final Map<String, String> configMap = getConfigPrameterMap(responseData, ConfigName.CONFIG);
        String xpath = configMap.get(Config.HTML_CANONICAL_XPATH);
        if (xpath == null) {
            xpath = fessConfig.getCrawlerDocumentHtmlCanonicalXpath();
        }
        if (StringUtil.isBlank(xpath)) {
            return null;
        }