fix: 스토리지 객체 유무 확인 로직 추가

layer-api/src/main/java/org/layer/domain/space/service/SpaceService.java

@@ -5,6 +5,7 @@
 import lombok.extern.slf4j.Slf4j;
 import org.layer.common.dto.Meta;
 import org.layer.domain.actionItem.repository.ActionItemRepository;
+import org.layer.domain.external.ncp.service.NcpService;
 import org.layer.domain.retrospect.repository.RetrospectRepository;
 import org.layer.domain.space.controller.dto.SpaceRequest;
 import org.layer.domain.space.controller.dto.SpaceResponse;
@@ -31,6 +32,7 @@
 @Slf4j
 @Transactional(readOnly = true)
 public class SpaceService {
+    private final NcpService ncpService;
     private final SpaceRepository spaceRepository;
     private final MemberSpaceRelationRepository memberSpaceRelationRepository;
     private final ActionItemRepository actionItemRepository;
@@ -55,8 +57,9 @@ public SpaceResponse.SpacePage getSpaceListFromMemberId(Long memberId, SpaceRequ
 
     @Transactional
     public Long createSpace(Long memberId, SpaceRequest.CreateSpaceRequest createSpaceRequest) {
-
-
+        if (createSpaceRequest.bannerUrl() != null) {
+            ncpService.checkObjectExistOrThrow(createSpaceRequest.bannerUrl());
+        }
         var newSpace = spaceRepository.save(createSpaceRequest.toEntity(memberId));
         var memberSpaceRelation = MemberSpaceRelation.builder().memberId(memberId).space(newSpace).build();
 

layer-external/src/main/java/org/layer/domain/external/ncp/service/NcpService.java

@@ -9,12 +9,15 @@
 import lombok.extern.slf4j.Slf4j;
 import org.layer.domain.external.ncp.dto.NcpResponse;
 import org.layer.domain.external.ncp.enums.ImageDomain;
+import org.layer.domain.external.ncp.exception.ExternalException;
 import org.springframework.beans.factory.annotation.Value;
 import org.springframework.stereotype.Service;
 
 import java.util.Date;
 import java.util.UUID;
 
+import static org.layer.common.exception.ExternalExceptionType.OBJECT_INVALID_ERROR;
+
 @Service
 @Slf4j
 @RequiredArgsConstructor
@@ -37,6 +40,15 @@ public NcpResponse.PresignedResult getPreSignedUrl(Long memberId, ImageDomain im
         );
     }
 
+    public void checkObjectExistOrThrow(String url) {
+
+        String objectKey = extractObjectKey(url);
+        boolean isExist = amazonS3Client.doesObjectExist(bucket, objectKey);
+        if (!isExist) {
+            throw new ExternalException(OBJECT_INVALID_ERROR);
+        }
+    }
+
     private GeneratePresignedUrlRequest getGeneratePreSignedUrlRequest(String fileName) {
         GeneratePresignedUrlRequest generatePresignedUrlRequest =
                 new GeneratePresignedUrlRequest(bucket, fileName)
@@ -57,4 +69,13 @@ private Date getPreSignedUrlExpiration() {
         expiration.setTime(expTimeMillis);
         return expiration;
     }
+
+    private String extractObjectKey(String url) {
+        String expectedPrefix = "https://layer-bucket.kr.object.ncloudstorage.com";
+
+        if (!url.startsWith(expectedPrefix)) {
+            throw new ExternalException(OBJECT_INVALID_ERROR);
+        }
+        return url.substring(expectedPrefix.length() + 1); // "/" 이후부터 추출
+    }
 }