[feat] 내 팔로잉 리스트 조회 api 개발

build.gradle

@@ -64,6 +64,10 @@ dependencies {
 
 	//s3 버킷
 	implementation 'org.springframework.cloud:spring-cloud-starter-aws:2.2.6.RELEASE'
+
+	// MapStruct
+	implementation 'org.mapstruct:mapstruct:1.5.5.Final'
+	annotationProcessor 'org.mapstruct:mapstruct-processor:1.5.5.Final'
 }
 
 def querydslDir = layout.buildDirectory.dir("generated/querydsl").get().asFile

src/main/java/konkuk/thip/common/util/CursorBasedList.java

@@ -0,0 +1,16 @@
+package konkuk.thip.common.util;
+
+import java.util.List;
+
+public record CursorBasedList<T>(
+        List<T> contents,
+        String nextCursor,
+        boolean hasNext
+) {
+    public static <T> CursorBasedList<T> of(List<T> queryList, int size, CursorExtractor<T> extractor) {
+        boolean hasNext = queryList.size() > size;
+        List<T> contents = hasNext ? queryList.subList(0, size) : queryList;
+        String nextCursor = hasNext ? extractor.extractCursor(contents.get(size - 1)) : null;
+        return new CursorBasedList<>(contents, nextCursor, hasNext);
+    }
+}

src/main/java/konkuk/thip/common/util/CursorExtractor.java

@@ -0,0 +1,6 @@
+package konkuk.thip.common.util;
+
+@FunctionalInterface
+public interface CursorExtractor<T> {
+    String extractCursor(T lastElement);
+}

src/main/java/konkuk/thip/user/adapter/in/web/UserCommandController.java

@@ -33,6 +33,9 @@ public class UserCommandController {
     private final UserFollowUsecase userFollowUsecase;
     private final JwtUtil jwtUtil;
 
+    /**
+     * 사용자 회원가입
+     */
     @PostMapping("/users/signup")
     public BaseResponse<UserSignupResponse> signup(@Valid @RequestBody final UserSignupRequest request,
                                                    @Oauth2Id final String oauth2Id,
@@ -43,14 +46,19 @@ public BaseResponse<UserSignupResponse> signup(@Valid @RequestBody final UserSig
         return BaseResponse.ok(UserSignupResponse.of(userId));
     }
 
+    /**
+     * 닉네임 중복 확인
+     */
     @PostMapping("/users/nickname")
     public BaseResponse<UserVerifyNicknameResponse> verifyNickname(@Valid @RequestBody final UserVerifyNicknameRequest request) {
         return BaseResponse.ok(UserVerifyNicknameResponse.of(
                 userVerifyNicknameUseCase.isNicknameUnique(request.nickname()))
         );
     }
 
-    // 팔루우 상태 변경 : true -> 팔로우, false -> 언팔로우
+    /**
+     * 사용자 팔로우 상태 변경 : true -> 팔로우, false -> 언팔로우
+     */
     @PostMapping("/users/following/{followingUserId}")
     public BaseResponse<UserFollowResponse> followUser(@UserId final Long userId,
                                             @PathVariable final Long followingUserId,

src/main/java/konkuk/thip/user/adapter/in/web/UserQueryController.java

@@ -1,9 +1,13 @@
 package konkuk.thip.user.adapter.in.web;
 
+import jakarta.validation.constraints.Max;
+import jakarta.validation.constraints.Min;
 import konkuk.thip.common.dto.BaseResponse;
+import konkuk.thip.common.security.annotation.UserId;
 import konkuk.thip.user.adapter.in.web.response.UserFollowersResponse;
+import konkuk.thip.user.adapter.in.web.response.UserFollowingResponse;
 import konkuk.thip.user.adapter.in.web.response.UserViewAliasChoiceResponse;
-import konkuk.thip.user.application.port.in.UserGetFollowersUsecase;
+import konkuk.thip.user.application.port.in.UserGetFollowUsecase;
 import konkuk.thip.user.application.port.in.UserViewAliasChoiceUseCase;
 import lombok.RequiredArgsConstructor;
 import org.springframework.web.bind.annotation.GetMapping;
@@ -16,18 +20,35 @@
 public class UserQueryController {
 
     private final UserViewAliasChoiceUseCase userViewAliasChoiceUseCase;
-    private final UserGetFollowersUsecase userGetFollowersUsecase;
+    private final UserGetFollowUsecase userGetFollowUsecase;
 
