@Test
public void mustBeAbleToUseZipWith() throws Exception {
final JavaTestKit probe = new JavaTestKit(system);
final Iterable<String> input1 = Arrays.asList("A", "B", "C");
final Iterable<String> input2 = Arrays.asList("D", "E", "F");
Source.from(input1)
.zipWith(
Source.from(input2),
new Function2<String, String, String>() {
public String apply(String s1, String s2) {
return s1 + "-" + s2;
}
})
.runForeach(
new Procedure<String>() {
public void apply(String elem) {
probe.getRef().tell(elem, ActorRef.noSender());
}
},
materializer);
probe.expectMsgEquals("A-D");
probe.expectMsgEquals("B-E");
probe.expectMsgEquals("C-F");
}
@Test
public void mustBeAbleToUseFlatMapMerge() throws Exception {
final JavaTestKit probe = new JavaTestKit(system);
final Iterable<Integer> input1 = Arrays.asList(0, 1, 2, 3, 4, 5, 6, 7, 8, 9);
final Iterable<Integer> input2 = Arrays.asList(10, 11, 12, 13, 14, 15, 16, 17, 18, 19);
final Iterable<Integer> input3 = Arrays.asList(20, 21, 22, 23, 24, 25, 26, 27, 28, 29);
final Iterable<Integer> input4 = Arrays.asList(30, 31, 32, 33, 34, 35, 36, 37, 38, 39);
final List<Source<Integer, NotUsed>> mainInputs = new ArrayList<Source<Integer, NotUsed>>();
mainInputs.add(Source.from(input1));
mainInputs.add(Source.from(input2));
mainInputs.add(Source.from(input3));
mainInputs.add(Source.from(input4));
CompletionStage<List<Integer>> future =
Source.from(mainInputs)
.flatMapMerge(3, ConstantFun.<Source<Integer, NotUsed>>javaIdentityFunction())
.grouped(60)
.runWith(Sink.<List<Integer>>head(), materializer);
List<Integer> result = future.toCompletableFuture().get(3, TimeUnit.SECONDS);
final Set<Integer> set = new HashSet<Integer>();
for (Integer i : result) {
set.add(i);
}
final Set<Integer> expected = new HashSet<Integer>();
for (int i = 0; i < 40; ++i) {
expected.add(i);
}
assertEquals(expected, set);
}
@Test
public void mustBeAbleToUseToFuture() throws Exception {
final JavaTestKit probe = new JavaTestKit(system);
final Iterable<String> input = Arrays.asList("A", "B", "C");
CompletionStage<String> future = Source.from(input).runWith(Sink.<String>head(), materializer);
String result = future.toCompletableFuture().get(3, TimeUnit.SECONDS);
assertEquals("A", result);
}
@Test
public void mustWorkFromFuture() throws Exception {
final Iterable<String> input = Arrays.asList("A", "B", "C");
CompletionStage<String> future1 = Source.from(input).runWith(Sink.<String>head(), materializer);
CompletionStage<String> future2 =
Source.fromCompletionStage(future1).runWith(Sink.<String>head(), materializer);
String result = future2.toCompletableFuture().get(3, TimeUnit.SECONDS);
assertEquals("A", result);
}
@Test
public void mustBeAbleToUseMerge2() {
final JavaTestKit probe = new JavaTestKit(system);
final Iterable<String> input1 = Arrays.asList("A", "B", "C");
final Iterable<String> input2 = Arrays.asList("D", "E", "F");
Source.from(input1)
.merge(Source.from(input2))
.runForeach(
new Procedure<String>() {
public void apply(String elem) {
probe.getRef().tell(elem, ActorRef.noSender());
}
},
materializer);
probe.expectMsgAllOf("A", "B", "C", "D", "E", "F");
}
@Ignore("StatefulStage to be converted to GraphStage when Java Api is available (#18817)")
