StudyLink-SW-Project · lehojun · May 21, 2025 · May 21, 2025
diff --git a/src/main/java/com/example/be/domain/Post.java b/src/main/java/com/example/be/domain/Post.java
@@ -4,6 +4,7 @@
 import lombok.*;
 
 import java.time.LocalDateTime;
+import java.util.ArrayList;
 import java.util.List;
 
 @Entity
@@ -32,6 +33,9 @@ public class Post {
     @OneToMany(mappedBy = "post", cascade = CascadeType.ALL, orphanRemoval = true)
     private List<Comment> comments;
 
+    @OneToMany(mappedBy = "post", cascade = CascadeType.ALL, orphanRemoval = true)
+    private List<PostLike> likes = new ArrayList<>();
+
     @ManyToOne(fetch = FetchType.LAZY)
     @JoinColumn(name = "user_id")
     private User user;

diff --git a/src/main/java/com/example/be/domain/PostLike.java b/src/main/java/com/example/be/domain/PostLike.java
@@ -0,0 +1,32 @@
+package com.example.be.domain;
+
+import jakarta.persistence.*;
+import lombok.*;
+
+import java.time.LocalDateTime;
+
+@Entity
+@Getter
+@Setter
+@Builder
+@NoArgsConstructor
+@AllArgsConstructor
+@Table(uniqueConstraints = {
+        @UniqueConstraint(columnNames = {"user_id", "post_id"})
+})
+public class PostLike {
+
+    @Id
+    @GeneratedValue(strategy = GenerationType.IDENTITY)
+    private Long id;
+
+    @ManyToOne(fetch = FetchType.LAZY)
+    @JoinColumn(name = "user_id")
+    private User user;
+
+    @ManyToOne(fetch = FetchType.LAZY)
+    @JoinColumn(name = "post_id")
+    private Post post;
+
+    private LocalDateTime createDate;
+}
diff --git a/src/main/java/com/example/be/repository/PostLikeRepository.java b/src/main/java/com/example/be/repository/PostLikeRepository.java
@@ -0,0 +1,22 @@
+package com.example.be.repository;
+
+import com.example.be.domain.Post;
+import com.example.be.domain.PostLike;
+import com.example.be.domain.User;
+import org.springframework.data.jpa.repository.JpaRepository;
+import org.springframework.data.jpa.repository.Query;
+import org.springframework.data.repository.query.Param;
+
+import java.util.Optional;
+
+public interface PostLikeRepository extends JpaRepository<PostLike, Long> {
+
+    Optional<PostLike> findByUserAndPost(User user, Post post);
+
+    boolean existsByUserAndPost(User user, Post post);
+
+    long countByPost(Post post);
+
+    @Query("SELECT COUNT(pl) FROM PostLike pl WHERE pl.post.id = :postId")
+    long countByPostId(@Param("postId") Long postId);
+}
diff --git a/src/main/java/com/example/be/repository/PostRepository.java b/src/main/java/com/example/be/repository/PostRepository.java
@@ -13,7 +13,7 @@
 public interface PostRepository extends JpaRepository<Post, Long> {
     // PostRepository에 추가
     @Query("SELECT p FROM Post p LEFT JOIN FETCH p.comments ORDER BY p.createDate DESC")
-    Page<Post> findAllWithCommentsOrderByCreateDateDesc(Pageable pageable);
+    Page<Post> findAllByOrderByCreateDateDesc(Pageable pageable);
 
