protected MemoryDataHelper dataHelper;

    /*
     * (non-Javadoc)
     *
     * @see
     * org.codelibs.fess.crawler.service.UrlQueueService#updateSessionId(java.lang.String
     * , java.lang.String)
     */
    @Override
    public void updateSessionId(final String oldSessionId, final String newSessionId) {
        // not MT-safe
        final Queue<UrlQueueImpl<Long>> urlQueueList = dataHelper.getUrlQueueList(oldSessionId);

import java.util.List;

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

/**
 * @author shinsuke
 *
 */
public interface UrlQueueService<QUEUE extends UrlQueue<?>> {

    void updateSessionId(String oldSessionId, String newSessionId);

    void add(String sessionId, String url);

    void insert(QUEUE urlQueue);

    void delete(String sessionId);

    void deleteAll();

    }

    public void setSessionId(final String sessionId) {
        if (StringUtil.isNotBlank(sessionId) && !sessionId.equals(crawlerContext.sessionId)) {
            urlQueueService.updateSessionId(crawlerContext.sessionId, sessionId);
            crawlerContext.sessionId = sessionId;
        }
    }

    public String execute() {

                logger.warn("Failed to restore " + urlQueue, e);
            }
        }));
    }

    public void clearCache() {
        sessionCache.clear();
    }

    @Override
    public void updateSessionId(final String oldSessionId, final String newSessionId) {
        SearchResponse response = getClient().get(c -> c.prepareSearch(index).setScroll(new TimeValue(scrollTimeout))