feat : 팔로잉,팔로워 수 조회 API 기능 개발

baebae-BE/src/main/java/com/web/baebaeBE/domain/Follow/controller/FollowController.java

@@ -67,6 +67,13 @@ public ResponseEntity<FollowResponse.hasNewFollowersResponse> getHasNewFollowers
         return ResponseEntity.ok(followService.hasFollowers(memberId));
     }
 
+    @GetMapping("followers/count/{memberId}")
+    public ResponseEntity<FollowResponse.FollowCountResponse> getFollowerCount(
+            @PathVariable Long memberId
+    ) {
+        return ResponseEntity.ok(followService.getFollowerCount(memberId));
+    }
+
     @PatchMapping("followers/relation/update/{memberId}")
     public ResponseEntity<Void> updateFollowRelation(
             @PathVariable Long memberId

baebae-BE/src/main/java/com/web/baebaeBE/domain/Follow/controller/api/FollowApi.java

@@ -196,6 +196,30 @@ public ResponseEntity<FollowResponse.hasNewFollowersResponse> getHasNewFollowers
             @PathVariable Long memberId
     );
 
+    @Operation(
+            summary = "팔로잉, 팔로워 수 조회",
+            description = "해당 유저의 팔로잉, 팔로워 수를 조회한다. (팔로워 수, 팔로잉 수)",
+            security = @SecurityRequirement(name = "bearerAuth")
+    )
+    @Parameter(
+            in = ParameterIn.HEADER,
+            name = "Authorization", required = true,
+            schema = @Schema(type = "string"),
+            description = "Bearer [Access 토큰]")
+    @ApiResponses(value = {
+            @ApiResponse(responseCode = "200", description = "조회"),
+            @ApiResponse(responseCode = "401", description = "토큰 인증 실패",
+                    content = @Content(mediaType = "application/json",
+                            examples = @ExampleObject(value = "{\n" +
+                                    "  \"errorCode\": \"T-002\",\n" +
+                                    "  \"message\": \"해당 토큰은 유효한 토큰이 아닙니다.\"\n" +
+                                    "}"))
+            )
+    })
+    @GetMapping("followers/count/{memberId}")
+    public ResponseEntity<FollowResponse.FollowCountResponse> getFollowerCount(
+            @PathVariable Long memberId
+    );
     @Operation(
             summary = "새 팔로워들을 기존 팔로워들로 변경",
             description = "해당 멤버의 새로운 팔로워들을 기존 팔로워들로 변경한다.",

baebae-BE/src/main/java/com/web/baebaeBE/domain/Follow/dto/FollowResponse.java

@@ -41,6 +41,23 @@ public static isFollowingResponse of(boolean isFollow) {
         }
     }
 
+    @Getter
+    @Setter
+    @Builder
+    @NoArgsConstructor
+    @AllArgsConstructor
+    public static class FollowCountResponse {
+        private long followerCount;
+        private long followingCount;
+
+        public static FollowCountResponse of(long followerCount, long followingCount) {
+            return FollowCountResponse.builder()
+                    .followerCount(followerCount)
+                    .followingCount(followingCount)
+                    .build();
+        }
+    }
+
     @Getter
     @Builder
     @NoArgsConstructor(access = AccessLevel.PROTECTED)

baebae-BE/src/main/java/com/web/baebaeBE/domain/Follow/repository/FollowRepository.java

@@ -19,6 +19,12 @@ public interface FollowRepository extends JpaRepository<Follow, Long> {
     // 중복 체크에 사용할 메서드
     boolean existsByFollowerIdAndFollowingId(Long followerId, Long followingId);
 
+    // 특정 사용자가 팔로우하는 사람 수
+    long countByFollower_Id(Long memberId);
+
+    // 특정 사용자를 팔로우하는 사람 수
+    long countByFollowing_Id(Long memberId);
+
     @Query("SELECT fol " +
             "FROM Follow f " +
             "JOIN f.follower fol " +

baebae-BE/src/main/java/com/web/baebaeBE/domain/Follow/service/FollowService.java

@@ -53,6 +53,13 @@ public void followMember(Long followerId, Long followingId) {
         followRepository.save(follow);
     }
 
+    public FollowResponse.FollowCountResponse getFollowerCount(Long memberId) {
+        long followerCount = followRepository.countByFollower_Id(memberId);
+        long followingCount = followRepository.countByFollowing_Id(memberId);
+
+        return FollowResponse.FollowCountResponse.of(followerCount, followingCount);
+    }
+
     public void deleteFollower(Long followerId, Long followingId) {
         Follow follow = followRepository.findByFollowerIdAndFollowingId(followerId, followingId)
                 .orElseThrow(() -> new BusinessException(FollowException.NOT_EXIST_FOLLOW));