Java Code Examples for java.util.stream.IntStream

@Test
public void collectsValuesFromCompletableFutures() throws ExecutionException, InterruptedException {
    ExecutorService threadPool = Executors.newFixedThreadPool(10);
    CompletableFuture<List<Integer>> integers = IntStream.range(0, 1000)
            .mapToObj(i -> CompletableFuture.supplyAsync(() -> {
                try {
                    Thread.sleep(random.nextInt(100));
                } catch (InterruptedException e) {
                    throw new RuntimeException(e);
                }
                return i;
            }, threadPool))
            .collect(CompletableFutures.toFutureList());

    assertThat(
            integers.get(),
            equalTo(IntStream.range(0, 1000).mapToObj(Integer::valueOf).collect(toList())));
}
 

/**
 * Create a number of worker nodes with random ports and start them
 * @param numWorkers number of Workers to create
 */
public void createWorkers(int numWorkers) {
    String meta = getMetaIdentity();
    List<LogServer> newWorkers = IntStream.range(0, numWorkers).parallel().mapToObj(i ->
            LogServer.newBuilder()
                    .setHostName("localhost")
                    .setPort(10000 + i)
                    .setMetaQuorum(meta)
                    .setWorkingDir(baseTestDir + "/workers/" + i)
                    .build()).collect(Collectors.toList());
    newWorkers.parallelStream().forEach( worker -> {
        try {
            worker.start();
        } catch (IOException e) {
            throw new RuntimeException(e);
        }
    });
    workers.addAll(newWorkers);
}
 

@Test
public void map() {
	final TrackSegment segment = TrackSegment.of(
		IntStream.range(0, 50)
			.mapToObj(i -> WayPoint.builder().build(i, i))
			.collect(Collectors.toList())
	);

	final TrackSegment mapped = segment.toBuilder()
		.map(wp -> wp.toBuilder()
			.lat(wp.getLatitude().doubleValue() + 1)
			.build())
		.build();

	for (int i = 0, n = mapped.getPoints().size(); i < n; ++i) {
		Assert.assertEquals(
			mapped.getPoints().get(i).getLatitude().doubleValue(),
			(double)(i + 1)
		);
	}
}
 

@Test
public void breadthFirstVisitShouldAllowUpToLimitNesting() {
    FilterCondition condition = FilterCondition.builder()
        .to("[email protected]")
        .build();

    Filter nestedFilter = IntStream.range(0, 10).boxed().reduce(
        (Filter) condition,
        (filter, i) -> FilterOperator.and(filter),
        (f1, f2) -> {
            throw new RuntimeException("unsupported combination");
        });

    assertThat(nestedFilter.breadthFirstVisit())
        .containsExactly(condition);
}
 

private int computeTimeDelta(List<Metric> list) {
  int size = list.size();
  IntSummaryStatistics stats = IntStream.range(1, size)
      .map(
          x ->
              (int)
                  (list.get(size - x).getTime().getTime()
                      - list.get(size - x - 1).getTime().getTime()))
      .filter(d -> (d >= 0 && d < minFrequencyMillisAllowed))
      .summaryStatistics();

  int result = -1;

  /**
   * In order to be marked as high frequency metric the number of points
   * should be above the BURST_THRESHOLD.
   * It ignores any small bursts of high frequency metrics.
   */
  if (stats.getCount() > BURST_THRESHOLD) {
    // uses minimal delta time from all consecutive data points
    result = stats.getMin();
    log.info("stats: " + stats);
  }
  return result;
}
 

