Learning RxJava

ReplaySubject

ReplaySubject is similar to PublishSubject followed by a cache() operator. It immediately captures emissions regardless of the presence of downstream Observers and optimizes the caching to occur inside the Subject itself:

import io.reactivex.subjects.ReplaySubject;import io.reactivex.subjects.Subject;public class Launcher {    public static void main(String[] args) {        Subject<String> subject =                ReplaySubject.create();        subject.subscribe(s -> System.out.println("Observer 1: " + s));        subject.onNext("Alpha");        subject.onNext("Beta");        subject.onNext("Gamma");        subject.onComplete();        subject.subscribe(s -> System.out.println("Observer 2: " + s));    }}

The output is as follows:

Observer 1: AlphaObserver 1: BetaObserver 1: GammaObserver 2: Alpha ...