Java Code Examples for reactor.core.publisher.Flux#range()

@Test
public void reduceWithCustomAccumulator() throws Exception {
    //given
    final Flux<Integer> nums = Flux.range(1, 100);

    //when
    final Mono<BigInteger> factorial = nums.reduce(BigInteger.ONE, (bi, x) -> {
        log.info("bi = {}, x = {}", bi, x);
        return bi.multiply(BigInteger.valueOf(x));
    });

    //then
    factorial
            .as(StepVerifier::create)
            .expectNext(new BigInteger(FACTORIAL_100))
            .verifyComplete();
}
 

@Test
public void overlapping() throws Exception {
	//given
	final Flux<Integer> nums = Flux.range(1, 8);

	//when
	final Flux<List<Integer>> windows = nums
			.window(3, 2)
			.flatMap(Flux::collectList);

	//then
	windows
			.as(StepVerifier::create)
			.expectNext(List.of(1, 2, 3))
			.expectNext(List.of(3, 4, 5))
			.expectNext(List.of(5, 6, 7))
			.expectNext(List.of(7, 8))
			.verifyComplete();
}
 

@Test
public void gaps() throws Exception {
	//given
	final Flux<Integer> nums = Flux.range(1, 10);

	//when
	final Flux<List<Integer>> windows = nums
			.window(2, 3)
			.flatMap(Flux::collectList);

	//then
	windows
			.as(StepVerifier::create)
			.expectNext(List.of(1, 2))
			.expectNext(List.of(4, 5))
			.expectNext(List.of(7, 8))
			.expectNext(List.of(10))
			.verifyComplete();
}
 

@Test
public void testReplay(){
    Flux<Integer> f1 = Flux.range(0,100);
    Flux<Integer> f2 = f1.map(i->i*2);

    System.out.println(f1.count().block());
    System.out.println(f2.count().block());

    ReactiveSeq<String> stream = of("hello","world");
    ReactiveSeq<String> stream1 = stream.map(str->"hello world " + str);
    stream.forEach(System.out::println);
    stream1.forEach(System.out::println);

    ReactiveSeq<Integer> streama = ReactiveSeq.range(1,100);
    ReactiveSeq<Integer> streamb = streama.map(i->i*2);

    System.out.println(streama.count());
    System.out.println(streama.map(i->i*3).zipWithIndex().count());
    System.out.println(streamb.zipWithIndex().count());
}
 

@Test
public void overlapping() throws Exception {
	//given
	final Flux<Integer> nums = Flux.range(1, 8);

	//when
	final Flux<List<Integer>> buffers = nums.buffer(3, 2);

	//then
	buffers
			.as(StepVerifier::create)
			.expectNext(List.of(1, 2, 3))
			.expectNext(List.of(3, 4, 5))
			.expectNext(List.of(5, 6, 7))
			.expectNext(List.of(7, 8))
			.verifyComplete();
}
 

@Test
void throttleDownStreamConcurrencyShouldNotExceedWindowMaxSize() {
    int windowMaxSize = 3;
    Duration windowDuration = Duration.ofMillis(100);

    AtomicInteger ongoingProcessing = new AtomicInteger();

    Flux<Integer> originalFlux = Flux.range(0, 10);
    Function<Integer, Publisher<Integer>> longRunningOperation =
        any -> Mono.fromCallable(ongoingProcessing::incrementAndGet)
            .flatMap(i -> Mono.delay(windowDuration.multipliedBy(2)).thenReturn(i))
            .flatMap(i -> Mono.fromRunnable(ongoingProcessing::decrementAndGet).thenReturn(i));

    ImmutableList<Integer> ongoingProcessingUponComputationStart = originalFlux
        .transform(ReactorUtils.<Integer, Integer>throttle()
            .elements(windowMaxSize)
            .per(windowDuration)
            .forOperation(longRunningOperation))
        .collect(Guavate.toImmutableList())
        .block();

    assertThat(ongoingProcessingUponComputationStart)
        .allSatisfy(processingCount -> assertThat(processingCount).isLessThanOrEqualTo(windowMaxSize));
}
 

/**
 * TODO Computer factorial (n!) using {@link Flux#reduce(BiFunction)}
 */
@Test
public void factorialUsingReduce() throws Exception {
    //given
    final Flux<Integer> nums = Flux.range(1, 10);

    //when
    final Mono<Integer> factorial = null;  //TODO

    //then
    factorial
            .as(StepVerifier::create)
            .expectNext(
                    (((((((((1 * 2) * 3) * 4) * 5) * 6) * 7) * 8) * 9) * 10)
            )
            .verifyComplete();
}
 

