Observable.empty（）の原因java.util.NoSuchElementException：シーケンスに要素がありません

Question

RxJava 1.0.14でRetrofit 2.0.0-beta2を使用しています。私はdoFinallyにいくつかのコードを実行する必要があるため、エラーをこのように扱う：

.onErrorResumeNext(Observable.empty());

をしかし、私は、スタックトレースでいない私のクラスで私のアプリがクラッシュするエラー（例えば401）とHTTPレスポンスを取得するとき。 Observable.neverを使用すると悪いことはありません。ここでは、完全なスタックトレースです。また、first()便利な演算子です。これは、take(1).single()に相当

java.lang.IllegalStateException: Exception thrown on Scheduler.Worker thread. Add `onError` handling. 
at rx.internal.schedulers.ScheduledAction.run (ScheduledAction.java:60) 
at android.os.Handler.handleCallback (Handler.java:739) 
at android.os.Handler.dispatchMessage (Handler.java:95) 
at android.os.Looper.loop (Looper.java:135) 
at android.app.ActivityThread.main (ActivityThread.java:5221) 
at java.lang.reflect.Method.invoke (Unknown source) 
at java.lang.reflect.Method.invoke (Method.java:372) 
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run (ZygoteInit.java:899) 
at com.android.internal.os.ZygoteInit.main (ZygoteInit.java:694) 

rx.exceptions.OnErrorNotImplementedException: Sequence contains no elements 
at rx.Observable$27.onError (Observable.java:7535) 
at rx.observers.SafeSubscriber._onError (SafeSubscriber.java:154) 
at rx.observers.SafeSubscriber.onError (SafeSubscriber.java:111) 
at rx.internal.operators.OperatorDoOnEach$1.onError (OperatorDoOnEach.java:70) 
at rx.internal.operators.OperatorDoOnEach$1.onError (OperatorDoOnEach.java:70) 
at rx.internal.operators.OperatorDoOnEach$1.onError (OperatorDoOnEach.java:70) 
at rx.internal.operators.OperatorObserveOn$ObserveOnSubscriber.pollQueue (OperatorObserveOn.java:197) 
at rx.internal.operators.OperatorObserveOn$ObserveOnSubscriber$2.call (OperatorObserveOn.java:170) 
at rx.internal.schedulers.ScheduledAction.run (ScheduledAction.java:55) 
at android.os.Handler.handleCallback (Handler.java:739) 
at android.os.Handler.dispatchMessage (Handler.java:95) 
at android.os.Looper.loop (Looper.java:135) 
at android.app.ActivityThread.main (ActivityThread.java:5221) 
at java.lang.reflect.Method.invoke (Unknown source) 
at java.lang.reflect.Method.invoke (Method.java:372) 
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run (ZygoteInit.java:899) 
at com.android.internal.os.ZygoteInit.main (ZygoteInit.java:694) 

java.util.NoSuchElementException: Sequence contains no elements 
at rx.internal.operators.OperatorSingle$ParentSubscriber.onCompleted (OperatorSingle.java:131) 
at rx.internal.operators.OperatorTake$1.onCompleted (OperatorTake.java:53) 
at rx.Observable$EmptyHolder$1.call (Observable.java:1077) 
at rx.Observable$EmptyHolder$1.call (Observable.java:1074) 
at rx.Observable.unsafeSubscribe (Observable.java:7710) 
at rx.internal.operators.OperatorOnErrorResumeNextViaObservable$1.onError (OperatorOnErrorResumeNextViaObservable.java:76) 
at rx.internal.operators.OperatorDoOnEach$1.onError (OperatorDoOnEach.java:70) 
at rx.internal.operators.OperatorSubscribeOn$1$1$1.onError (OperatorSubscribeOn.java:71) 
at rx.observers.SerializedObserver.onError (SerializedObserver.java:159) 
at rx.observers.SerializedSubscriber.onError (SerializedSubscriber.java:79) 
at rx.internal.operators.OperatorTakeUntil$1.onError (OperatorTakeUntil.java:49) 
at rx.internal.operators.OperatorMerge$MergeSubscriber.reportError (OperatorMerge.java:239) 
at rx.internal.operators.OperatorMerge$MergeSubscriber.checkTerminate (OperatorMerge.java:774) 
at rx.internal.operators.OperatorMerge$MergeSubscriber.emitLoop (OperatorMerge.java:532) 
at rx.internal.operators.OperatorMerge$MergeSubscriber.emit (OperatorMerge.java:521) 
at rx.internal.operators.OperatorMerge$InnerSubscriber.onError (OperatorMerge.java:808) 
at rx.Observable$ThrowObservable$1.call (Observable.java:9600) 
at rx.Observable$ThrowObservable$1.call (Observable.java:9590) 
at rx.Observable.unsafeSubscribe (Observable.java:7710) 
at rx.internal.operators.OperatorMerge$MergeSubscriber.onNext (OperatorMerge.java:231) 
at rx.internal.operators.OperatorMerge$MergeSubscriber.onNext (OperatorMerge.java:140) 
at rx.internal.operators.OperatorMap$1.onNext (OperatorMap.java:55) 
at retrofit.RxJavaCallAdapterFactory$CallOnSubscribe.call (RxJavaCallAdapterFactory.java:113) 
at retrofit.RxJavaCallAdapterFactory$CallOnSubscribe.call (RxJavaCallAdapterFactory.java:88) 
at rx.Observable$2.call (Observable.java:162) 
at rx.Observable$2.call (Observable.java:154) 
at rx.Observable$2.call (Observable.java:162) 
at rx.Observable$2.call (Observable.java:154) 
at rx.Observable$2.call (Observable.java:162) 
at rx.Observable$2.call (Observable.java:154) 
at rx.Observable.unsafeSubscribe (Observable.java:7710) 
at rx.internal.operators.OperatorSubscribeOn$1$1.call (OperatorSubscribeOn.java:62) 
at rx.internal.schedulers.ScheduledAction.run (ScheduledAction.java:55) 
at java.util.concurrent.Executors$RunnableAdapter.call (Executors.java:422) 
at java.util.concurrent.FutureTask.run (FutureTask.java:237) 
at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.access$201 (ScheduledThreadPoolExecutor.java:152) 
at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run (ScheduledThreadPoolExecutor.java:265) 
at java.util.concurrent.ThreadPoolExecutor.runWorker (ThreadPoolExecutor.java:1112) 
at java.util.concurrent.ThreadPoolExecutor$Worker.run (ThreadPoolExecutor.java:587) 
at java.lang.Thread.run (Thread.java:818) 

おかげで、
アントンスタックトレースから

Answer 1

、

at rx.internal.operators.OperatorSingle$ParentSubscriber.onCompleted (OperatorSingle.java:131) 
at rx.internal.operators.OperatorTake$1.onCompleted (OperatorTake.java:53) 

。私はあなたが後者を使用していると思われますが、どちらも少なくとも1つの要素が必要です。

empty()を使用すると、下流の演算子の契約に違反する要素のない観測値を作成しています。観測可能なonErrorResumeNextの既定のアイテムを放出するか、下流のコードを変更して要素のないストリームをサポートしてください。