     // ID로 게시글 조회 (댓글 포함)
     @EntityGraph(attributePaths = {"comments", "comments.user", "user"})

diff --git a/src/main/java/com/example/be/service/PostLikeServiceImpl.java b/src/main/java/com/example/be/service/PostLikeServiceImpl.java
@@ -0,0 +1,89 @@
+package com.example.be.service;
+
+import com.example.be.apiPayload.code.status.ErrorStatus;
+import com.example.be.apiPayload.exception.handler.UserHandler;
+import com.example.be.domain.Post;
+import com.example.be.domain.PostLike;
+import com.example.be.domain.User;
+import com.example.be.repository.PostLikeRepository;
+import com.example.be.repository.PostRepository;
+import com.example.be.repository.UserRepository;
+import com.example.be.web.dto.PostDTO;
+import jakarta.servlet.http.HttpServletRequest;
+import lombok.RequiredArgsConstructor;
+import org.springframework.stereotype.Service;
+import org.springframework.transaction.annotation.Transactional;
+
+import java.time.LocalDateTime;
+import java.util.Optional;
+import java.util.UUID;
+
+@Service
+@RequiredArgsConstructor
+public class PostLikeServiceImpl {
+
+    private final JwtUtilServiceImpl jwtUtilService;
+    private final UserRepository userRepository;
+    private final PostRepository postRepository;
+    private final PostLikeRepository postLikeRepository;
+
+    @Transactional
+    public PostDTO.PostLikeResponseDTO togglePostLike(Long postId, HttpServletRequest request) {
+        // 토큰에서 사용자 정보 가져오기
+        String accessToken = jwtUtilService.extractTokenFromCookie(request, "accessToken");
+        if (accessToken == null) {
+            throw new UserHandler(ErrorStatus._NOT_FOUND_USER);
+        }
+
+        String userId = jwtUtilService.getUserIdFromToken(accessToken);
+        User user = userRepository.findByUserId(UUID.fromString(userId))
+                .orElseThrow(() -> new UserHandler(ErrorStatus._NOT_FOUND_USER));
+
+        // 게시글 정보 가져오기
+        Post post = postRepository.findById(postId)
+                .orElseThrow(() -> new UserHandler(ErrorStatus._NOT_FOUND_POST));
+
+        // 이미 좋아요를 눌렀는지 확인
+        Optional<PostLike> existingLike = postLikeRepository.findByUserAndPost(user, post);
+
+        boolean isLiked;
+        if (existingLike.isPresent()) {
+            // 좋아요가 이미 있으면 삭제 (좋아요 취소)
+            postLikeRepository.delete(existingLike.get());
+            isLiked = false;
+        } else {
+            // 좋아요가 없으면 추가
+            PostLike postLike = PostLike.builder()
+                    .user(user)
+                    .post(post)
+                    .createDate(LocalDateTime.now())
+                    .build();
+            postLikeRepository.save(postLike);
+            isLiked = true;
+        }
+
+        // 좋아요 수 조회
+        long likeCount = postLikeRepository.countByPost(post);
+
+        return PostDTO.PostLikeResponseDTO.builder()
+                .postId(postId)
+                .liked(isLiked)
+                .likeCount(likeCount)
+                .build();
+    }
+
+    // 특정 게시글에 대한 사용자의 좋아요 여부 확인
+    public boolean isPostLikedByUser(Post post, User user) {
+        return postLikeRepository.existsByUserAndPost(user, post);
+    }
+
+    // 특정 게시글의 좋아요 수 조회
+    public long getPostLikeCount(Post post) {
+        return postLikeRepository.countByPost(post);
+    }
+
+    // 특정 게시글 ID의 좋아요 수 조회
+    public long getPostLikeCount(Long postId) {
+        return postLikeRepository.countByPostId(postId);
+    }
+}
diff --git a/src/main/java/com/example/be/service/PostServiceImpl.java b/src/main/java/com/example/be/service/PostServiceImpl.java
@@ -31,9 +31,11 @@ public class PostServiceImpl {
     private final JwtUtilServiceImpl jwtUtilService;
     private final UserRepository userRepository;
     private final PostRepository postRepository;
+    private final PostLikeServiceImpl postLikeService;
 
-    public CommonDTO.IsSuccessDTO write(PostDTO.postRequestDTO request, HttpServletRequest req) {
 
