@Secured({ ROLE })
    public HtmlResponse reloadDocIndex(final ActionForm form) {
        validate(form, messages -> {}, this::asIndexHtml);
        verifyToken(this::asIndexHtml);
        searchEngineClient.flushConfigFiles(() -> {
            final String docIndex = fessConfig.getIndexDocumentUpdateIndex();
            searchEngineClient.admin().indices().prepareClose(docIndex).execute(ActionListener.wrap(res -> {

        }
    }

    /**
     * Flushes configuration files to the search engine and executes a callback.
     *
     * @param callback the callback to execute after flushing
     */
    public void flushConfigFiles(final Runnable callback) {
        final FessConfig fessConfig = ComponentUtil.getFessConfig();

        final String fesenType = fessConfig.getFesenType();
        switch (fesenType) {