* @return The default group list.
     */
    protected List<String> getDefaultGroupList() {
        final String value = ComponentUtil.getFessConfig().getSystemProperty("aad.default.groups");
        if (StringUtil.isBlank(value)) {
            return Collections.emptyList();
        }
        return split(value, ",").get(stream -> stream.filter(StringUtil::isNotBlank).map(String::trim).collect(Collectors.toList()));
    }

    /**

     * @return a list of pairs containing client names and their corresponding compiled patterns
     */
    protected List<Pair<String, Pattern>> getClientRuleList(final String value) {
        if (StringUtil.isBlank(value)) {
            return Collections.emptyList();
        }
        return split(value, ",").get(stream -> stream.map(String::trim)//
                .map(s -> clientRuleCache.computeIfAbsent(s, t -> {

                }, hook);
            }
        }
    }

    private static String[] splitLine(final String value) {
        if (StringUtil.isBlank(value)) {
            return StringUtil.EMPTY_STRINGS;
        }
        final String[] values = value.split("[\r\n]");
        final List<String> list = new ArrayList<>(values.length);

     */
    @Execute
    @Secured({ ROLE })
    public HtmlResponse createDir(final ItemForm form) {
        validate(form, messages -> {}, () -> asListHtml(form.path));
        if (StringUtil.isBlank(form.name)) {
            throwValidationError(messages -> messages.addErrorsStorageDirectoryNameIsInvalid(GLOBAL), () -> asListHtml(form.path));
        }

        final FessConfig fessConfig = ComponentUtil.getFessConfig();
        final String value = fessConfig.getPurgeByBots();
        String[] botNames;
        if (StringUtil.isBlank(value)) {
            botNames = StringUtil.EMPTY_STRINGS;
        } else {
            botNames = value.split(",");
        }

        final int batchSize = fessConfig.getSearchlogProcessBatchSizeAsInteger();

        if (config == null) {
            return OptionalThing.empty();
        }
        final String pipeline = config.getConfigParameterMap(ConfigName.CONFIG).get(Config.PIPELINE);
        if (StringUtil.isBlank(pipeline)) {
            return OptionalThing.empty();
        }
        return OptionalThing.of(pipeline);
    }

    /**
     * Refreshes the crawling configuration cache by invalidating all cached entries.

     * @return HTML response with search results
     */
    protected HtmlResponse doSearch(final ListForm form) {
        validate(form, messages -> {}, this::asListHtml);

        if (StringUtil.isBlank(form.q)) {
            // query matches on all documents.
            form.q = Constants.MATCHES_ALL_QUERY;
        }
        final WebRenderData renderData = new WebRenderData();
        form.initialize();

        if (StringUtil.isNotBlank(fessConfig.getIndexDictionaryPrefix())) {
            String dictionaryPath = System.getProperty("fess.dictionary.path", StringUtil.EMPTY);
            if (StringUtil.isBlank(dictionaryPath)) {
                System.setProperty("fess.dictionary.path", fessConfig.getIndexDictionaryPrefix() + "/");
            } else {
                if (!dictionaryPath.endsWith("/")) {

            try {
                final String contentsReadingAnalyzerName = getContentsReadingAnalyzerName(field, lang);
                if (StringUtil.isBlank(contentsReadingAnalyzerName)) {
                    return null;
                }
                final AnalyzeAction.Response analyzeResponse = client.admin()
                        .indices()

     * are available for use in rank fusion processing.
     */
    protected void load() {
        final String value = System.getProperty("rank.fusion.searchers");
        if (StringUtil.isBlank(value)) {
            availableSearcherNameSet = Collections.emptySet();
        } else {
            availableSearcherNameSet = StreamUtil.split(value, ",")