@Test
public void mapTransformsItemsOnTheFly() throws Exception {
	//given
	final Flux<Integer> numbers = Flux.range(5, 4);

	//when
	final Flux<Integer> even = numbers.map(x -> x * 2);

	//then
	even
			.as(StepVerifier::create)
			.expectNext(10, 12, 14, 16)
			.verifyComplete();
}
 

@Test
public void fluxNextNormalCallsAssemblyHook() {
	Flux<Integer> source = Flux.range(1, 10);

	//set the hook AFTER the original operators have been invoked (since they trigger assembly themselves)
	AtomicInteger wrappedCount = new AtomicInteger();
	Hooks.onEachOperator(p -> {
		wrappedCount.incrementAndGet();
		return p;
	});

	source.next();
	Assertions.assertThat(wrappedCount).hasValue(1);
}
 

@Test
public void createAFlux_range() {
  Flux<Integer> intervalFlux = 
      Flux.range(1, 5);
  
  StepVerifier.create(intervalFlux)
      .expectNext(1)
      .expectNext(2)
      .expectNext(3)
      .expectNext(4)
      .expectNext(5)
      .verifyComplete();
}
 

@Test
public void createFlux() {
    Flux<String> stream1 = Flux.just("Hello", "world");
    Flux<Integer> stream2 = Flux.fromArray(new Integer[]{1, 2, 3});
    Flux<Integer> stream3 = Flux.range(1, 500);

    Flux<String> emptyStream = Flux.empty();
    Flux<String> streamWithError = Flux.error(new RuntimeException("Hi!"));
}
 

@Test
public void fluxFromFluxSourceDoesntCallAssemblyHook() {
	final Flux<Integer> source = Flux.range(1, 10);

	//set the hook AFTER the original operators have been invoked (since they trigger assembly themselves)
	AtomicInteger wrappedCount = new AtomicInteger();
	Hooks.onEachOperator(p -> {
		wrappedCount.incrementAndGet();
		return p;
	});

	Flux.from(source);
	Assertions.assertThat(wrappedCount).hasValue(0);
}
 

@Test
public void delayErrorConcatMapVsFlatMap() {
	Function<Integer, Flux<String>> mapFunction = i -> {
		char c = (char) ('A' + i);
		return Flux.range(1, i + 1)
		           .doOnNext(v -> {
		           	if (i == 3 && v == 3) {
		           		throw new IllegalStateException("boom " + c + v);
		            }
		           })
		    .map(v -> "" + c + "" + v);
	};

	Flux<Integer> source = Flux.range(0, 5);

	Flux<String> concatMap = source.concatMapDelayError(mapFunction)
	                               .materialize()
			                       .map(Object::toString);
	Flux<String> flatMap = source.flatMapDelayError(mapFunction, 2, 32)
	                               .materialize()
			                       .map(Object::toString);

	List<String> signalsConcat = concatMap.collectList().block();
	List<String> signalsFlat = flatMap.collectList().block();

	Assertions.assertThat(signalsConcat)
	          .containsExactlyElementsOf(signalsFlat);
}
 

@Test
public void expectNextsMoreThan6() {
	Flux<Integer> flux = Flux.range(1, 7);

	StepVerifier.create(flux)
	            .expectNext(1, 2, 3, 4, 5, 6, 7)
	            .expectComplete()
	            .verify();
}
 

public Flux<Integer> emitMultiple() {
    int start = ThreadLocalRandom.current().nextInt(0, 6000);
    return Flux.range(start, 10);
}
 

@RequestMapping("/channel1")
public Flux<User> channel1() {
    Flux<Integer> userIdFlux = Flux.range(1, 20);
    return userService.recent(userIdFlux);
}
 

@RequestManyMapping(value = "/requestMany", mimeType = "application/json")
public Flux<Integer> range(Integer count){
	return Flux.range(0, count);
}
 

@GetMapping("/flux")
public Flux<Integer> apiFlux() {
    return Flux.range(0, 5);
}
 

public Flux<Integer> emitMultiple() {
    int start = ThreadLocalRandom.current().nextInt(0, 6000);
    return Flux.range(start, 10);
}
 

@RequestMapping("/channel2")
public Flux<User> channel2() {
    Flux<Integer> userIdFlux = Flux.range(1, 20);
    return userService.recentWithType("VIP", userIdFlux);
}