// set urlQueue to thread
        CrawlingParameterUtil.setCrawlerContext(crawlerContext);
        CrawlingParameterUtil.setUrlQueueService(urlQueueService);
        CrawlingParameterUtil.setDataService(dataService);
        try {
            while (crawlerContext.getStatus() != CrawlerStatus.DONE && isContinue(threadCheckCount)) {
                final UrlQueue<?> urlQueue = urlQueueService.poll(crawlerContext.sessionId);