✨Feat: 댓글 목록/카운트 Redis 캐시 적용

src/main/java/com/be/sportizebe/domain/comment/controller/CommentController.java

@@ -1,6 +1,7 @@
 package com.be.sportizebe.domain.comment.controller;
 
 import com.be.sportizebe.domain.comment.dto.request.CreateCommentRequest;
+import com.be.sportizebe.domain.comment.dto.response.CommentListResponse;
 import com.be.sportizebe.domain.comment.dto.response.CommentResponse;
 import com.be.sportizebe.domain.comment.service.CommentService;
 import com.be.sportizebe.domain.user.entity.User;
@@ -38,10 +39,10 @@ public ResponseEntity<BaseResponse<CommentResponse>> createComment(
 
     @GetMapping
     @Operation(summary = "댓글 목록 조회", description = "게시글의 댓글 목록 조회 (대댓글 포함)")
-    public ResponseEntity<BaseResponse<List<CommentResponse>>> getComments(
+    public ResponseEntity<BaseResponse<CommentListResponse>> getComments(
         @Parameter(description = "게시글 ID") @PathVariable Long postId) {
-        List<CommentResponse> responses = commentService.getCommentsByPostId(postId);
-        return ResponseEntity.ok(BaseResponse.success(responses));
+        CommentListResponse response = commentService.getCommentsByPostId(postId);
+        return ResponseEntity.ok(BaseResponse.success(response));
     }
 
     @DeleteMapping("/{commentId}")
@@ -50,7 +51,7 @@ public ResponseEntity<BaseResponse<Void>> deleteComment(
         @Parameter(description = "게시글 ID") @PathVariable Long postId,
         @Parameter(description = "댓글 ID") @PathVariable Long commentId,
         @AuthenticationPrincipal User user) {
-        commentService.deleteComment(commentId, user);
+        commentService.deleteComment(postId, commentId, user);
         return ResponseEntity.ok(BaseResponse.success("댓글 삭제 성공", null));
     }
 

src/main/java/com/be/sportizebe/domain/comment/dto/response/CommentListResponse.java

@@ -0,0 +1,11 @@
+package com.be.sportizebe.domain.comment.dto.response;
+
+import java.util.List;
+
+public record CommentListResponse(
+        List<CommentResponse> comments
+) {
+    public static CommentListResponse of(List<CommentResponse> comments) {
+        return new CommentListResponse(comments);
+    }
+}

src/main/java/com/be/sportizebe/domain/comment/service/CommentService.java

@@ -1,6 +1,7 @@
 package com.be.sportizebe.domain.comment.service;
 
 import com.be.sportizebe.domain.comment.dto.request.CreateCommentRequest;
+import com.be.sportizebe.domain.comment.dto.response.CommentListResponse;
 import com.be.sportizebe.domain.comment.dto.response.CommentResponse;
 import com.be.sportizebe.domain.user.entity.User;
 
@@ -12,10 +13,10 @@ public interface CommentService {
   CommentResponse createComment(Long postId, CreateCommentRequest request, User user);
 
   // 게시글의 댓글 목록 조회
-  List<CommentResponse> getCommentsByPostId(Long postId);
+  CommentListResponse getCommentsByPostId(Long postId);
 
   // 댓글 삭제
-  void deleteComment(Long commentId, User user);
+  void deleteComment(Long postId, Long commentId, User user);
 
   // 게시글의 댓글 수 조회
   long getCommentCount(Long postId);

src/main/java/com/be/sportizebe/domain/comment/service/CommentServiceImpl.java

@@ -1,6 +1,7 @@
 package com.be.sportizebe.domain.comment.service;
 
 import com.be.sportizebe.domain.comment.dto.request.CreateCommentRequest;
+import com.be.sportizebe.domain.comment.dto.response.CommentListResponse;
 import com.be.sportizebe.domain.comment.dto.response.CommentResponse;
 import com.be.sportizebe.domain.comment.entity.Comment;
 import com.be.sportizebe.domain.comment.exception.CommentErrorCode;
@@ -13,6 +14,8 @@
 import jakarta.transaction.Transactional;
 import lombok.RequiredArgsConstructor;
 import lombok.extern.slf4j.Slf4j;
+import org.springframework.cache.annotation.CacheEvict;
+import org.springframework.cache.annotation.Cacheable;
 import org.springframework.stereotype.Service;
 
 import java.util.List;
@@ -26,6 +29,7 @@ public class CommentServiceImpl implements CommentService {
   private final PostRepository postRepository;
 
   @Override
+  @CacheEvict(cacheNames = {"commentList", "commentCount"}, key = "#postId")
   @Transactional
   public CommentResponse createComment(Long postId, CreateCommentRequest request, User user) {
     // 게시글 조회
@@ -57,22 +61,25 @@ public CommentResponse createComment(Long postId, CreateCommentRequest request,
   }
 
   @Override
+  @Cacheable(cacheNames = "commentList", key = "#postId")
   @Transactional
-  public List<CommentResponse> getCommentsByPostId(Long postId) {
+  public CommentListResponse getCommentsByPostId(Long postId) {
     // 게시글 조회
     Post post = postRepository.findById(postId)
         .orElseThrow(() -> new CustomException(PostErrorCode.POST_NOT_FOUND));
 
