本文整理了Java中java.util.stream.LongStream.average()方法的一些代码示例，展示了LongStream.average()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。LongStream.average()方法的具体详情如下：
包路径：java.util.stream.LongStream
类名称：LongStream
方法名：average

LongStream.average介绍

[英]Returns an OptionalDouble describing the arithmetic mean of elements of this stream, or an empty optional if this stream is empty. This is a special case of a reduction.

This is a terminal operation.
[中]返回描述此流元素算术平均值的OptionalDouble，如果此流为空，则返回空可选值。这是reduction的一个特例。
这是一个terminal operation。

代码示例

代码示例来源：origin: prestodb/presto

public Optional<IndexInfo> build()
  {
    List<Integer> partitions = partitionsSizes.build();
    if (partitions.size() == 0) {
      return Optional.empty();
    }
    double avgSize = partitions.stream().mapToLong(Integer::longValue).average().getAsDouble();
    double squaredDifferences = partitions.stream().mapToDouble(size -> Math.pow(size - avgSize, 2)).sum();
    checkState(partitions.stream().mapToLong(Integer::longValue).sum() == rowsNumber, "Total number of rows in index does not match number of rows in partitions within that index");
    return Optional.of(new IndexInfo(rowsNumber, sizeInBytes, squaredDifferences, partitions.size()));
  }
}

代码示例来源：origin: prestodb/presto

@VisibleForTesting
static OptionalDouble calculateAverageRowsPerPartition(Collection<PartitionStatistics> statistics)
{
  return statistics.stream()
      .map(PartitionStatistics::getBasicStatistics)
      .map(HiveBasicStatistics::getRowCount)
      .filter(OptionalLong::isPresent)
      .mapToLong(OptionalLong::getAsLong)
      .peek(count -> verify(count >= 0, "count must be greater than or equal to zero"))
      .average();
}

代码示例来源：origin: wildfly/wildfly

private static void printStats(Map<String, List<Long>> results) {
    for (Map.Entry<String, List<Long>> entry : results.entrySet()) {
      System.out.printf("Results for %s%n", entry.getKey());
      System.out.printf("Min merge time=%d%n", entry.getValue().stream().min(Long::compare).get());
      System.out.printf("Max merge time=%d%n", entry.getValue().stream().max(Long::compare).get());
      System.out.printf("Avg merge time=%s%n", entry.getValue().stream().mapToLong(x -> x).average().getAsDouble());
      System.out.printf("===================================================================%n");
    }
  }
}

代码示例来源：origin: apache/hbase

@Override
public OptionalDouble getAvgStoreFileAge() {
 return getStoreFileAgeStream().average();
}

代码示例来源：origin: prestodb/presto

double averageIndexSize = indexInfos.stream()
    .mapToLong(IndexInfo::getSizeInBytes)
    .average()
    .getAsDouble();
double squaredDifferencesSizeOfIndex = indexInfos.stream()

代码示例来源：origin: atomix/atomix

@Override
public void run() {
 for (int i = 0; i < ITERATIONS; i++) {
  try {
   iterations.add(runIteration());
  } catch (Exception e) {
   e.printStackTrace();
   return;
  }
 }
 System.out.println("Completed " + ITERATIONS + " iterations");
 long averageRunTime = (long) iterations.stream().mapToLong(v -> v).average().getAsDouble();
 System.out.println(String.format("averageRunTime: %dms", averageRunTime));
 try {
  shutdown();
 } catch (Exception e) {
  e.printStackTrace();
 }
}

代码示例来源：origin: atomix/atomix

@Override
public void run() {
 for (int i = 0; i < ITERATIONS; i++) {
  try {
   iterations.add(runIteration());
  } catch (Exception e) {
   e.printStackTrace();
   return;
  }
 }
 System.out.println("Completed " + ITERATIONS + " iterations");
 long averageRunTime = (long) iterations.stream().mapToLong(v -> v).average().getAsDouble();
 System.out.println(String.format("averageRunTime: %dms", averageRunTime));
 try {
  shutdown();
 } catch (Exception e) {
  e.printStackTrace();
 }
}

代码示例来源：origin: speedment/speedment

default OptionalDouble average(LongPipeline pipeline) {
  requireNonNull(pipeline);
  return optimize(pipeline).getAsLongStream().average();
}

代码示例来源：origin: prestodb/presto

.filter(WindowOperatorStats::isMeaningful)
.mapToLong(DriverWindowInfo::getNumberOfIndexes)
.average()
.orElse(Double.NaN);
.filter(WindowOperatorStats::isMeaningful)
.mapToLong(DriverWindowInfo::getTotalRowsCount)
.average()
.orElse(Double.NaN);

代码示例来源：origin: prestodb/presto

StageStats stageStats = stageInfo.get().getStageStats();
double avgPositionsPerTask = stageInfo.get().getTasks().stream().mapToLong(task -> task.getStats().getProcessedInputPositions()).average().orElse(Double.NaN);
double squaredDifferences = stageInfo.get().getTasks().stream().mapToDouble(task -> Math.pow(task.getStats().getProcessedInputPositions() - avgPositionsPerTask, 2)).sum();
double sdAmongTasks = Math.sqrt(squaredDifferences / stageInfo.get().getTasks().size());

代码示例来源：origin: DV8FromTheWorld/JDA

/**
 * The average time in milliseconds between all shards that discord took to respond to our last heartbeat.
 * This roughly represents the WebSocket ping of this session. If there is no shard running this wil return {@code -1}.
 *
 * <p><b>{@link net.dv8tion.jda.core.requests.RestAction RestAction} request times do not
 * correlate to this value!</b>
 *
 * @return The average time in milliseconds between heartbeat and the heartbeat ack response
 */
default double getAveragePing()
{
  return this.getShardCache()
      .stream()
      .mapToLong(JDA::getPing)
      .filter(ping -> ping != -1)
      .average()
      .orElse(-1D);
}

