Examples with IntStream java.util.stream.IntStream used on opensource projects

Example 1 with IntStream

use of java.util.stream.IntStream in project cradle by BingLau7.

the class TestStream method main.

public static void main(String[] args) {
    int[] numbers = new int[] { 1, 2, 3, 4, 5, 6 };
    // 记住区分惰性求值或是及早求值
    IntStream ns = Arrays.stream(numbers).filter(i -> i < 3);
    ns.forEach(x -> System.out.print(x + " "));
    System.out.println();
    List<String> collected = Stream.of("a", "b", "c").collect(Collectors.toList());
    System.out.println(collected);
    List<String> collected2 = Stream.of("a", "b", "hello").map(string -> string.toUpperCase()).collect(Collectors.toList());
    System.out.println(collected2);
    int count = Stream.of(1, 2, 3).reduce(0, (acc, element) -> acc + element);
    System.out.println(count);
}

Example 2 with IntStream

use of java.util.stream.IntStream in project jdk8u_jdk by JetBrains.

the class BitSetStreamTest method testRandomStream.

@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);
        }
    }
}

Example 3 with IntStream

use of java.util.stream.IntStream in project TeeTime by teetime-framework.

the class ProducerConsumerGlobalTaskPoolIT method shouldExecuteProducerConsumer.

private void shouldExecuteProducerConsumer(final int numThreads, final int numExecutions) {
    int numElements = 10_000;
    List<Integer> processedElements = new ArrayList<>();
    IntStream inputElements = IntStream.iterate(0, i -> i + 1).limit(numElements);
    Configuration config = new Configuration().from(new StreamProducer<>(inputElements)).end(new CollectorSink<>(processedElements));
    TeeTimeScheduler scheduling = new GlobalTaskPoolScheduling(numThreads, config, numExecutions);
    Execution<Configuration> execution = new Execution<>(config, true, scheduling);
    execution.executeBlocking();
    for (int i = 0; i < numElements; i++) {
        assertThat(processedElements.get(i), is(i));
    }
    assertThat(processedElements, hasSize(numElements));
}

Example 4 with IntStream

use of java.util.stream.IntStream in project TeeTime by teetime-framework.

the class ThreeStagesGlobalTaskPoolIT method shouldExecutePipelineCorrectlyManyElements.

private void shouldExecutePipelineCorrectlyManyElements(final int numElements, final int numThreads, final int numExecutions) {
    List<Integer> processedElements = new ArrayList<>();
    IntStream inputElements = IntStream.iterate(0, i -> i + 1).limit(numElements);
    Configuration config = new Configuration().from(new StreamProducer<>(inputElements)).to(new Counter<>()).end(new CollectorSink<>(processedElements));
    TeeTimeScheduler scheduling = new GlobalTaskPoolScheduling(numThreads, config, numExecutions);
    Execution<Configuration> execution = new Execution<>(config, true, scheduling);
    execution.executeBlocking();
    for (int i = 0; i < numElements; i++) {
        Integer actualElement = processedElements.get(i);
        assertThat(actualElement, is(i));
    }
    assertThat(processedElements, hasSize(numElements));
}

Example 5 with IntStream

use of java.util.stream.IntStream in project jdk8u_jdk by JetBrains.

the class StreamSpliteratorTest method testIntSplitting.

//
public void testIntSplitting() {
    List<Consumer<IntStream>> terminalOps = Arrays.asList(s -> s.toArray(), s -> s.forEach(e -> {
    }), s -> s.reduce(Integer::sum));
    List<UnaryOperator<IntStream>> intermediateOps = Arrays.asList(s -> s.parallel(), // The following ensures the wrapping spliterator is tested
    s -> s.map(i -> i).parallel());
    for (int i = 0; i < terminalOps.size(); i++) {
        setContext("termOpIndex", i);
        Consumer<IntStream> terminalOp = terminalOps.get(i);
        for (int j = 0; j < intermediateOps.size(); j++) {
            setContext("intOpIndex", j);
            UnaryOperator<IntStream> intermediateOp = intermediateOps.get(j);
            for (boolean proxyEstimateSize : new boolean[] { false, true }) {
                setContext("proxyEstimateSize", proxyEstimateSize);
                // Size is assumed to be larger than the target size for no splitting
                // @@@ Need way to obtain the target size
                Spliterator.OfInt sp = intermediateOp.apply(IntStream.range(0, 1000)).spliterator();
                ProxyNoExactSizeSpliterator.OfInt psp = new ProxyNoExactSizeSpliterator.OfInt(sp, proxyEstimateSize);
                IntStream s = StreamSupport.intStream(psp, true);
                terminalOp.accept(s);
                Assert.assertTrue(psp.splits > 0, String.format("Number of splits should be greater that zero when proxyEstimateSize is %s", proxyEstimateSize));
                Assert.assertTrue(psp.prefixSplits > 0, String.format("Number of non-null prefix splits should be greater that zero when proxyEstimateSize is %s", proxyEstimateSize));
                Assert.assertTrue(psp.sizeOnTraversal < 1000, String.format("Size on traversal of last split should be less than the size of the list, %d, when proxyEstimateSize is %s", 1000, proxyEstimateSize));
            }
        }
    }
}