private static void serializeData(final BufferedWriter bw, final ILabeledDataset<? extends ILabeledInstance> data) throws IOException {
	bw.write(EArffItem.DATA.getValue() + "\n");
	for (ILabeledInstance instance : data) {
		if (instance instanceof DenseInstance) {
			Object[] atts = instance.getAttributes();
			bw.write(IntStream.range(0, atts.length).mapToObj(x -> serializeAttributeValue(data.getInstanceSchema().getAttribute(x), atts[x])).collect(Collectors.joining(",")));
			bw.write(",");
			bw.write(serializeAttributeValue(data.getInstanceSchema().getLabelAttribute(), instance.getLabel()));
			bw.write("\n");
		} else {
			bw.write("{");
			bw.write(((SparseInstance) instance).getAttributeMap().entrySet().stream().map(x -> x.getKey() + " " + serializeAttributeValue(data.getInstanceSchema().getAttribute(x.getKey()), x.getValue()))
					.collect(Collectors.joining(",")));
			if (instance.isLabelPresent()) {
				bw.write(",");
			}
			bw.write(data.getNumAttributes());
			bw.write(" ");
			bw.write(serializeAttributeValue(data.getInstanceSchema().getLabelAttribute(), instance.getLabel()));
			bw.write("}\n");
		}
	}
}
 

@Test
public void testDataIndexOnlyOnCustomType() throws Exception {
  final DataStore dataStore = dataIdxOnlyDataStoreOptions.createDataStore();
  final LatLonTimeAdapter adapter = new LatLonTimeAdapter();
  dataStore.addType(adapter);
  try (Writer<LatLonTime> writer = dataStore.createWriter(adapter.getTypeName())) {
    for (int i = 0; i < 10; i++) {
      writer.write(new LatLonTime(i, 100 * i, 0.25f * i, -0.5f * i));
    }
  }

  final Set<Integer> expectedIntIds =
      IntStream.rangeClosed(0, 9).boxed().collect(Collectors.toSet());
  try (CloseableIterator<LatLonTime> it =
      (CloseableIterator) dataStore.query(QueryBuilder.newBuilder().build())) {
    while (it.hasNext()) {
      Assert.assertTrue(expectedIntIds.remove(it.next().getId()));
    }
  }
  Assert.assertTrue(expectedIntIds.isEmpty());
  TestUtils.deleteAll(dataIdxOnlyDataStoreOptions);
}
 

/**
 * Calculates the posterior expectation of the mean of hidden state values on a segment
 *
 * @param firstTargetIndex first target index of the segment
 * @param segmentLength length of the segment
 * @param fbResult result of forward-backward algorithm
 * @param <STATE> type of hidden state; must implement {@link ScalarProducer}
 * @param <TARGET> type of target; must implement {@link Locatable}
 * @throws IllegalStateException if segment length is negative
 * @return segment mean
 */
public static <STATE extends ScalarProducer, TARGET extends Locatable> double calculateSegmentMean(
        final int firstTargetIndex,
        final int segmentLength,
        final ForwardBackwardAlgorithm.Result<?, TARGET, STATE> fbResult) {
    Utils.validateArg(segmentLength >= 0, "Segment length must be non-negative");
    /* trivial case when the segment has length 0 */
    if (segmentLength == 0) {
        return Double.NaN;
    } else {
        final List<STATE> hiddenStates = fbResult.model().hiddenStates();
        final double[] hiddenStateValues = hiddenStates.stream()
                .mapToDouble(STATE::getScalar)
                .toArray();
        return IntStream.range(firstTargetIndex, firstTargetIndex + segmentLength).boxed()
                .flatMapToDouble(targetIndex -> IntStream.range(0, hiddenStates.size())
                        .mapToDouble(si -> hiddenStateValues[si] *
                                FastMath.exp(fbResult.logProbability(targetIndex, hiddenStates.get(si)))))
                .sum() / segmentLength;
    }
}
 

@Test
public void testRandomStream() {
    final int size = 1024 * 1024;
    final int[] seeds = {
            2, 3, 5, 7, 11, 13, 17, 19, 23, 29, 31, 37, 41,
            43, 47, 53, 59, 61, 67, 71, 73, 79, 83, 89, 97};
    final byte[] bytes = new byte[size];
    for (int seed : seeds) {
        final Random random = new Random(seed);
        random.nextBytes(bytes);
        final BitSet bitSet = BitSet.valueOf(bytes);
        final int cardinality = bitSet.cardinality();
        final IntStream stream = bitSet.stream();
        final int[] array = stream.toArray();
        assertEquals(array.length, cardinality);
        int nextSetBit = -1;
        for (int i=0; i < cardinality; i++) {
            nextSetBit = bitSet.nextSetBit(nextSetBit + 1);
            assertEquals(array[i], nextSetBit);
        }
    }
}
 

public void createOrders() {

		Random random = new Random();
		Address address = new Address("it", "doesn't", "matter");

