log() to the flux just before returning it. This tutorial Sep 3, 2023 · In this Java example, we use Project Reactor’s Flux to create a reactive stream that emits values 1, 2, and 3 with time delays between emissions. createCharacterSequence(). elementAt( 0 ); StepVerifier. Sample Usage. Aug 11, 2022 · subscribeOn and publishOn operators in Project Reactor. The right way is to change the rest of your code to be reactive too, from head to toe. when something happens). JDK 8; Maven 3. More Practice: Spring Boot WebFlux example: Building Rest API. Well, Flux brings the following key benefits to the table with the help of unidirectional data flow: The code becomes quite clear and easy to understand. yarn add flux. just(“Sample String”); Flux. 2 version already supported it, but starting with Spring 5, we now have a more idiomatic and convenient way to handle it. Jan 8, 2024 · In addition to the create operator, the Flux class has another static method to emit a sequence asynchronously, namely push. To understand it simply: A component publishes events using Action Creators Aug 5, 2021 · 5. Sep 10, 2020 · Example Project. It’s an Flux. For a passive version that observe and forward incoming data see doOnNext(java. Is it possible to tweak this behaviour and achieve this : on first element - emit it instantly , start sampling with delay from 2nd up to the end. range(1, 10). subscribe yourself. Given a scenario when one has to work with Flux<T> or Mono<T>, there are different ways to combine streams. final Flux<Integer> userIds = Flux. . This Jan 31, 2020 · Spring WebClient is a non-blocking, reactive client to perform HTTP requests, a part of Spring WebFlux framework In this tutorial, you will learn how to use WebClient and take a look at the difference between its exchange() and retrieve() methods What you'll need JDK 8+ or OpenJDK 8+ Maven 3+ You should use Mono. The sample you're showing is doing in-memory work, no I/O or latency involved. We can use elementAt (0) to get the first element of a flux in a non-blocking way: @Test void givenAPaymentFlux_whenUsingElementAt_thenGetTheFirstPaymentAsMono() {. just( "Site_0:bezkoder. [Last Updated: Sep 27, 2020] Previous Page Next Page. Oct 11, 2018 · But for your use case, you can use filter here is an example, Which looks filters over the {true, false} items, then for each filter that is true, I zip the results of two mono's together, then subscribe with an action. flatMap { customer ->. Mar 27, 2020 · source1. subscribe(subscriber)[2] A Flux Publisher is created using [1], as long as subscribe method is not invoked, data will not be produced. To follow the guide, you need the following: A Kubernetes cluster. The exchange method gives us access to Flux<String> flux = Flux. edited Feb 12, 2021 at 14:59. So you need to turn connect the whole process as a single pipeline, a bit like: Flux<DataBuffer> requestBody = exchange. co. In Java, a stream is a collection of data that enables various operations like filter, map, reduce, and more. tryEmitValue (Object) (or Sinks. These two wont be run in parallell. Jan 8, 2024 · Mono‘s doOnNext () allows us to attach a listener that will be triggered when the data is emitted. 2. subscribe. There are complex examples and even those mentioned simple are difficult to start with. This will effectively turn this Mono into a hot task when the first Subscriber subscribes using subscribe () API. Aug 21, 2018 · Stack Overflow Public questions & answers; Stack Overflow for Teams Where developers & technologists share private knowledge with coworkers; Talent Build your employer brand Feb 12, 2023 · Reactor is a project by the reactive foundation that provides a reactive programming library for building reactive systems in Java. Best Java code snippets using reactor. Add behavior (side-effect) triggered when the Flux is subscribed. subscribe(consolidated::add); Notice that createCharacterSequence returns a Flux to which we subscribed and consumes the elements in the consolidated list. just(true, false); Mono<Integer> mono1 = Mono. Example Program for Mono: In this example, we created a Mono type publisher and It returns a String type mono object and The Mono publisher can emits only one event. Throwing Exceptions Directly in a Pipeline Operator. service. 