Hands-On Reactive Programming in Spring 5

Mapping elements of reactive sequences 

The most natural way of transforming a sequence is by mapping every element to some new value. Flux and Mono give the map operator, which behaves similarly to the map operator from the Java Stream API. The function with a map(Function<T, R>) signature allows the processing of elements one by one. Of course, as it changes the type of element from T to R, the whole sequence changes its type, so after the map operator Flux<T> becomes Flux<R>, Mono<T> becomes Mono<R>. The marble diagram for Flux.map() is as follows:

Diagram 4.4 Operator: map

Of course, the map operator of the Mono class behaves similarly ...