RxJava操作符 ~ defer

RxJava的 defer 操作符作以确保Observable代码在被订阅后才执行,而不是创建后立即执行

@Test
    public void defer() {

        Disposable disposable = Observable.defer(new Callable>() {
            @Override
            public ObservableSource call() throws Exception {
                return getRxJavaCreateExampleData();
            }
        })

                .subscribeOn(Schedulers.io())
                .unsubscribeOn(Schedulers.io())
                .observeOn(Schedulers.io())
                .subscribe(new Consumer