assertNull(CrawlingParameterUtil.getUrlQueue());

        // Create and set a mock UrlQueue
        UrlQueue<?> urlQueue = createMockUrlQueue("test-session", "http://example.com");
        CrawlingParameterUtil.setUrlQueue(urlQueue);

        // Verify it can be retrieved
        UrlQueue<?> retrieved = CrawlingParameterUtil.getUrlQueue();
        assertNotNull(retrieved);

 * </ul>
 *
 * <p>Each parameter is stored in a ThreadLocal variable to ensure thread safety.</p>
 *
 * <p>Usage example:</p>
 * <pre>
 * {@code
 * UrlQueue<?> urlQueue = CrawlingParameterUtil.getUrlQueue();
 * CrawlingParameterUtil.setUrlQueue(newUrlQueue);
 *
 * CrawlerContext context = CrawlingParameterUtil.getCrawlerContext();
 * CrawlingParameterUtil.setCrawlerContext(newContext);
 *

     * @throws CrawlerSystemException if an error occurs while processing the URL
     */
    @Override
    protected void delayBeforeProcessing() {
        final UrlQueue<?> urlQueue = CrawlingParameterUtil.getUrlQueue();
        if (urlQueue == null) {
            return;
        }

        final String url = urlQueue.getUrl();
        if (StringUtil.isBlank(url) || url.startsWith("file:")) {
            // not target

        final int numTasks = 100;
        // Interval in milliseconds
        final Long waittime = 100L;

        CrawlingParameterUtil.setUrlQueue(new UrlQueueImpl());
        final UrlQueue q = CrawlingParameterUtil.getUrlQueue();
        for (int i = 0; i < numTasks; i++) {
            q.setUrl("http://example.com");
        }

        final HostIntervalController controller = new HostIntervalController();

        String enc = Constants.UTF_8;
        if (StringUtil.isBlank(fessConfig.getCrawlerDocumentFileNameEncoding())) {
            final UrlQueue<?> urlQueue = CrawlingParameterUtil.getUrlQueue();
            if (urlQueue != null) {
                final String parentUrl = urlQueue.getParentUrl();
                if (StringUtil.isNotEmpty(parentUrl)) {

        final FieldConfigs fieldConfigs = new FieldConfigs(crawlingConfig.getConfigParameterMap(ConfigName.FIELD));

        String urlEncoding;
        final UrlQueue<?> urlQueue = CrawlingParameterUtil.getUrlQueue();
        if (urlQueue != null && urlQueue.getEncoding() != null) {
            urlEncoding = urlQueue.getEncoding();
        } else {
            urlEncoding = responseData.getCharSet();
        }

        final Map<String, String> xpathConfigMap = crawlingConfig.getConfigParameterMap(ConfigName.XPATH);

        String urlEncoding;
        final UrlQueue<?> urlQueue = CrawlingParameterUtil.getUrlQueue();
        if (urlQueue != null && urlQueue.getEncoding() != null) {
            urlEncoding = urlQueue.getEncoding();
        } else {
            urlEncoding = responseData.getCharSet();
        }