本文整理了Java中java.util.concurrent.ConcurrentSkipListMap.firstEntry()方法的一些代码示例，展示了ConcurrentSkipListMap.firstEntry()的具体用法。这些代码示例主要来源于Github/Stackoverflow/Maven等平台，是从一些精选项目中提取出来的代码，具有较强的参考意义，能在一定程度帮忙到你。ConcurrentSkipListMap.firstEntry()方法的具体详情如下：
包路径：java.util.concurrent.ConcurrentSkipListMap
类名称：ConcurrentSkipListMap
方法名：firstEntry

ConcurrentSkipListMap.firstEntry介绍

[英]Returns a key-value mapping associated with the least key in this map, or null if the map is empty. The returned entry does not support the Entry.setValue method.
[中]

代码示例

代码示例来源：origin: qunarcorp/qmq

public LogSegment firstSegment() {
  final Map.Entry<Long, LogSegment> entry = segments.firstEntry();
  return entry == null ? null : entry.getValue();
}

代码示例来源：origin: apache/ignite

/** */
public UUID getCoordinator() {
  Map.Entry<Long, ZookeeperClusterNode> e = rtState.top.nodesByOrder.firstEntry();
  return e != null ? e.getValue().id() : null;
}

代码示例来源：origin: apache/hbase

@Test
public void testFirstEntry() throws Exception {
 assertEquals(csm.firstEntry().getKey(), m.firstEntry().getKey());
 assertEquals(csm.firstEntry().getValue(), m.firstEntry().getValue());
 assertEquals(csm.firstEntry(), m.firstEntry());
}

代码示例来源：origin: loklak/loklak_server

Map.Entry<Date, Track> t = this.pendingQueue.firstEntry();
if (t == null) break timeoutcheck;
boolean timeout = t.getKey().getTime() + AccessTracker.this.track_timeout < System.currentTimeMillis();

代码示例来源：origin: apache/incubator-druid

currentlyProcessing = segmentsToDrop.firstEntry().getValue();
 log.debug("Server[%s] dropping [%s]", basePath, currentlyProcessing.getSegmentId());
} else if (!segmentsToLoad.isEmpty()) {
 currentlyProcessing = segmentsToLoad.firstEntry().getValue();
 log.debug("Server[%s] loading [%s]", basePath, currentlyProcessing.getSegmentId());
} else {

代码示例来源：origin: mulesoft/mule

private int expireAndCount() {
 // first we trim the store according to max size
 int expiredEntries = 0;
 final long now = System.nanoTime();
 Map.Entry<?, ?> oldestEntry;
 purge: while ((oldestEntry = store.firstEntry()) != null) {
  Long oldestKey = (Long) oldestEntry.getKey();
  long oldestKeyValue = oldestKey.longValue();
  if (NANOSECONDS.toMillis(now - oldestKeyValue) >= entryTTL) {
   store.remove(oldestKey);
   expiredEntries++;
  } else {
   break purge;
  }
 }
 return expiredEntries;
}

代码示例来源：origin: co.paralleluniverse/galaxy

private Node getFirstNode() {
  assert ordered;
  synchronized (nodes) {
    final Map.Entry<String, Node> entry = nodes.firstEntry();
    return (entry != null ? entry.getValue() : null);
  }
}

代码示例来源：origin: cinchapi/concourse

@Override
public Entry<T> firstEntry() {
  return backing.firstEntry().getValue();
}

代码示例来源：origin: org.jclouds.api/nova

public URI getURI() {
 if (orderedSelfReferences.isEmpty())
   populateOrderedSelfReferences();
 return orderedSelfReferences.firstEntry().getValue();
}

代码示例来源：origin: teiid/teiid

public V firstEntry(boolean poll) {
  Map.Entry<CacheKey, V> entry = null;
  if (poll) {
    entry = evictionQueue.pollFirstEntry();
    if (entry != null) {
      int result = size.addAndGet(-1);
      assert result >=0 || !isSuspectSize(size);
    }
  } else {
    entry = evictionQueue.firstEntry();
  }
  if (entry != null) {
    return entry.getValue();
  }
  return null;
}

代码示例来源：origin: org.teiid/teiid-engine

public V firstEntry(boolean poll) {
  Map.Entry<CacheKey, V> entry = null;
  if (poll) {
    entry = evictionQueue.pollFirstEntry();
    if (entry != null) {
      int result = size.addAndGet(-1);
      assert result >=0 || !isSuspectSize(size);
    }
  } else {
    entry = evictionQueue.firstEntry();
  }
  if (entry != null) {
    return entry.getValue();
  }
  return null;
}

代码示例来源：origin: org.jboss.teiid/teiid-engine

public V firstEntry(boolean poll) {
  Map.Entry<CacheKey, V> entry = null;
  if (poll) {
    entry = evictionQueue.pollFirstEntry();
    if (entry != null) {
      int result = size.addAndGet(-1);
      assert result >=0 || !isSuspectSize(size);
    }
  } else {
    entry = evictionQueue.firstEntry();
  }
  if (entry != null) {
    return entry.getValue();
  }
  return null;
}

