gistfile1.java

        Observable.create(new Observable.OnSubscribeFunc<Cursor>() {
            @Override
            public Subscription onSubscribe(Observer<? super Cursor> observer) {
                try {
                    Cursor cursor = getCursor();
                    observer.onNext(cursor);
                    observer.onCompleted();
                } catch (Exception e) {
                    observer.onError(e);
                }

                return Subscriptions.empty();
            }
        }).subscribeOn(Schedulers.io()).observeOn(AndroidSchedulers.mainThread())
                .subscribe(new Action1<Cursor>() {
                    @Override
                    public void call(Cursor cursor) {
                        adapter.changeCursor(cursor);
                    }
                });