final String value = clientConfigMap.get(CRAWLER_CLIENTS);
        final CrawlerClient client = getClientRuleList(value).stream().map(e -> {
            if (e.getSecond().matcher(url).matches()) {
                return e.getFirst();
            }
            return null;
        })
                .filter(StringUtil::isNotBlank)
                .findFirst()//

            responseData.setMimeType(statObject.contentType());
            statObject.headers().forEach(e -> responseData.addMetaData(e.getFirst(), e.getSecond()));

            if (contentLengthHelper != null) {
                final long maxLength = contentLengthHelper.getMaxLength(responseData.getMimeType());
                if (responseData.getContentLength() > maxLength) {

    }

    @Override
    protected void writeHeaders(final HttpServletResponse response) {
        ComponentUtil.getFessConfig().getApiJsonResponseHeaderList().forEach(e -> response.setHeader(e.getFirst(), e.getSecond()));
    }

    /**
     * Writes a JSON response.
     * @param status The status code.
     * @param t The throwable.
     */

                List<RequestData> requestDataList = new ArrayList<>();
                for (final String childUrl : getUrlFromTagAttribute(baseUri, document, entry.getFirst(), entry.getSecond(),
                        responseData.getCharSet())) {
                    requestDataList.add(RequestDataBuilder.newRequestData().get().url(childUrl).build());
                }

                }
            }
        }

        formSchemeList.forEach(p -> {
            final FormScheme scheme = p.getFirst();
            final Credentials credentials = p.getSecond();
            scheme.authenticate(credentials, (request, consumer) -> {

                // request header
                for (final Header header : requestHeaderList) {
                    request.addHeader(header);