public static void main(String[] args) throws Exception {
    Flux<Integer> flux1 = Flux.generate(emitter -> {
        emitter.next(1);
    });

    Flux<Integer> flux2 = Flux.generate(emitter -> {
        emitter.next(2);

    });

    Flux<Integer> merged = flux1.mergeWith(flux2);
    merged.subscribe(s -> System.out.println(s));

    Thread.currentThread().join();
}

public static void main(String[] args) throws Exception {
    Flux<Integer> flux1 = Flux.generate(emitter -> {
        emitter.next(1);
        try {
            Thread.sleep(100);
        } catch (Exception e) {}
    });

    Flux<Integer> flux2 = Flux.generate(emitter -> {
        emitter.next(2);
        try {
            Thread.sleep(100);
        } catch (Exception e) {}
    });

    TopicProcessor<Integer> processor = TopicProcessor.create();
    flux1.subscribe(processor);
    flux2.subscribe(processor);

    processor.subscribe(s -> System.out.println(s));


    Thread.currentThread().join();
}