if (isLoginRequired()) {
            return redirectToLogin();
        }

        final Map<String, Object> doc =
                searchHelper.getDocumentByDocId(form.docId, queryFieldConfig.getResponseFields(), getUserBean()).orElse(null);
        final String url = DocumentUtil.getValue(doc, fessConfig.getIndexFieldThumbnail(), String.class);

        if (isLoginRequired()) {
            return redirectToLogin();
        }

        Map<String, Object> doc = null;
        try {
            doc = searchHelper.getDocumentByDocId(form.docId, queryFieldConfig.getCacheResponseFields(), getUserBean()).orElse(null);
        } catch (final Exception e) {
            logger.warn("Failed to request: {}", form.docId, e);
        }
        if (doc == null) {

        if (isLoginRequired()) {
            return redirectToLogin();
        }

        Map<String, Object> doc = null;
        try {
            doc = searchHelper.getDocumentByDocId(form.docId,
                    new String[] { fessConfig.getIndexFieldUrl(), fessConfig.getIndexFieldConfigId() }, getUserBean()).orElse(null);
        } catch (final Exception e) {

                }
            }
        }
        return StringUtil.EMPTY_STRINGS;
    }

    public OptionalEntity<Map<String, Object>> getDocumentByDocId(final String docId, final String[] fields,
            final OptionalThing<FessUserBean> userBean) {
        final FessConfig fessConfig = ComponentUtil.getFessConfig();

            if (docIds == null) {
                throw new WebApiException(HttpServletResponse.SC_BAD_REQUEST, "No searched urls.");
            }

            searchHelper.getDocumentByDocId(docId, new String[] { fessConfig.getIndexFieldUrl(), fessConfig.getIndexFieldLang() },
                    OptionalThing.empty()).ifPresent(doc -> {