当互联网恢复时应用程序崩溃，RxJava和改造

Question

我需要从 Api 获取每个列表元素的数据，还需要实现互联网连接检查器。

1. 然后程序启动一切正常。
2. 我在直播中禁用互联网，然后再次运行方法(使用滑动刷新布局(，我收到互联网错误吐司，太好了！
3. 我在直播中恢复了互联网，并再次运行方法(使用滑动刷新布局(，应用程序崩溃并显示错误。

现在我有以下方法。 注意！dataManager.getCityConditionsResponse(( 返回单

@Override
public void updateCitiesList() {
List<City> citiesList = dataManager.getCitiesFromDb();
if (!dataManager.isInternetConnected()) {
view.showCitiesList(citiesList);
view.showInternetErrorToast();
} else {
compositeDisposable.add(Observable.fromIterable(citiesList)
.doOnNext(city -> dataManager.getCityConditionsResponse(city.getQuery())
.subscribe(
response -> {
city.setTemp(response.getTemp());
city.setIcon(response.getIcon());
},
error -> view.showServerErrorToast()))
.toList()
.subscribeOn(Schedulers.io())
.observeOn(AndroidSchedulers.mainThread())
.subscribe(
list -> view.showCitiesList(list),
error -> view.showServerErrorToast()
));
}
view.hideRefreshingStatus();
}

在步骤3中，我遇到了此错误

018-10-12 16:34:54.033 19013-19046/mike.weather E/AndroidRuntime: FATAL EXCEPTION: RxCachedThreadScheduler-1
Process: mike.weather, PID: 19013
io.reactivex.exceptions.CompositeException: 2 exceptions occurred. 
at io.reactivex.internal.observers.ConsumerSingleObserver.onError(ConsumerSingleObserver.java:49)
at io.reactivex.internal.operators.observable.ObservableSingleSingle$SingleElementObserver.onError(ObservableSingleSingle.java:93)
at retrofit2.adapter.rxjava2.BodyObservable$BodyObserver.onError(BodyObservable.java:72)
at retrofit2.adapter.rxjava2.CallExecuteObservable.subscribeActual(CallExecuteObservable.java:56)
at io.reactivex.Observable.subscribe(Observable.java:12090)
at retrofit2.adapter.rxjava2.BodyObservable.subscribeActual(BodyObservable.java:34)
at io.reactivex.Observable.subscribe(Observable.java:12090)
at io.reactivex.internal.operators.observable.ObservableSingleSingle.subscribeActual(ObservableSingleSingle.java:35)
at io.reactivex.Single.subscribe(Single.java:3438)
at io.reactivex.Single.subscribe(Single.java:3424)
at mike.weather.ui.main.MainActivityPresenter.lambda$updateCitiesList$3(MainActivityPresenter.java:49)
at mike.weather.ui.main.-$$Lambda$MainActivityPresenter$UqLPaAef0SB9PT-Rz654tgX3dnA.accept(Unknown Source:4)
at io.reactivex.internal.operators.observable.ObservableDoOnEach$DoOnEachObserver.onNext(ObservableDoOnEach.java:93)
at io.reactivex.internal.operators.observable.ObservableDoOnEach$DoOnEachObserver.onNext(ObservableDoOnEach.java:101)
at io.reactivex.internal.operators.observable.ObservableFromIterable$FromIterableDisposable.run(ObservableFromIterable.java:98)
at io.reactivex.internal.operators.observable.ObservableFromIterable.subscribeActual(ObservableFromIterable.java:58)
at io.reactivex.Observable.subscribe(Observable.java:12090)
at io.reactivex.internal.operators.observable.ObservableDoOnEach.subscribeActual(ObservableDoOnEach.java:42)
at io.reactivex.Observable.subscribe(Observable.java:12090)
at io.reactivex.internal.operators.observable.ObservableDoOnEach.subscribeActual(ObservableDoOnEach.java:42)
at io.reactivex.Observable.subscribe(Observable.java:12090)
at io.reactivex.internal.operators.observable.ObservableToListSingle.subscribeActual(ObservableToListSingle.java:58)
at io.reactivex.Single.subscribe(Single.java:3438)
at io.reactivex.internal.operators.single.SingleDoOnSuccess.subscribeActual(SingleDoOnSuccess.java:35)
at io.reactivex.Single.subscribe(Single.java:3438)
at io.reactivex.internal.operators.single.SingleSubscribeOn$SubscribeOnObserver.run(SingleSubscribeOn.java:89)
at io.reactivex.Scheduler$DisposeTask.run(Scheduler.java:578)
at io.reactivex.internal.schedulers.ScheduledRunnable.run(ScheduledRunnable.java:66)
at io.reactivex.internal.schedulers.ScheduledRunnable.call(ScheduledRunnable.java:57)
at java.util.concurrent.FutureTask.run(FutureTask.java:266)
at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(ScheduledThreadPoolExecutor.java:301)
........................

Answer 1

如果你像这样重写你的可观察量，那会更 Rx 惯用

compositeDisposable.add(Observable.fromArray(citiesList)
.flatMap(Observable::fromIterable)
.flatMapSingle(city -> 
dataManager.getCityConditionsResponse(city.getQuery())
.map(response -> { 
city.setTemp(response.getTemp());
city.setIcon(response.getIcon()); 
return city;
})
)
.toList()
.subscribeOn(Schedulers.io())
.observeOn(AndroidSchedulers.mainThread())
.subscribe(
list -> view.showCitiesList(list),
error -> view.showServerErrorToast()
));

在那之后，我认为你的问题会消失。