Feature/78 커뮤니티 댓글 조회 기능

src/main/java/com/somemore/community/domain/CommunityComment.java

@@ -51,4 +51,14 @@ public boolean isWriter(UUID writerId) {
     public void updateWith(CommunityCommentUpdateRequestDto dto) {
         this.content = dto.content();
     }
+
+    @Override
+    public void markAsDeleted() {
+        super.markAsDeleted();
+        this.content = "삭제된 댓글입니다";
+    }
+
+    public boolean isDeleted() {
+        return this.getDeleted();
+    }
 }

src/main/java/com/somemore/community/dto/response/CommunityBoardGetResponseDto.java

@@ -2,7 +2,7 @@
 
 import com.fasterxml.jackson.databind.PropertyNamingStrategies.SnakeCaseStrategy;
 import com.fasterxml.jackson.databind.annotation.JsonNaming;
-import com.somemore.community.domain.CommunityBoardView;
+import com.somemore.community.repository.mapper.CommunityBoardView;
 
 import java.time.LocalDateTime;
 

src/main/java/com/somemore/community/dto/response/CommunityCommentResponseDto.java

@@ -0,0 +1,36 @@
+package com.somemore.community.dto.response;
+
+import com.fasterxml.jackson.databind.PropertyNamingStrategies;
+import com.fasterxml.jackson.databind.annotation.JsonNaming;
+import com.somemore.community.repository.mapper.CommunityCommentView;
+
+import java.time.LocalDateTime;
+import java.util.ArrayList;
+import java.util.List;
+
+@JsonNaming(PropertyNamingStrategies.SnakeCaseStrategy.class)
+public record CommunityCommentResponseDto(
+        Long id,
+        String writerNickname,
+        String content,
+        LocalDateTime updatedAt,
+        List<CommunityCommentResponseDto> replies
+) {
+    public CommunityCommentResponseDto {
+        replies = replies == null ? new ArrayList<>() : replies;
+    }
+
+    public static CommunityCommentResponseDto fromView(CommunityCommentView comment) {
+        return new CommunityCommentResponseDto(
+                comment.communityComment().getId(),
+                comment.writerNickname(),
+                comment.communityComment().getContent(),
+                comment.communityComment().getUpdatedAt(),
+                new ArrayList<>()
+        );
+    }
+
+    public void addReply(CommunityCommentResponseDto reply) {
+        this.replies.add(reply);
+    }
+}

src/main/java/com/somemore/community/repository/board/CommunityBoardRepository.java

@@ -1,7 +1,7 @@
 package com.somemore.community.repository.board;
 
 import com.somemore.community.domain.CommunityBoard;
-import com.somemore.community.domain.CommunityBoardView;
+import com.somemore.community.repository.mapper.CommunityBoardView;
 
 import java.util.List;
 import java.util.Optional;

src/main/java/com/somemore/community/repository/board/CommunityBoardRepositoryImpl.java

@@ -4,7 +4,7 @@
 import com.querydsl.jpa.impl.JPAQuery;
 import com.querydsl.jpa.impl.JPAQueryFactory;
 import com.somemore.community.domain.CommunityBoard;
-import com.somemore.community.domain.CommunityBoardView;
+import com.somemore.community.repository.mapper.CommunityBoardView;
 import com.somemore.community.domain.QCommunityBoard;
 import com.somemore.volunteer.domain.QVolunteer;
 import lombok.RequiredArgsConstructor;

src/main/java/com/somemore/community/repository/comment/CommunityCommentRepository.java

@@ -1,12 +1,15 @@
 package com.somemore.community.repository.comment;
 
 import com.somemore.community.domain.CommunityComment;
+import com.somemore.community.repository.mapper.CommunityCommentView;
 