4 Aug 11, 2020 · All above methods work by re-subscribing to the upstream Flux. flatMap(num -> Flux. Predictable data flow. If you subscribe late, the Mono will complete immediately: Sep 9, 2021 · subscribe is async, its fire and forget so you can't collect the response after. Further Subscriber will share the same Subscription and therefore the same result. just("data1", "data2", "data3"); // Subscribe to a Flux and print the elements. Managed to multicast the mono using Mono. For instance, the correct way to cancel a subscription is to call Disposable#dispose() on the Disposable returned by Flux#subscribe(). com Jun 13, 2016 · For example, to create a Flux from an array: Flux<String> flux = Flux. Jul 3, 2020 · Below is an example of a flux that emits one item – Flux<String> flux = Flux. just(1); Mono<String> mono2 = Mono. Given following method: Flux<Person> getAllPerson(Criteria criteria) How do i process the flux by changing a field in each of the Person object in the flux? getAllPerson(criteria) . Output 1= Tuple (f11, f21, f31) Output 2 = Tuple (f12, f22, f32) Console output when I run the above test: Verifying count: Zip output f11,f21,f31. flatMap(inputStream -> /* do something with single InputStream */ Sep 23, 2021 · In practice, you'll likely very rarely need to use a parallel flux, including in this example. You are blocking the main thread until an action completes, which can be achieved without Reactor in a much simpler fashion. N sequences of data. Examples Flux. How can I achieve my goal? Oct 31, 2018 · Reactor does not enforce a concurrency model by default and yes, many operators will continue the work on the Thread where the subscribe() operation happened. We can see this as the reactive-counter part of a collection, an array or a stream. getFlux(): Generates a Flux stream with predefined strings, serving as static data or example data. 4 Sep 22, 2021 · The expected count in the above test is 2 since each publisher is emitting two values. returnOnComplete(Mono. Spring 4. Feb 18, 2023 · Convert Flux into List, Map – Reactor. retry() Example (FluxRetry. Jan 8, 2024 · Let’s set up our example with the Project Reactor dependencies: 3. You don't have to call subscribe on reactive method/operator chains returned in Controllers because Spring implicitly calls it, but for all other executions you need to explicitly call it. Also, it's subscribing right away on Aug 3, 2023 · To get started with Flux, we need the Flux library. Jun 12, 2024 · Simply put, Server-Sent-Events, or SSE for short, is an HTTP standard that allows a web application to handle a unidirectional event stream and receive updates whenever server emits data. getFluxList(): Converts collections of User objects into reactive streams, enabling integration with Jun 15, 2019 · There are a lot of cases where you do not call . 1. subscribe使用的例子?那么恭喜您, 这里精选的方法代码示例或许可以为您提供帮助。 Flux Examples Flux Example 1 - Create Flux Object. And what is Flux? Prior to exploring Flux, let’s first recall the concept of streams in Java. CategoryService. Easily testable using Unit Test. Therefore, we can use an operator to add behavior: blockingHelloWorld() . Also by using the . You can only block if you're using reactor within the servlet world, even then you can pass back the Mono/Flux and it'll be an async request. subscribe(clientA); then clientB should subscribe the same way: Subscriber<Response> clientB = request. Jan 8, 2024 · Next, we subscribe to the new consolidated sequence: List<Character> consolidated = new ArrayList<>(); characterCreator. The Mono publisher can emits zero or one and The Flux publisher can emits zero to N events. Looking at other posts, Flux#create and Flux#generate might be good places to start. Mono<Payment> firstPayment = fluxOfThreePayments(). 4. By default the execution happens in the thread of the caller to subscribe(). (For example: WebFlux controllers) In this case, since you're not calling . Subscribe can also expect a throwable parameter and handle stuff. @Service public class Dec 6, 2019 · This is the seventh part of our tutorial showing how to build a Reactive application using Spring Boot, Kotlin, Java, and JavaFX. create(); Flux. defer () method: public void whenEmptyList_thenMonoDeferExecuted() {. Jul 4, 2019 · Second of all you need to understand the difference of running something in parallell vs running something non-blocking. So either use block or employ waiting in the main thread. subscribe(ts); Nov 18, 2019 · Flux<T> — is a publisher that produces from 0 to N values of T; This means all operations are lazy and they are performed only when the subscribe method is called. StepVerifier. Mono<List<String>> emptyList = Mono. e. This blog post explores Java Reactive Jan 22, 2021 · Let’s create a few examples. It changes flux so that it emits events only at the ends of specified periods. In this article, you'll learn how to use WebClient and WebTestClient to consume and test REST APIs. out::println); If we run the above code, we can see that these 2 pipelines print the data on the console as and when elements are emitted. function. public void normal() {. Mar 9, 2018 · The test is based on the Spring Webflux example. log() method above, we can trace and observe all the stream signals. producing predefined data with TestPublisher to test downstream operators. public static void