104 lines
2.9 KiB
Java
104 lines
2.9 KiB
Java
/*
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* Copyright (C) 2015-2021 Lightbend Inc. <https://www.lightbend.com>
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*/
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package jdocs.stream;
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import akka.actor.ActorSystem;
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import akka.stream.javadsl.Sink;
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import akka.stream.javadsl.Source;
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import akka.testkit.javadsl.TestKit;
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import jdocs.AbstractJavaTest;
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import org.junit.AfterClass;
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import org.junit.BeforeClass;
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import org.junit.Test;
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import java.util.Arrays;
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public class SubstreamDocTest extends AbstractJavaTest {
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static ActorSystem system;
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@BeforeClass
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public static void setup() {
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system = ActorSystem.create("FlowDocTest");
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}
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@AfterClass
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public static void tearDown() {
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TestKit.shutdownActorSystem(system);
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system = null;
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}
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@Test
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public void demonstrateGroupBy() throws Exception {
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// #groupBy1
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Source.from(Arrays.asList(1, 2, 3, 4, 5, 6, 7, 8, 9, 10)).groupBy(3, elem -> elem % 3);
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// #groupBy1
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// #groupBy2
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Source.from(Arrays.asList(1, 2, 3, 4, 5, 6, 7, 8, 9, 10))
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.groupBy(3, elem -> elem % 3)
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.to(Sink.ignore())
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.run(system);
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// #groupBy2
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// #groupBy3
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Source.from(Arrays.asList(1, 2, 3, 4, 5, 6, 7, 8, 9, 10))
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.groupBy(3, elem -> elem % 3)
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.mergeSubstreams()
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.runWith(Sink.ignore(), system);
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// #groupBy3
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// #groupBy4
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Source.from(Arrays.asList(1, 2, 3, 4, 5, 6, 7, 8, 9, 10))
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.groupBy(3, elem -> elem % 3)
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.mergeSubstreamsWithParallelism(2)
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.runWith(Sink.ignore(), system);
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// concatSubstreams is equivalent to mergeSubstreamsWithParallelism(1)
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Source.from(Arrays.asList(1, 2, 3, 4, 5, 6, 7, 8, 9, 10))
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.groupBy(3, elem -> elem % 3)
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.concatSubstreams()
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.runWith(Sink.ignore(), system);
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// #groupBy4
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}
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@Test
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public void demonstrateSplitWhenAfter() throws Exception {
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// #splitWhenAfter
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Source.from(Arrays.asList(1, 2, 3, 4, 5, 6, 7, 8, 9, 10)).splitWhen(elem -> elem == 3);
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Source.from(Arrays.asList(1, 2, 3, 4, 5, 6, 7, 8, 9, 10)).splitAfter(elem -> elem == 3);
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// #splitWhenAfter
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// #wordCount
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String text =
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"This is the first line.\n" + "The second line.\n" + "There is also the 3rd line\n";
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Source.from(Arrays.asList(text.split("")))
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.map(x -> x.charAt(0))
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.splitAfter(x -> x == '\n')
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.filter(x -> x != '\n')
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.map(x -> 1)
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.reduce((x, y) -> x + y)
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.to(Sink.foreach(x -> System.out.println(x)))
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.run(system);
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// #wordCount
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Thread.sleep(1000);
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}
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@Test
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public void demonstrateflatMapConcatMerge() throws Exception {
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// #flatMapConcat
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Source.from(Arrays.asList(1, 2))
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.flatMapConcat(i -> Source.from(Arrays.asList(i, i, i)))
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.runWith(Sink.ignore(), system);
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// #flatMapConcat
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// #flatMapMerge
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Source.from(Arrays.asList(1, 2))
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.flatMapMerge(2, i -> Source.from(Arrays.asList(i, i, i)))
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.runWith(Sink.ignore(), system);
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// #flatMapMerge
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}
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}
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