Merge pull request #240 from prgrms-web-devcourse-final-project/Refactor/234

Refactor: 알림 도메인 리팩토링 (#234)

Author: jueunk617

src/main/java/com/back/domain/notification/controller/NotificationController.java

@@ -1,12 +1,9 @@
 package com.back.domain.notification.controller;
 
-import com.back.domain.notification.dto.NotificationCreateRequest;
 import com.back.domain.notification.dto.NotificationResponse;
 import com.back.domain.notification.dto.NotificationListResponse;
 import com.back.domain.notification.entity.Notification;
-import com.back.domain.notification.entity.NotificationSettingType;
 import com.back.domain.notification.service.NotificationService;
-import com.back.domain.studyroom.entity.Room;
 import com.back.domain.studyroom.repository.RoomRepository;
 import com.back.domain.user.entity.User;
 import com.back.domain.user.repository.UserRepository;
@@ -37,116 +34,7 @@ public class NotificationController {
     private final UserRepository userRepository;
     private final RoomRepository roomRepository;
 
-    @Operation(
-            summary = "알림 전송",
-            description = "USER/ROOM/COMMUNITY/SYSTEM 타입별 알림 생성 및 전송\n\n" +
-                    "- USER: 개인 알림 (actorId, targetId 필수)\n" +
-                    "- ROOM: 스터디룸 알림 (actorId, targetId(roomId) 필수)\n" +
-                    "- COMMUNITY: 커뮤니티 알림 (actorId, targetId 필수)\n" +
-                    "- SYSTEM: 시스템 전체 알림 (actorId, targetId 불필요)"
-    )
-    @PostMapping
-    public ResponseEntity<RsData<NotificationResponse>> createNotification(
-            @Parameter(hidden = true) @AuthenticationPrincipal CustomUserDetails userDetails,
-            @RequestBody NotificationCreateRequest request) {
-
-        log.info("알림 전송 요청 - 타입: {}, 제목: {}", request.targetType(), request.title());
-
-        // targetType 검증
-        if (!isValidTargetType(request.targetType())) {
-            throw new CustomException(ErrorCode.NOTIFICATION_INVALID_TARGET_TYPE);
-        }
-
-        // SYSTEM이 아닌 경우 필수 필드 검증
-        if (!"SYSTEM".equals(request.targetType())) {
-            if (request.actorId() == null) {
-                throw new CustomException(ErrorCode.NOTIFICATION_MISSING_ACTOR);
-            }
-            if (request.targetId() == null) {
-                throw new CustomException(ErrorCode.NOTIFICATION_MISSING_TARGET);
-            }
-        }
-
-        Notification notification = switch (request.targetType()) {
-            case "USER" -> {
-                // 수신자 조회
-                User receiver = userRepository.findById(request.targetId())
-                        .orElseThrow(() -> new CustomException(ErrorCode.USER_NOT_FOUND));
-
-                // 발신자 조회
-                User actor = userRepository.findById(request.actorId())
-                        .orElseThrow(() -> new CustomException(ErrorCode.USER_NOT_FOUND));
-
-                // 개인 알림 생성
-                yield notificationService.createPersonalNotification(
-                        receiver,
-                        actor,
-                        request.title(),
-                        request.message(),
-                        request.redirectUrl(),
-                        NotificationSettingType.SYSTEM
-                );
-            }
-            case "ROOM" -> {
-                // 스터디룸 조회
-                Room room = roomRepository.findById(request.targetId())
-                        .orElseThrow(() -> new CustomException(ErrorCode.ROOM_NOT_FOUND));
-
-                // 발신자 조회
-                User actor = userRepository.findById(request.actorId())
-                        .orElseThrow(() -> new CustomException(ErrorCode.USER_NOT_FOUND));
-
-                // 스터디룸 알림 생성
-                yield notificationService.createRoomNotification(
-                        room,
-                        actor,
-                        request.title(),
-                        request.message(),
-                        request.redirectUrl(),
-                        NotificationSettingType.ROOM_NOTICE
-                );
-            }
-            case "COMMUNITY" -> {
-                // 수신자 조회 (리뷰/게시글 작성자)
-                User receiver = userRepository.findById(request.targetId())
-                        .orElseThrow(() -> new CustomException(ErrorCode.USER_NOT_FOUND));
-
-                // 발신자 조회 (댓글/좋아요 작성자)
-                User actor = userRepository.findById(request.actorId())
-                        .orElseThrow(() -> new CustomException(ErrorCode.USER_NOT_FOUND));
-
-                // 커뮤니티 알림 생성
-                yield notificationService.createCommunityNotification(
-                        receiver,
-                        actor,
-                        request.title(),
-                        request.message(),
-                        request.redirectUrl(),
-                        NotificationSettingType.POST_COMMENT
-                );
-            }
-            case "SYSTEM" -> {
-                // 시스템 알림은 발신자/수신자 없음
-                yield notificationService.createSystemNotification(
-                        request.title(),
-                        request.message(),
-                        request.redirectUrl()
-                );
-            }
-            default -> throw new CustomException(ErrorCode.NOTIFICATION_INVALID_TARGET_TYPE);
-        };
-
-        NotificationResponse response = NotificationResponse.from(notification);
-
-        return ResponseEntity.ok(RsData.success("알림 전송 성공", response));
-    }
-
-    @Operation(
-            summary = "알림 목록 조회",
-            description = "사용자의 알림 목록 조회 (페이징)\n\n" +
-                    "- unreadOnly=true: 읽지 않은 알림만\n" +
-                    "- unreadOnly=false: 모든 알림"
-    )
+    @Operation(summary = "알림 목록 조회")
     @GetMapping
     public ResponseEntity<RsData<NotificationListResponse>> getNotifications(
             @Parameter(hidden = true) @AuthenticationPrincipal CustomUserDetails userDetails,
@@ -157,13 +45,10 @@ public ResponseEntity<RsData<NotificationListResponse>> getNotifications(
         log.info("알림 목록 조회 - 유저 ID: {}, 읽지 않은 것만: {}", userDetails.getUserId(), unreadOnly);
 