+import java.util.List;
 import java.util.Optional;
 
 public interface CommunityCommentRepository {
     CommunityComment save(CommunityComment communityComment);
     Optional<CommunityComment> findById(Long id);
+    List<CommunityCommentView> findCommentsByBoardId(Long boardId);
     boolean existsById(Long id);
     default boolean doesNotExistById(Long id) {
         return !existsById(id);

src/main/java/com/somemore/community/repository/comment/CommunityCommentRepositoryImpl.java

@@ -1,11 +1,15 @@
 package com.somemore.community.repository.comment;
 
+import com.querydsl.core.types.Projections;
 import com.querydsl.jpa.impl.JPAQueryFactory;
 import com.somemore.community.domain.CommunityComment;
 import com.somemore.community.domain.QCommunityComment;
+import com.somemore.community.repository.mapper.CommunityCommentView;
+import com.somemore.volunteer.domain.QVolunteer;
 import lombok.RequiredArgsConstructor;
 import org.springframework.stereotype.Repository;
 
+import java.util.List;
 import java.util.Optional;
 
 @RequiredArgsConstructor
@@ -31,6 +35,21 @@ public Optional<CommunityComment> findById(Long id) {
                 .fetchOne());
     }
 
+    public List<CommunityCommentView> findCommentsByBoardId(Long boardId) {
+        QCommunityComment communityComment = QCommunityComment.communityComment;
+        QVolunteer volunteer = QVolunteer.volunteer;
+
+        return queryFactory
+                .select(Projections.constructor(CommunityCommentView.class,
+                        communityComment,
+                        volunteer.nickname))
+                .from(communityComment)
+                .join(volunteer).on(communityComment.writerId.eq(volunteer.id))
+                .where(communityComment.communityBoardId.eq(boardId))
+                .orderBy(communityComment.parentCommentId.asc().nullsFirst(), communityComment.createdAt.asc())
+                .fetch();
+    }
+
     @Override
     public boolean existsById(Long id) {
         QCommunityComment communityComment = QCommunityComment.communityComment;

src/main/java/com/somemore/community/domain/CommunityBoardView.java → src/main/java/com/somemore/community/repository/mapper/CommunityBoardView.java

@@ -1,4 +1,6 @@
-package com.somemore.community.domain;
+package com.somemore.community.repository.mapper;
+
+import com.somemore.community.domain.CommunityBoard;
 
 public record CommunityBoardView(
         CommunityBoard communityBoard,

src/main/java/com/somemore/community/repository/mapper/CommunityCommentView.java

@@ -0,0 +1,16 @@
+package com.somemore.community.repository.mapper;
+
+import com.somemore.community.domain.CommunityComment;
+import lombok.Builder;
+
+@Builder
+public record CommunityCommentView(
+        CommunityComment communityComment,
+        String writerNickname
+) {
+    public CommunityCommentView replaceWriterNickname(CommunityCommentView communityCommentView) {
+        return CommunityCommentView.builder()
+                .communityComment(communityCommentView.communityComment)
+                .writerNickname("").build();
+    }
+}

src/main/java/com/somemore/community/service/board/CommunityBoardQueryService.java

@@ -1,7 +1,7 @@
 package com.somemore.community.service.board;
 
 import com.somemore.community.domain.CommunityBoard;
-import com.somemore.community.domain.CommunityBoardView;
+import com.somemore.community.repository.mapper.CommunityBoardView;
 import com.somemore.community.dto.response.CommunityBoardGetDetailResponseDto;
 import com.somemore.community.dto.response.CommunityBoardGetResponseDto;
 import com.somemore.community.repository.board.CommunityBoardRepository;

src/main/java/com/somemore/community/service/comment/CommunityCommentQueryService.java