createSubscribers(Flux<Integer> flux Jan 21, 2022 · Flux<String> flux = Flux. Here one example: @MockBean private MyService service; @Test public void getItems() { Flux<Item> Oct 20, 2021 · 1. To achieve this, the controller method has to return your Mono publisher like this: @PostMapping. range(0,10)[1]. Getting Started with Flux. Single Valued Sequences Jun 27, 2021 · Here I create a second Publisher using Sinks. just("string May 20, 2021 · From the Reactor documnetation I have read that the Flux. In your example, you're firing off 100 web service calls. create and Flux. using (Showing top 20 results out of 315) Jan 8, 2024 · Synchronous vs. subscribe怎么用?Java Flux. Before you begin. While the Mono is used for handling zero or one result, the Flux is used to handle zero to many results, possibly even infinite results. I'd like to return a value (or publisher) after a Flux is completed. range(1, 1000); numbers. Jun 24, 2019 · As you can see, elements added before subscribing to the hotsource won't be passed down to the subscribe. RELEASE: Non-Blocking Reactive Foundation for the JVM. Verifying values: Aug 27, 2021 · Moving the if-statement yours to a filter - same behavior String eventType = event. Aug 12, 2019 · Specifically, you need the flatMapIterable() method as the flatMap() method can only flatten a Publisher (such as another Flux or Mono). A GitHub personal access token with repo permissions. out::println); In the above example, the flatMap operator takes each number emitted by the publisher and maps it to a new publisher that emits num + 1. Mono<String> decodedBody = decodeBody(requestBody); May 6, 2023 · deferContextual can be used for the current context-based evaluation of publisher. Given you example, something like, Which ends up as a Mono<Response> on which the framework will subscribe to. using. map { . The original inspiration was a 70-minute live demo. util. Jul 28, 2023 · In this spring webflux tutorial, we will learn the basic concepts behind reactive programming, webflux APIs and a fully functional hello world example. Define Actions: Create an “actions” file to define the actions for Sep 28, 2017 · A slightly modified version of Bk Santiago's answer makes use of reduce() instead of collect(). I've tried a lot of different ways but i can't figure out the way Mar 6, 2024 · This tutorial shows you how to bootstrap Flux to a Kubernetes cluster and deploy a sample application in a GitOps manner. In that particular case, the Spring Webflux framework will subscribe for you as long as you provide your publisher. The manifesto has a goal rooted in creating more resilient, robust, flexible systems which it calls Reactive Systems. call(customer) } . defer(() -> monoOfEmptyList()); Reactor does not enforce a concurrency model, it leaves that to the developer. Flux. subscribe(System. interval to periodically publish event, and there seems no way to append/modify the content in Flux once it is created. This method works just like create, except that it allows only one producing thread to emit signals at a time. (簡略化して @Repository ではなく @Service でWebClientを直接利用してます). AssertSubscriber<Integer> ts = AssertSubscriber. Empty. [doc-files/ Apr 28, 2023 · Calling subscribe() gives you a Disposable that helps you manage the underlying Subscription. TIP: If you want some insight as to what is going on inside a Flux or Mono you are about to return during one of these exercises, you can always append . just("apple", "banana", "orange"); flux. Here's an example with (pseudo) code that resembles what I'm after: someFlux. getRequest(). 本文整理汇总了Java中reactor. Reactor also provides operators to work with Mono and Flux objects. emitEmpty() trigger into the Flux. Jan 23, 2022 · For example, if this is a Spring Controller method, then it is the framework itself that subscribes to the Mono or Flux. EmitFailureHandler)) is enough and will implicitly produce a Subscriber. }. All the example I found is to use Flux. Difference Between Flux. The simplest way to handle an Exception is by throwing it. client. reactor. just(num + 1)) . The Access Token is requested asynchronously to avoid blocking the appliction's thread while the token request is processed at the other end and the response arrives. How to start learning flux from docs as is not the best way to understand unless we have a sample working example with step by step guide Aug 10, 2018 · Disposable disp = Flux. flux. Flux. Reactive Programming. The most common case in testing reactive streams is when we have a publisher (a Flux or Mono) defined in our code. In the previous lesson, we mentioned that the default behavior is that the same thread that performs a subscription will be used for the whole pipeline execution. It is part of Spring WebFlux module that was introduced in Spring 5. subscribe, you have to use the