         Pageable pageable = PageRequest.of(page, size);
-        Page<Notification> notifications;
 
-        if (unreadOnly) {
-            notifications = notificationService.getUnreadNotifications(userDetails.getUserId(), pageable);
-        } else {
-            notifications = notificationService.getUserNotifications(userDetails.getUserId(), pageable);
-        }
+        Page<Notification> notifications = notificationService.getNotifications(
+                userDetails.getUserId(), pageable, unreadOnly
+        );
 
         long unreadCount = notificationService.getUnreadCount(userDetails.getUserId());
 
@@ -221,14 +106,4 @@ public ResponseEntity<RsData<Void>> markAllAsRead(
 
         return ResponseEntity.ok(RsData.success("전체 알림 읽음 처리 성공"));
     }
-
-    // ==================== 헬퍼 메서드 ====================
-
-    private boolean isValidTargetType(String targetType) {
-        return targetType != null &&
-                (targetType.equals("USER") ||
-                        targetType.equals("ROOM") ||
-                        targetType.equals("COMMUNITY") ||
-                        targetType.equals("SYSTEM"));
-    }
 }

src/main/java/com/back/domain/notification/dto/NotificationCreateRequest.java

@@ -5,6 +5,7 @@
 import org.springframework.data.domain.Page;
 
 import java.util.List;
+import java.util.Set;
 
 /**
  * 알림 목록 응답 DTO
@@ -27,9 +28,13 @@ public static NotificationListResponse from(
             long unreadCount,
             NotificationService notificationService) {
 
+        // 현재 페이지의 알림들에 대해 읽음 처리된 ID 목록을 한 번에 조회
+        Set<Long> readNotificationIds = notificationService.getReadNotificationIds(userId, notifications.getContent());
+
         List<NotificationItemDto> items = notifications.getContent().stream()
                 .map(notification -> {
-                    boolean isRead = notificationService.isNotificationRead(notification.getId(), userId);
+                    // DB 조회가 아닌 메모리에서 읽음 여부를 빠르게 확인
+                    boolean isRead = readNotificationIds.contains(notification.getId());
                     return NotificationItemDto.from(notification, isRead);
                 })
                 .toList();

src/main/java/com/back/domain/notification/dto/NotificationListResponse.java

@@ -2,10 +2,6 @@
 
 import com.back.domain.notification.entity.NotificationSettingType;
 import com.back.domain.notification.service.NotificationService;
-import com.back.domain.user.entity.User;
-import com.back.domain.user.repository.UserRepository;
-import com.back.global.exception.CustomException;
-import com.back.global.exception.ErrorCode;
 import lombok.RequiredArgsConstructor;
 import lombok.extern.slf4j.Slf4j;
 import org.springframework.context.event.EventListener;
@@ -18,7 +14,6 @@
 public class CommunityNotificationEventListener {
 
     private final NotificationService notificationService;
-    private final UserRepository userRepository;
 