@@ -0,0 +1,78 @@
+package com.somemore.community.service.comment;
+
+import com.somemore.community.domain.CommunityComment;
+import com.somemore.community.dto.response.CommunityCommentResponseDto;
+import com.somemore.community.repository.comment.CommunityCommentRepository;
+import com.somemore.community.repository.mapper.CommunityCommentView;
+import com.somemore.community.usecase.comment.CommunityCommentQueryUseCase;
+import lombok.RequiredArgsConstructor;
+import org.springframework.stereotype.Service;
+import org.springframework.transaction.annotation.Transactional;
+
+import java.util.*;
+
+@RequiredArgsConstructor
+@Transactional(readOnly = true)
+@Service
+public class CommunityCommentQueryService implements CommunityCommentQueryUseCase {
+
+    private final CommunityCommentRepository communityCommentRepository;
+
+    @Override
+    public List<CommunityCommentResponseDto> getCommunityCommentsByBoardId(Long boardId) {
+        List<CommunityCommentView> allComments = communityCommentRepository.findCommentsByBoardId(boardId);
+        List<CommunityCommentView> filteredComments = filterValidComments(allComments);
+        return createCommentHierarchy(filteredComments);
+    }
+
+    private List<CommunityCommentView> filterValidComments(List<CommunityCommentView> comments) {
+        List<Long> parentCommentIds = findParentCommentIds(comments);
+
+        return comments.stream()
+                .flatMap(comment -> processDeletedComment(parentCommentIds, comment).stream())
+                .toList();
+    }
+
+    private List<Long> findParentCommentIds(List<CommunityCommentView> comments) {
+        return comments.stream()
+                .filter(comment -> !comment.communityComment().getDeleted())
+                .map(comment -> comment.communityComment().getParentCommentId())
+                .filter(Objects::nonNull)
+                .toList();
+    }
+
+    private Optional<CommunityCommentView> processDeletedComment(List<Long> parentCommentIds, CommunityCommentView commentView) {
+        CommunityComment comment = commentView.communityComment();
+
+        if (comment.isDeleted()) {
+            if (parentCommentIds.contains(comment.getId())) {
+                return Optional.of(commentView.replaceWriterNickname(commentView));
+            }
+            return Optional.empty();
+        }
+
+        return Optional.of(commentView);
+    }
+
+    private List<CommunityCommentResponseDto> createCommentHierarchy(List<CommunityCommentView> comments) {
+
+        Map<Long, CommunityCommentResponseDto> commentMap = new HashMap<>();
+        List<CommunityCommentResponseDto> rootComments = new ArrayList<>();
+
+        for (CommunityCommentView comment : comments) {
+            CommunityCommentResponseDto dto = CommunityCommentResponseDto.fromView(comment);
+            commentMap.put(dto.id(), dto);
+
+            Long parentCommentId = comment.communityComment().getParentCommentId();
+
+            if (parentCommentId == null) {
+                rootComments.add(dto);
+            } else {
+                commentMap.get(parentCommentId).addReply(dto);
+            }
+        }
+
+        return rootComments;
+    }
+}
+

src/main/java/com/somemore/community/usecase/comment/CommunityCommentQueryUseCase.java

@@ -0,0 +1,9 @@
+package com.somemore.community.usecase.comment;
+
+import com.somemore.community.dto.response.CommunityCommentResponseDto;
+
+import java.util.List;
+
+public interface CommunityCommentQueryUseCase {
+    List<CommunityCommentResponseDto> getCommunityCommentsByBoardId(Long boardId);
+}

src/test/java/com/somemore/community/repository/CommunityBoardRepositoryTest.java

@@ -3,7 +3,7 @@
 import com.somemore.IntegrationTestSupport;
 import com.somemore.auth.oauth.OAuthProvider;
 import com.somemore.community.domain.CommunityBoard;
-import com.somemore.community.domain.CommunityBoardView;
+import com.somemore.community.repository.mapper.CommunityBoardView;
 import com.somemore.community.repository.board.CommunityBoardRepository;
 import com.somemore.volunteer.domain.Volunteer;
 import com.somemore.volunteer.repository.VolunteerRepository;

src/test/java/com/somemore/community/repository/CommunityCommentRepositoryTest.java

