if (logger.isDebugEnabled()) {
            logger.debug("writing the content of: {}", doc);
        }
        final FessConfig fessConfig = ComponentUtil.getFessConfig();
        final CrawlingConfigHelper crawlingConfigHelper = ComponentUtil.getCrawlingConfigHelper();
        final String configId = DocumentUtil.getValue(doc, fessConfig.getIndexFieldConfigId(), String.class);
        if (configId == null) {