[NB-203, NB-204] 게시글 좋아요 및 좋아요 취소 기능 구현

src/main/java/com/soyeon/nubim/domain/post/Post.java

@@ -61,6 +61,16 @@ public class Post extends BaseEntity {
 	@OrderBy("createdAt DESC")
 	private List<Comment> comments = new ArrayList<>();
 
+	/**
+	 * 다른 엔티티 생성 시 매핑만을 위해 임시 Post 엔티티 생성
+	 * 실제 Post의 값은 가지지 않으니 사용 시 주의할 것
+	 */
+	public Post(Long postId, Long userId) {
+		this.postId = postId;
+		this.user = new User(userId);
+		this.postTitle = "MAPPING_POST";
+	}
+
 	public void linkAlbum(Album album) {
 		this.album = album;
 		album.linkPost(this);

src/main/java/com/soyeon/nubim/domain/post/PostService.java

@@ -36,24 +36,6 @@ public class PostService {
 	private final CommentMapper commentMapper;
 	private final UserMapper userMapper;
 
-	public PostDetailResponseDto findPostDetailById(Long id) {
-		Post post = postRepository.findById(id).orElseThrow(() -> new PostNotFoundException(id));
-
-		return postMapper.toPostDetailResponseDto(post);
-	}
-
-	public PostSimpleResponseDto findPostSimpleById(Long id) {
-		Post post = postRepository.findById(id).orElseThrow(() -> new PostNotFoundException(id));
-
-		return postMapper.toPostSimpleResponseDto(post);
-	}
-
-	public Page<PostSimpleResponseDto> findAllPostsByUserOrderByCreatedAt(User user, Pageable pageable) {
-		Page<Post> postList = postRepository.findByUser(user, pageable);
-		return postList
-			.map(postMapper::toPostSimpleResponseDto);
-	}
-
 	public PostCreateResponseDto createPost(PostCreateRequestDto postCreateRequestDto, User authorUser) {
 		Album linkedAlbum = albumService.findById(postCreateRequestDto.getAlbumId());
 		albumService.validateAlbumOwner(linkedAlbum.getAlbumId(), authorUser.getUserId());
@@ -65,39 +47,34 @@ public PostCreateResponseDto createPost(PostCreateRequestDto postCreateRequestDt
 		return postMapper.toPostCreateResponseDto(post);
 	}
 
-	public void deleteById(Long postId, Long userId) {
-		validatePostOwner(postId, userId);
+	public Post findPostByIdOrThrow(Long id) {
+		return postRepository.findById(id).orElseThrow(() -> new PostNotFoundException(id));
+	}
 
-		Post post = findPostByIdOrThrow(postId);
-		post.unlinkAlbum();
+	public PostSimpleResponseDto findPostSimpleById(Long id) {
+		Post post = findPostByIdOrThrow(id);
 
-		postRepository.deleteById(postId);
+		return postMapper.toPostSimpleResponseDto(post);
 	}
 
-	public Post findPostByIdOrThrow(Long id) {
+	public PostDetailResponseDto findPostDetailById(Long id) {
+		Post post = findPostByIdOrThrow(id);
 
-		return postRepository
-			.findById(id)
-			.orElseThrow(() -> new PostNotFoundException(id));
+		return postMapper.toPostDetailResponseDto(post);
 	}
 
-	public void validatePostExist(Long postId) {
-		if (!postRepository.existsById(postId)) {
-			throw new PostNotFoundException(postId);
-		}
+	public Page<PostSimpleResponseDto> searchPostsByTitleOrContent(Pageable pageable, String query) {
+		return postRepository.findByPostTitleContainingOrPostContentContaining(query, query, pageable)
+			.map(postMapper::toPostSimpleResponseDto);
 	}
 
-	public void validatePostOwner(Long postId, Long userId) {
-		Post post = findPostByIdOrThrow(postId);
-		Long postOwnerId = post.getUser().getUserId();
-
-		if (!postOwnerId.equals(userId)) {
-			throw new UnauthorizedPostAccessException(postId);
-		}
+	public Page<PostSimpleResponseDto> findAllPostsByUserOrderByCreatedAt(User user, Pageable pageable) {
+		Page<Post> postList = postRepository.findByUser(user, pageable);
+		return postList
+			.map(postMapper::toPostSimpleResponseDto);
 	}
 
-	public Page<PostMainResponseDto> findRecentPostsOfFollowees(
-		User user, Pageable pageable, int recentCriteriaDays) {
+	public Page<PostMainResponseDto> findRecentPostsOfFollowees(User user, Pageable pageable, int recentCriteriaDays) {
 		return postRepository.findRecentPostsByFollowees(user, LocalDateTime.now().minusDays(recentCriteriaDays),
 				pageable)
 			.map(post -> postMapper.toPostMainResponseDto(post, findRecentCommentByPostOrNull(post)));
@@ -116,13 +93,6 @@ public Page<PostMainResponseDto> findRandomPosts(Pageable pageable, Float random
 		return customPage;
 	}
 