@@ -1,16 +1,21 @@
 package com.somemore.community.repository;
 
 import com.somemore.IntegrationTestSupport;
+import com.somemore.auth.oauth.OAuthProvider;
 import com.somemore.community.domain.CommunityBoard;
 import com.somemore.community.domain.CommunityComment;
 import com.somemore.community.repository.board.CommunityBoardRepository;
 import com.somemore.community.repository.comment.CommunityCommentRepository;
+import com.somemore.community.repository.mapper.CommunityCommentView;
+import com.somemore.volunteer.domain.Volunteer;
+import com.somemore.volunteer.repository.VolunteerRepository;
 import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.DisplayName;
 import org.junit.jupiter.api.Test;
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.transaction.annotation.Transactional;
 
+import java.util.List;
 import java.util.Optional;
 import java.util.UUID;
 
@@ -23,26 +28,32 @@ class CommunityCommentRepositoryTest extends IntegrationTestSupport {
     CommunityCommentRepository communityCommentRepository;
     @Autowired
     CommunityBoardRepository communityBoardRepository;
+    @Autowired
+    VolunteerRepository volunteerRepository;
 
     private Long boardId;
     private UUID writerId;
     private CommunityComment savedComment;
 
     @BeforeEach
     void setUp() {
+        String oAuthId = "example-oauth-id";
+        Volunteer volunteer = Volunteer.createDefault(OAuthProvider.NAVER, oAuthId);
+        volunteerRepository.save(volunteer);
+
+        writerId = volunteer.getId();
+
         CommunityBoard communityBoard = CommunityBoard.builder()
                 .title("테스트 커뮤니티 게시글 제목")
                 .content("테스트 커뮤니티 게시글 내용")
                 .imgUrl("http://community.example.com/123")
-                .writerId(UUID.randomUUID())
+                .writerId(writerId)
                 .build();
 
         communityBoardRepository.save(communityBoard);
 
         boardId = communityBoard.getId();
 
-        writerId = UUID.randomUUID();
-
         CommunityComment communityComment = CommunityComment.builder()
                 .communityBoardId(boardId)
                 .writerId(writerId)
@@ -74,7 +85,7 @@ void createCommunityCommentReply() {
                 .communityBoardId(boardId)
                 .writerId(writerId)
                 .content("커뮤니티 댓글 테스트 내용")
-                .parentCommentId(1L)
+                .parentCommentId(savedComment.getId())
                 .build();
 
         //when
@@ -83,7 +94,7 @@ void createCommunityCommentReply() {
         //then
         assertThat(savedCommentReply.getWriterId()).isEqualTo(writerId);
         assertThat(savedCommentReply.getContent()).isEqualTo("커뮤니티 댓글 테스트 내용");
-        assertThat(savedCommentReply.getParentCommentId()).isEqualTo(1L);
+        assertThat(savedCommentReply.getParentCommentId()).isEqualTo(savedComment.getId());
     }
 
     @DisplayName("댓글을 id로 조회할 수 있다. (Repository)")
@@ -112,4 +123,27 @@ void existsById() {
         //then
         assertThat(isExist).isTrue();
     }
+
+    @DisplayName("게시글 id로 게시글에 달린 댓글을 조회할 수 있다. (Repository)")
+    @Test
+    void findCommunityCommentByBoardId() {
+
+        //given
+        CommunityComment communityCommentReply = CommunityComment.builder()
+                .communityBoardId(boardId)
+                .writerId(writerId)
+                .content("커뮤니티 댓글 테스트 내용")
+                .parentCommentId(savedComment.getId())
+                .build();
+
+        CommunityComment savedCommentReply = communityCommentRepository.save(communityCommentReply);
+
+        //when
+        List<CommunityCommentView> comments = communityCommentRepository.findCommentsByBoardId(boardId);
+
+        //then
+        assertThat(comments).hasSize(2);
+        assertThat(comments.getFirst().communityComment().getId()).isEqualTo(savedComment.getId());
+        assertThat(comments.getLast().communityComment().getId()).isEqualTo(savedCommentReply.getId());
+    }
 }