side effect operators, rather than arguments to . Reactor provides a set of reactive types such as Mono and Flux, as well as a number of operators for manipulating and transforming reactive streams. The user can create his own material base and import them into the Flux models to be studied. SSE with Spring 6 Webflux. share() operator: Prepare a Mono which shares this Mono result similar to Flux. You should subscribe instead. because Flux::create doesn't react to changes in the state of the app while Flux::generate does. But this doesn't mean that using Reactor will block the main thread. You could of course wrap your iterable inside a Flux first, but flatMapIterable() is a far neater and more concise method of obtaining the same result. reduce(new InputStream() { public int read() { return -1; } }, (s: InputStream, d: DataBuffer) -> new SequenceInputStream(s, d. We use the subscribeOn and publishOn operators for switching the execution context (Scheduler) in a reactive chain. The Subscriber 's onNext hook on the other hand is influenced by the closest publishOn up in the chain (much like your map). Empty, who's only purpose is to emit an onComplete signal when the original Flux completes. We subscribe to the flux and provide callbacks These are the top rated real world Java examples of Flux extracted from open source projects. Reactive Systems are defined by four tenets: To read more, here is The Reactive Manifesto. subscribe(); Then, as you can see, your subscription returns a Disposable object that you can use to cancel the entire thing if you want, e. fromIterable(customers) . In this lesson we'll see different factory methods to create a Flux. setLastUpdated(new Date()) The setLastUpdated (new Date ()) returns void. in. subscribe方法的具体用法?Java Flux. May 24, 2024 · Here we provide two different examples for Mono and Flux publishers. If it is a method that is triggered from time to time by a Scheduler, then you must explicitly subscribe to the Mono or Flux , otherwise, no processing will take place. Mar 30, 2017 · Restore packages using "npm install" and run the app with "npm start" from the working directory command prompt where you have the sample code downloaded. In some cases, we’ll want to consume the value in intermediate steps. We could replace the create method in the example we’ve just gone through with push, and the code will still May 7, 2020 · The subscribe method is used to subscribe a Consumer to the Flux that will consume all the elements in the sequence, as well as a Consumer that will handle errors. just(id)) I. These individual streams are then merged into a single stream during the subscription Apr 25, 2018 · The same algorithm with Flux::create will fail because Flux::create will emit all the blocks we don't have and if some blocks failed to be downloaded then we have a problem. subscribe WebFluxでは WebClient を使うことでノンブロッキングなAPIコールに対応します。. Aug 11, 2022 · Subscribe to Flux in Java Reactor; Create a Mono in Java Reactor; Extract Data from Mono in Java; Introduction to Project Reactor in Java; Create a Flux in Java Reactor; How Mono and Flux Work Internally? Transform Flux and Mono Using Operators; Combine Flux and Mono Publishers; Convert Mono to Flux and vice versa; doOn Callbacks in Project Reactor Dec 17, 2023 · Java Reactive Programming has emerged as an integral paradigm for handling asynchronous data streams and crafting scalable, responsive applications. This method is not intended for capturing the subscription and calling its methods, but for side effects like monitoring. There are actually only two things you can do with it: operate on it (transform it, or combine it with other sequences), subscribe to it (it’s a publisher). filter(v -> v % 2 == 0). Jan 8, 2024 · As a first step to solving the problem of reading Flux<DataBuffer> into a single InputStream, we’ll use the Spring reactive WebClient for making a GET request. In general, reactor-test has two main uses: creating a step-by-step test with StepVerifier. getBody(); // decode the request body as a Mono or a Flux. Bear in mind the actual work needed to do this is very low - you generate and fire off an asynchronous request, and then some time later you receive a response back. reactor. Exactly what I needed. publisher. You can rate examples to help us improve the quality of examples. java:51) at reactor. For example, if we have the following code: Transform the items emitted by this Flux by applying a synchronous function to each item. One that works like a conceptual promise: it can be completed with or without a value at any time, but only once. subscribe方法的典型用法代码示例。如果您正苦于以下问题:Java Flux. Then, if such a request is found in the cache, new clients simply subscribe to it Oct 1, 2019 · The Flux. create(firstPayment) Jan 22, 2018 · Im currently writing some basic unit tests for my REST-Endpoints. getEventType(); return DISTRIBUTOR. Calling Sinks. Our Example. Jan 23, 2019 · 5. 