代码示例来源：origin: limeng32/mybatis.flying

private void observerMethodsFission(ConcurrentSkipListMap<Class<?>, Set<Method>> observerMethodMap,
    Entry<Class<?>, Set<Method>> currentE, ConcurrentSkipListMap<Class<?>, Set<Method>> observerMethodMapNew) {
  if (observerMethodMap.size() != 0) {
    if (currentE == null) {
      currentE = observerMethodMap.firstEntry();
    }
    observerMethodMapNew.put(currentE.getKey(), currentE.getValue());
    observerMethodsFissionFission(observerMethodMap, observerMethodMapNew);
    Entry<Class<?>, Set<Method>> nextE = observerMethodMap.higherEntry(currentE.getKey());
    if (nextE != null) {
      observerMethodsFission(observerMethodMap, nextE, observerMethodMapNew);
    }
  }
}

代码示例来源：origin: cinchapi/concourse

@Override
public java.util.Map.Entry<K, V> firstEntry() {
  long[] stamps = grabAllSegmentWriteLocks();
  try {
    sort();
    return sorted.firstEntry();
  }
  finally {
    releaseSegmentLocks(stamps);
  }
}

代码示例来源：origin: com.github.vladimir-bukhtoyarov/rolling-metrics

@Override
protected void updateConcurrently(long timestamp, long latencyTime, TimeUnit latencyUnit, Supplier<String> descriptionSupplier, long latencyNanos) {
  Map.Entry<PositionKey, Position> firstEntry = positions.firstEntry();
  PositionKey firstKey = firstEntry.getKey();
  Position firstPosition = firstEntry.getValue();
  long currentPhase = phaseSequence.get();
  if (!isNeedToAdd(timestamp, latencyNanos, firstPosition, firstKey, currentPhase)) {
    return;
  }
  Position position = new Position(timestamp, latencyTime, latencyUnit, descriptionSupplier, maxDescriptionLength);
  if (positions.putIfAbsent(new PositionKey(currentPhase, position), position) == null) {
    positions.pollFirstEntry();
  }
}

代码示例来源：origin: vladimir-bukhtoyarov/rolling-metrics

@Override
protected void updateConcurrently(long timestamp, long latencyTime, TimeUnit latencyUnit, Supplier<String> descriptionSupplier, long latencyNanos) {
  Map.Entry<PositionKey, Position> firstEntry = positions.firstEntry();
  PositionKey firstKey = firstEntry.getKey();
  Position firstPosition = firstEntry.getValue();
  long currentPhase = phaseSequence.get();
  if (!isNeedToAdd(timestamp, latencyNanos, firstPosition, firstKey, currentPhase)) {
    return;
  }
  Position position = new Position(timestamp, latencyTime, latencyUnit, descriptionSupplier, maxDescriptionLength);
  if (positions.putIfAbsent(new PositionKey(currentPhase, position), position) == null) {
    positions.pollFirstEntry();
  }
}

代码示例来源：origin: org.infinispan/infinispan-hibernate-cache-commons

private int randomFamilyId(ThreadLocalRandom random) {
 Map.Entry<Integer, AtomicInteger> first = familyIds.firstEntry();
 Map.Entry<Integer, AtomicInteger> last = familyIds.lastEntry();
 if (first == null || last == null) return 0;
 Map.Entry<Integer, AtomicInteger> ceiling = familyIds.ceilingEntry(random.nextInt(first.getKey(), last.getKey() + 1));
 return ceiling == null ? 0 : ceiling.getKey();
}

代码示例来源：origin: org.apache.hbase/hbase-common

@Test
public void testFirstEntry() throws Exception {
 assertEquals(csm.firstEntry().getKey(), m.firstEntry().getKey());
 assertEquals(csm.firstEntry().getValue(), m.firstEntry().getValue());
 assertEquals(csm.firstEntry(), m.firstEntry());
}

代码示例来源：origin: com.aliyun.hbase/alihbase-common

@Test
public void testFirstEntry() throws Exception {
 assertEquals(csm.firstEntry().getKey(), m.firstEntry().getKey());
 assertEquals(csm.firstEntry().getValue(), m.firstEntry().getValue());
 assertEquals(csm.firstEntry(), m.firstEntry());
}

代码示例来源：origin: addthis/hydra

/**
 * Helper method for {@link #getFirstKey()}.
 */
protected K firstKeyFastPath() {
  Page<K, V> leftSentinel = getCache().firstEntry().getValue();
  readLock(leftSentinel);
  try {
    if (leftSentinel.keys() == null) {
      pullPageFromDisk(leftSentinel, LockMode.READMODE);
    }
    assert (!leftSentinel.inTransientState());
    if (leftSentinel.size() > 0) {
      return leftSentinel.keys().get(0);
    }
  } finally {
    readUnlock(leftSentinel);
  }
  return null;
}