댓글 생성/삭제 기능 구현

src/main/java/com/example/log4u/domain/comment/controller/CommentController.java

@@ -0,0 +1,42 @@
+package com.example.log4u.domain.comment.controller;
+
+import org.springframework.http.ResponseEntity;
+import org.springframework.web.bind.annotation.DeleteMapping;
+import org.springframework.web.bind.annotation.PathVariable;
+import org.springframework.web.bind.annotation.PostMapping;
+import org.springframework.web.bind.annotation.RequestBody;
+import org.springframework.web.bind.annotation.RequestMapping;
+import org.springframework.web.bind.annotation.RestController;
+
+import com.example.log4u.domain.comment.dto.request.CommentCreateRequestDto;
+import com.example.log4u.domain.comment.dto.response.CommentCreateResponseDto;
+import com.example.log4u.domain.comment.service.CommentService;
+
+import io.swagger.v3.oas.annotations.tags.Tag;
+import jakarta.validation.Valid;
+import lombok.RequiredArgsConstructor;
+
+@Tag(name = "댓글 API")
+@RestController
+@RequiredArgsConstructor
+@RequestMapping("/comments")
+public class CommentController {
+
+	private final CommentService commentService;
+
+	@PostMapping
+	public ResponseEntity<CommentCreateResponseDto> addComment(@RequestBody @Valid CommentCreateRequestDto requestDto) {
+		Long userId = 1L; //임시 처리
+
+		CommentCreateResponseDto response = commentService.addComment(userId, requestDto);
+		return ResponseEntity.ok(response);
+	}
+
+	@DeleteMapping("/{commentId}")
+	public ResponseEntity<Void> deleteComment(@PathVariable Long commentId) {
+		Long userId = 1L; //임시 처리
+
+		commentService.deleteComment(userId, commentId);
+		return ResponseEntity.noContent().build();
+	}
+}

src/main/java/com/example/log4u/domain/comment/dto/request/CommentCreateRequestDto.java

@@ -0,0 +1,26 @@
+package com.example.log4u.domain.comment.dto.request;
+
+import com.example.log4u.domain.comment.entity.Comment;
+
+import jakarta.validation.constraints.Max;
+import jakarta.validation.constraints.NotBlank;
+import jakarta.validation.constraints.NotNull;
+import jakarta.validation.constraints.Size;
+
+public record CommentCreateRequestDto(
+
+	@NotNull
+	Long diaryId,
+
+	@NotBlank
+	@Size(max = 1000)
+	String content
+) {
+	public Comment toEntity(Long userId) {
+		return Comment.builder()
+			.userId(userId)
+			.diaryId(diaryId)
+			.content(content)
+			.build();
+	}
+}

src/main/java/com/example/log4u/domain/comment/dto/response/CommentCreateResponseDto.java

@@ -0,0 +1,14 @@
+package com.example.log4u.domain.comment.dto.response;
+
+import com.example.log4u.domain.comment.entity.Comment;
+
+public record CommentCreateResponseDto(
+	Long commentId,
+	String content
+) {
+	public static CommentCreateResponseDto of(Comment comment) {
+		return new CommentCreateResponseDto(
+			comment.getCommentId(),
+			comment.getContent());
+	}
+}

src/main/java/com/example/log4u/domain/comment/entity/Comment.java

@@ -0,0 +1,34 @@
+package com.example.log4u.domain.comment.entity;
+
+import com.example.log4u.common.entity.BaseEntity;
+
+import jakarta.persistence.Column;
+import jakarta.persistence.Entity;
+import jakarta.persistence.GeneratedValue;
+import jakarta.persistence.GenerationType;
+import jakarta.persistence.Id;
+import lombok.AccessLevel;
+import lombok.AllArgsConstructor;
+import lombok.Builder;
+import lombok.Getter;
+import lombok.NoArgsConstructor;
+
+@Entity
+@Getter
+@NoArgsConstructor(access = AccessLevel.PROTECTED)
+@AllArgsConstructor
+@Builder
+public class Comment extends BaseEntity {
+
+	@Id
+	@GeneratedValue(strategy = GenerationType.IDENTITY)
+	private Long commentId;
+
+	@Column(nullable = false)
+	private Long userId;
+
+	@Column(nullable = false)
+	private Long diaryId;
+
+	private String content;
+}

src/main/java/com/example/log4u/domain/comment/exception/CommentErrorCode.java

@@ -11,7 +11,9 @@
 @RequiredArgsConstructor
 public enum CommentErrorCode implements ErrorCode {
 
