/** The metadata associated with the URL queue. */
    protected String metaData;

    /** The encoding of the URL queue. */
    protected String encoding;

    /** The parent URL of the current URL in the queue. */
    protected String parentUrl;

    /** The depth of the URL in the queue. */
    protected Integer depth;

    /** The last modified timestamp of the URL in the queue. */
    protected Long lastModified;

 * }
 * </pre>
 */
public class ESSourceReader implements DocumentReader {
    private static final Logger logger = LogManager.getLogger(ESSourceReader.class);

    /** Queue of documents. */
    protected final Queue<Map<String, Object>> queue = new ConcurrentLinkedQueue<>();
    /** Flag indicating if reading is finished. */
    protected final AtomicBoolean isFinished = new AtomicBoolean(false);
    /** Random number generator. */

        final Queue<String> queue = new LinkedList<>();
        queue.add(text);
        final List<String> convertedTexts = new ArrayList<>(getMaxReadingNum());
        convertedTexts.add(text);

        for (final ReadingConverter converter : converters) {
            String s;
            while ((s = queue.poll()) != null && convertedTexts.size() <= getMaxReadingNum()) {

        assertTrue(fesenClient.prepareSearch("fess_crawler.queue")
                .setQuery(QueryBuilders.termQuery("sessionId", "id1"))
                .execute()
                .actionGet()
                .getHits()
                .getTotalHits()
                .value() > 0);
        assertTrue(fesenClient.prepareSearch("fess_crawler.queue")
                .setQuery(QueryBuilders.termQuery("sessionId", "id2"))

        block = new StringBuilder();
        nextBlkStart = 0;
        queue = new PriorityQueue<>(100, new MyTokensComparator());
        this.synonyms = new ArrayList<>();
    }

    @Override
    public boolean incrementToken() throws IOException {
        while (true) {
            final MyToken nextToken = getNextUniqueToken(queue, prevToken);
            if (nextToken == null) {
                getNextBlock();

    /** Indicates an access exception during crawling. */
    CRAWLING_ACCESS_EXCEPTION,
    /** Indicates a general exception during crawling. */
    CRAWLING_EXCEPTION,
    /** Indicates no URL is available in the queue. */
    NO_URL_IN_QUEUE,
    /** Indicates the start of a crawler thread. */
    START_THREAD,
    /** Indicates the finish of a crawler thread. */
    FINISHED_THREAD,

 * and when waiting for new URLs.
 * The delays are configurable via constructor parameters.
 *
 */
public class DefaultIntervalController extends AbstractIntervalController {

    /** Delay in milliseconds after processing a URL */
    protected long delayMillisAfterProcessing = 0L;

    /** Delay in milliseconds when no URL is in the queue */

 *   <li>{@code PRE_PROCESSING} - Represents the pre-processing state.</li>
 *   <li>{@code POST_PROCESSING} - Represents the post-processing state.</li>
 *   <li>{@code NO_URL_IN_QUEUE} - Indicates that there are no URLs in the queue.</li>
 *   <li>{@code WAIT_NEW_URL} - Indicates that the crawler is waiting for new URLs.</li>
 * </ul>
 */
public interface IntervalController {
    /** Constant representing the pre-processing state. */

 *   <li>Before processing a URL ({@link #delayBeforeProcessing()})</li>
 *   <li>After processing a URL ({@link #delayAfterProcessing()})</li>
 *   <li>When there are no URLs in the queue ({@link #delayAtNoUrlInQueue()})</li>
 *   <li>While waiting for new URLs to be added to the queue ({@link #delayForWaitingNewUrl()})</li>
 * </ul>
 *
 * <p>
 * Subclasses are responsible for implementing the abstract methods to define the actual delay

     */
    public static final String WEIGHT = "weight";

    /**
     * Converts this URL queue entry to XContent format for OpenSearch indexing.
     *
     * @param builder The XContentBuilder to write to.
     * @param params Additional parameters for the conversion.
     * @return The XContentBuilder with the URL queue data.
     * @throws IOException if the conversion fails.
     */
    @Override