-	private Float getOrGenerateRandomSeed(Float seed) {
-		if (seed == null) {
-			return random.nextFloat();
-		}
-		return seed;
-	}
-
 	private CommentResponseDto findRecentCommentByPostOrNull(Post post) {
 		Comment lastCommentByPost = post.getComments().stream().findFirst().orElse(null);
 		if (lastCommentByPost == null) {
@@ -134,8 +104,33 @@ private CommentResponseDto findRecentCommentByPostOrNull(Post post) {
 		}
 	}
 
-	public Page<PostSimpleResponseDto> searchPostsByTitleOrContent(Pageable pageable, String query) {
-		return postRepository.findByPostTitleContainingOrPostContentContaining(query, query, pageable)
-			.map(postMapper::toPostSimpleResponseDto);
+	public void deleteById(Long postId, Long userId) {
+		Post post = findPostByIdOrThrow(postId);
+		validatePostOwner(post, userId);
+
+		post.unlinkAlbum();
+
+		postRepository.deleteById(postId);
+	}
+
+	public void validatePostExist(Long postId) {
+		if (!postRepository.existsById(postId)) {
+			throw new PostNotFoundException(postId);
+		}
+	}
+
+	public void validatePostOwner(Post post, Long userId) {
+		Long postOwnerId = post.getUser().getUserId();
+
+		if (!postOwnerId.equals(userId)) {
+			throw new UnauthorizedPostAccessException(post.getPostId());
+		}
+	}
+
+	private Float getOrGenerateRandomSeed(Float seed) {
+		if (seed == null) {
+			return random.nextFloat();
+		}
+		return seed;
 	}
 }

src/main/java/com/soyeon/nubim/domain/post/exceptions/PostNotFoundException.java

@@ -4,8 +4,7 @@
 import org.springframework.web.server.ResponseStatusException;
 
 public class PostNotFoundException extends ResponseStatusException {
-	public PostNotFoundException(Long albumId) {
-		super(HttpStatus.NOT_FOUND, "Album not found with id " + albumId);
+	public PostNotFoundException(Long postId) {
+		super(HttpStatus.NOT_FOUND, "Post not found with id " + postId);
 	}
-
 }

src/main/java/com/soyeon/nubim/domain/postlike/PostLike.java

@@ -0,0 +1,39 @@
+package com.soyeon.nubim.domain.postlike;
+
+import com.soyeon.nubim.domain.post.Post;
+import com.soyeon.nubim.domain.user.User;
+
+import jakarta.persistence.Entity;
+import jakarta.persistence.FetchType;
+import jakarta.persistence.GeneratedValue;
+import jakarta.persistence.GenerationType;
+import jakarta.persistence.Id;
+import jakarta.persistence.JoinColumn;
+import jakarta.persistence.ManyToOne;
+import lombok.AllArgsConstructor;
+import lombok.Builder;
+import lombok.Getter;
+import lombok.NoArgsConstructor;
+import lombok.Setter;
+
+@Entity
+@Getter
+@Setter
+@Builder
+@NoArgsConstructor
+@AllArgsConstructor
+public class PostLike {
+
+	@Id
+	@GeneratedValue(strategy = GenerationType.IDENTITY)
+	private Long postLikeId;
+
+	@ManyToOne(fetch = FetchType.LAZY)
+	@JoinColumn(name = "post_id", nullable = false)
+	private Post post;
+
+	@ManyToOne(fetch = FetchType.LAZY)
+	@JoinColumn(name = "user_id", nullable = false)
+	private User user;
+
+}

src/main/java/com/soyeon/nubim/domain/postlike/PostLikeControllerV1.java

@@ -0,0 +1,28 @@
+package com.soyeon.nubim.domain.postlike;
+
+import org.springframework.http.ResponseEntity;
+import org.springframework.web.bind.annotation.PathVariable;
+import org.springframework.web.bind.annotation.PostMapping;
+import org.springframework.web.bind.annotation.RequestMapping;
+import org.springframework.web.bind.annotation.RestController;
+
+import com.soyeon.nubim.domain.postlike.dto.PostLikeCreateResponse;
+
+import io.swagger.v3.oas.annotations.Operation;
+import lombok.RequiredArgsConstructor;
+
+@RestController
+@RequestMapping("/v1/postlikes")
+@RequiredArgsConstructor
+public class PostLikeControllerV1 {
+
+	private final PostLikeService postLikeService;
+
+	@Operation(description = "게시글 좋아요 및 좋아요 취소. 게시글에 좋아요를 누르고, 이미 좋아요가 되어있을 시 취소한다.")
+	@PostMapping("/{postId}")
+	public ResponseEntity<PostLikeCreateResponse> togglePostLike(@PathVariable("postId") Long postId) {
+		PostLikeCreateResponse postLike = postLikeService.togglePostLike(postId);
+
+		return ResponseEntity.ok().body(postLike);
+	}
+}

