feat #85 북마크 단일 조회 기능 추가

src/main/java/leets/bookmark/domain/bookmark/application/usecase/BookmarkUseCase.java

@@ -26,4 +26,6 @@ public interface BookmarkUseCase {
     List<BookmarkPreviewResponse> extractPreviewFromUrl(String url);
 
     List<BookmarkPlatformResponse> getAllPlatforms(Long userId);
+
+    BookmarkResponse findBookmark(Long userId, Long bookmarkId);
 }

src/main/java/leets/bookmark/domain/bookmark/application/usecase/BookmarkUseCaseImpl.java

@@ -72,6 +72,18 @@ public class BookmarkUseCaseImpl implements BookmarkUseCase {
     private final BookmarkTagMappingRepository bookmarkTagMappingRepository;
     private final BookmarkPlatformMapper bookmarkPlatformMapper;
 
+    @Override
+    @Transactional(readOnly = true)
+    public BookmarkResponse findBookmark(Long userId, Long bookmarkId){
+        User user = userGetService.findById(userId);
+        Bookmark bookmark = bookmarkGetService.getBookmarkById(bookmarkId);
+
+        validateBookmarkOwner(user.getId(), bookmark);
+
+        FileResponse fileResponse = fileMapper.toFileResponse(bookmark.getFile());
+        return bookmarkMapper.toResponse(bookmark, bookmarkGetService.getMappingsByBookmark(bookmark), fileResponse);
+    }
+
     @Override
     @Transactional(readOnly = true)
     public Slice<BookmarkResponse> getFilteredBookmarks(Long userId, BookmarkSearchRequest request) {

src/main/java/leets/bookmark/domain/bookmark/presentation/BookmarkController.java

@@ -25,12 +25,19 @@ public class BookmarkController {
     private final BookmarkUseCase bookmarkUseCase;
     private final NotificationUseCase notificationUseCase;
 
+    @GetMapping("/{bookmarkId}")
+    @Operation(summary = "북마크 단일 조회 API", description = "북마크를 조회합니다.")
+    public CommonResponse<BookmarkResponse> getBookmark(@CurrentUser Long userId, @PathVariable Long bookmarkId) {
+        BookmarkResponse response = bookmarkUseCase.findBookmark(userId, bookmarkId);
+        return CommonResponse.createSuccess(BOOKMARK_FIND_SUCCESS.getMessage(), response);
+    }
+
     @PostMapping("/search")
     @Operation(summary = "북마크 필터링 API")
     public CommonResponse<Slice<BookmarkResponse>> getFilteredBookmarks(@CurrentUser Long userId,
                                                                         @RequestBody @Valid BookmarkSearchRequest bookmarkSearchRequest) {
         Slice<BookmarkResponse> responses = bookmarkUseCase.getFilteredBookmarks(userId, bookmarkSearchRequest);
-        return CommonResponse.createSuccess(BOOKMARK_FILTER_SUCCESS.getMessage(), responses);
+        return CommonResponse.createSuccess(BOOKMARK_FIND_SUCCESS.getMessage(), responses);
     }
 
     @PostMapping()

src/main/java/leets/bookmark/domain/bookmark/presentation/BookmarkResponseMessage.java

@@ -6,6 +6,8 @@
 @Getter
 @AllArgsConstructor
 public enum BookmarkResponseMessage {
+
+    BOOKMARK_FIND_SUCCESS("북마크 단일 조회에 성공했습니다"),
     BOOKMARK_SEARCH_SUCCESS("북마크 검색에 성공했습니다."),
     BOOKMARK_MEMO_SEARCH_SUCCESS("북마크 메모 검색에 성공했습니다."),
     BOOKMARK_FILTER_SUCCESS("북마크 필터링에 성공했습니다."),