+    //글 작성 메서드
+    public CommonDTO.IsSuccessDTO write(PostDTO.postRequestDTO request, HttpServletRequest req) {
         String accessToken = jwtUtilService.extractTokenFromCookie(req, "accessToken");
 
         // 토큰이 없는 경우 처리
@@ -63,7 +65,7 @@ public CommonDTO.IsSuccessDTO write(PostDTO.postRequestDTO request, HttpServletR
 
     public PostDTO.PageResponseDTO getPosts(int page, int size) {
         Pageable pageable = PageRequest.of(page, size);
-        Page<Post> postPage = postRepository.findAllWithCommentsOrderByCreateDateDesc(pageable);
+        Page<Post> postPage = postRepository.findAllByOrderByCreateDateDesc(pageable);
 
         List<PostDTO.postResponseDTO> postDtoList = postPage.getContent().stream()
                 .map(post -> PostDTO.postResponseDTO.builder()
@@ -73,8 +75,8 @@ public PostDTO.PageResponseDTO getPosts(int page, int size) {
                         .userName(post.getUser().getName())
                         .createDate(post.getCreateDate().toLocalDate())
                         .isDone(post.isDone())
-                        // 댓글 개수 추가
                         .commentCount(post.getComments() != null ? post.getComments().size() : 0)
+                        .likeCount(postLikeService.getPostLikeCount(post))
                         .build())
                 .collect(Collectors.toList());
 
@@ -89,10 +91,29 @@ public PostDTO.PageResponseDTO getPosts(int page, int size) {
     }
 
     // 게시글 상세 조회 메서드
-    public PostDTO.PostDetailResponseDTO getPostDetail(Long postId) {
+    public PostDTO.PostDetailResponseDTO getPostDetail(Long postId, HttpServletRequest request) {
         Post post = postRepository.findById(postId)
                 .orElseThrow(() -> new UserHandler(ErrorStatus._NOT_FOUND_POST));
 
+        // 현재 로그인한 사용자 정보 가져오기 (좋아요 여부 확인용)
+        User currentUser = null;
+        boolean isLiked = false;
+
+        try {
+            String accessToken = jwtUtilService.extractTokenFromCookie(request, "accessToken");
+            if (accessToken != null) {
+                String userId = jwtUtilService.getUserIdFromToken(accessToken);
+                currentUser = userRepository.findByUserId(UUID.fromString(userId)).orElse(null);
+
+                // 현재 사용자가 이 게시글에 좋아요를 눌렀는지 확인
+                if (currentUser != null) {
+                    isLiked = postLikeService.isPostLikedByUser(post, currentUser);
+                }
+            }
+        } catch (Exception e) {
+            // 비로그인 사용자도 게시글을 볼 수 있도록 예외를 무시하고 진행
+        }
+
         // 댓글 목록 변환
         List<PostDTO.CommentResponseDTO> commentDtoList = post.getComments().stream()
                 .map(comment -> PostDTO.CommentResponseDTO.builder()
@@ -104,6 +125,9 @@ public PostDTO.PostDetailResponseDTO getPostDetail(Long postId) {
                         .build())
                 .collect(Collectors.toList());
 
+        // 좋아요 수 조회
+        long likeCount = postLikeService.getPostLikeCount(post);
+
         // 게시글 상세 정보 변환
         return PostDTO.PostDetailResponseDTO.builder()
                 .id(post.getId())
@@ -114,6 +138,9 @@ public PostDTO.PostDetailResponseDTO getPostDetail(Long postId) {
                 .isDone(post.isDone())
                 .commentCount(commentDtoList.size())
                 .comments(commentDtoList)
+                // 좋아요 정보 추가
+                .likeCount(likeCount)
+                .liked(isLiked)
                 .build();
     }
 }
diff --git a/src/main/java/com/example/be/web/controller/PostController.java b/src/main/java/com/example/be/web/controller/PostController.java
@@ -6,7 +6,9 @@
 import com.example.be.domain.User;
 import com.example.be.repository.UserRepository;
 import com.example.be.service.JwtUtilServiceImpl;
+import com.example.be.service.PostLikeServiceImpl;
 import com.example.be.service.PostServiceImpl;
+import com.example.be.service.UserServiceImpl;
 import com.example.be.web.dto.CommonDTO;
 import com.example.be.web.dto.PostDTO;
 import com.example.be.web.dto.UserDTO;
@@ -24,6 +26,7 @@
 public class PostController {
 
     private final PostServiceImpl postService;
+    private final PostLikeServiceImpl postLikeService;
 