@Test
public void mustBeAbleToUseTransform() {
final JavaTestKit probe = new JavaTestKit(system);
final Iterable<Integer> input = Arrays.asList(0, 1, 2, 3, 4, 5, 6, 7);
// duplicate each element, stop after 4 elements, and emit sum to the end
Source.from(input)
.transform(
new Creator<Stage<Integer, Integer>>() {
@Override
public PushPullStage<Integer, Integer> create() throws Exception {
return new StatefulStage<Integer, Integer>() {
int sum = 0;
int count = 0;
@Override
public StageState<Integer, Integer> initial() {
return new StageState<Integer, Integer>() {
@Override
public SyncDirective onPush(Integer element, Context<Integer> ctx) {
sum += element;
count += 1;
if (count == 4) {
return emitAndFinish(
Arrays.asList(element, element, sum).iterator(), ctx);
} else {
return emit(Arrays.asList(element, element).iterator(), ctx);
}
}
};
}
@Override
public TerminationDirective onUpstreamFinish(Context<Integer> ctx) {
return terminationEmit(Collections.singletonList(sum).iterator(), ctx);
}
};
}
})
.runForeach(
new Procedure<Integer>() {
public void apply(Integer elem) {
probe.getRef().tell(elem, ActorRef.noSender());
}
},
materializer);
probe.expectMsgEquals(0);
probe.expectMsgEquals(0);
probe.expectMsgEquals(1);
probe.expectMsgEquals(1);
probe.expectMsgEquals(2);
probe.expectMsgEquals(2);
probe.expectMsgEquals(3);
probe.expectMsgEquals(3);
probe.expectMsgEquals(6);
}
public void demonstrateAGraphStageWithATimer() throws Exception {
// tests:
CompletionStage<Integer> result =
Source.from(Arrays.asList(1, 2, 3))
.via(new TimedGate<>(Duration.create(2, "seconds")))
.takeWithin(Duration.create(250, "millis"))
.runFold(0, (n, sum) -> n + sum, mat);
assertEquals(new Integer(1), result.toCompletableFuture().get(3, TimeUnit.SECONDS));
}
@Test
public void mustBeAbleToUseZip() throws Exception {
final JavaTestKit probe = new JavaTestKit(system);
final Iterable<String> input1 = Arrays.asList("A", "B", "C");
final Iterable<String> input2 = Arrays.asList("D", "E", "F");
Source.from(input1)
.zip(Source.from(input2))
.runForeach(
new Procedure<Pair<String, String>>() {
public void apply(Pair<String, String> elem) {
probe.getRef().tell(elem, ActorRef.noSender());
}
},
materializer);
probe.expectMsgEquals(new Pair<String, String>("A", "D"));
probe.expectMsgEquals(new Pair<String, String>("B", "E"));
probe.expectMsgEquals(new Pair<String, String>("C", "F"));
}
@Test
public void mustBeAbleToUseMapFuture() throws Exception {
final JavaTestKit probe = new JavaTestKit(system);
final Iterable<String> input = Arrays.asList("a", "b", "c");
Source.from(input)
.mapAsync(4, elem -> CompletableFuture.completedFuture(elem.toUpperCase()))
.runForeach(elem -> probe.getRef().tell(elem, ActorRef.noSender()), materializer);
probe.expectMsgEquals("A");
probe.expectMsgEquals("B");
probe.expectMsgEquals("C");
}
@Test
public void mustBeAbleToUseConflate() throws Exception {
final JavaTestKit probe = new JavaTestKit(system);
final List<String> input = Arrays.asList("A", "B", "C");
CompletionStage<String> future =
Source.from(input)
.conflateWithSeed(s -> s, (aggr, in) -> aggr + in)
.runFold("", (aggr, in) -> aggr + in, materializer);
String result = future.toCompletableFuture().get(3, TimeUnit.SECONDS);
