D'après la dernière <a href="https://www.jetbrains.com/research/python-developers-survey-2018/#development-tools" class="external-link" target="_blank">Enquête Développeurs Python</a>, cela couvre environ 80% des utilisateurs.

import java.util.LinkedList;
import java.util.List;
import java.util.Map;
import java.util.Queue;
import java.util.regex.Pattern;

import org.codelibs.fess.crawler.entity.AccessResultImpl;
import org.codelibs.fess.crawler.entity.UrlQueueImpl;

/**
 * @author shinsuke
 *
 */
public class MemoryDataHelper {
    protected volatile Map<String, Queue<UrlQueueImpl<Long>>> urlQueueMap = new HashMap<>();

        final String url = urlQueue.getUrl();
        if (StringUtil.isBlank(url)) {
            if (logger.isDebugEnabled()) {
                logger.debug("URL is a blank: {}", url);
            }
            return false;
        }

        // check it in queue
        for (final UrlQueue<Long> urlInQueue : urlQueueList) {

            final Queue<SearchLog> queue = searchLogQueue;
            searchLogQueue = new ConcurrentLinkedQueue<>();
            processSearchLogQueue(queue);
        }

        if (!clickLogQueue.isEmpty()) {
            final Queue<ClickLog> queue = clickLogQueue;
            clickLogQueue = new ConcurrentLinkedQueue<>();
            processClickLogQueue(queue);
        }
    }

        }
    }

    @Override
    public OpenSearchUrlQueue poll(final String sessionId) {
        final QueueHolder queueHolder = getQueueHolder(sessionId);
        final Queue<OpenSearchUrlQueue> waitingQueue = queueHolder.waitingQueue;
        final Queue<OpenSearchUrlQueue> crawlingQueue = queueHolder.crawlingQueue;
        OpenSearchUrlQueue urlQueue = waitingQueue.poll();
        if (urlQueue != null) {

import java.util.List;
import java.util.Queue;

/**
 * Create queue of strings for tests.
 *
 * @author Jared Levy
 */
@GwtCompatible
@ElementTypesAreNonnullByDefault
public abstract class TestStringQueueGenerator implements TestQueueGenerator<String> {
  @Override
  public SampleElements<String> samples() {
    return new Strings();
  }

  @Override
  public Queue<String> create(Object... elements) {

import java.util.NoSuchElementException;
import java.util.Queue;
import javax.annotation.CheckForNull;
import org.checkerframework.checker.nullness.qual.Nullable;

/**
 * A queue which forwards all its method calls to another queue. Subclasses should override one or
 * more methods to modify the behavior of the backing queue as desired per the <a

  /** Returns the next entry in the access queue. */
  ReferenceEntry<K, V> getNextInAccessQueue();

  /** Sets the next entry in the access queue. */
  void setNextInAccessQueue(ReferenceEntry<K, V> next);

  /** Returns the previous entry in the access queue. */
  ReferenceEntry<K, V> getPreviousInAccessQueue();

  /** Sets the previous entry in the access queue. */

    /**
     * A queue of elements currently in the map, ordered by write time. Elements are added to the
     * tail of the queue on write.
     */
    @GuardedBy("this")
    final Queue<ReferenceEntry<K, V>> writeQueue;

    /**
     * A queue of elements currently in the map, ordered by access time. Elements are added to the
     * tail of the queue on access (note that writes count as accesses).

 */
public final class Crawler {
  private final OkHttpClient client;
  private final Set<HttpUrl> fetchedUrls = Collections.synchronizedSet(new LinkedHashSet<>());
  private final LinkedBlockingQueue<HttpUrl> queue = new LinkedBlockingQueue<>();
  private final ConcurrentHashMap<String, AtomicInteger> hostnames = new ConcurrentHashMap<>();

  public Crawler(OkHttpClient client) {
    this.client = client;
  }