		LongStream.rangeClosed(1, 100).forEach((orderId) -> LongStream.rangeClosed(1, 3).forEach((customerId) -> {
			Order order = new Order(orderId, customerId, address);
			IntStream.rangeClosed(0, random.nextInt(3) + 1).forEach((lineItemCount) -> {
				int quantity = random.nextInt(3) + 1;
				long productId = random.nextInt(3) + 1;
				order.add(new LineItem(productRepository.findById(productId).get(), quantity));
			});
			orderRepository.save(order);
		}));

		assertThat(orders.keySetOnServer().size()).isEqualTo(100);
	}
 

@Test
public void test2c() {
    ChronicleMap<Integer, Bar2> map = ChronicleMapBuilder.simpleMapOf(Integer.class, Bar2.class)
            .name("bar")
            .averageValueSize(1024)
            .entries(10)
            .create();

    String expected = IntStream.range(0, 4096)
            .mapToObj(i -> i % 50 == 0 ? String.format("\n%04d", i) : "" + i % 10)
            .collect(Collectors.joining(""));

    Bar2 value = new Bar2(expected);
    map.put(1, value);
    String actual = map.get(1).x;

    assertEquals(expected, actual);
}
 

/**
 * Flux : 返回0-n个元素 注：需要指定MediaType
 * 
 * @return
 */
@GetMapping(value = "/flux", produces = MediaType.TEXT_EVENT_STREAM_VALUE)
private Flux<String> flux() {
	Flux<String> result = Flux.fromStream(IntStream.range(1, 5).mapToObj(i -> {
		if (i == 3) {
			throw new ResultException("flux 错误测试");
		}
		try {
			TimeUnit.SECONDS.sleep(1);
		} catch (InterruptedException e) {
		}
		return "flux data--" + i;
	}));
	
	return result;
}
 

@Override public void mouseDragged(MouseEvent e) {
  JList<?> l = (JList<?>) e.getComponent();
  l.setFocusable(true);
  Point destPoint = e.getPoint();
  Path2D rb = getRubberBand();
  rb.reset();
  rb.moveTo(srcPoint.x, srcPoint.y);
  rb.lineTo(destPoint.x, srcPoint.y);
  rb.lineTo(destPoint.x, destPoint.y);
  rb.lineTo(srcPoint.x, destPoint.y);
  rb.closePath();

  int[] indices = IntStream.range(0, l.getModel().getSize())
      .filter(i -> rb.intersects(l.getCellBounds(i, i))).toArray();
  l.setSelectedIndices(indices);
  l.repaint();
}
 

/**
 * Sets the value to <code>raft.server.storage.dir</code> via
 * RaftServerConfigKeys and verifies it by reading directly from property.
 */
@Test
public void testStorageDirProperty() {
  final File testDir = new File(
      rootTestDir.get(), UUID.randomUUID().toString());
  final List<File> directories = new ArrayList<>();
  final  RaftProperties properties = new RaftProperties();

  IntStream.range(0, 10).mapToObj((i) -> new File(testDir,
      Integer.toString(i))).forEach(directories::add);
  RaftServerConfigKeys.setStorageDir(properties, directories);

  final String expected = directories.stream().map(File::getAbsolutePath)
      .collect(Collectors.joining(","));
  final String actual = properties.get(RaftServerConfigKeys.STORAGE_DIR_KEY);
  Assert.assertEquals(expected, actual);
}
 

private double estimateProbabilityOfPartialAssignment(Assignment MAPassignment, boolean useConditionalDistributions) {

        double probabilityEstimate;
        final int numSamplesAverage = 150;

