问理解基础数据源具有新值时可观察到的RxJava

EN

List<Integer> numbers = new ArrayList<>();
Runnable r = new Runnable() {
            @Override
            public void run() {
                int i = 100;
                while(i < 110) {
                    numbers.add(i);
                    try {
                        Thread.sleep(10);
                    } catch (InterruptedException e) {
                        e.printStackTrace();
                    }
                    i++;
                }
            }
        };
        numbers.add(0);
        numbers.add(1);
        numbers.add(2);
        Observable.fromIterable(numbers)
                .observeOn(Schedulers.io())
                .subscribe(i -> System.out.println("Received "+i+ " on "+ Thread.currentThread().getName()),
                        e -> e.printStackTrace());
        try {
            Thread.sleep(1000);
        } catch (InterruptedException e) {
            e.printStackTrace();
        }
        Thread t = new Thread(r);
        t.start();

        try {
            Thread.sleep(10000);
        } catch (InterruptedException e) {
            e.printStackTrace();
        }