* the URL queue for the current thread is removed.
     *
     * @param urlQueue the URL queue to be set for the current thread, or null to remove the URL queue
     */
    public static void setUrlQueue(final UrlQueue<?> urlQueue) {
        if (urlQueue == null) {
            URL_QUEUE_THREAD_LOCAL.remove();
        } else {
            URL_QUEUE_THREAD_LOCAL.set(urlQueue);
        }
    }

    /**

            UrlQueue urlQueue;
            while ((urlQueue = urlQueueService.poll(sessionId1)) != null) {
                assertTrue(urlQueue.getUrl() + "=>" + url1, urlQueue.getUrl().startsWith(url1));
            }
            while ((urlQueue = urlQueueService.poll(sessionId2)) != null) {
                assertTrue(urlQueue.getUrl() + "=>" + url2, urlQueue.getUrl().startsWith(url2));
            }

            return;
        }
        final OpenSearchUrlQueue urlQueue = new OpenSearchUrlQueue();
        urlQueue.setSessionId(sessionId);
        urlQueue.setUrl(url);
        urlQueue.setCreateTime(System.currentTimeMillis());
        urlQueue.setLastModified(0L);
        urlQueue.setDepth(0);
        urlQueue.setMethod(Constants.GET_METHOD);
        insert(urlQueue);
    }

    /**

        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);

/**
 * Implementation of the {@link UrlQueue} interface.
 * This class represents a URL to be crawled, storing its ID, session ID,
 * HTTP method, URL, metadata, encoding, parent URL, depth, last modified time,
 * creation time, and weight.
 *
 * @param <IDTYPE> the type of the identifier for the URL queue entry
 */
public class UrlQueueImpl<IDTYPE> implements UrlQueue<IDTYPE> {

            assertEquals(maxCount, dataService.getCount(sessionId2));

            UrlQueue urlQueue;
            while ((urlQueue = urlQueueService.poll(sessionId1)) != null) {
                assertTrue(urlQueue.getUrl().startsWith(url1));
            }
            while ((urlQueue = urlQueueService.poll(sessionId2)) != null) {
                assertTrue(urlQueue.getUrl().startsWith(url2));
            }

     */
    @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
            return;
        }

            final UrlQueue<?> urlQueue = CrawlingParameterUtil.getUrlQueue();
            if (urlQueue != null) {
                final String parentUrl = urlQueue.getParentUrl();
                if (StringUtil.isNotEmpty(parentUrl)) {
                    final String sessionId = urlQueue.getSessionId();

     * @return the URL string or a default value if not extractable
     */
    protected String getUrl(final Object keyObj) {
        if (keyObj instanceof final UrlQueue<?> urlQueue) {
            return escapeValue(urlQueue.getUrl());
        }
        if (keyObj instanceof final StatsKeyObject statsKey) {
            return escapeValue(statsKey.getUrl());
        }

import java.util.List;

import org.codelibs.fess.crawler.entity.UrlQueue;

/**
 * Service interface for managing URL queues.
 * Provides methods for adding, retrieving, and managing URLs within a crawling session.
 *
 * @param <QUEUE> the type of URL queue
 */
public interface UrlQueueService<QUEUE extends UrlQueue<?>> {

    /**
     * Updates the session ID.
     *