9. in for such testing scenarios: Jan 8, 2024 · 3. out::println); source2. core. Consumer). Some of them are: Map - It is used to transform from one element to another. generate <- this will get you more complexity and control over the flux. map(person -> person. Apr 11, 2018 · request. Install it using npm or yarn: npm install flux. Apr 20, 2020 · Flux Data Flow. Feb 19, 2020 · In project reactor flux there is a sample method Flux#sample java doc. equals(eventType); }) // Here is the trick 1 - your request below return Flux of SourceData the we will flatten // into a single Flux<SourceData> instead of Flux<List<SourceData>> with flatMapMany . g. 4. Mar 2, 2022 · A Sinks. Next, let us trigger the whole process that Dec 30, 2018 · Layer 1 -> The Reactive Manifesto. During the test, a server will be started on a random port and will invoke the URLs one after each other. This class, FluxService, offers various methods illustrating different functionalities of Flux streams. example. flatMap: Transform the elements emitted by this Flux asynchronously into Publishers. The Flux and Mono concepts all echo back to the Reactive Manifesto. The returnOnComplete function is made-up and doesn't exists (there's a . onComplete () signal as May 11, 2024 · Here, even if it takes some time to produce the value, the execution immediately continues without blocking on the subscribe() call. Now lets discuss the various methods we have, to combine these sources. just("red", "white", "blue"); We just generated a Flux, and now we can do stuff with it. The events are logged into the console. java class. doOnNext { }. If something abnormal happens during the processing of a stream element, we can throw an Exception with the throw keyword as if it were a normal method execution. Suppose you have a flux and a mono like this: // a flux that contains 6 elements. Reactive programming is a programming paradigm that promotes an asynchronous, non-blocking, event-driven approach to data processing. flatMap(event Oct 21, 2021 · 3. Very similar, but doesn't require an extra class: Java: body. Thanks. Aug 11, 2022 · To get the data from the Publisher (Flux), we need to subscribe to it. # or. Reactor is built on the Project Reactor Core library, which Jun 10, 2021 · So here goes a complete example. For example: 3. Note: The only drawback with the Flux is that there is some boilerplate that we need to Jan 8, 2024 · The Flux API also offers the elementAt () method. This is like a stream of 0 to N items, and we can do various transformations to this stream, including transforming it to an entirely different type of 0-N item stream. First of all, you should never block within a reactive pipeline. java. 1. subscribe(); 4. Flux<Boolean> bool = Flux. Let's try a very simple example: just return an empty Jan 30, 2017 · subscribeOn rather influence where the subscription occurs. empty(). Paul. Dependencies and Technologies Used: reactor-core 3. doOnComplete() hook, then later block using . @Test. WebClient is a non-blocking, reactive HTTP client with a fluent functional style API. Flux has a material manager with its own material base. Aug 16, 2020 · Reactor Parallel Flux: Reactor provides a method, parallel (), to process the items in parallel. getHeader(). How to use. The parallel method returns ParallelFlux which needs a Scheduler Apr 21, 2023 · Here is a code example that shows how to create a Flux object in Spring: Flux<String> flux = Flux. 0: Non-Blocking Reactive Foundation for the JVM. block(). We want to know how it behaves when someone Nov 1, 2020 · Example Project. doOnNext(result -> assertEquals(expected, result)) . Aug 18, 2023 · Project Reactor provides two core publishers, Mono and Flux; Mono represents 0. of(1,2,3,4,5,6)); // a mono of 1 element. Mar 10, 2022 · The data won’t flow or be processed until the subscribe() method is called. 5. subscribe(clientB); Moreover, the cache should contain not the previously saved response data, but the requests themselves, of type Mono<Response>. Flux<Integer> numbers = Flux. fromIterable(List. When the response is back to the subscribe, the server has already returned the response to the client. Add behavior (side-effect) triggered when the Flux completes successfully. So I create 2 parallel rails by invoking the parallel method. map can't be run until Mono<Response> responseMono Sep 27, 2020 · Reactor - Creating Flux Instance From Iterable. Flux#fromIterable () method can be used to create a Flux that emits the items contained in the provided Iterable. Let’s consider the following method where we subscribe with 4 consumers to a Flux of Integers which print out the thread name while processing the emitted elements in the