-	NOT_FOUND_COMMENT(HttpStatus.NOT_FOUND, "댓글을 찾을 수 없습니다.");
+	NOT_FOUND_COMMENT(HttpStatus.NOT_FOUND, "댓글을 찾을 수 없습니다."),
+	UNAUTHORIZED_COMMENT_ACCESS(HttpStatus.FORBIDDEN, "댓글에 대한 삭제 권한이 없습니다.");
+	;
 
 	private final HttpStatus httpStatus;
 	private final String message;

src/main/java/com/example/log4u/domain/comment/exception/UnauthorizedAccessException.java

@@ -0,0 +1,7 @@
+package com.example.log4u.domain.comment.exception;
+
+public class UnauthorizedAccessException extends CommentException {
+	public UnauthorizedAccessException() {
+		super(CommentErrorCode.UNAUTHORIZED_COMMENT_ACCESS);
+	}
+}

src/main/java/com/example/log4u/domain/comment/repository/CommentRepository.java

@@ -0,0 +1,9 @@
+package com.example.log4u.domain.comment.repository;
+
+import org.springframework.data.jpa.repository.JpaRepository;
+
+import com.example.log4u.domain.comment.entity.Comment;
+
+public interface CommentRepository extends JpaRepository<Comment, Long> {
+
+}

src/main/java/com/example/log4u/domain/comment/service/CommentService.java

@@ -0,0 +1,52 @@
+package com.example.log4u.domain.comment.service;
+
+import org.springframework.stereotype.Service;
+import org.springframework.transaction.annotation.Transactional;
+
+import com.example.log4u.domain.comment.dto.request.CommentCreateRequestDto;
+import com.example.log4u.domain.comment.dto.response.CommentCreateResponseDto;
+import com.example.log4u.domain.comment.entity.Comment;
+import com.example.log4u.domain.comment.exception.NotFoundCommentException;
+import com.example.log4u.domain.comment.exception.UnauthorizedAccessException;
+import com.example.log4u.domain.comment.repository.CommentRepository;
+import com.example.log4u.domain.diary.service.DiaryService;
+
+import lombok.RequiredArgsConstructor;
+
+@Service
+@RequiredArgsConstructor
+public class CommentService {
+
+	private final CommentRepository commentRepository;
+	private final DiaryService diaryService;
+
+	@Transactional
+	public CommentCreateResponseDto addComment(Long userId, CommentCreateRequestDto requestDto) {
+		checkDiaryExists(requestDto);
+		Comment comment = requestDto.toEntity(userId);
+		commentRepository.save(comment);
+		return CommentCreateResponseDto.of(comment);
+	}
+
+	@Transactional
+	public void deleteComment(Long userId, Long commentId) {
+		Comment comment = getComment(commentId);
+		validateCommentOwner(userId, comment);
+		commentRepository.delete(comment);
+	}
+
+	private void checkDiaryExists(CommentCreateRequestDto requestDto) {
+		diaryService.checkDiaryExists(requestDto.diaryId());
+	}
+
+	private void validateCommentOwner(Long userId, Comment comment) {
+		if (!comment.getUserId().equals(userId)) {
+			throw new UnauthorizedAccessException();
+		}
+	}
+
+	private Comment getComment(Long commentId) {
+		return commentRepository.findById(commentId)
+			.orElseThrow(NotFoundCommentException::new);
+	}
+}

src/main/java/com/example/log4u/domain/diary/service/DiaryService.java

@@ -34,4 +34,11 @@ public Long getLikeCount(Long diaryId) {
 		Diary diary = getDiary(diaryId);
 		return diary.getLikeCount();
 	}
+
+	public void checkDiaryExists(Long diaryId) {
+		if (!diaryRepository.existsById(diaryId)) {
+			throw new NotFoundDiaryException();
+		}
+	}
+
 }