fix

internal/application/finance/invoice_application_service.go

@@ -391,27 +391,56 @@ func (s *InvoiceApplicationServiceImpl) DownloadInvoiceFile(ctx context.Context,
 		return nil, fmt.Errorf("发票尚未通过审核")
 	}
 
-	// 4. 验证文件信息
+	fileContent, fileID, fileName, fileSize, fileURL, err := downloadInvoiceFileFromStorage(ctx, s.storageService, application)
-	if application.FileURL == nil || *application.FileURL == "" {
-		return nil, fmt.Errorf("发票文件不存在")
-	}
-
-	// 5. 从七牛云下载文件内容
-	fileContent, err := s.storageService.DownloadFile(ctx, *application.FileURL)
 	if err != nil {
-		return nil, fmt.Errorf("下载文件失败: %w", err)
+		return nil, err
 	}
 
-	// 6. 构建响应DTO
 	return &dto.FileDownloadResponse{
-		FileID:      *application.FileID,
+		FileID:      fileID,
-		FileName:    *application.FileName,
+		FileName:    fileName,
-		FileSize:    *application.FileSize,
+		FileSize:    fileSize,
-		FileURL:     *application.FileURL,
+		FileURL:     fileURL,
 		FileContent: fileContent,
 	}, nil
 }
 
+// downloadInvoiceFileFromStorage 从七牛云下载发票文件（优先用 FileID 生成新 URL，避免私有空间签名过期）
+func downloadInvoiceFileFromStorage(ctx context.Context, storageService *storage.QiNiuStorageService, application *entities.InvoiceApplication) ([]byte, string, string, int64, string, error) {
+	if application.FileID == nil || *application.FileID == "" {
+		if application.FileURL == nil || *application.FileURL == "" {
+			return nil, "", "", 0, "", fmt.Errorf("发票文件不存在")
+		}
+		fileContent, err := storageService.DownloadFile(ctx, *application.FileURL)
+		if err != nil {
+			return nil, "", "", 0, "", fmt.Errorf("下载文件失败: %w", err)
+		}
+		return fileContent, derefString(application.FileID), derefString(application.FileName), derefInt64(application.FileSize), *application.FileURL, nil
+	}
+
+	fileContent, err := storageService.DownloadFileByKey(ctx, *application.FileID)
+	if err != nil {
+		return nil, "", "", 0, "", fmt.Errorf("下载文件失败: %w", err)
+	}
+
+	fileURL := storageService.GetFileURL(ctx, *application.FileID)
+	return fileContent, *application.FileID, derefString(application.FileName), derefInt64(application.FileSize), fileURL, nil
+}
+
+func derefString(v *string) string {
+	if v == nil {
+		return ""
+	}
+	return *v
+}
+
+func derefInt64(v *int64) int64 {
+	if v == nil {
+		return 0
+	}
+	return *v
+}
+
 // GetAvailableAmount 获取可开票金额
 func (s *InvoiceApplicationServiceImpl) GetAvailableAmount(ctx context.Context, userID string) (*dto.AvailableAmountResponse, error) {
 	// 1. 验证用户是否存在
@@ -764,23 +793,16 @@ func (s *AdminInvoiceApplicationServiceImpl) DownloadInvoiceFile(ctx context.Con
 		return nil, fmt.Errorf("发票尚未通过审核")
 	}
 
-	// 3. 验证文件信息
+	fileContent, fileID, fileName, fileSize, fileURL, err := downloadInvoiceFileFromStorage(ctx, s.storageService, application)
-	if application.FileURL == nil || *application.FileURL == "" {
-		return nil, fmt.Errorf("发票文件不存在")
-	}
-
-	// 4. 从七牛云下载文件内容
-	fileContent, err := s.storageService.DownloadFile(ctx, *application.FileURL)
 	if err != nil {
-		return nil, fmt.Errorf("下载文件失败: %w", err)
+		return nil, err
 	}
 
-	// 5. 构建响应DTO
 	return &dto.FileDownloadResponse{
-		FileID:      *application.FileID,
+		FileID:      fileID,
-		FileName:    *application.FileName,
+		FileName:    fileName,
-		FileSize:    *application.FileSize,
+		FileSize:    fileSize,
-		FileURL:     *application.FileURL,
+		FileURL:     fileURL,
 		FileContent: fileContent,
 	}, nil
 }

internal/infrastructure/external/storage/qiniu_storage_service.go

@@ -281,6 +281,15 @@ func (s *QiNiuStorageService) UploadFromReader(ctx context.Context, reader io.Re
 	return s.UploadFile(ctx, fileBytes, fileName)
 }
 
+// DownloadFileByKey 通过存储 key 下载文件（每次生成最新访问 URL，避免私有空间签名过期）
+func (s *QiNiuStorageService) DownloadFileByKey(ctx context.Context, key string) ([]byte, error) {
+	if key == "" {
+		return nil, fmt.Errorf("文件 key 不能为空")
+	}
+	fileURL := s.GetFileURL(ctx, key)
+	return s.DownloadFile(ctx, fileURL)
+}
+
 // DownloadFile 从七牛云下载文件
 func (s *QiNiuStorageService) DownloadFile(ctx context.Context, fileURL string) ([]byte, error) {
 	s.logger.Info("开始从七牛云下载文件", zap.String("file_url", fileURL))

internal/infrastructure/http/handlers/finance_handler.go

@@ -1070,6 +1070,10 @@ func (h *FinanceHandler) AdminDownloadInvoiceFile(c *gin.Context) {
 
 	result, err := h.adminInvoiceAppService.DownloadInvoiceFile(c.Request.Context(), applicationID)
 	if err != nil {
+		h.logger.Error("下载发票文件失败",
+			zap.String("application_id", applicationID),
+			zap.Error(err),
+		)
 		h.responseBuilder.InternalError(c, "下载发票文件失败")
 		return
 	}