a standard for asynchronous stream processing with non-blocking back pressure on the JVM
Reactive Streams is an initiative to provide a standard for asynchronous stream processing with non-blocking back pressure on the JVM.
Questions tagged [reactive-streams]
358 questions
3
votes
1 answer
Nonblocking Java Async Processing - how to constrain memory usage?
I'm coming back to Java after a few years away, and have been excited to see the introduction of non-blocking async support in the new java.net.http.HttpClient and in the AWS Java SDK 2.0. I heard about the concepts of Reactive Programming years…
Jared Stewart
- 571
- 3
- 10
3
votes
1 answer
Is it safe to use the same FluxSink from multiple threads concurrently
I know a Publisher must not publish concurrently, but if I use Flux#create(FluxSink), can I safely call FluxSink#next concurrently?
In other words, does Spring have internal magic that ensures proper serial publishing of events even if FluxSink#next…
kaqqao
- 12,984
- 10
- 64
- 118
3
votes
1 answer
How to call both subscribe and blockLast on Flux?
I have been experimenting with Project Reactor and reactive streams in general. I encountered an issue when using subscribeOn to make stream run on a different thread. Having my code in a main, I need main thread block until the stream finishes, so…
Nima Ajdari
- 2,754
- 2
- 14
- 18
3
votes
1 answer
Complete request with latest item in a flow
I'd like to complete a GET request with the latest available item in a flow. This flow in particular aggregates events produced by an actor and already individually consumed by a WebSocket.
Let's say that the event can be represented as…
stefanobaghino
- 11,253
- 4
- 35
- 63
3
votes
1 answer
Spring Boot Webflux - Set UTF-8 Encoding
I've been working with Spring Boot 2.0.0.RC1 and use spring-boot-starter-webflux in order to build a REST Controller that returns a flux of text data.
@GetMapping(value = "/")
public Flux getData(){
return…
Michael Stadler
- 441
- 1
- 4
- 12
3
votes
2 answers
Is there a way to print out the chain of all operations in a Flux?
Given a Flux or a Mono from project reactor is a there a way to get the Flux or Mono to print out what the operator chain looks like. For example given the code below.
Fulx flux = Flux.just("a","b","c")
.map( v -> v.toUpperCase())
…
ams
- 60,316
- 68
- 200
- 288
3
votes
3 answers
Single Stream and Multiple Subscribers
I'm testing the waters with Java9 reactive streams and RxJava2. I dont really have a preference on either but am looking for some guidance on if this is possible.
I'm creating a pre-configured amount of subscribers like so:
for(int i = 0;…
massnerder
- 63
- 1
- 8
3
votes
1 answer
Difference between Flux.concat and Flux.concatWith
I am new to reactive streams and learning the combine two publishers (Flux to be specific) using the concat/concatWith methods.
Everything which i can do with concat method, the same can be achieved using the concatWith method. Here is the sample…
KayV
- 12,987
- 11
- 98
- 148
3
votes
2 answers
Why are there HandlerFunctions in Spring 5 webflux?
I am learning the spring 5 webflux and reactive streams. And there are new HandlerFunctions and RouterFunctions to implement the Http requests and response.
and as per the documentations:
The annotation counterpart to a handler function would be a…
KayV
- 12,987
- 11
- 98
- 148
3
votes
3 answers
Good implementation/support for java.util.concurrent.Flow.Processor
Recently, I found a good support for Publisher by projectreactor.io:
Flux.create(fluxSink -> {
for (int i = 0; i < 10; i++)
fluxSink.next(i);
fluxSink.complete();
})
.map(...)
…
Andrew Sasha
- 1,254
- 1
- 11
- 21
3
votes
1 answer
Spring WebFlux: block() method return null in Spring Data Reactive MongoDB
i'm trying to learn project Reactor and have the problem.
@Test
@DisplayName("check that standaloneUser fields are correct")
void validateUserFields() {
userService.save(standaloneUser).subscribe();
assertEquals(userService.count().block(),…
maistrovyi
- 63
- 1
- 7
3
votes
1 answer
Is it generally OK to use a Reactive Streams Processor as an event bus?
I started learning about reactive streams because I was curious about this new trend of using RxJava as a replacement for more traditional event buses. This blog post is a typical description of how this is done. If I understand correctly, RxJava…
Kevin Krumwiede
- 9,868
- 4
- 34
- 82
3
votes
2 answers
Backpressure strategies for Akka Stream Source.queue not working
I'm trying to understand why the below code snippet is doing what it's doing. I would have thought that because the Sink cannot produce demand faster than the Source is producing content, then I would be getting dropped messages in response to some…
bmooney
- 391
- 6
- 15
3
votes
1 answer
Akka Streams filter & group by on a collection of keys
I have a stream of
case class Msg(keys: Seq[Char], value: String)
Now I want to filter for a subset of keys e.g.
val filterKeys = Set[Char]('k','f','c') and Filter(k.exists(filterKeys.contains)))
And then split these so certain keys are processed…
NightWolf
- 7,694
- 9
- 74
- 121
3
votes
2 answers
Akka Reactive Streams always one message behind
For some reason, my Akka streams always wait for a second message before "emitting"(?) the first.
Here is some example code that demonstrates my problem.
val rx = Source((1 to 100).toStream.map { t =>
Thread.sleep(1000)
println(s"doing $t")
…
SGHAF
- 105
- 1
- 1
- 5