merge : 댓글 단건 조회 API 구현 #194

Feature/#194 댓글 단건 조회 api 구현

backend/emm-sale/src/docs/asciidoc/index.adoc

@@ -1,4 +1,4 @@
-= EMM-SALE API Docs
+= Kerdy API Docs
 :doctype: book
 :icons: font
 :source-highlighter: highlightjs
@@ -229,7 +229,7 @@ include::{snippets}/get-comment/http-response.adoc[]
 .HTTP response 설명
 include::{snippets}/get-comment/response-fields.adoc[]
 
-=== `GET` : 대댓글 모두 조회
+=== `GET` : 특정 댓글 조회(대댓글 있을 경우 같이 조회)
 
 .HTTP request 설명
 include::{snippets}/get-children-comment/path-parameters.adoc[]

backend/emm-sale/src/main/java/com/emmsale/comment/api/CommentApi.java

@@ -40,11 +40,11 @@ public List<CommentHierarchyResponse> findAll(@RequestParam final Long eventId)
     return commentQueryService.findAllCommentsByEventId(eventId);
   }
 
-  @GetMapping("/comments/{comment-id}/children")
-  public List<CommentResponse> findChildren(
+  @GetMapping("/comments/{comment-id}")
+  public CommentHierarchyResponse findParentWithChildren(
       @PathVariable("comment-id") final Long commentId
   ) {
-    return commentQueryService.findChildrenComments(commentId);
+    return commentQueryService.findParentWithChildren(commentId);
   }
 
   @DeleteMapping("/comments/{comment-id}")

backend/emm-sale/src/main/java/com/emmsale/comment/application/CommentQueryService.java

@@ -1,13 +1,9 @@
 package com.emmsale.comment.application;
 
-import com.emmsale.base.BaseEntity;
 import com.emmsale.comment.application.dto.CommentHierarchyResponse;
-import com.emmsale.comment.application.dto.CommentResponse;
 import com.emmsale.comment.domain.Comment;
 import com.emmsale.comment.domain.CommentRepository;
-import java.util.Comparator;
 import java.util.List;
-import java.util.stream.Collectors;
 import lombok.RequiredArgsConstructor;
 import org.springframework.stereotype.Service;
 import org.springframework.transaction.annotation.Transactional;
@@ -23,16 +19,14 @@ public List<CommentHierarchyResponse> findAllCommentsByEventId(final Long eventI
 
     final List<Comment> comments = commentRepository.findByEventId(eventId);
 
-    return CommentHierarchyResponse.from(comments);
+    return CommentHierarchyResponse.convertAllFrom(comments);
   }
 
-  public List<CommentResponse> findChildrenComments(final Long parentId) {
+  public CommentHierarchyResponse findParentWithChildren(final Long commentId) {
 
-    final List<Comment> childrenComments = commentRepository.findByParentId(parentId);
+    final List<Comment> parentWithChildrenComments
+        = commentRepository.findParentAndChildrenByParentId(commentId);
 
-    return childrenComments.stream()
-        .sorted(Comparator.comparing(BaseEntity::getCreatedAt))
-        .map(CommentResponse::from)
-        .collect(Collectors.toList());
+    return CommentHierarchyResponse.from(parentWithChildrenComments);
   }
 }

backend/emm-sale/src/main/java/com/emmsale/comment/application/dto/CommentHierarchyResponse.java

@@ -2,6 +2,8 @@
 
 import com.emmsale.base.BaseEntity;
 import com.emmsale.comment.domain.Comment;
+import com.emmsale.comment.exception.CommentException;
+import com.emmsale.comment.exception.CommentExceptionType;
 import java.util.ArrayList;
 import java.util.Comparator;
 import java.util.LinkedHashMap;
@@ -19,7 +21,22 @@ public class CommentHierarchyResponse {
   private final CommentResponse parentComment;
   private final List<CommentResponse> childComments;
 
-  public static List<CommentHierarchyResponse> from(final List<Comment> comments) {
+  public static CommentHierarchyResponse from(final List<Comment> comments) {
+    final List<CommentResponse> childComments = comments.stream()
+        .filter(Comment::isChild)
+        .map(CommentResponse::from)
+        .collect(Collectors.toList());
+
+    final CommentResponse parentComment = comments.stream()
+        .filter(Comment::isRoot)
+        .map(CommentResponse::from)
+        .findFirst()
+        .orElseThrow(() -> new CommentException(CommentExceptionType.NOT_FOUND_COMMENT));
+
+    return new CommentHierarchyResponse(parentComment, childComments);
+  }
+
+  public static List<CommentHierarchyResponse> convertAllFrom(final List<Comment> comments) {
 
     final Map<Comment, List<Comment>> groupedByParent =
         groupingByParentAndSortedByCreatedAt(comments);
@@ -39,7 +56,7 @@ public static List<CommentHierarchyResponse> from(final List<Comment> comments)
     return result;
   }
 
-  private static LinkedHashMap<Comment, List<Comment>> groupingByParentAndSortedByCreatedAt(
+  private static Map<Comment, List<Comment>> groupingByParentAndSortedByCreatedAt(
       final List<Comment> comments
   ) {
     return comments.stream()

backend/emm-sale/src/main/java/com/emmsale/comment/domain/Comment.java

@@ -78,6 +78,14 @@ public void modify(final String content) {
     this.content = content;
   }
 
+  public boolean isRoot() {
+    return parent == null;
+  }
+
+  public boolean isChild() {
+    return parent != null;
+  }
+
   public Optional<Comment> getParent() {
     return Optional.ofNullable(parent);
   }

backend/emm-sale/src/main/java/com/emmsale/comment/domain/CommentRepository.java

@@ -10,5 +10,6 @@ public interface CommentRepository extends JpaRepository<Comment, Long> {
   @Query("select c From Comment c inner join Event e on c.event.id = e.id where e.id = :eventId")
   List<Comment> findByEventId(@Param("eventId") final Long eventId);
 
-  List<Comment> findByParentId(Long parentId);
+  @Query("select c1 From Comment c1 left outer join c1.parent p where c1.id=:id or p.id=:id")
+  List<Comment> findParentAndChildrenByParentId(@Param("id") Long commentId);
 }

backend/emm-sale/src/main/resources/http/comment.http

@@ -27,8 +27,8 @@ Authorization: bearer eyJhbGciOiJIUzI1NiJ9.eyJzdWIiOiIxIiwiaWF0IjoxNjkwMTk2OTY5L
 GET http://localhost:8080/comments?eventId=1
 Content-Type: application/json
 
-### 부모 ID로 대댓글 조회하기
-GET http://localhost:8080/comments/1/children
+### 댓글 ID로 조회하기(대댓글 있을 경우 같이 조회)
+GET http://localhost:8080/comments/1
 
 ### 댓글 삭제 /comments/{comment-id}