assertEquals("ABC", result);
final Flow<String, String, NotUsed> flow2 = Flow.of(String.class).conflate((a, b) -> a + b);
CompletionStage<String> future2 =
Source.from(input)
.conflate((String a, String b) -> a + b)
.runFold("", (a, b) -> a + b, materializer);
String result2 = future2.toCompletableFuture().get(3, TimeUnit.SECONDS);
assertEquals("ABC", result2);
}
@Test
public void demonstrateASimplerOneToManyStage() throws Exception {
// tests:
Graph<FlowShape<Integer, Integer>, NotUsed> duplicator =
Flow.fromGraph(new Duplicator2<Integer>());
CompletionStage<Integer> result =
Source.from(Arrays.asList(1, 2, 3)).via(duplicator).runFold(0, (n, sum) -> n + sum, mat);
assertEquals(new Integer(12), result.toCompletableFuture().get(3, TimeUnit.SECONDS));
}
public void demonstrateACustomMaterializedValue() throws Exception {
// tests:
RunnableGraph<CompletionStage<Integer>> flow =
Source.from(Arrays.asList(1, 2, 3))
.viaMat(new FirstValue(), Keep.right())
.to(Sink.ignore());
CompletionStage<Integer> result = flow.run(mat);
assertEquals(new Integer(1), result.toCompletableFuture().get(3, TimeUnit.SECONDS));
}
@Test
public void mustBeAbleToUseConcatAllWithSources() throws Exception {
final JavaTestKit probe = new JavaTestKit(system);
final Iterable<Integer> input1 = Arrays.asList(1, 2, 3);
final Iterable<Integer> input2 = Arrays.asList(4, 5);
final List<Source<Integer, NotUsed>> mainInputs = new ArrayList<Source<Integer, NotUsed>>();
mainInputs.add(Source.from(input1));
mainInputs.add(Source.from(input2));
CompletionStage<List<Integer>> future =
Source.from(mainInputs)
.<Integer, NotUsed>flatMapConcat(
ConstantFun.<Source<Integer, NotUsed>>javaIdentityFunction())
.grouped(6)
.runWith(Sink.<List<Integer>>head(), materializer);
List<Integer> result = future.toCompletableFuture().get(3, TimeUnit.SECONDS);
assertEquals(Arrays.asList(1, 2, 3, 4, 5), result);
}
@Test
public void mustBeAbleToCombine() throws Exception {
final JavaTestKit probe = new JavaTestKit(system);
final Source<Integer, NotUsed> source1 = Source.from(Arrays.asList(0, 1));
final Source<Integer, NotUsed> source2 = Source.from(Arrays.asList(2, 3));
final Source<Integer, NotUsed> source =
Source.combine(
source1,
source2,
new ArrayList<Source<Integer, ?>>(),
width -> Merge.<Integer>create(width));
final CompletionStage<Done> future =
source.runWith(
Sink.foreach(elem -> probe.getRef().tell(elem, ActorRef.noSender())), materializer);
probe.expectMsgAllOf(0, 1, 2, 3);
future.toCompletableFuture().get(200, TimeUnit.MILLISECONDS);
}
@Test
public void partialGraph() throws Exception {
// #partial-graph
final Graph<FlowShape<Integer, Integer>, NotUsed> partial =
GraphDSL.create(
builder -> {
final UniformFanOutShape<Integer, Integer> B = builder.add(Broadcast.create(2));
final UniformFanInShape<Integer, Integer> C = builder.add(Merge.create(2));
final UniformFanOutShape<Integer, Integer> E = builder.add(Balance.create(2));
final UniformFanInShape<Integer, Integer> F = builder.add(Merge.create(2));
builder.from(F.out()).toInlet(C.in(0));
builder.from(B).viaFanIn(C).toFanIn(F);
builder
.from(B)
.via(builder.add(Flow.of(Integer.class).map(i -> i + 1)))
.viaFanOut(E)
.toFanIn(F);
return new FlowShape<Integer, Integer>(B.in(), E.out(1));
});
// #partial-graph
// #partial-use
Source.single(0).via(partial).to(Sink.ignore());
// #partial-use
// #partial-flow-dsl
// Convert the partial graph of FlowShape to a Flow to get
// access to the fluid DSL (for example to be able to call .filter())
final Flow<Integer, Integer, NotUsed> flow = Flow.fromGraph(partial);
// Simple way to create a graph backed Source
final Source<Integer, NotUsed> source =
Source.fromGraph(
GraphDSL.create(
builder -> {
final UniformFanInShape<Integer, Integer> merge = builder.add(Merge.create(2));
builder.from(builder.add(Source.single(0))).toFanIn(merge);
builder.from(builder.add(Source.from(Arrays.asList(2, 3, 4)))).toFanIn(merge);
// Exposing exactly one output port
return new SourceShape<Integer>(merge.out());
}));
// Building a Sink with a nested Flow, using the fluid DSL
final Sink<Integer, NotUsed> sink =
Flow.of(Integer.class).map(i -> i * 2).drop(10).named("nestedFlow").to(Sink.head());
// Putting all together
final RunnableGraph<NotUsed> closed = source.via(flow.filter(i -> i > 1)).to(sink);
// #partial-flow-dsl
}
@Test
public void mustBeAbleToUseThrottle() throws Exception {
Integer result =
Source.from(Arrays.asList(0, 1, 2))
.throttle(10, FiniteDuration.create(1, TimeUnit.SECONDS), 10, ThrottleMode.shaping())
.throttle(10, FiniteDuration.create(1, TimeUnit.SECONDS), 10, ThrottleMode.enforcing())
.runWith(Sink.head(), materializer)
.toCompletableFuture()
.get(3, TimeUnit.SECONDS);
assertEquals((Object) 0, result);
}
@Test
public void mustBeAbleToUsePrepend() {
final JavaTestKit probe = new JavaTestKit(system);
final Iterable<String> input1 = Arrays.asList("A", "B", "C");
final Iterable<String> input2 = Arrays.asList("D", "E", "F");
final Source<String, NotUsed> in1 = Source.from(input1);
final Source<String, NotUsed> in2 = Source.from(input2);
in2.prepend(in1)
.runForeach(
new Procedure<String>() {
public void apply(String elem) {
probe.getRef().tell(elem, ActorRef.noSender());
}
},
materializer);
List<Object> output = Arrays.asList(probe.receiveN(6));
assertEquals(Arrays.asList("A", "B", "C", "D", "E", "F"), output);
}
@Test
public void mustBeAbleToUseBuffer() throws Exception {
final JavaTestKit probe = new JavaTestKit(system);
final List<String> input = Arrays.asList("A", "B", "C");
final CompletionStage<List<String>> future =
Source.from(input)
.buffer(2, OverflowStrategy.backpressure())
.grouped(4)
.runWith(Sink.<List<String>>head(), materializer);
List<String> result = future.toCompletableFuture().get(3, TimeUnit.SECONDS);
assertEquals(input, result);
}
@Test
public void demonstrateAManyToOneElementGraphStage() throws Exception {
// tests:
Graph<FlowShape<Integer, Integer>, NotUsed> evenFilter =
Flow.fromGraph(new Filter<Integer>(n -> n % 2 == 0));
CompletionStage<Integer> result =
Source.from(Arrays.asList(1, 2, 3, 4, 5, 6))
.via(evenFilter)
.runFold(0, (elem, sum) -> sum + elem, mat);
assertEquals(new Integer(12), result.toCompletableFuture().get(3, TimeUnit.SECONDS));
}
@Test
public void mustBeAbleToUseVoidTypeInForeach() {
final JavaTestKit probe = new JavaTestKit(system);
final java.lang.Iterable<String> input = Arrays.asList("a", "b", "c");
