Introduction to Reactive Programming with Reactor 3.1

Transcript

10. • • • • •
11. • • • •
12. • • • •
17. • org.reactivestreams:reactive-streams:jar:1.0.2 • java.util.concurrent.Flow
18. •
19. • • • • •
20. • • • •
21. • • • • •
22. •
23. • • • •
24. • • • • • •
25. Flux.just("Foo", "Bar", "Foobar", "FizzBuzz") .filter(x -> x.startsWith("Foo")) .map(String::toLowerCase) .subscribe(System.out::println); foo foobar
26. Flux.just("Foo", "Bar", "Foobar", "FizzBuzz") .filter(x -> x.startsWith("Foo")) .map(String::toLowerCase) .subscribe(System.out::println); foo foobar
27. Flux.just("Foo", "Bar", "Foobar", "FizzBuzz") .filter(x -> x.startsWith("Foo")) .map(String::toLowerCase) .subscribe(System.out::println);
28. Flux.just("Foo", "Bar", "Foobar", "FizzBuzz") .filter(x -> x.startsWith("Foo")) .map(String::toLowerCase) .subscribe(System.out::println);
29. Flux.just("Foo", "Bar", "Foobar", "FizzBuzz") .filter(x -> x.startsWith("Foo")) .map(String::toLowerCase) .subscribe(System.out::println);
30. Flux.just("Foo", "Bar", "Foobar", "FizzBuzz") .filter(x -> x.startsWith("Foo")) .map(String::toLowerCase) .subscribe(System.out::println);
31. Flux.just("Foo", "Bar", "Foobar", "FizzBuzz") .filter(x -> x.startsWith("Foo")) .map(String::toLowerCase) .subscribe(System.out::println);
32. Flux.just("Foo", "Bar", "Foobar", "FizzBuzz") .filter(x -> x.startsWith("Foo")) .map(String::toLowerCase) .subscribe(System.out::println);
33. Flux.just("Foo", "Bar", "Foobar", "FizzBuzz") .filter(x -> x.startsWith("Foo")) .map(String::toLowerCase) .subscribe(System.out::println);
35. • •
36. • •
37. • •
38. • •
39. • • • •
40. unbounded buffer
41. dropped
42. dropped
43. • •
45. public interface PriceFeed { void addPriceListener(PriceListener listener); } public interface PriceListener { void onPriceTick(PriceTick priceTick); void onError(Throwable error); void onComplete(); } public interface PriceTick { String getSymbol(); BigDecimal getPrice(); }
46. Flux.<PriceTick>create(emitter -> priceFeed.addPriceListener( new PriceListener() { @Override public void onPriceTick(PriceTick priceTick) { emitter.next(priceTick); } @Override public void onError(Throwable err) { emitter.error(err); } @Override public void onComplete() { emitter.complete(); } }), FluxSink.OverflowStrategy.LATEST );
48. •
49. •
51. •
52. •
53. •
55. •
56. •
58. •
59. •
60. • • •
61. Flux.range(1, 10) .map(this::doDangerousProcessing) .subscribe(value -> System.out.println(value), error -> log.error(error)); • •
62. •
63. •
64. •
65. • • •
66. • • • •
71. • • reactor-test • •
72. @Test public void testFooBar() { Flux<String> source = Flux.just("foo", "bar"); StepVerifier.create(source) .expectNext("foo") .expectNext("bar") .expectComplete() .verify(); }
73. @Test public void testWithVirtualTime() { StepVerifier.withVirtualTime( () -> Mono.delay(Duration.ofDays(1))) .expectSubscription() .expectNoEvent(Duration.ofDays(1)) .expectNext(0) .verifyComplete(); }
74. @Test public void testWithVirtualTime() { StepVerifier.withVirtualTime( () -> Mono.delay(Duration.ofDays(1))) .expectSubscription() .expectNoEvent(Duration.ofDays(1)) .expectNext(0) .verifyComplete(); }
