* </p>
 *
 * <p>
 * It also provides thread-local storage for sitemaps, allowing each thread to have its own set of sitemaps.
 * </p>
 */
public class CrawlerContext {
    /**
     * Constructs a new CrawlerContext.
     */
    public CrawlerContext() {
        // Default constructor
    }

    /**
     * Session identifier for the crawling session.
     */
    protected String sessionId;

    /**

        final UrlQueue<?> urlQueue = objs.length > 1 && objs[1] instanceof UrlQueue<?> ? (UrlQueue<?>) objs[1] : null;
        try {
            final CrawlerContext crawlerContext = (CrawlerContext) objs[0];
            final Throwable e = (Throwable) objs[2];

            storeFailureUrl(crawlerContext, urlQueue, e.getClass().getCanonicalName(), e);
        } catch (final ContainerNotAvailableException e) {
            if (logger.isDebugEnabled()) {

            assertFalse(crawler1.crawlerContext == crawler2.crawlerContext);

            for (int i = 0; i < 100; i++) {
                if (crawler1.crawlerContext.getStatus() == CrawlerStatus.RUNNING) {
                    break;
                }
                Thread.sleep(50);
            }
            assertEquals(CrawlerStatus.RUNNING, crawler1.crawlerContext.getStatus());

---

## Key Components

### Core Classes

- **Crawler** (`Crawler.java`): Main orchestrator - `execute()`, `addUrl()`, `cleanup()`, `stop()`
- **CrawlerContext** (`CrawlerContext.java`): Execution context - `sessionId`, `status`, `accessCount`, `numOfThread`, `maxDepth`, `maxAccessCount`
- **CrawlerThread** (`CrawlerThread.java`): Worker thread - Poll URL → Validate → Execute → Process → Queue children