#256 Feat: 댓글 관련 API 구현

src/main/java/com/codiary/backend/domain/comment/controller/CommentController.java

@@ -1,49 +1,68 @@
 package com.codiary.backend.domain.comment.controller;
 
+import com.codiary.backend.domain.comment.converter.CommentConverter;
+import com.codiary.backend.domain.comment.dto.request.CommentRequestDTO;
+import com.codiary.backend.domain.comment.dto.response.CommentResponseDTO;
+import com.codiary.backend.domain.comment.entity.Comment;
 import com.codiary.backend.domain.comment.service.CommentService;
+import com.codiary.backend.domain.member.security.CustomMemberDetails;
 import com.codiary.backend.global.apiPayload.ApiResponse;
+import com.codiary.backend.global.apiPayload.code.status.SuccessStatus;
 import io.swagger.v3.oas.annotations.Operation;
 import io.swagger.v3.oas.annotations.tags.Tag;
+import java.util.List;
 import lombok.RequiredArgsConstructor;
 import org.springframework.data.domain.Pageable;
 import org.springframework.data.web.PageableDefault;
+import org.springframework.security.core.annotation.AuthenticationPrincipal;
 import org.springframework.web.bind.annotation.DeleteMapping;
 import org.springframework.web.bind.annotation.GetMapping;
 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;
 
 @RequiredArgsConstructor
 @RestController
-@RequestMapping("/api/v2/posts/{post_id}/comments")
+@RequestMapping("/api/v2/posts")
 @Tag(name = "댓글 API", description = "댓글 관련 API 입니다.")
 public class CommentController {
 
     private final CommentService commentService;
 
     @Operation(summary = "댓글 달기")
-    @PostMapping()
-    public ApiResponse<?> commentPost(@PathVariable("post_id") Long postId) {
-        return null;
+    @PostMapping("/posts/{post_id}/comments")
+    public ApiResponse<CommentResponseDTO.CommentDTO> commentOnPost(
+            @PathVariable("post_id") Long postId,
+            @RequestBody CommentRequestDTO.CreateCommentDTO request,
+            @AuthenticationPrincipal CustomMemberDetails memberDetails
+    ) {
+        Long commenterId = memberDetails.getId();
+        Comment newComment = commentService.commentOnPost(postId, commenterId, request);
+        return ApiResponse.onSuccess(SuccessStatus.COMMENT_OK, CommentConverter.toCommentResponseDto(newComment));
     }
 
     @Operation(summary = "댓글 삭제")
-    @DeleteMapping("/{comment_id}")
-    public ApiResponse<?> deleteComment(
-            @PathVariable("post_id") Long postId,
-            @PathVariable("comment_id") Long commentId
+    @DeleteMapping("comments/{comment_id}")
+    public ApiResponse<String> deleteComment(
+            @PathVariable("comment_id") Long commentId,
+            @AuthenticationPrincipal CustomMemberDetails memberDetails
     ) {
-        return null;
+        Long memberId = memberDetails.getId();
+        String response = commentService.deleteComment(commentId, memberId);
+        return ApiResponse.onSuccess(SuccessStatus.COMMENT_OK, response);
     }
 
-    @Operation(summary = "댓글 조회", description = "기본적으로 10개씩 페이지네이션 하여 제공됩니다.")
-    @GetMapping("/{comment_id}")
-    public ApiResponse<?> getComments(
+    @Operation(summary = "댓글 조회", description = "기본적으로 10개씩 페이지네이션하여 제공됩니다.")
+    @GetMapping("/posts/{post_id}/comments")
+    public ApiResponse<List<CommentResponseDTO.CommentDTO>> getComments(
             @PathVariable("post_id") Long postId,
-            @PathVariable("comment_id") Long commentId,
+            @AuthenticationPrincipal CustomMemberDetails memberDetails,
             @PageableDefault(size = 10) Pageable pageable
     ) {
-        return null;
+        Long memberId = memberDetails.getId();
+        List<Comment> comments = commentService.getComments(postId, memberId, pageable);
+        return ApiResponse.onSuccess(SuccessStatus.COMMENT_OK, CommentConverter.toCommentResponseListDto(comments));
     }
 }

src/main/java/com/codiary/backend/domain/comment/converter/CommentConverter.java

@@ -0,0 +1,29 @@
+package com.codiary.backend.domain.comment.converter;
+
+import com.codiary.backend.domain.comment.dto.response.CommentResponseDTO;
+import com.codiary.backend.domain.comment.entity.Comment;
+import java.util.List;
+import java.util.stream.Collectors;
+
+public class CommentConverter {
+
+    public static CommentResponseDTO.CommentDTO toCommentResponseDto(Comment comment) {
+        return CommentResponseDTO.CommentDTO.builder()
+                .commentId(comment.getCommentId())
+                .commentBody(comment.getCommentBody())
+                .postId(comment.getPost().getPostId())
+                .commenterId(comment.getMember().getMemberId())
+                .commenterProfileImageUrl(
+                        (comment.getMember().getImage() != null) ? (comment.getMember().getImage().getImageUrl()) : "")
+                .commenterNickname(comment.getMember().getNickname())
+                .createdAt(comment.getCreatedAt())
+                .updatedAt(comment.getUpdatedAt())
+                .build();
+    }
+
+    public static List<CommentResponseDTO.CommentDTO> toCommentResponseListDto(List<Comment> comments) {
+        return comments.stream()
+                .map(CommentConverter::toCommentResponseDto)
+                .collect(Collectors.toList());
+    }
+}

src/main/java/com/codiary/backend/domain/comment/dto/request/CommentRequestDTO.java