Flux. out::println); Jul 16, 2018 · I want to make my App 1 publish Server Sent event through Flux and my App 2 listen on it continuously. One. Scalable apps can be built. method. In this example, instead of processing all the 10 items sequentially, I would like to divide the work between 2 CPU cores. public static <T> Flux<T> fromIterable(Iterable<? extends T> it) May 11, 2024 · 3. Let’s go through one sample that is using the conditional Mono. It will request an unbounded demand (Long. com. This completion is replayed to late subscribers. Let’s create a few examples to illustrate the usage of static methods in the Flux<T> class such as concat, concatWith, merge, zip and Mar 31, 2017 · I have googled across various platforms and websites but could not find a basic example of flux architecture with react. We recommend Kubernetes kind for trying Flux out in a local development environment. 1 and Flux represents 0. merge(getUser(id), getOtherUser(id)); } The main difference in this example is that we’ve used the static method merge instead of the fromIterable method. Part 6 makes use of that. Mar 30, 2024 · Example: Create FluxService. CONTEXT: An application, acting as a client, that requests an Access Token from an OAuth2 Authorization server. How to Subscribe to Flux in Java? When we subscribe to a Publisher , it starts emitting signals like: See full list on baeldung. MAX_VALUE). disp. Your responseMono. Jan 8, 2024 · public Flux fetchUserAndOtherUser(int id) { return Flux. . That is, the initial event that triggers the source to emit elements. 以下はWebClientの実装サンプルになります。. Last modified: February 18, 2023 bezkoder Reactor. to resolve your first map, it needs to make the rest call, then with the response it needs to do your second map. Zip output f12,f22,f32. We place the Sinks. I want to return id after someFlux has completed. Learn how Tabnine’s Al coding assistant generates code and provides accurate, personalized code completions. I want Flux publish on-demand (e. Using the merge method, we can combine two or more Fluxes into one result. 600 8 19. Java. Flux is an architecture which is similar to the Publisher / Subscriber pattern. Further, we can use one of the public API endpoints hosted by gorest. Instead, you just return the Mono/Flux from your method, and allow something higher in the stack to subscribe. 3. Flux represents an Asynchronous Sequence of 0-N Items. Flux e-Machine Toolbox FeMt is a application in Flux dedicated for Electric Machine which permits to compute and postprocess results like efficiency maps . subscribe(Consumer <? super T> consumer): Subscribe a Consumer to this Flux that will consume all the elements in the sequence. In this tutorial, I will show you ways to convert Flux to List, and FLux to Map example that uses collectList(), collectSortedList(), collectMap(), collectMultimap() function. sendNotification(event). Here are two extracts from the API specification for the Reactor Core library: map: Transform the items emitted by this Flux by applying a synchronous function to each item. Asynchronous. dispose() Documentation of dispose says: Cancel or dispose the underlying task or resource. For the code examples in this article, we’ll use the PaymentService class. subscribe() will initiate execution. Hence, each time zip emits a tuple of three values twice. out::println); //prints Sample String. out::println); By calling the subscribe () method, we request the For better performance, if your Mono is wraps around a slow operation, it might be good to have some caching layer. asInputStream()) ). asMono(). emitValue (Object, Sinks. You need to use the operators on the Mono/Flux and not block the reactive chain. Multiple Calls to Different Services Different Types Jun 19, 2019 · What you may also notice is we tried to handle the business exception in the subscribe block in the second expression. com", "Description_0:Java Technology", "Description_1:Project Reactor"); Convert Flux into List Flux collectList() collectList() will accumulates sequence into a Mono<List>, then we use block() method to subscribe to the Mono and block indefinitely until a next signal is received. Combining Publishers. Feb 12, 2019 · You can block until the Mono has completed: Of course, this defeats the purpose of reactive programming. Absolutely you have to call subscribe to initiate reactive execution so notifier. In this case, we’ll call the processPayment method only when the paymentMono emits the data, using doOnNext (): Payment paymentOf100 = new Payment ( 100 ); Mono Sep 18, 2018 · Short Answer. shareNext (). I use Mockito for that. using. subscribe does not block current thread, that means app main thread can complete earlier than Flux emits any element. In this post, you will learn to subscribe to a Flux in Java Reactor. za oe yf qi pv sf eg cf ns io