Feat: 알림 목록 조회 구현

src/main/java/UMC/news/newsIntelligent/domain/notification/controller/NotificationController.java

@@ -0,0 +1,38 @@
+package UMC.news.newsIntelligent.domain.notification.controller;
+
+import org.springframework.web.bind.annotation.GetMapping;
+import org.springframework.web.bind.annotation.RequestMapping;
+import org.springframework.web.bind.annotation.RequestParam;
+import org.springframework.web.bind.annotation.RestController;
+
+import UMC.news.newsIntelligent.domain.notification.dto.NotificationResponse;
+import UMC.news.newsIntelligent.domain.notification.service.NotificationService;
+import UMC.news.newsIntelligent.global.apiPayload.CustomResponse;
+import UMC.news.newsIntelligent.global.apiPayload.code.success.GeneralSuccessCode;
+import io.swagger.v3.oas.annotations.Operation;
+import io.swagger.v3.oas.annotations.tags.Tag;
+import lombok.RequiredArgsConstructor;
+
+@RestController
+@RequestMapping("/api/notification")
+@RequiredArgsConstructor
+@Tag(name = "사용자 알림 관련 API")
+public class NotificationController {
+
+	private final NotificationService notificationService;
+
+	@Operation(summary = "알림 목록 조회 API",
+		description = "<p>구독한 토픽, 읽은 토픽에 대한 홈화면 알림 목록입니다."
+			+ "<p>커서 페이징 처리하였습니다.")
+	@GetMapping
+	public CustomResponse<NotificationResponse.NotificationCursorDto> getNotifications(
+		@RequestParam(required = false) String cursor,
+		@RequestParam(defaultValue = "10") int size
+	) {
+		Long memberId = 0L;
+		NotificationResponse.NotificationCursorDto body =
+			notificationService.getNotifications(memberId, cursor, size);
+
+		return CustomResponse.onSuccess(GeneralSuccessCode.OK, body);
+	}
+}

src/main/java/UMC/news/newsIntelligent/domain/notification/dto/NotificationRequest.java

@@ -0,0 +1,5 @@
+package UMC.news.newsIntelligent.domain.notification.dto;
+
+public class NotificationRequest {
+
+}

src/main/java/UMC/news/newsIntelligent/domain/notification/dto/NotificationResponse.java

@@ -0,0 +1,61 @@
+package UMC.news.newsIntelligent.domain.notification.dto;
+
+import java.time.format.DateTimeFormatter;
+import java.util.List;
+import java.util.stream.Collectors;
+
+import UMC.news.newsIntelligent.domain.notification.Notification;
+import UMC.news.newsIntelligent.domain.notification.NotificationType;
+import lombok.AllArgsConstructor;
+import lombok.Builder;
+import lombok.Getter;
+import lombok.NoArgsConstructor;
+
+public class NotificationResponse {
+
+	@Builder
+	@Getter
+	@NoArgsConstructor
+	@AllArgsConstructor
+	public static class NotificationCursorDto {
+		private List<NotificationDto> notifications;
+		private String nextCursor;
+		private boolean hasNext;
+
+		// dto 변환 메서드
+		public static NotificationCursorDto of(List<Notification> items, String nextCursor, boolean hasNext) {
+			List<NotificationDto> dtos = items.stream()
+				.map(NotificationDto::of).collect(Collectors.toList());
+			return NotificationCursorDto.builder()
+				.notifications(dtos)
+				.nextCursor(nextCursor)
+				.hasNext(hasNext)
+				.build();
+		}
+	}
+
+	@Builder
+	@Getter
+	@NoArgsConstructor
+	@AllArgsConstructor
+	public static class NotificationDto {
+		private NotificationType type;
+		private String content;
+		private Boolean isChecked;
+		private String createdAt;
+
+		// '2011-12-03T10:15:30+01:00' 형식의 포매터
+		private static final DateTimeFormatter FORMATTER = DateTimeFormatter.ISO_OFFSET_DATE_TIME;
+
+		// Notification entity -> Dto
+		public static NotificationDto of(Notification notification) {
+
+			return NotificationDto.builder()
+				.content(notification.getContent())
+				.type(notification.getNotificationType())
+				.isChecked(notification.getIsChecked())
+				.createdAt(notification.getCreatedAt().format(FORMATTER))
+				.build();
+		}
+	}
+}

src/main/java/UMC/news/newsIntelligent/domain/notification/repository/NotificationRepository.java