@@ -0,0 +1,19 @@
+package com.codiary.backend.domain.comment.dto.request;
+
+import com.fasterxml.jackson.annotation.JsonInclude;
+import com.fasterxml.jackson.databind.PropertyNamingStrategies;
+import com.fasterxml.jackson.databind.annotation.JsonNaming;
+import lombok.Builder;
+
+public class CommentRequestDTO {
+
+    // Comment 생성 DTO
+    @JsonInclude(JsonInclude.Include.NON_NULL)
+    @JsonNaming(PropertyNamingStrategies.SnakeCaseStrategy.class)
+    @Builder
+    public record CreateCommentDTO(
+            String commentBody
+    ) {
+    }
+
+}

src/main/java/com/codiary/backend/domain/comment/dto/response/CommentResponseDTO.java

@@ -0,0 +1,25 @@
+package com.codiary.backend.domain.comment.dto.response;
+
+import com.fasterxml.jackson.annotation.JsonInclude;
+import com.fasterxml.jackson.databind.PropertyNamingStrategies;
+import com.fasterxml.jackson.databind.annotation.JsonNaming;
+import java.time.LocalDateTime;
+import lombok.Builder;
+
+public class CommentResponseDTO {
+
+    @JsonInclude(JsonInclude.Include.NON_NULL)
+    @JsonNaming(PropertyNamingStrategies.SnakeCaseStrategy.class)
+    @Builder
+    public record CommentDTO(
+            Long commentId,
+            String commentBody,
+            Long postId,
+            Long commenterId,
+            String commenterProfileImageUrl,
+            String commenterNickname,
+            LocalDateTime createdAt,
+            LocalDateTime updatedAt
+    ) {
+    }
+}

src/main/java/com/codiary/backend/domain/comment/entity/Comment.java

@@ -1,13 +1,24 @@
 package com.codiary.backend.domain.comment.entity;
 
 import com.codiary.backend.domain.member.entity.Member;
-import com.codiary.backend.global.common.BaseEntity;
 import com.codiary.backend.domain.post.entity.Post;
-import jakarta.persistence.*;
-import lombok.*;
-
+import com.codiary.backend.global.common.BaseEntity;
+import jakarta.persistence.CascadeType;
+import jakarta.persistence.Column;
+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 jakarta.persistence.OneToMany;
 import java.util.ArrayList;
 import java.util.List;
+import lombok.AccessLevel;
+import lombok.Builder;
+import lombok.Getter;
+import lombok.NoArgsConstructor;
 
 @Entity
 @Getter
@@ -37,6 +48,13 @@ public class Comment extends BaseEntity {
     @OneToMany(mappedBy = "parentId", cascade = CascadeType.ALL, orphanRemoval = true)
     private List<Comment> childComments = new ArrayList<>();
 
+    @Builder
+    public Comment(String commentBody, Member member, Post post) {
+        this.commentBody = commentBody;
+        this.member = member;
+        this.post = post;
+    }
+
     public void setMember(Member member) {
         if (this.member != null) {
             member.getCommentList().remove(this);

src/main/java/com/codiary/backend/domain/comment/repository/CommentRepository.java

@@ -3,5 +3,5 @@
 import com.codiary.backend.domain.comment.entity.Comment;
 import org.springframework.data.jpa.repository.JpaRepository;
 
-public interface CommentRepository extends JpaRepository<Comment, Long> {
+public interface CommentRepository extends JpaRepository<Comment, Long>, CommentRepositoryCustom {
 }

src/main/java/com/codiary/backend/domain/comment/repository/CommentRepositoryCustom.java

@@ -0,0 +1,10 @@
+package com.codiary.backend.domain.comment.repository;
+
+import com.codiary.backend.domain.comment.entity.Comment;
+import java.util.List;
+import org.springframework.data.domain.Pageable;
+
+public interface CommentRepositoryCustom {
+
+    List<Comment> findByPostWithMemberInfoOrderByCreatedAtDesc(Long postId, Pageable pageable);
+}

src/main/java/com/codiary/backend/domain/comment/repository/CommentRepositoryImpl.java

