCount(post_id);
+        PostLikedResponse postLikedResponse = new PostLikedResponse(likeCount);
+
+        return new RsData<>("200", "게시글 싫어요 조회 성공", postLikedResponse);
+    }
+
     @Operation(summary = "게시글 싫어요")
     @PostMapping("/{post_id}/disliked")
     public RsData<PostLikedResponse> disLikePost(@PathVariable Long post_id) {
-        postService.disLikePost(post_id);
+        postLikeService.disLikePost(post_id);
 
         return new RsData<>("200", "게시글 싫어요 성공", null);
     }

back/src/main/java/com/back/domain/post/post/dto/PostAllResponse.java

@@ -12,15 +12,13 @@ public class PostAllResponse {
     private String authorName;
     private LocalDateTime createdAt;
     private int viewCount;
-    private int like;
 
     public PostAllResponse(Post post) {
         this.id = post.getId();
         this.title = post.getTitle();
         this.authorName = post.getAuthorName();
         this.createdAt = post.getCreateDate();
         this.viewCount = post.getViewCount();
-        this.like = post.getLiked();
     }
 
 }

back/src/main/java/com/back/domain/post/post/dto/PostLikedResponse.java

@@ -1,9 +1,12 @@
 package com.back.domain.post.post.dto;
 
+import lombok.Data;
+
+@Data
 public class PostLikedResponse {
-    int liked;
+    private int likeCount;
 
-    public PostLikedResponse(int liked) {
-        this.liked= liked;
+    public PostLikedResponse(int likeCount) {
+        this.likeCount = likeCount;
     }
 }

back/src/main/java/com/back/domain/post/post/dto/PostSingleResponse.java

@@ -12,14 +12,12 @@ public class PostSingleResponse {
     private String authorName;
     private LocalDateTime createdAt;
     private int viewCount;
-    private int like;
 
     public PostSingleResponse(Post post) {
         this.id = post.getId();
         this.title = post.getTitle();
         this.authorName = post.getAuthorName();
         this.createdAt = post.getCreateDate();
         this.viewCount = post.getViewCount();
-        this.like = post.getLiked();
     }
 }