+    /**
+     * 사용자 별칭 선택 화면 조회
+     */
     @GetMapping("/users/alias")
     public BaseResponse<UserViewAliasChoiceResponse> showAliasChoiceView() {
         return BaseResponse.ok(UserViewAliasChoiceResponse.of(
                 userViewAliasChoiceUseCase.getAllAliasesAndCategories()
         ));
     }
 
+    /**
+     * 사용자 팔로워 조회
+     */
     @GetMapping("/users/{userId}/followers")
     public BaseResponse<UserFollowersResponse> showFollowers(@PathVariable final Long userId,
-                                                             @RequestParam(required = false) final String cursor) {
-        return BaseResponse.ok(userGetFollowersUsecase.getUserFollowers(userId, cursor));
+                                                             @RequestParam(required = false) final String cursor,
+                                                             @RequestParam(defaultValue = "10") @Max(value = 10) @Min(value = 1) final int size) {
+        return BaseResponse.ok(userGetFollowUsecase.getUserFollowers(userId, cursor, size));
+    }
+
+    /**
+     * 내 팔로잉 리스트 조회
+     */
+    @GetMapping("/users/my/following")
+    public BaseResponse<UserFollowingResponse> showMyFollowing(@UserId final Long userId,
+                                                               @RequestParam(required = false) final String cursor,
+                                                               @RequestParam(defaultValue = "10") @Max(value = 10) @Min(value = 1) final int size) {
+        return BaseResponse.ok(userGetFollowUsecase.getMyFollowing(userId, cursor, size));
     }
 }

src/main/java/konkuk/thip/user/adapter/in/web/response/UserFollowersResponse.java

@@ -2,15 +2,12 @@
 
 import lombok.Builder;
 
-import java.time.LocalDateTime;
 import java.util.List;
 
 @Builder
 public record UserFollowersResponse(
-        List<Follower> followerList,
-        int size,
-        LocalDateTime nextCursor,
-        boolean isFirst,
+        List<Follower> followers,
+        String nextCursor,
         boolean isLast
 ) {
     @Builder
@@ -21,6 +18,7 @@ public record Follower(
             String aliasName,
             Integer followerCount
     ){
+
     }
 
 }

src/main/java/konkuk/thip/user/adapter/in/web/response/UserFollowingResponse.java

@@ -0,0 +1,22 @@
+package konkuk.thip.user.adapter.in.web.response;
+
+import lombok.Builder;
+
+import java.util.List;
+
+@Builder
+public record UserFollowingResponse(
+        List<Following> followings,
+        String nextCursor,
+        boolean isLast
+) {
+    @Builder
+    public record Following(
+            Long userId,
+            String nickname,
+            String profileImageUrl,
+            String aliasName
+    ){
+    }
+
+}

src/main/java/konkuk/thip/user/adapter/out/jpa/FollowingJpaEntity.java

@@ -21,9 +21,9 @@ public class FollowingJpaEntity extends BaseJpaEntity {
 
     @ManyToOne(fetch = FetchType.LAZY)
     @JoinColumn(name = "user_id")
-    private UserJpaEntity userJpaEntity;
+    private UserJpaEntity userJpaEntity; // 팔로잉 하는 유저
 
     @ManyToOne(fetch = FetchType.LAZY)
     @JoinColumn(name = "following_user_id")
-    private UserJpaEntity followingUserJpaEntity;
+    private UserJpaEntity followingUserJpaEntity; // 팔로우 당하는 유저
 }

src/main/java/konkuk/thip/user/adapter/out/persistence/FollowingQueryPersistenceAdapter.java

@@ -1,9 +1,8 @@
 package konkuk.thip.user.adapter.out.persistence;
 
+import konkuk.thip.common.util.CursorBasedList;
 import konkuk.thip.common.util.DateUtil;
-import konkuk.thip.user.adapter.in.web.response.UserFollowersResponse;
-import konkuk.thip.user.adapter.out.jpa.FollowingJpaEntity;
-import konkuk.thip.user.adapter.out.jpa.UserJpaEntity;
+import konkuk.thip.user.application.port.out.dto.FollowQueryDto;
 import konkuk.thip.user.adapter.out.persistence.repository.following.FollowingJpaRepository;
 import konkuk.thip.user.application.port.out.FollowingQueryPort;
 import lombok.RequiredArgsConstructor;
@@ -19,39 +18,26 @@ public class FollowingQueryPersistenceAdapter implements FollowingQueryPort {
     private final FollowingJpaRepository followingJpaRepository;
 
