Question

应该使用哪个运算符将许多Flowable<CurrencyStamp>转换为Flowable<List<CurrencyStamp>>？

转换代码：

public static Single<List<CurrencyStamp>> getStampByDay(String symbol, Date date, String... convertsSymbols){
    long count = 0;

    Single<List<CurrencyStamp>> result = null;
    while (count < secByDay){
        Flowable<CurrencyStamp> item = CoinApi.getCompareApi().getCurrencyHistory(symbol, date.getTime() - count,
                convertsSymbols).subscribeOn(Schedulers.io())
                .observeOn(AndroidSchedulers.mainThread());


        count += secByFiveMin;
    }

    return result;
}

在“ while”构造中，我需要将每个“ item”添加到“ base”并在结果中创建Single<List<Currency>>（例如）

Answer 1

要从Flowable转换为Flowable>，您需要使用Flowable＃toList，它将返回Single>

Single<List<Integer>> listSingle = Flowable.just(1, 2, 3).toList();

请记住，给定的Single将仅返回一个值或错误。给定Flowable完成后，将发出收集的列表。 Flowable中的OnError将与onError一起传播。

警告：当Flowable为无穷大时，将导致内存泄漏，因为由于给定Flowable没有“ onComplete”，因此列表永远不会被发出。

Answer 2

我写这段代码：

public static Single<Currencies> getCurrencyFlowable(){

        Single<Currencies> usd = CoinApi.getMarketCupApi().getCurrencies();
        Single<Currencies> rub = CoinApi.getMarketCupApi().getCurrencies("RUB");
        Single<Currencies> eur = CoinApi.getMarketCupApi().getCurrencies("EUR");
        Single<Currencies> btc = CoinApi.getMarketCupApi().getCurrencies("BTC");

        List<Single<Currencies>> singles = new ArrayList<>();
        singles.add(usd);
        singles.add(rub);
        singles.add(eur);
        singles.add(btc);

        return Single.zip(singles, objects -> {
            Currencies[] currencies = new Currencies[objects.length];
            for (int i = 0; i < objects.length; i++) {
                currencies[i] = (Currencies)objects[i];
            }
            return ramming(currencies);
        }).subscribeOn(Schedulers.io() )
                .observeOn(AndroidSchedulers.mainThread());

    }

为我工作。

将Flowables <item>转换为Flowable <list <item >>或其他可观察到的

2 个答案: