project-reactor

问题 I'm having the following simplified handler function (Spring WebFlux and the functional API using Kotlin). However, I need a hint how to detect an empty Flux and then use noContent() for 404, when the Flux is empty. fun findByLastname(request: ServerRequest): Mono<ServerResponse> { val lastnameOpt = request.queryParam("lastname") val customerFlux = if (lastnameOpt.isPresent) { service.findByLastname(lastnameOpt.get()) } else { service.findAll() } // How can I detect an empty Flux and then

问题 The following code StepVerifier.withVirtualTime((Supplier<Publisher<?>>) () -> Flux.just(1, 2, 3).cache(2, Duration.ofSeconds(10))) .thenAwait(Duration.ofSeconds(5)) .expectNext(2, 3) .verifyComplete(); fails with exception java.lang.AssertionError: expectation "expectNext(2)" failed (expected value: 2; actual value: 1) If I change the expected values to .expectNext(1, 2, 3) it will pass. So it does not respect the history provided in cache method? 回答1: Caching and TTL are a bit more tricky

问题 I have a simple aspect (see below) with @Around annotation. This aspect works when the the application don't use reactive paradigm. But when the application returns Mono or Flux doesn't works properly. I need to get the object returned from the method to generate a JSON object to use as log, generate events, etc. Here is my code that works in a non reactive classes: @Around("@annotation(simpleEvent)") public Object logExecutionTime(ProceedingJoinPoint joinPoint, SimpleEvent simpleEvent)

问题 I have a reactive core WebClient to post to a given endpoint. The payload is a flux of Job objects and the content-type is application/stream+json Flux jobFlux = Flux.just(new Job()); Mono<JsonNode> response = localEP.post().uri( "/dev/job" ) .contentType(MediaType.APPLICATION_STREAM_JSON) .body( BodyInserters.fromObject(jobFlux)) .retrieve() .bodyToMono( JsonNode.class ); On the server end I have tried both a Spring Controller style and Spring Web Reactive FunctionHandler to process the

问题 I've written an application with the server side applying the Event Sourcing pattern, with all incoming commands processed sequentially with the Reactor. I get those commands from client connexions. Alas, my Netty Pipeline publishes commands with no respect for the Reactive Contract. Reactor Netty could be a part of a solution, because it enforces the Reactive Contract down to the Netty Pipeline. But with Reactor Netty, each connection in a Flux. Connections are added and removed. How do I

问题 What are the situations which cause Flux::flatMap to listen to multiple sources (0...infinity) concurrently? I found out, while experimenting, that when the upstream send signals to flatMap in thread thread-upstream-1 and there are N inner streams which flatMap will listen to and each of them send signals in different thread: thread-inner-stream-i for 1<=i<=N , than for every 1<=i<=N if thread-upstream-1 != thread-inner-stream-i , flatMap will listen concurrently to all the inner streams. I

问题 IS there any simple way to use Micrometer timers with Webflux controllers? It seems that @Timed works only with non-reactive methods. For reactive it records very low time values. I found a similar question: How to use Micrometer Timer to record duration of async method (returns Mono or Flux) but the answers were too complex for such a common issue Any ideas? 回答1: If you want to measure time for Web-flux methods/calls you can then use easily metrics directly from Flux/Mono (plus configure

问题 I have an issue with a reactive chain relying on flatMap() and switchIfEmpty() . For some reason, one of the Mono does not emit anything... This is the public handler method calling the others: //Throws: NoSuchElementException: Source was empty public Mono<ServerResponse> createUser(ServerRequest serverRequest) { Hooks.onOperatorDebug(); Mono<User> userMono = serverRequest.bodyToMono(User.class); return validateUser(userMono) .switchIfEmpty(saveUser(userMono)) .single(); } This is the first

问题 I have a spring integration sftp flow which I load as a child context within my overall application context. This is based on the dynamic ftp SI example. My integration flow has nothing about reactor or streams in it. Its a simple flow with one direct channel connected with a sftp-outbound-gateway to transfer files to a sftp server. I can even run units tests and the flow work fine (is able to transfer files) but when I run an integration test which loads the full parent application and then

问题 I have two endpoints : /parent and /child/{parentId} I need to return list of all Child public class Parent { private long id; private Child child; } public class Child { private long childId; private String someAttribute; } However, call to /child/{parentId} is quite slow, so Im trying to do this: Call /parent to get 100 parent data, using asynchronous RestTemplate For each parent data, call /child/{parentId} to get detail Add the result call to /child/{parentId} into resultList When 100