@@ -0,0 +1,31 @@
+package com.codiary.backend.domain.comment.repository;
+
+import static com.codiary.backend.domain.comment.entity.QComment.comment;
+import static com.codiary.backend.domain.member.entity.QMember.member;
+import static com.codiary.backend.domain.post.entity.QPost.post;
+
+import com.codiary.backend.domain.comment.entity.Comment;
+import com.querydsl.jpa.impl.JPAQueryFactory;
+import java.util.List;
+import lombok.RequiredArgsConstructor;
+import org.springframework.data.domain.Pageable;
+
+@RequiredArgsConstructor
+public class CommentRepositoryImpl implements CommentRepositoryCustom {
+
+    private final JPAQueryFactory queryFactory;
+
+    @Override
+    public List<Comment> findByPostWithMemberInfoOrderByCreatedAtDesc(Long postId, Pageable pageable) {
+        List<Comment> comments = queryFactory
+                .selectFrom(comment)
+                .leftJoin(comment.member, member)
+                .leftJoin(comment.post, post)
+                .where(comment.post.postId.eq(postId))
+                .offset(pageable.getOffset())
+                .limit(pageable.getPageSize())
+                .fetch();
+
+        return comments;
+    }
+}

src/main/java/com/codiary/backend/domain/comment/service/CommentService.java

@@ -1,14 +1,76 @@
 package com.codiary.backend.domain.comment.service;
 
+import com.codiary.backend.domain.comment.dto.request.CommentRequestDTO;
+import com.codiary.backend.domain.comment.entity.Comment;
 import com.codiary.backend.domain.comment.repository.CommentRepository;
+import com.codiary.backend.domain.member.entity.Member;
+import com.codiary.backend.domain.member.repository.MemberRepository;
+import com.codiary.backend.domain.post.entity.Post;
+import com.codiary.backend.domain.post.repository.PostRepository;
+import com.codiary.backend.global.apiPayload.code.status.ErrorStatus;
+import com.codiary.backend.global.apiPayload.exception.GeneralException;
+import com.codiary.backend.global.apiPayload.exception.handler.MemberHandler;
+import com.codiary.backend.global.apiPayload.exception.handler.PostHandler;
+import java.util.List;
 import lombok.RequiredArgsConstructor;
+import org.springframework.data.domain.Pageable;
 import org.springframework.stereotype.Service;
 import org.springframework.transaction.annotation.Transactional;
 
 @Service
 @RequiredArgsConstructor
-@Transactional(readOnly = true)
+@Transactional
 public class CommentService {
 
     private final CommentRepository commentRepository;
+    private final MemberRepository memberRepository;
+    private final PostRepository postRepository;
+
+    public Comment commentOnPost(Long postId, Long commenterId, CommentRequestDTO.CreateCommentDTO request) {
+        // validation: 사용자, post 유무 확인
+        // + 사용자가 해당 게시물에 대한 댓글 권한 있는지( 이후 구현 )
+        Member commenter = memberRepository.findById(commenterId)
+                .orElseThrow(() -> new MemberHandler(ErrorStatus.MEMBER_NOT_FOUND));
+        Post post = postRepository.findById(postId).orElseThrow(() -> new PostHandler(ErrorStatus.POST_NOT_FOUND));
+
+        // business logic: 댓글 생성
+        Comment comment = Comment.builder()
+                .commentBody(request.commentBody())
+                .member(commenter)
+                .post(post)
+                .build();
+
+        // response: 댓글 반환
+        return commentRepository.save(comment);
+    }
+
+    public String deleteComment(Long commentId, Long memberId) {
+        // validation: 사용자, comment 유무 확인
+        // + 사용자가 해당 댓글에 대한 댓글 권한 있는지( 이후 구현 )
+        Member commenter = memberRepository.findById(memberId)
+                .orElseThrow(() -> new MemberHandler(ErrorStatus.MEMBER_NOT_FOUND));
+        Comment comment = commentRepository.findById(commentId)
+                .orElseThrow(() -> new GeneralException(ErrorStatus.COMMENT_NOT_FOUND));
+
+        // business logic: 댓글 삭제
+        commentRepository.delete(comment);
+
+        // response: 삭제 성공 반환
+        return "성공적으로 삭제되었습니다!";
+    }
+
+    @Transactional(readOnly = true)
+    public List<Comment> getComments(Long postId, Long memberId, Pageable pageable) {
+        // validation: 사용자, post 유무 확인
+        // + 사용자가 해당 게시물에 대한 읽기 권한 있는지( 이후 구현 )
+        Member commenter = memberRepository.findById(memberId)
+                .orElseThrow(() -> new MemberHandler(ErrorStatus.MEMBER_NOT_FOUND));
+        Post post = postRepository.findById(postId).orElseThrow(() -> new PostHandler(ErrorStatus.POST_NOT_FOUND));
+
+        // business logic: 댓글 조회
+        List<Comment> comments = commentRepository.findByPostWithMemberInfoOrderByCreatedAtDesc(postId, pageable);
+
+        // response: comment list 반환
+        return comments;
+    }
 }