Reactor-core: Upgrade version 2.X to 3.X - Using Spring framework

[BerlinAdam87]

I have an issue while trying to make the upgrade.

Currently i'm using version 2.0.x, and in particular -

reactor.bus
reactor.rx.Stream
reactor.rx.Streams
reactor.core.processor.RingBufferProcessor
reactor.fn.Consumer

I'm using maven, and i have a single dependency regarding 'projectreactor' -

<groupId>io.projectreactor.spring</groupId>
<artifactId>reactor-spring-core</artifactId>

When upgrading to version 3.0.4.RELEASE, in order to keep using all the things i used before, i need to explicitly import -

<groupId>io.projectreactor</groupId>
<artifactId>reactor-bus</artifactId>

And

<groupId>io.projectreactor</groupId>
<artifactId>reactor-stream</artifactId>

but i'm still missing

reactor.core.processor.RingBufferProcessor
reactor.fn.Consumer

and i'm not sure what to do.

[BerlinAdam87]

I have understood that a lot of the 2.X features were dropped or drastically changed.. What about evenBus? It will be deprecated soon? I need to replace this framework? Not sure what to do i needed to change a lot of my code base and the eventBus will not work. I have missing: reactor.Environment, reactor.core.Dispatcher, reactor.core.dispatch.RingBufferDispatcher. Tried to find migration tutorial but couldn't find anything

[smaldini]

Quick map:

reactor.rx.Stream -> reactor.core.publisher.Flux
reactor.rx.Streams -> reactor.core.publisher.Flux
reactor.rx.Promise -> reactor.core.publisher.Mono and reactor.core.publisher.MonoProcessor
reactor.core.processor.RingBufferProcessor -> reactor.core.publisher.TopicProcessor
reactor.fn.Consumer -> java.until.function.Consumer (Java 8)

There is no new spring module since spring 5 directly includes Reactor support with these new types.

As for reactor-bus :
By design now all stream routes (Flux/Mono chains) are typed, so dynamic routing is not part of our features yet. Still there are alternative in a typed way, for instance :

ReplayProcessor<MyEvent> rp = ReplayProcessor.create();
Flux<MyEvent> interest1 = rp.filter(ev -> filterInterest1(ev));
Flux<MyEvent> interest2 = rp.filter(ev -> filterInterest2(ev));
Flux<MyEvent> interest1_2 = rp.filter(ev -> filterInterest1(ev) || filterInterest2(ev));

interest1.subscribe(doSomethingForInterest1);
interest2.subscribe(doSomethingForInterest2);
interest1_2.subscribe(doSomethingForInterest1_2);

rp.onNext(new MyEvent("interest1")); //subscriber 1 and 3 react
rp.onNext(new MyEvent("interest1")); //subscriber 1 and 3 react
rp.onNext(new MyEvent("interest2")); //subscriber 2 and 3 react
rp.onNext(new MyEvent("interest4")); // buffered until interest subscriber because ReplayProcessor

//shutdown/cleanup/close
rp.onComplete();

[yigubigu]

I am writing a demo about EventBus in reactor3.x. The demo code is https://github.com/yigubigu/reactor-start-sample.git. But publisher is blocked until the subscribe finishes operation. This is not what we expect. What should I change?