     List<Comment> comments = commentRepository.findByPostAndParentIsNullOrderByCreatedAtAsc(post);
-
-    return comments.stream()
+    List<CommentResponse> list = comments.stream()
         .map(CommentResponse::from) // 여기서 LazyInitializationException가 터질 수 있기때문에 @Transaction필요
         .toList();
+
+    return CommentListResponse.of(list);
   }
 
   @Override
+  @CacheEvict(cacheNames = {"commentList", "commentCount"}, key = "#postId")
   @Transactional
-  public void deleteComment(Long commentId, User user) {
+  public void deleteComment(Long postId, Long commentId, User user) {
     Comment comment = commentRepository.findById(commentId)
         .orElseThrow(() -> new CustomException(CommentErrorCode.COMMENT_NOT_FOUND));
 
@@ -85,6 +92,7 @@ public void deleteComment(Long commentId, User user) {
   }
 
   @Override
+  @Cacheable(cacheNames = "commentCount", key = "#postId")
   public long getCommentCount(Long postId) {
     Post post = postRepository.findById(postId)
         .orElseThrow(() -> new CustomException(PostErrorCode.POST_NOT_FOUND));

src/main/java/com/be/sportizebe/global/config/RedisCacheConfig.java

@@ -1,5 +1,6 @@
 package com.be.sportizebe.global.config;
 
+import com.be.sportizebe.domain.comment.dto.response.CommentListResponse;
 import com.be.sportizebe.domain.post.dto.response.PostPageResponse;
 import com.fasterxml.jackson.databind.ObjectMapper;
 import com.fasterxml.jackson.databind.SerializationFeature;
@@ -27,12 +28,11 @@ public class RedisCacheConfig {
     public CacheManager cacheManager(RedisConnectionFactory redisConnectionFactory) {
         // 캐시 역직렬화를 위해 타입 정보(@class)를 포함하도록 설정
         ObjectMapper objectMapper = JsonMapper.builder()
-                .addModule(new JavaTimeModule())
+                 .addModule(new JavaTimeModule())
                 .disable(SerializationFeature.WRITE_DATES_AS_TIMESTAMPS)
                 // ❗ 타입 정보 절대 쓰지 않음
                 .build();
         // 캐시에 들어가는 값의 직렬화 방식 결정
-
         // 기본 캐시(대부분)는 Object로 직렬화/역직렬화
         Jackson2JsonRedisSerializer<Object> defaultValueSerializer =
                 new Jackson2JsonRedisSerializer<>(Object.class);
@@ -42,8 +42,19 @@ public CacheManager cacheManager(RedisConnectionFactory redisConnectionFactory)
         Jackson2JsonRedisSerializer<PostPageResponse> postListValueSerializer =
                 new Jackson2JsonRedisSerializer<>(PostPageResponse.class);
         postListValueSerializer.setObjectMapper(objectMapper);
-        // TTL(캐시 수명) 정책 정의
-        // 아무 설정 없는 캐시(Default) = 5분
+
+        // CommentList 캐시는 CommentListResponse 타입으로 역직렬화
+        Jackson2JsonRedisSerializer<CommentListResponse> commentListSerializer =
+                new Jackson2JsonRedisSerializer<>(CommentListResponse.class);
+        commentListSerializer.setObjectMapper(objectMapper);
+
+        // commentCount 캐시는 Long 타입으로 역직렬화
+        Jackson2JsonRedisSerializer<Long> commentCountSerializer =
+                new Jackson2JsonRedisSerializer<>(Long.class);
+        commentCountSerializer.setObjectMapper(objectMapper);
+
+        // 기본 캐시 설정
+        // TTL: 5분, Serializer: Object 기준
         RedisCacheConfiguration defaultConfig =
                 RedisCacheConfiguration.defaultCacheConfig()
                         .serializeValuesWith(
@@ -54,7 +65,8 @@ public CacheManager cacheManager(RedisConnectionFactory redisConnectionFactory)
         Map<String, RedisCacheConfiguration> cacheConfigs = new HashMap<>();
 
 
-        // 캐시별로 TTL override 가능 ( post, commet 등 우리가 원하는 값으로 TTL 설정 가능 )
+        // 개별 캐시 설정
+        // Post, Comment 등 역직렬화 문제 생기는 것들은 우리가 임의로 설정해주기
         cacheConfigs.put(
                 "facilityNear",
                 defaultConfig.entryTtl(Duration.ofSeconds(60))
@@ -71,6 +83,14 @@ public CacheManager cacheManager(RedisConnectionFactory redisConnectionFactory)
                         )
                         .entryTtl(Duration.ofSeconds(30))
         );
+        cacheConfigs.put(
+                "commentList",
+                RedisCacheConfiguration.defaultCacheConfig()
+                        .serializeValuesWith(
+                                RedisSerializationContext.SerializationPair.fromSerializer(commentListSerializer)
+                        )
+                        .entryTtl(Duration.ofSeconds(30))
+        );
         return RedisCacheManager.builder(redisConnectionFactory)
                 .cacheDefaults(defaultConfig)
                 .withInitialCacheConfigurations(cacheConfigs)