Source<String, NotUsed> ints = Source.from(input);
final CompletionStage<Done> completion =
ints.runForeach(elem -> probe.getRef().tell(elem, ActorRef.noSender()), materializer);
completion.thenAccept(elem -> probe.getRef().tell(String.valueOf(elem), ActorRef.noSender()));
probe.expectMsgEquals("a");
probe.expectMsgEquals("b");
probe.expectMsgEquals("c");
probe.expectMsgEquals("Done");
}
@Test
public void demonstrateChainingOfGraphStages() throws Exception {
Graph<SinkShape<Integer>, CompletionStage<String>> sink =
Sink.fold("", (acc, n) -> acc + n.toString());
// #graph-stage-chain
CompletionStage<String> resultFuture =
Source.from(Arrays.asList(1, 2, 3, 4, 5))
.via(new Filter<Integer>((n) -> n % 2 == 0))
.via(new Duplicator<Integer>())
.via(new Map<Integer, Integer>((n) -> n / 2))
.runWith(sink, mat);
// #graph-stage-chain
assertEquals("1122", resultFuture.toCompletableFuture().get(3, TimeUnit.SECONDS));
}
@Test
public void mustBeAbleToUsePrefixAndTail() throws Exception {
final JavaTestKit probe = new JavaTestKit(system);
final Iterable<Integer> input = Arrays.asList(1, 2, 3, 4, 5, 6);
CompletionStage<Pair<List<Integer>, Source<Integer, NotUsed>>> future =
Source.from(input)
.prefixAndTail(3)
.runWith(Sink.<Pair<List<Integer>, Source<Integer, NotUsed>>>head(), materializer);
Pair<List<Integer>, Source<Integer, NotUsed>> result =
future.toCompletableFuture().get(3, TimeUnit.SECONDS);
assertEquals(Arrays.asList(1, 2, 3), result.first());
CompletionStage<List<Integer>> tailFuture =
result.second().limit(4).runWith(Sink.<Integer>seq(), materializer);
List<Integer> tailResult = tailFuture.toCompletableFuture().get(3, TimeUnit.SECONDS);
assertEquals(Arrays.asList(4, 5, 6), tailResult);
}
@Test
public void mustBeAbleToUseOnCompleteSuccess() {
final JavaTestKit probe = new JavaTestKit(system);
final Iterable<String> input = Arrays.asList("A", "B", "C");
Source.from(input)
.runWith(
Sink.<String>onComplete(
new Procedure<Try<Done>>() {
@Override
public void apply(Try<Done> param) throws Exception {
probe.getRef().tell(param.get(), ActorRef.noSender());
}
}),
materializer);
probe.expectMsgClass(Done.class);
}
public void run(final Materializer mat)
throws TimeoutException, InterruptedException, ExecutionException {
// #backpressure-by-readline
final CompletionStage<Done> completion =
Source.from(Arrays.asList(1, 2, 3, 4, 5, 6, 7, 8, 9, 10))
.map(
i -> {
System.out.println("map => " + i);
return i;
})
.runForeach(
i ->
System.console()
.readLine("Element = %s continue reading? [press enter]\n", i),
mat);
completion.toCompletableFuture().get(1, TimeUnit.SECONDS);
// #backpressure-by-readline
}
@Test
public void demonstrateOneToOne() throws Exception {
// tests:
final Graph<FlowShape<String, Integer>, NotUsed> stringLength =
Flow.fromGraph(
new Map<String, Integer>(
new Function<String, Integer>() {
@Override
public Integer apply(String str) {
return str.length();
}
}));
CompletionStage<Integer> result =
Source.from(Arrays.asList("one", "two", "three"))
.via(stringLength)
.runFold(0, (sum, n) -> sum + n, mat);
assertEquals(new Integer(11), result.toCompletableFuture().get(3, TimeUnit.SECONDS));
}
@Test
