A Reactive Streams publisher with Rx operators that emits 0 to N elements, and then completes (successfully or with an error). For more information, you can check the following link: https://projectreactor.io

Flux<T> is a Publisher<T> with basic flow operations and supports 0..n elements.

The definition of Flux is as follows:

public abstract class Flux<T>
 extends Object
 implements Publisher<T>

The following figure, as depicted in the Flux documentation, explains the working of Flux in more detail:

Flux support is in Spring 5 and a variety of other important modules, including Spring Security. Operators acting on Flux would create new publishers.

Please refer to the Reactor Flux documentation for more information: https://projectreactor.io/docs/core/release/api/reactor/core/publisher/Flux.html.

Now, let's have a look at some code examples where usage of Flux is shown:

• Creating empty Flux:

Flux<String> emptyFlux = Flux.empty();

• Creating Flux with items in it:

Flux<String> itemFlux = Flux.just("Spring”, "Security”, "Reactive”);

• Creating Flux from an existing list:

List<String> existingList = Arrays.asList("Spring”, "Security”, "Reactive”);
Flux<String> listFlux = Flux.fromIterable(existingList);

• Creating Flux that emits every x milliseconds in an infinite manner:

Flux<Long> timer = Flux.interval(Duration.ofMillis(x));

• Creating Flux that emits an exception:

Flux.error(new CreatedException());