* @return an array of related query strings, or empty array if none found
     */
    public String[] getRelatedQueries(final String query) {
        final String key = ComponentUtil.getVirtualHostHelper().getVirtualHostKey();
        final Map<String, String[]> map = relatedQueryMap.get(key);
        if (map != null) {
            final String[] queries = map.get(toLowerCase(query));
            if (queries != null) {

        if (StringUtil.isBlank(requestPath)) {
            return null;
        }
        final String virtualHostKey = ComponentUtil.getVirtualHostHelper().getVirtualHostKey();
        if (StringUtil.isBlank(virtualHostKey)) {
            return null;
        }
        final String prefix = "/" + virtualHostKey;
        if (requestPath.startsWith(prefix)) {

     * The key is determined by matching HTTP headers against configured virtual hosts.
     *
     * @return The virtual host key, or empty string if no match found
     */
    public String getVirtualHostKey() {
        return LaRequestUtil.getOptionalRequest().map(req -> (String) req.getAttribute(FessConfig.VIRTUAL_HOST_VALUE)).orElseGet(() -> {
            final String value = processVirtualHost(s -> s, StringUtil.EMPTY);

     * @return array of related content strings, or empty array if no matches found
     */
    public String[] getRelatedContents(final String query) {
        final String key = ComponentUtil.getVirtualHostHelper().getVirtualHostKey();
        final Pair<Map<String, String>, List<Pair<Pattern, String>>> pair = relatedContentMap.get(key);
        if (pair != null) {
            final List<String> contentList = new ArrayList<>();