src/main/java/com/soyeon/nubim/domain/postlike/PostLikeRepository.java

@@ -0,0 +1,17 @@
+package com.soyeon.nubim.domain.postlike;
+
+import org.springframework.data.jpa.repository.JpaRepository;
+import org.springframework.data.jpa.repository.Modifying;
+import org.springframework.data.jpa.repository.Query;
+import org.springframework.stereotype.Repository;
+
+@Repository
+public interface PostLikeRepository extends JpaRepository<PostLike, Long> {
+
+	@Query("SELECT EXISTS (FROM PostLike pl WHERE pl.post.postId = :postId AND pl.user.userId = :userId)")
+	boolean existsPostLikeByPostAndUser(Long postId, Long userId);
+
+	@Modifying
+	@Query("DELETE FROM PostLike pl WHERE pl.post.postId = :postId AND pl.user.userId = :userId")
+	int deletePostLikeByPostAndUser(Long postId, Long userId);
+}

src/main/java/com/soyeon/nubim/domain/postlike/PostLikeService.java

@@ -0,0 +1,49 @@
+package com.soyeon.nubim.domain.postlike;
+
+import org.springframework.stereotype.Service;
+
+import com.soyeon.nubim.domain.post.Post;
+import com.soyeon.nubim.domain.post.PostService;
+import com.soyeon.nubim.domain.postlike.dto.PostLikeCreateResponse;
+import com.soyeon.nubim.domain.postlike.exception.MultiplePostLikeDeleteException;
+import com.soyeon.nubim.domain.user.User;
+import com.soyeon.nubim.domain.user.UserService;
+
+import jakarta.transaction.Transactional;
+import lombok.RequiredArgsConstructor;
+
+@Service
+@RequiredArgsConstructor
+public class PostLikeService {
+
+	public static final int POST_LIKE_DELETE_SUCCESS = 1;
+	private final UserService userService;
+	private final PostService postService;
+	private final PostLikeRepository postLikeRepository;
+
+	@Transactional
+	public PostLikeCreateResponse togglePostLike(Long postId) {
+		Long currentUserId = userService.getCurrentUserId();
+
+		postService.validatePostExist(postId);
+		userService.validateUserExists(currentUserId);
+
+		// 좋아요 되어 있을 시 좋아요 삭제
+		if (postLikeRepository.existsPostLikeByPostAndUser(postId, currentUserId)) {
+			int deleteResult = postLikeRepository.deletePostLikeByPostAndUser(postId, currentUserId);
+
+			if (deleteResult != POST_LIKE_DELETE_SUCCESS) {
+				throw new MultiplePostLikeDeleteException();
+			}
+			return new PostLikeCreateResponse("post like removed");
+		}
+
+		PostLike postLike = PostLike.builder()
+			.post(new Post(postId, currentUserId))
+			.user(new User(currentUserId))
+			.build();
+		postLikeRepository.save(postLike);
+
+		return new PostLikeCreateResponse("post like successfully");
+	}
+}

src/main/java/com/soyeon/nubim/domain/postlike/dto/PostLikeCreateResponse.java

@@ -0,0 +1,10 @@
+package com.soyeon.nubim.domain.postlike.dto;
+
+import lombok.AllArgsConstructor;
+import lombok.Getter;
+
+@Getter
+@AllArgsConstructor
+public class PostLikeCreateResponse {
+	private String message;
+}

src/main/java/com/soyeon/nubim/domain/postlike/exception/MultiplePostLikeDeleteException.java

@@ -0,0 +1,11 @@
+package com.soyeon.nubim.domain.postlike.exception;
+
+import org.springframework.http.HttpStatus;
+import org.springframework.web.server.ResponseStatusException;
+
+public class MultiplePostLikeDeleteException extends ResponseStatusException {
+	public MultiplePostLikeDeleteException() {
+		super(HttpStatus.INTERNAL_SERVER_ERROR,
+			"Multiple post like were unexpectedly deleted. Only one post like can be deleted");
+	}
+}

src/main/java/com/soyeon/nubim/domain/user/User.java

@@ -93,6 +93,17 @@ public class User extends BaseEntity {
 	@OneToMany(mappedBy = "follower", fetch = FetchType.LAZY)
 	private List<UserFollow> followees = new ArrayList<>();
 
+	/**
+	 * 다른 엔티티 생성 시 매핑만을 위한 임시 User 엔티티 생성
+	 * 실제 User의 값은 가지지 않으니 사용 시 주의할 것
+	 */
+	public User(Long userId) {
+		this.userId = userId;
+		this.username = "MAPPING_USER";
+		this.nickname = "MAPPING_USER";
+		this.email = "MAPPING_USER@email.com";
+	}
+
 	public User updateNameFromOAuthProfile(String name) {
 		this.username = name;
 		return this;