76. java.lang.IndexOutOfBoundsException: Source emitted more than one item at MonoSingle$SingleSubscriber.onNext(MonoSingle.java:120) at reactor.core.publisher.FluxFlatMap$FlatMapMain.emitScalar(FluxFlatMap.java:380) at reactor.core.publisher.FluxFlatMap$FlatMapMain.onNext(FluxFlatMap.java:349) at reactor.core.publisher.FluxMapFuseable$MapFuseableSubscriber.onNext(FluxMapFuseable. java:119) at reactor.core.publisher.FluxRange$RangeSubscription.slowPath(FluxRange.java:144) at reactor.core.publisher.FluxRange$RangeSubscription.request(FluxRange.java:99) at reactor.core.publisher.FluxMapFuseable$MapFuseableSubscriber.request(FluxMapFuseable .java:172) at reactor.core.publisher.FluxFlatMap$FlatMapMain.onSubscribe(FluxFlatMap.java:316) at reactor.core.publisher.FluxMapFuseable$MapFuseableSubscriber.onSubscribe(FluxMapFuse able.java:94) at reactor.core.publisher.FluxRange.subscribe(FluxRange.java:68) at reactor.core.publisher.FluxMapFuseable.subscribe(FluxMapFuseable.java:67) at reactor.core.publisher.FluxFlatMap.subscribe(FluxFlatMap.java:98) at reactor.core.publisher.MonoSingle.subscribe(MonoSingle.java:58) at reactor.core.publisher.Mono.subscribeWith(Mono.java:2668) at reactor.core.publisher.Mono.subscribe(Mono.java:2629) at reactor.core.publisher.Mono.subscribe(Mono.java:2604) at reactor.core.publisher.Mono.subscribe(Mono.java:2582) at reactor.guide.GuideTests.debuggingCommonStacktrace(GuideTests.java:722)
77. java.lang.IndexOutOfBoundsException: Source emitted more than one item at MonoSingle$SingleSubscriber.onNext(MonoSingle.java:120) at reactor.core.publisher.FluxFlatMap$FlatMapMain.emitScalar(FluxFlatMap.java:380) at reactor.core.publisher.FluxFlatMap$FlatMapMain.onNext(FluxFlatMap.java:349) at reactor.core.publisher.FluxMapFuseable$MapFuseableSubscriber.onNext(FluxMapFuseable. java:119) at reactor.core.publisher.FluxRange$RangeSubscription.slowPath(FluxRange.java:144) at reactor.core.publisher.FluxRange$RangeSubscription.request(FluxRange.java:99) at reactor.core.publisher.FluxMapFuseable$MapFuseableSubscriber.request(FluxMapFuseable .java:172) at reactor.core.publisher.FluxFlatMap$FlatMapMain.onSubscribe(FluxFlatMap.java:316) at reactor.core.publisher.FluxMapFuseable$MapFuseableSubscriber.onSubscribe(FluxMapFuse able.java:94) at reactor.core.publisher.FluxRange.subscribe(FluxRange.java:68) at reactor.core.publisher.FluxMapFuseable.subscribe(FluxMapFuseable.java:67) at reactor.core.publisher.FluxFlatMap.subscribe(FluxFlatMap.java:98) at reactor.core.publisher.MonoSingle.subscribe(MonoSingle.java:58) at reactor.core.publisher.Mono.subscribeWith(Mono.java:2668) at reactor.core.publisher.Mono.subscribe(Mono.java:2629) at reactor.core.publisher.Mono.subscribe(Mono.java:2604) at reactor.core.publisher.Mono.subscribe(Mono.java:2582) at reactor.guide.GuideTests.debuggingCommonStacktrace(GuideTests.java:722)
79. ... at reactor.core.publisher.Mono.subscribeWith(Mono.java:2668) at reactor.core.publisher.Mono.subscribe(Mono.java:2629) at reactor.core.publisher.Mono.subscribe(Mono.java:2604) at reactor.core.publisher.Mono.subscribe(Mono.java:2582) at reactor.guide.GuideTests.debuggingActivated(GuideTests.java:727) Suppressed: reactor.core.publisher.FluxOnAssembly$OnAssemblyException: Assembly trace from producer [reactor.core.publisher.MonoSingle] : reactor.core.publisher.Flux.single(Flux.java:5335) reactor.guide.GuideTests.scatterAndGather(GuideTests.java:689) reactor.guide.GuideTests.populateDebug(GuideTests.java:702) org.junit.rules.TestWatcher$1.evaluate(TestWatcher.java:55) org.junit.rules.RunRules.evaluate(RunRules.java:20) Error has been observed by the following operator(s): |_ Flux.single(TestWatcher.java:55)