HotObservableExample.java

        /*
         * Step 1: Create a subject and emit a
         * single integer from the subject. (Subject is acting
         * as an Observable in this case)
         * */
        PublishSubject<Integer> pSubject = PublishSubject.create();
        pSubject.onNext(0);


        /*
         * Step 2: Subscribe to the Subject - emissions from the subject
         * will be printed
         * */
        pSubject.subscribe(it -> System.out.println("Observer 1 onNext: " + it),
                (Throwable onError) -> { },
                () -> {},
                on1 -> System.out.println("Observer 1 onSubscribe"));

        /*
         * Step 3: Again emit values from subject.
         * */
        pSubject.onNext(1);
        pSubject.onNext(2);


        /*
         * Step 4: Again observe the emissions by adding
         * another Observer to the Subject.
         * */
        pSubject.subscribe(it -> System.out.println("Observer 2 onNext: " + it),
                (Throwable onError) -> { },
                () -> {},
                on1 -> System.out.println("Observer 2 onSubscribe"));


        pSubject.onNext(3);
        pSubject.onNext(4);