        Assignment evidenceAugmented=new HashMapAssignment(evidence);
        MAPvariables.forEach(voi -> evidenceAugmented.setValue(voi, MAPassignment.getValue(voi)));

        final Assignment finalAssignment=new HashMapAssignment(MAPassignment);

        IntStream auxIntStream = IntStream.range(0, numSamplesAverage);
        //probabilityEstimate = auxIntStream.mapToObj(i -> obtainValuesRandomly(finalAssignment,evidenceAugmented,new Random())).mapToDouble(as -> Math.exp(this.model.getLogProbabiltyOf(as))).average().getAsDouble();
        try {
            probabilityEstimate = auxIntStream.mapToObj(i -> {
                if (useConditionalDistributions)
                    return obtainValues(finalAssignment, evidenceAugmented, new Random(MAPrandom.nextInt()));
                else
                    return obtainValuesRandomly(finalAssignment, evidenceAugmented, new Random(MAPrandom.nextInt()));
                })
                .mapToDouble(as -> Math.exp(this.model.getLogProbabiltyOf(as)))
                .filter(Double::isFinite).average().getAsDouble();
        }
        catch(Exception e) {
            probabilityEstimate=0;
        }

        return probabilityEstimate;
    }
 

/**
 * Assert that exception is thrown if normalized posterior probabilities do not add up to 1
 */
@Test(expectedExceptions = IllegalArgumentException.class)
public void testCopyNumberPosteriorDistributionValidation() {
    new CopyNumberPosteriorDistribution(IntStream.range(0, TEST_INVALID_LOG_POSTERIOR_VECTOR.length)
            .boxed()
            .collect(Collectors.toMap(IntegerCopyNumberState::new,
                    cn -> TEST_INVALID_LOG_POSTERIOR_VECTOR[cn])));
}
 

@Override
public void setPlotMaxXList(final @NotNull List<Optional<Double>> values) {
	if(values.size() == shapes.size()) {
		IntStream.range(0, values.size()).
			filter(i -> values.get(i).isPresent() && shapes.get(i) instanceof PlotProp).
			forEach(i -> ((PlotProp) shapes.get(i)).setPlotMaxX(values.get(i).orElseThrow()));
	}
}
 

@Override
public void setGridStartList(final @NotNull List<Optional<Point>> values) {
	if(values.size() == shapes.size()) {
		IntStream.range(0, values.size()).
			filter(i -> values.get(i).isPresent() && shapes.get(i) instanceof IStdGridProp).
			forEach(i -> ((IStdGridProp) shapes.get(i)).setGridStart(values.get(i).orElseThrow().getX(),  values.get(i).orElseThrow().getY()));
	}
}
 

protected List<Double> predictSequence(List<Integer> tokens) {
	if (this.selfTesting) this.model.forget(tokens);
	List<List<Integer>> preds = toPredictions(this.model.predict(tokens));
	List<Double> mrrs = IntStream.range(0, tokens.size())
			.mapToObj(i -> preds.get(i).indexOf(tokens.get(i)))
			.map(ModelRunner::toMRR)
			.collect(Collectors.toList());
	if (this.selfTesting) this.model.learn(tokens);
	return mrrs;
}
 

public void testIntStreamMatches() {
    assertIntPredicates(() -> IntStream.range(0, 0), Kind.ANY, INT_PREDICATES, false, false, false, false);
    assertIntPredicates(() -> IntStream.range(0, 0), Kind.ALL, INT_PREDICATES, true, true, true, true);
    assertIntPredicates(() -> IntStream.range(0, 0), Kind.NONE, INT_PREDICATES, true, true, true, true);

    assertIntPredicates(() -> IntStream.range(1, 2), Kind.ANY, INT_PREDICATES, true, false, false, true);
    assertIntPredicates(() -> IntStream.range(1, 2), Kind.ALL, INT_PREDICATES, true, false, false, true);
    assertIntPredicates(() -> IntStream.range(1, 2), Kind.NONE, INT_PREDICATES, false, true, true, false);

    assertIntPredicates(() -> IntStream.range(1, 6), Kind.ANY, INT_PREDICATES, true, false, true, true);
    assertIntPredicates(() -> IntStream.range(1, 6), Kind.ALL, INT_PREDICATES, true, false, false, false);
    assertIntPredicates(() -> IntStream.range(1, 6), Kind.NONE, INT_PREDICATES, false, true, false, false);
}
 