@@ -0,0 +1,48 @@
+package UMC.news.newsIntelligent.domain.notification.repository;
+
+import java.awt.print.Pageable;
+import java.time.LocalDateTime;
+import java.util.List;
+
+import org.springframework.data.jpa.repository.JpaRepository;
+import org.springframework.data.jpa.repository.Query;
+import org.springframework.data.repository.query.Param;
+
+import UMC.news.newsIntelligent.domain.notification.Notification;
+
+public interface NotificationRepository extends JpaRepository<Notification, Long> {
+	List<Notification> findByMemberIdOrderByCreatedAtAsc(Long memberId);
+
+	/**
+	 * 초기 조회: 최신순으로 size+1 개 가져온다.
+	 */
+	@Query("""
+		SELECT n
+		FROM Notification n
+		WHERE n.member.id = :memberId
+		ORDER BY n.createdAt DESC, n.id DESC
+	""")
+	List<Notification> findByMemberIdBeforeCursor(
+		@Param("memberId") Long memberId,
+		@Param("limit") int limit);
+
+	/**
+	 *  커서 다음 조회:
+	 *   createdAt < cursor.createdAt
+	 *   (createdAt = cursor.createdAt AND id < cursor.id)
+	 */
+	@Query("""
+		SELECT n
+		FROM Notification n
+		WHERE n.member.id = :memberId
+			AND (n.createdAt < :createdAt
+				OR (n.createdAt = :createdAt AND n.id < :id))
+			ORDER BY n.createdAt DESC, n.id DESC
+	""")
+	List<Notification> findByMemberIdAfterCursor(
+		@Param("memberId") Long memberId,
+		@Param("createdAt")LocalDateTime createdAt,
+		@Param("id") Long id,
+		@Param("limit") int limit
+	);
+}

src/main/java/UMC/news/newsIntelligent/domain/notification/service/NotificationService.java

@@ -0,0 +1,7 @@
+package UMC.news.newsIntelligent.domain.notification.service;
+
+import UMC.news.newsIntelligent.domain.notification.dto.NotificationResponse;
+
+public interface NotificationService {
+	 NotificationResponse.NotificationCursorDto getNotifications(Long memberId, String cursor, int size);
+}

src/main/java/UMC/news/newsIntelligent/domain/notification/service/NotificationServiceImpl.java

@@ -0,0 +1,62 @@
+package UMC.news.newsIntelligent.domain.notification.service;
+
+import java.time.DateTimeException;
+import java.time.LocalDateTime;
+import java.util.Base64;
+import java.util.List;
+
+import org.springframework.stereotype.Service;
+import org.springframework.transaction.annotation.Transactional;
+
+import UMC.news.newsIntelligent.domain.notification.Notification;
+import UMC.news.newsIntelligent.domain.notification.dto.NotificationResponse;
+import UMC.news.newsIntelligent.domain.notification.repository.NotificationRepository;
+import UMC.news.newsIntelligent.global.apiPayload.code.error.GeneralErrorCode;
+import UMC.news.newsIntelligent.global.apiPayload.exception.CustomException;
+import lombok.RequiredArgsConstructor;
+
+@Service
+@RequiredArgsConstructor
+@Transactional
+public class NotificationServiceImpl implements NotificationService {
+
+	private final NotificationRepository notificationRepository;
+
+	@Override
+	public NotificationResponse.NotificationCursorDto getNotifications(
+		Long memberId, String cursor, int size
+	) {
+		// 커서 디코딩
+		LocalDateTime createdAt = null;
+		Long id = null;
+		if(cursor != null && !cursor.isBlank()) {
+			try {
+				String decoded = new String(Base64.getUrlDecoder().decode(cursor));
+				String[] parts = decoded.split("_", 2);
+				createdAt = LocalDateTime.parse(parts[0]);
+				id = Long.parseLong(parts[1]);
+
+			} catch (IllegalArgumentException | DateTimeException e) {
+				throw new CustomException(GeneralErrorCode.CURSOR_INVALID);
+			}
+		}
+		// size+1 만큼 조회
+		int limit = size +1;
+		List<Notification> items = (createdAt == null)
+			? notificationRepository.findByMemberIdBeforeCursor(memberId, limit)
+			: notificationRepository.findByMemberIdAfterCursor(memberId, createdAt, id, limit);
+
+		boolean hasNext = items.size() > size;
+		String nextCursor = null;
+		if (hasNext) {
+			Notification pivot = items.get(size);
+			String raw = pivot.getCreatedAt().toString() + "_" + pivot.getId();
+			nextCursor = Base64.getUrlEncoder().encodeToString(raw.getBytes());
+		}
+		List<Notification> page = hasNext
+			? items.subList(0, size)
+			: items;
+
+		return NotificationResponse.NotificationCursorDto.of(page, nextCursor, hasNext);
+	}
+}

src/main/java/UMC/news/newsIntelligent/global/apiPayload/code/error/GeneralErrorCode.java

@@ -19,7 +19,9 @@ public enum GeneralErrorCode implements BaseErrorCode{
     INTERNAL_SERVER_ERROR_500(HttpStatus.INTERNAL_SERVER_ERROR, "COMMON500", "서버 내부 오류가 발생했습니다"),
 
     // 유효성 검사
-    VALIDATION_FAILED(HttpStatus.BAD_REQUEST, "VALID400_0", "잘못된 파라미터 입니다.")
+    VALIDATION_FAILED(HttpStatus.BAD_REQUEST, "VALID400_0", "잘못된 파라미터 입니다."),
+    // 커서 에러
+    CURSOR_INVALID(HttpStatus.BAD_REQUEST, "CURSOR400", "커서가 유효하지 않습니다.")
     ;
 
     // 필요한 필드값 선언