     @PostMapping("/write")
     @Operation(summary = "게시글 작성 API")
@@ -42,8 +45,18 @@ public ApiResponse<PostDTO.PageResponseDTO> getPosts(
     @GetMapping("/{postId}")
     @Operation(summary = "게시글 상세 조회 API", description = "게시글 ID로 게시글 상세 정보와 댓글 목록을 조회합니다.")
     public ApiResponse<PostDTO.PostDetailResponseDTO> getPostDetail(
-            @Parameter(description = "게시글 ID") @PathVariable Long postId) {
-        return ApiResponse.onSuccess(postService.getPostDetail(postId));
+            @Parameter(description = "게시글 ID") @PathVariable Long postId,
+            HttpServletRequest request) {
+        return ApiResponse.onSuccess(postService.getPostDetail(postId, request));
+    }
+
+    // 좋아요 토글 API 추가
+    @PostMapping("/{postId}/like")
+    @Operation(summary = "게시글 좋아요 토글 API", description = "게시글에 좋아요를 누르거나 취소합니다.")
+    public ApiResponse<PostDTO.PostLikeResponseDTO> togglePostLike(
+            @Parameter(description = "게시글 ID") @PathVariable Long postId,
+            HttpServletRequest request) {
+        return ApiResponse.onSuccess(postLikeService.togglePostLike(postId, request));
     }
 
 }
diff --git a/src/main/java/com/example/be/web/dto/CommonDTO.java b/src/main/java/com/example/be/web/dto/CommonDTO.java
@@ -13,6 +13,6 @@ public class CommonDTO {
     @AllArgsConstructor
     @Schema(title = "COMMON_RES_06 : API 실행 성공 여부 응답 DTO")
     public static class IsSuccessDTO{
-        Boolean isSuccess;
+        private Boolean isSuccess;
     }
 }
diff --git a/src/main/java/com/example/be/web/dto/PostDTO.java b/src/main/java/com/example/be/web/dto/PostDTO.java
@@ -19,23 +19,24 @@ public class PostDTO {
     @AllArgsConstructor
 
     public static class postRequestDTO{
-        String title;
-        String content;
+        private String title;
+        private String content;
     }
 
     @Builder
     @Getter
     @NoArgsConstructor
     @AllArgsConstructor
     public static class postResponseDTO {
-        Long id;
-        String title;
-        String content;
-        String userName;
+        private Long id;
+        private String title;
+        private String content;
+        private String userName;
+        private long likeCount;
         @JsonFormat(pattern = "yyyy-MM-dd")
-        LocalDate createDate;
-        int commentCount;
-        boolean isDone;
+        private LocalDate createDate;
+        private int commentCount;
+        private boolean isDone;
     }
 
     @Builder
@@ -78,14 +79,24 @@ public static class PostDetailResponseDTO {
         private String title;
         private String content;
         private String userName;
-
+        private long likeCount;
+        private boolean liked;
         @JsonFormat(pattern = "yyyy-MM-dd HH:mm:ss")
         private LocalDateTime createDate;
-
         private boolean isDone;
         private int commentCount;
         private List<CommentResponseDTO> comments;
     }
 
+    @Builder
+    @Getter
+    @NoArgsConstructor
+    @AllArgsConstructor
+    @Schema(description = "게시글 좋아요 응답 DTO")
+    public static class PostLikeResponseDTO {
+        private Long postId;
+        private boolean liked;
+        private long likeCount;
+    }
 
 }