@Test(dataProvider = "sizes")
public void testDoubleAfterBuilding(int size) {
    DoubleStream.Builder sb = DoubleStream.builder();
    IntStream.range(0, size).asDoubleStream().forEach(sb);
    sb.build();

    checkISE(() -> sb.accept(1));
    checkISE(() -> sb.add(1));
    checkISE(() -> sb.build());
}
 

private static IntSet toSet(SelectedPositions selectedPositions)
{
    int start = selectedPositions.getOffset();
    int end = start + selectedPositions.size();
    if (selectedPositions.isList()) {
        return new IntArraySet(Arrays.copyOfRange(selectedPositions.getPositions(), start, end));
    }
    return new IntArraySet(IntStream.range(start, end).toArray());
}
 

@Override
public boolean equals(Object o) {
  if (this == o) return true;
  if (o == null) return false;
  if (!(o instanceof AutogenS3DatasetDiff)) return false;
  AutogenS3DatasetDiff other = (AutogenS3DatasetDiff) o;

  {
    Function3<List<AutogenS3DatasetComponentDiff>, List<AutogenS3DatasetComponentDiff>, Boolean>
        f =
            (x2, y2) ->
                IntStream.range(0, Math.min(x2.size(), y2.size()))
                    .mapToObj(
                        i -> {
                          Function3<
                                  AutogenS3DatasetComponentDiff,
                                  AutogenS3DatasetComponentDiff,
                                  Boolean>
                              f2 = (x, y) -> x.equals(y);
                          return f2.apply(x2.get(i), y2.get(i));
                        })
                    .filter(x -> x.equals(false))
                    .collect(Collectors.toList())
                    .isEmpty();
    if (this.Components != null || other.Components != null) {
      if (this.Components == null && other.Components != null) return false;
      if (this.Components != null && other.Components == null) return false;
      if (!f.apply(this.Components, other.Components)) return false;
    }
  }
  return true;
}
 

/**
 * Normalizes a vector of double values
 *
 * @param vector
 * @return The normalized vector
 */
public static double[] getNormalizedVector(double[] vector, double min, double max) {
  double[] normalizedVector = new double[vector.length];

  IntStream.range(0, vector.length)
          .forEach(i -> normalizedVector[i] = normalize(vector[i], min, max));

  return normalizedVector;
}
 

public static void main(String[] args) throws PulsarClientException {
    PulsarClient client = PulsarClient.builder()
            .serviceUrl(SERVICE_URL)
            .build();

    log.info("Created a client for the Pulsar cluster running at {}", SERVICE_URL);

    client.newProducer()
            .topic(TOPIC_NAME)
            .compressionType(CompressionType.LZ4)
            .createAsync()
            .thenAccept(producer -> {
                log.info("Producer created asynchronously for the topic {}", TOPIC_NAME);

                MessageBuilder<byte[]> msgBuilder = MessageBuilder.create();

                // Send 10 messages with varying content
                IntStream.range(1, 11).forEach(i -> {
                    byte[] msgContent = String.format("hello-pulsar-%d", i).getBytes();
                    msgBuilder.setContent(msgContent);
                    producer.sendAsync(msgBuilder.build())
                            .handle((msgId, e) -> {
                                if (e != null) {
                                    e.printStackTrace();
                                }