代码示例来源：origin: gravitee-io/gravitee-gateway

private void report(final EndpointStatus endpointStatus) {
  final int previousStatusCode = rule.endpoint().getStatus().code();
  final String previousStatusName = rule.endpoint().getStatus().name();
  this.endpointStatus.updateStatus(endpointStatus.isSuccess());
  endpointStatus.setState(rule.endpoint().getStatus().code());
  endpointStatus.setAvailable(!rule.endpoint().getStatus().isDown());
  endpointStatus.setResponseTime((long) endpointStatus.getSteps().stream().mapToLong(Step::getResponseTime).average().getAsDouble());
  final boolean transition = previousStatusCode != rule.endpoint().getStatus().code();
  endpointStatus.setTransition(transition);
  if (transition && alertEngineService != null) {
    final Event.Builder event = new Event.Builder()
        .timestamp(currentTimeMillis())
        .context("Gateway", node.id())
        .context("Hostname", node.hostname())
        .context("Port", port)
        .type("HEALTH_CHECK")
        .prop("API", rule.api())
        .prop("Endpoint name", rule.endpoint().getName())
        .prop("Old status", previousStatusName)
        .prop("New status", rule.endpoint().getStatus().name())
        .prop("Success", endpointStatus.isSuccess());
    final Object tenant = node.metadata().get("tenant");
    if (tenant != null) {
      event.context("Tenant", (String) tenant);
    }
    alertEngineService.send(event.build());
  }
  statusHandler.handle(endpointStatus);
}

代码示例来源：origin: org.jboss.eap/wildfly-client-all

private static void printStats(Map<String, List<Long>> results) {
    for (Map.Entry<String, List<Long>> entry : results.entrySet()) {
      System.out.printf("Results for %s%n", entry.getKey());
      System.out.printf("Min merge time=%d%n", entry.getValue().stream().min(Long::compare).get());
      System.out.printf("Max merge time=%d%n", entry.getValue().stream().max(Long::compare).get());
      System.out.printf("Avg merge time=%s%n", entry.getValue().stream().mapToLong(x -> x).average().getAsDouble());
      System.out.printf("===================================================================%n");
    }
  }
}

代码示例来源：origin: io.prestosql/presto-main

public Optional<IndexInfo> build()
  {
    List<Integer> partitions = partitionsSizes.build();
    if (partitions.size() == 0) {
      return Optional.empty();
    }
    double avgSize = partitions.stream().mapToLong(Integer::longValue).average().getAsDouble();
    double squaredDifferences = partitions.stream().mapToDouble(size -> Math.pow(size - avgSize, 2)).sum();
    checkState(partitions.stream().mapToLong(Integer::longValue).sum() == rowsNumber, "Total number of rows in index does not match number of rows in partitions within that index");
    return Optional.of(new IndexInfo(rowsNumber, sizeInBytes, squaredDifferences, partitions.size()));
  }
}

代码示例来源：origin: prestosql/presto

public Optional<IndexInfo> build()
  {
    List<Integer> partitions = partitionsSizes.build();
    if (partitions.size() == 0) {
      return Optional.empty();
    }
    double avgSize = partitions.stream().mapToLong(Integer::longValue).average().getAsDouble();
    double squaredDifferences = partitions.stream().mapToDouble(size -> Math.pow(size - avgSize, 2)).sum();
    checkState(partitions.stream().mapToLong(Integer::longValue).sum() == rowsNumber, "Total number of rows in index does not match number of rows in partitions within that index");
    return Optional.of(new IndexInfo(rowsNumber, sizeInBytes, squaredDifferences, partitions.size()));
  }
}

代码示例来源：origin: wmr513/reactive

private double calcStdDev() {
  mean = durations.stream().mapToLong(d->d).average().orElse(0.0);
  double squareDiffSum = 0;
  for (long dur : durations) {
    squareDiffSum += Math.pow((dur-mean),2);
  }
  return Math.sqrt((squareDiffSum/(durations.size()-1.0)));
}

代码示例来源：origin: Rsl1122/Plan-PlayerAnalytics

public long toAverageSessionLength() {
  OptionalDouble average = sessions.stream().map(Session::getLength)
      .mapToLong(i -> i)
      .average();
  if (average.isPresent()) {
    return (long) average.getAsDouble();
  }
  return 0L;
}

代码示例来源：origin: prestosql/presto

@VisibleForTesting
static OptionalDouble calculateAverageRowsPerPartition(Collection<PartitionStatistics> statistics)
{
  return statistics.stream()
      .map(PartitionStatistics::getBasicStatistics)
      .map(HiveBasicStatistics::getRowCount)
      .filter(OptionalLong::isPresent)
      .mapToLong(OptionalLong::getAsLong)
      .peek(count -> verify(count >= 0, "count must be greater than or equal to zero"))
      .average();
}

代码示例来源：origin: one.util/streamex

@Override
public OptionalDouble average() {
  if (context.fjp != null)
    return context.terminate(stream()::average);
  return stream().average();
}

代码示例来源：origin: com.aol.cyclops/cyclops-streams

/**
 * Perform an asynchronous average operation
 * @see java.util.stream.Stream#mapToLong(ToLongFunction)
 *      @see java.util.stream.LongStream#average()
 * */
default CompletableFuture<OptionalDouble> averageLong(ToLongFunction<? super T> fn){
  
  return CompletableFuture.supplyAsync(()->getStream()
              .flatMapToLong(t-> LongStream.of(fn.applyAsLong(t)))
              .average(),getExec());
      
}
/**