     // 댓글 작성 시 - 게시글 작성자에게 알림
     @EventListener
@@ -28,15 +23,9 @@ public void handleCommentCreated(CommentCreatedEvent event) {
                 event.getPostId(), event.getCommentId(), event.getActorId());
 
         try {
-            User actor = userRepository.findById(event.getActorId())
-                    .orElseThrow(() -> new CustomException(ErrorCode.USER_NOT_FOUND));
-
-            User receiver = userRepository.findById(event.getReceiverId())
-                    .orElseThrow(() -> new CustomException(ErrorCode.USER_NOT_FOUND));
-
             notificationService.createCommunityNotification(
-                    receiver,
-                    actor,
+                    event.getReceiverId(),
+                    event.getActorId(),
                     event.getTitle(),
                     event.getContent(),
                     "/posts/" + event.getPostId(),
@@ -58,15 +47,9 @@ public void handleReplyCreated(ReplyCreatedEvent event) {
                 event.getParentCommentId(), event.getReplyId(), event.getActorId());
 
         try {
-            User actor = userRepository.findById(event.getActorId())
-                    .orElseThrow(() -> new CustomException(ErrorCode.USER_NOT_FOUND));
-
-            User receiver = userRepository.findById(event.getReceiverId())
-                    .orElseThrow(() -> new CustomException(ErrorCode.USER_NOT_FOUND));
-
             notificationService.createCommunityNotification(
-                    receiver,
-                    actor,
+                    event.getReceiverId(),
+                    event.getActorId(),
                     event.getTitle(),
                     event.getContent(),
                     "/posts/" + event.getPostId() + "#comment-" + event.getParentCommentId(),
@@ -88,15 +71,9 @@ public void handlePostLiked(PostLikedEvent event) {
                 event.getPostId(), event.getActorId());
 
         try {
-            User actor = userRepository.findById(event.getActorId())
-                    .orElseThrow(() -> new CustomException(ErrorCode.USER_NOT_FOUND));
-
-            User receiver = userRepository.findById(event.getReceiverId())
-                    .orElseThrow(() -> new CustomException(ErrorCode.USER_NOT_FOUND));
-
             notificationService.createCommunityNotification(
-                    receiver,
-                    actor,
+                    event.getReceiverId(),
+                    event.getActorId(),
                     event.getTitle(),
                     event.getContent(),
                     "/posts/" + event.getPostId(),
@@ -118,15 +95,9 @@ public void handleCommentLiked(CommentLikedEvent event) {
                 event.getCommentId(), event.getActorId());
 
         try {
-            User actor = userRepository.findById(event.getActorId())
-                    .orElseThrow(() -> new CustomException(ErrorCode.USER_NOT_FOUND));
-
-            User receiver = userRepository.findById(event.getReceiverId())
-                    .orElseThrow(() -> new CustomException(ErrorCode.USER_NOT_FOUND));
-
             notificationService.createCommunityNotification(
-                    receiver,
-                    actor,
+                    event.getReceiverId(),
+                    event.getActorId(),
                     event.getTitle(),
                     event.getContent(),
                     "/posts/" + event.getPostId() + "#comment-" + event.getCommentId(),

src/main/java/com/back/domain/notification/event/community/CommunityNotificationEventListener.java

@@ -18,7 +18,6 @@
 public class StudyNotificationEventListener {
 
     private final NotificationService notificationService;
-    private final UserRepository userRepository;
 
     // 학습 기록 등록 시 - 본인에게 알림
     @EventListener
@@ -28,11 +27,8 @@ public void handleStudyRecordCreated(StudyRecordCreatedEvent event) {
                 event.getUserId(), event.getDuration());
 
         try {
-            User user = userRepository.findById(event.getUserId())
-                    .orElseThrow(() -> new CustomException(ErrorCode.USER_NOT_FOUND));
-
             notificationService.createSelfNotification(
-                    user,
+                    event.getUserId(),
                     event.getTitle(),
                     event.getContent(),
                     "/study/records/" + event.getStudyRecordId(),
@@ -55,11 +51,8 @@ public void handleDailyGoalAchieved(DailyGoalAchievedEvent event) {
                 event.getCompletedPlans(), event.getTotalPlans());
 
         try {
-            User user = userRepository.findById(event.getUserId())
-                    .orElseThrow(() -> new CustomException(ErrorCode.USER_NOT_FOUND));
-
             notificationService.createSelfNotification(
-                    user,
+                    event.getUserId(),
                     event.getTitle(),
                     event.getContent(),
                     "/study/plans?date=" + event.getAchievedDate(),