assertEquals("", documentHelper.getContent(null, responseData, "  ", dataMap));
        assertEquals("", documentHelper.getContent(null, responseData, "\t", dataMap));
        assertEquals("", documentHelper.getContent(null, responseData, "\t\t", dataMap));
        assertEquals("", documentHelper.getContent(null, responseData, "\t \t", dataMap));

        try (final InputStream in = responseData.getResponseBody()) {
            final ExtractData extractData = getExtractData(extractor, in, createExtractParams(responseData, crawlingConfig));
            content = extractData.getContent();
            if (fessConfig.isCrawlerDocumentFileIgnoreEmptyContent() && StringUtil.isBlank(content)) {
                return null;
            }
            if (getLogger().isDebugEnabled()) {

                .header("Accept", "application/json").execute()) {
            final Map<String, Object> contentMap = response.getContent(OpenSearchCurl.jsonParser());
            if (logger.isDebugEnabled()) {
                logger.debug("response: {}", contentMap);
            }
            if (contentMap.containsKey("value")) {

    protected <RESULT extends RelatedContent> RESULT createEntity(Map<String, Object> source, Class<? extends RESULT> entityType) {
        try {
            final RESULT result = entityType.newInstance();
            result.setContent(DfTypeUtil.toString(source.get("content")));
            result.setCreatedBy(DfTypeUtil.toString(source.get("createdBy")));
            result.setCreatedTime(DfTypeUtil.toLong(source.get("createdTime")));

    //                                       ---------------
    protected final Map<String, PropertyGateway> _epgMap = newHashMap();
    {
        setupEpg(_epgMap, et -> ((RelatedContent) et).getContent(), (et, vl) -> ((RelatedContent) et).setContent(DfTypeUtil.toString(vl)),
                "content");
        setupEpg(_epgMap, et -> ((RelatedContent) et).getCreatedBy(),

        } catch (final IOException e) {
            return StringUtil.EMPTY; // empty
        }
    }

    public String getContent(final CrawlingConfig crawlingConfig, final ResponseData responseData, final String content,
            final Map<String, Object> dataMap) {
        if (content == null) {
            return StringUtil.EMPTY; // empty

            final CrawlingConfig crawlingConfig, final DocumentHelper documentHelper, final String body, final String fileName) {
        final String content = documentHelper.getContent(crawlingConfig, responseData, body, dataMap);
        if (StringUtil.isNotBlank(fileName) && fessConfig.isCrawlerDocumentAppendFilename()) {

            if (response.getHttpStatusCode() == 200) {
                final Map<String, Object> contentMap = response.getContent(OpenSearchCurl.jsonParser());
                if (contentMap.get("path") instanceof final List<?> pathList) {
                    return pathList.stream().map(Object::toString).toArray(n -> new String[n]);
                }