     @Override
-    public UserFollowersResponse getFollowersByUserId(Long userId, String cursor, int size) {
-        LocalDateTime nextCursor = null;
-        if (cursor != null && !cursor.isBlank()) {
-            nextCursor = DateUtil.parseDateTime(cursor);
-        }
-
-        List<FollowingJpaEntity> followerEntities =
-                followingJpaRepository.findFollowersByUserIdBeforeCreatedAt(userId, nextCursor, size);
-
-        List<UserJpaEntity> followers = followerEntities.stream()
-                .map(FollowingJpaEntity::getUserJpaEntity) // 팔로워 사용자
-                .toList();
-
-        List<UserFollowersResponse.Follower> followerList = followers.stream()
-                .map(follower -> UserFollowersResponse.Follower.builder()
-                        .userId(follower.getUserId())
-                        .nickname(follower.getNickname())
-                        .profileImageUrl(follower.getAliasForUserJpaEntity().getImageUrl())
-                        .aliasName(follower.getAliasForUserJpaEntity().getValue())
-                        .followerCount(follower.getFollowerCount())
-                        .build())
-                .toList();
-
-        boolean isLast = followerEntities.size() < size;
-        nextCursor = isLast ? null :
-                followerEntities.get(followerEntities.size() - 1).getCreatedAt();
-
-        return UserFollowersResponse.builder()
-                .followerList(followerList)
-                .size(followerList.size())
-                .nextCursor(nextCursor)
-                .isFirst(cursor == null)  // cursor가 null이면 첫 페이지
-                .isLast(isLast)
-                .build();
+    public CursorBasedList<FollowQueryDto> getFollowersByUserId(Long userId, String cursor, int size) {
+        LocalDateTime cursorVal = cursor != null && !cursor.isBlank() ? DateUtil.parseDateTime(cursor) : null;
+        List<FollowQueryDto> followerDtos = followingJpaRepository.findFollowerDtosByUserIdBeforeCreatedAt(
+                userId,
+                cursorVal,
+                size
+        );
+
+        return CursorBasedList.of(followerDtos, size, followerDto -> followerDto.createdAt().toString());
+    }
+
+    @Override
+    public CursorBasedList<FollowQueryDto> getFollowingByUserId(Long userId, String cursor, int size) {
+        LocalDateTime cursorVal = cursor != null && !cursor.isBlank() ? DateUtil.parseDateTime(cursor) : null;
+        List<FollowQueryDto> followingDtos = followingJpaRepository.findFollowingDtosByUserIdBeforeCreatedAt(
+                userId,
+                cursorVal,
+                size
+        );
+
+        return CursorBasedList.of(followingDtos, size, followingDto -> followingDto.createdAt().toString());
     }
 }

src/main/java/konkuk/thip/user/adapter/out/persistence/repository/following/FollowingQueryRepository.java

@@ -1,6 +1,7 @@
 package konkuk.thip.user.adapter.out.persistence.repository.following;
 
 import konkuk.thip.user.adapter.out.jpa.FollowingJpaEntity;
+import konkuk.thip.user.application.port.out.dto.FollowQueryDto;
 
 import java.time.LocalDateTime;
 import java.util.List;
@@ -9,5 +10,6 @@
 public interface FollowingQueryRepository {
     Optional<FollowingJpaEntity> findByUserAndTargetUser(Long userId, Long targetUserId);
 
-    List<FollowingJpaEntity> findFollowersByUserIdBeforeCreatedAt(Long userId, LocalDateTime cursor, int size);
+    List<FollowQueryDto> findFollowerDtosByUserIdBeforeCreatedAt(Long userId, LocalDateTime cursor, int size);
+    List<FollowQueryDto> findFollowingDtosByUserIdBeforeCreatedAt(Long userId, LocalDateTime cursor, int size);
 }

src/main/java/konkuk/thip/user/adapter/out/persistence/repository/following/FollowingQueryRepositoryImpl.java

@@ -7,6 +7,8 @@
 import konkuk.thip.user.adapter.out.jpa.QAliasJpaEntity;
 import konkuk.thip.user.adapter.out.jpa.QFollowingJpaEntity;
 import konkuk.thip.user.adapter.out.jpa.QUserJpaEntity;
+import konkuk.thip.user.application.port.out.dto.FollowQueryDto;
+import konkuk.thip.user.application.port.out.dto.QFollowQueryDto;
 import lombok.RequiredArgsConstructor;
 import org.springframework.stereotype.Repository;
 
@@ -34,26 +36,55 @@ public Optional<FollowingJpaEntity> findByUserAndTargetUser(Long userId, Long ta
     }
 
