Example usage for java.util.stream Stream iterate

Introduction

In this page you can find the example usage for java.util.stream Stream iterate.

Prototype

public static <T> Stream<T> iterate(final T seed, final UnaryOperator<T> f) 

Source Link

Document

Returns an infinite sequential ordered Stream produced by iterative application of a function f to an initial element seed , producing a Stream consisting of seed , f(seed) , f(f(seed)) , etc.

Usage

From source file:Main.java

public static void main(String[] args) {
    Stream.iterate(1, n -> n + 1).limit(10).forEach(System.out::println);

}

---

From source file:Main.java

public static void main(String[] args) {
    Stream.iterate(2L, n -> n + 1).filter(Main::isOdd).limit(5).forEach(System.out::println);
}

---

From source file:Main.java

public static void main(String[] args) {
    Stream.iterate(2L, n -> n + 1).filter(Main::isOdd).skip(100).limit(5).forEach(System.out::println);
}

---

From source file:Main.java

public static void main(String... args) {
    long l = Stream.iterate(1L, i -> i + 1).limit(3).reduce(Long::sum).get();
    System.out.println(l);/*from   ww w  .  j  a  va2s  . com*/
}

---

From source file:Main.java

public static void main(String... args) {
    long l = Stream.iterate(1L, i -> i + 1).limit(300).parallel().reduce(Long::sum).get();
    System.out.println(l);//from www  .java2 s  .c  o m
}

---

From source file:Main.java

public static void main(String[] args) {
    Stream<Long> tenNaturalNumbers = Stream.iterate(1L, n -> n + 1).limit(10);

    tenNaturalNumbers.forEach(System.out::println);
}

---

From source file:Main.java

public static void main(String[] args) {
    // fibonnaci with iterate
    Stream.iterate(new int[] { 0, 1 }, t -> new int[] { t[1], t[0] + t[1] }).limit(10)
            .forEach(t -> System.out.println("(" + t[0] + ", " + t[1] + ")"));
}

---

From source file:kymr.github.io.controller.FluxExampleController.java

private Flux<String> getList(String name) {
    return Flux.fromStream(Stream.iterate(1, i -> i + 1).limit(10)).map(i -> name + i);
}

---

From source file:de.qaware.chronix.storage.solr.timeseries.metric.MetricTimeSeries.java

/**
 * A stream over the points//from w ww . j  a va  2s. c  om
 *
 * @return the points as points
 */
public Stream<Point> points() {
    if (timestamps.isEmpty()) {
        return Stream.empty();
    }
    return Stream.iterate(of(0), pair -> of(pair.getIndex() + 1)).limit(timestamps.size());
}

---

From source file:com.ikanow.aleph2.example.flume_harvester.services.FlumeHarvestTechnology.java

/** Worker for starting a flume job or test
 * @param new_bucket - the bucket to start/test
 * @param context - the harvest context/*from w w w .j  a  v a2 s  .  c  om*/
 * @param enabled - whether the job is enabled
 * @param test_mode - whether the job is being run as a test
 * @return
 */
public CompletableFuture<BasicMessageBean> onNewSource(DataBucketBean new_bucket, IHarvestContext context,
        boolean enabled, boolean test_mode) {
    //TODO (ALEPH-10): unit test for this 

    try {
        // Create an agent per config element:

        if (enabled) {
            final List<FlumeBucketConfigBean> agents = FlumeUtils.getAgents(new_bucket);

            @SuppressWarnings("unused")
            final int stopped = removeAgentConfigs(new_bucket, 1);

            final Tuple2<String, Boolean> delete_result = FlumeLaunchUtils
                    .killProcess(FlumeLaunchUtils.getPid(new_bucket));
            //(safe side, always kill - should fail harmlessly if px already dead....)

            final List<Tuple2<String, File>> agent_paths = StreamUtils
                    .zip(agents.stream(), Stream.iterate(1, i -> i + 1), (a, b) -> Tuples._2T(a, b))
                    .map(Lambdas.wrap_u(agent_index -> updateAgentConfig(agent_index._2(), new_bucket,
                            agent_index._1(), context, test_mode)))
                    .collect(Collectors.toList());

            final List<Tuple2<String, String>> err_pids = agent_paths.stream().map(
                    agent_path -> FlumeLaunchUtils.launchProcess(new_bucket, _globals, agent_path, context))
                    .collect(Collectors.toList());

            if (err_pids.isEmpty()) {
                return CompletableFuture
                        .completedFuture(ErrorUtils.buildErrorMessage(this.getClass().getSimpleName(),
                                "onNewSource", "Found no valid Flume configs " + delete_result._1()));
            } else {
                final Tuple2<String, String> err_pid = err_pids.get(0);
                if (null != err_pid._1()) {
                    return CompletableFuture
                            .completedFuture(ErrorUtils.buildErrorMessage(this.getClass().getSimpleName(),
                                    "onNewSource", "Bucket error: " + err_pid._1() + " " + delete_result._1()));
                } else {
                    return CompletableFuture.completedFuture(
                            ErrorUtils.buildSuccessMessage(this.getClass().getSimpleName(), "onNewSource",
                                    "Bucket launched: " + err_pid._2() + " " + delete_result._1()));

                }
            }
        } else {
            return CompletableFuture.completedFuture(ErrorUtils.buildSuccessMessage(
                    this.getClass().getSimpleName(), "onNewSource", "Created in suspended mode"));
        }
    } catch (Exception e) {
        _logger.error(ErrorUtils.getLongForm("onNewSource: Unknown error {0}", e));
        return FutureUtils.returnError(e);
    }
}

---

• «
• 1
• 2
• »