public void mustBeAbleToUseDropWhile() throws Exception {
final JavaTestKit probe = new JavaTestKit(system);
final Source<Integer, NotUsed> source =
Source.from(Arrays.asList(0, 1, 2, 3))
.dropWhile(
new Predicate<Integer>() {
public boolean test(Integer elem) {
return elem < 2;
}
});
final CompletionStage<Done> future =
source.runWith(
Sink.foreach(elem -> probe.getRef().tell(elem, ActorRef.noSender())), materializer);
probe.expectMsgEquals(2);
probe.expectMsgEquals(3);
future.toCompletableFuture().get(200, TimeUnit.MILLISECONDS);
}
@Test
public void mustBeAbleToUseSimpleOperators() {
final JavaTestKit probe = new JavaTestKit(system);
final String[] lookup = {"a", "b", "c", "d", "e", "f"};
final java.lang.Iterable<Integer> input = Arrays.asList(0, 1, 2, 3, 4, 5);
final Source<Integer, NotUsed> ints = Source.from(input);
ints.drop(2)
.take(3)
.takeWithin(FiniteDuration.create(10, TimeUnit.SECONDS))
.map(elem -> lookup[elem])
.filter(elem -> !elem.equals("c"))
.grouped(2)
.mapConcat(elem -> elem)
.groupedWithin(100, FiniteDuration.create(50, TimeUnit.MILLISECONDS))
.mapConcat(elem -> elem)
.runFold("", (acc, elem) -> acc + elem, materializer)
.thenAccept(elem -> probe.getRef().tell(elem, ActorRef.noSender()));
probe.expectMsgEquals("de");
}
@Test
public void mustBeAbleToUseStatefulMaponcat() throws Exception {
final JavaTestKit probe = new JavaTestKit(system);
final java.lang.Iterable<Integer> input = Arrays.asList(1, 2, 3, 4, 5);
final Source<Integer, NotUsed> ints =
Source.from(input)
.statefulMapConcat(
() -> {
int[] state = new int[] {0};
return (elem) -> {
List<Integer> list = new ArrayList<>(Collections.nCopies(state[0], elem));
state[0] = elem;
return list;
};
});
ints.runFold("", (acc, elem) -> acc + elem, materializer)
.thenAccept(elem -> probe.getRef().tell(elem, ActorRef.noSender()));
probe.expectMsgEquals("2334445555");
}
@Test
public void mustBeAbleToUseIntersperse() throws Exception {
final JavaTestKit probe = new JavaTestKit(system);
final Source<String, NotUsed> source =
Source.from(Arrays.asList("0", "1", "2", "3")).intersperse("[", ",", "]");
final CompletionStage<Done> future =
source.runWith(
Sink.foreach(elem -> probe.getRef().tell(elem, ActorRef.noSender())), materializer);
probe.expectMsgEquals("[");
probe.expectMsgEquals("0");
probe.expectMsgEquals(",");
probe.expectMsgEquals("1");
probe.expectMsgEquals(",");
probe.expectMsgEquals("2");
probe.expectMsgEquals(",");
probe.expectMsgEquals("3");
probe.expectMsgEquals("]");
future.toCompletableFuture().get(200, TimeUnit.MILLISECONDS);
}
@Test
public void demonstrateAnAsynchronousSideChannel() throws Exception {
// tests:
CompletableFuture<Done> switchF = new CompletableFuture<>();
Graph<FlowShape<Integer, Integer>, NotUsed> killSwitch =
Flow.fromGraph(new KillSwitch<>(switchF));
ExecutionContext ec = system.dispatcher();
CompletionStage<Integer> valueAfterKill = switchF.thenApply(in -> 4);
CompletionStage<Integer> result =
Source.from(Arrays.asList(1, 2, 3))
.concat(Source.fromCompletionStage(valueAfterKill))
.via(killSwitch)
.runFold(0, (n, sum) -> n + sum, mat);
switchF.complete(Done.getInstance());
assertEquals(new Integer(6), result.toCompletableFuture().get(3, TimeUnit.SECONDS));
}