     @Override
-    public List<FollowingJpaEntity> findFollowersByUserIdBeforeCreatedAt(Long userId, LocalDateTime cursor, int size) {
+    public List<FollowQueryDto> findFollowerDtosByUserIdBeforeCreatedAt(Long userId, LocalDateTime cursor, int size) {
+        return findFollowDtos(
+                userId,
+                cursor,
+                size,
+                true // isFollowerQuery
+        );
+    }
+
+    @Override
+    public List<FollowQueryDto> findFollowingDtosByUserIdBeforeCreatedAt(Long userId, LocalDateTime cursor, int size) {
+        return findFollowDtos(
+                userId,
+                cursor,
+                size,
+                false // isFollowingQuery
+        );
+    }
+
+    private List<FollowQueryDto> findFollowDtos(Long userId, LocalDateTime cursor, int size, boolean isFollowerQuery) {
         QFollowingJpaEntity following = QFollowingJpaEntity.followingJpaEntity;
         QUserJpaEntity user = QUserJpaEntity.userJpaEntity;
         QAliasJpaEntity alias = QAliasJpaEntity.aliasJpaEntity;
 
         BooleanBuilder condition = new BooleanBuilder()
-                .and(following.followingUserJpaEntity.userId.eq(userId))
+                .and((isFollowerQuery ? following.followingUserJpaEntity.userId.eq(userId) : following.userJpaEntity.userId.eq(userId)))
                 .and(following.status.eq(StatusType.ACTIVE));
 
         if (cursor != null) {
             condition.and(following.createdAt.lt(cursor));
         }
 
+        QUserJpaEntity targetUser = isFollowerQuery ? following.userJpaEntity : following.followingUserJpaEntity;
+
         return jpaQueryFactory
-                .selectFrom(following)
-                .leftJoin(following.userJpaEntity, user).fetchJoin() // N+1 문제 방지를 위해 fetchJoin
-                .leftJoin(user.aliasForUserJpaEntity, alias).fetchJoin()
+                .select(new QFollowQueryDto(
+                        targetUser.userId,
+                        targetUser.nickname,
+                        alias.imageUrl,
+                        alias.value,
+                        targetUser.followerCount,
+                        following.createdAt
+                ))
+                .from(following)
+                .leftJoin(targetUser, user)
+                .leftJoin(user.aliasForUserJpaEntity, alias)
                 .where(condition)
                 .orderBy(following.createdAt.desc())
-                .limit(size)
+                .limit(size + 1)
                 .fetch();
     }
 }

src/main/java/konkuk/thip/user/application/mapper/FollowDtoMapper.java

@@ -0,0 +1,14 @@
+package konkuk.thip.user.application.mapper;
+
+import konkuk.thip.user.adapter.in.web.response.UserFollowersResponse;
+import konkuk.thip.user.adapter.in.web.response.UserFollowingResponse;
+import konkuk.thip.user.application.port.out.dto.FollowQueryDto;
+import org.mapstruct.Mapper;
+
+@Mapper(componentModel = "spring")
+public interface FollowDtoMapper {
+
+    UserFollowersResponse.Follower toFollowerList(FollowQueryDto dto);
+
+    UserFollowingResponse.Following toFollowingList(FollowQueryDto dto);
+}

src/main/java/konkuk/thip/user/application/port/in/UserGetFollowUsecase.java

@@ -0,0 +1,10 @@
+package konkuk.thip.user.application.port.in;
+
+import konkuk.thip.user.adapter.in.web.response.UserFollowersResponse;
+import konkuk.thip.user.adapter.in.web.response.UserFollowingResponse;
+
+public interface UserGetFollowUsecase {
+    UserFollowersResponse getUserFollowers(Long userId, String cursor, int size);
+
+    UserFollowingResponse getMyFollowing(Long userId, String cursor, int size);
+}

src/main/java/konkuk/thip/user/application/port/out/FollowingQueryPort.java

@@ -1,8 +1,10 @@
 package konkuk.thip.user.application.port.out;
 
-import konkuk.thip.user.adapter.in.web.response.UserFollowersResponse;
+import konkuk.thip.common.util.CursorBasedList;
+import konkuk.thip.user.application.port.out.dto.FollowQueryDto;
 
 public interface FollowingQueryPort {
-    UserFollowersResponse getFollowersByUserId(Long userId, String cursor, int size);
+    CursorBasedList<FollowQueryDto> getFollowersByUserId(Long userId, String cursor, int size);
+    CursorBasedList<FollowQueryDto> getFollowingByUserId(Long userId, String cursor, int size);
 }