                                log.info("Successfully produced message with ID {}",
                                        new String(msgId.toByteArray()));
                                return null;
                            });
                });
            })
            .exceptionally(e -> {
                log.error(e.toString());
                return null;
            });
}
 

private void registerSkippedTransports(BundleContext bundleContext) {
    IntStream.range(0, SKIPPED_SERVICE_COUNT)
            .forEach($ -> {
                Dictionary<String, Object> properties = new Hashtable<>();
                properties.put("skipCarbonStartupResolver", true);
                bundleContext.registerService(Transport.class, new FtpTransport(), properties);
            });
}
 

@Test
public void testSelectHost() throws Exception {
    assertThat(leastConnHostSelector, instanceOf(StrictLeastConnHostSelector.class));
    for (int retry = 1; retry <= NUM_RETRIES; retry++) {
        int hostsLength = new Random().nextInt(NUM_HOSTS);
        IntStream.range(0, hostsLength - 1).forEach(x -> {
            final Host[] newHosts = Arrays.copyOf(hosts, hostsLength);
            long result = leastConnHostSelector.selectHost(newHosts, commonExchange);
            assertThat(result, equalTo(0L));
        });
    }
}
 

private static List<MatrixBlock> generateExpectedDataDR(MatrixBlock mb, MatrixBlock perm) {
	int batchSize = (int) Math.ceil((double) ROW_SIZE / WORKER_NUM);
	return IntStream.range(0, WORKER_NUM).mapToObj(i -> {
		int begin = i * batchSize;
		int end = Math.min((i + 1) * batchSize, mb.getNumRows());
		MatrixBlock slicedPerm = perm.slice(begin, end - 1);
		return slicedPerm.aggregateBinaryOperations(slicedPerm, mb, new MatrixBlock(),
				InstructionUtils.getMatMultOperator(WORKER_NUM));
	}).collect(Collectors.toList());
}
 

@Test
public void testWithDropBackPressure() {
    MultiAssertSubscriber<Integer> subscriber = Multi.createFrom().<Integer> emitter(emitter -> {
        IntStream.range(0, 1000).forEach(emitter::emit);
        emitter.complete();
    }, BackPressureStrategy.DROP).subscribe()
            .withSubscriber(MultiAssertSubscriber.create(20))
            .request(Long.MAX_VALUE)
            .assertCompletedSuccessfully();
    // 20 because the 20 first are consumed, others are dropped
    assertThat(subscriber.items()).hasSize(20);

    subscriber = Multi.createFrom().<Integer> emitter(emitter -> {
        IntStream.range(0, 1000).forEach(emitter::emit);
        emitter.complete();
    }, BackPressureStrategy.DROP).subscribe()
            .withSubscriber(MultiAssertSubscriber.create())
            .request(20)
            .request(Long.MAX_VALUE)
            .assertCompletedSuccessfully();
    assertThat(subscriber.items()).isEmpty();

    Multi.createFrom().<Integer> emitter(MultiEmitter::complete, BackPressureStrategy.DROP)
            .subscribe().withSubscriber(MultiAssertSubscriber.create(20))
            .assertCompletedSuccessfully()
            .assertHasNotReceivedAnyItem();

    Multi.createFrom().<Integer> emitter(emitter -> {
        IntStream.range(0, 1000).forEach(emitter::emit);
        emitter.fail(new IOException("boom"));
    }, BackPressureStrategy.DROP).subscribe()
            .withSubscriber(MultiAssertSubscriber.create())
            .request(20)
            .request(Long.MAX_VALUE)
            .assertHasFailedWith(IOException.class, "boom")
            .assertHasNotReceivedAnyItem();
}
 

@Test(dataProvider = "StreamTestData<Integer>", dataProviderClass = StreamTestDataProvider.class)
public void testOp(String name, TestData.OfRef<Integer> data) {
    Collection<Integer> result = exerciseOpsInt(
            data,
            Stream::distinct,
            IntStream::distinct,
            LongStream::distinct,
            DoubleStream::distinct);

    assertUnique(result);
    assertTrue((data.size() > 0) ? result.size() > 0 : result.size() == 0);
    assertTrue(result.size() <= data.size());
}