if (logger.isDebugEnabled()) {
            logger.debug("Backup file upload initiated: fileName={}", fileName);
        }

        final File tempFile = ComponentUtil.getSystemHelper().createTempFile("fess_restore_", ".tmp");
        try (final InputStream in = form.bulkFile.getInputStream(); final OutputStream out = new FileOutputStream(tempFile)) {
            CopyUtil.copy(in, out);
            asyncImport(fileName, tempFile);