由于rxJava函数中的foreach导致android设备崩溃

Question

I use rxJava in my application. And often i used such code:

couponListInteractor.getObservableData(storeId)
        .subscribe(data -> 
                data.forEach(item ->
                {
                    if (!couponsCode.contains(item.getCode()))
                    {
                        couponsCode.add(item.getCode());
                    }
                }
        );

When i was developing application in my emulator everething was ok. But when i was starting test my application in devices (4.0 android version). I was getting some erors.

FATAL EXCEPTION: RxNewThreadScheduler-1
                                                                        Process: com.mrrebates.cashback, PID: 20428
                                                                        java.lang.IllegalStateException: Fatal Exception thrown on Scheduler.Worker thread.
                                                                            at rx.internal.schedulers.ScheduledAction.run(ScheduledAction.java:59)
                                                                            at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:423)
                                                                            at java.util.concurrent.FutureTask.run(FutureTask.java:237)
                                                                            at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(ScheduledThreadPoolExecutor.java:269)
                                                                            at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1113)
                                                                            at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:588)
                                                                            at java.lang.Thread.run(Thread.java:818)
                                                                         Caused by: java.lang.NoClassDefFoundError: com.couponautoapplier.cashback.model.api.apistorage.DataConfigApiStorage$1$$Lambda$1
                                                                            at com.couponautoapplier.cashback.model.api.apistorage.DataConfigApiStorage$1.call(DataConfigApiStorage.java:50)
                                                                            at com.couponautoapplier.cashback.model.api.apistorage.DataConfigApiStorage$1.call(DataConfigApiStorage.java:28)
                                                                            at rx.internal.operators.OnSubscribeMap$MapSubscriber.onNext(OnSubscribeMap.java:69)
                                                                            at retrofit2.adapter.rxjava.OperatorMapResponseToBodyOrError$1.onNext(OperatorMapResponseToBodyOrError.java:41)
                                                                            at retrofit2.adapter.rxjava.OperatorMapResponseToBodyOrError$1.onNext(OperatorMapResponseToBodyOrError.java:38)
                                                                            at retrofit2.adapter.rxjava.RxJavaCallAdapterFactory$RequestArbiter.request(RxJavaCallAdapterFactory.java:173)
                                                                            at rx.Subscriber.setProducer(Subscriber.java:211)
                                                                            at rx.internal.operators.OnSubscribeMap$MapSubscriber.setProducer(OnSubscribeMap.java:102)
                                                                            at rx.Subscriber.setProducer(Subscriber.java:205)
                                                                            at retrofit2.adapter.rxjava.RxJavaCallAdapterFactory$CallOnSubscribe.call(RxJavaCallAdapterFactory.java:152)
                                                                            at retrofit2.adapter.rxjava.RxJavaCallAdapterFactory$CallOnSubscribe.call(RxJavaCallAdapterFactory.java:138)
                                                                            at rx.internal.operators.OnSubscribeLift.call(OnSubscribeLift.java:48)
                                                                            at rx.internal.operators.OnSubscribeLift.call(OnSubscribeLift.java:30)
                                                                            at rx.Observable.unsafeSubscribe(Observable.java:10200)
                                                                            at rx.internal.operators.OnSubscribeMap.call(OnSubscribeMap.java:48)
                                                                            at rx.internal.operators.OnSubscribeMap.call(OnSubscribeMap.java:33)
                                                                            at rx.internal.operators.OnSubscribeLift.call(OnSubscribeLift.java:48)
                                                                            at rx.internal.operators.OnSubscribeLift.call(OnSubscribeLift.java:30)
                                                                            at rx.Observable.unsafeSubscribe(Observable.java:10200)
                                                                            at rx.internal.operators.OperatorSubscribeOn$1.call(OperatorSubscribeOn.java:94)

I easy corrected this error:

couponListInteractor.getObservableData(storeId)
        .subscribe(data -> {
                for(CouponListItemViewModel item: data)
                {
                    if(!couponsCode.contains(item.getCode()))
                    {
                        couponsCode.add(item.getCode());
                    }
                }
          });

Do I have to correct everywhere foreach to for?

I don't want to do this because it's looks beautiful:

 couponsCode.forEach(value -> couponsCodes.add(new CouponsCode(value)));

Answer 1

The issue is that you're using Stream API of Java 8 at API level below 24.

Currently it's supported from API level 24 only.

Java 8 features support mechanism has been changed recently when Google ditch the new toolchain of Jack and Jill, And lately announced of supporting Java 8 features using old Toolchain with something calls 'desugar' which will transform the Java8 class files to Java 7 compatible class files (available from Android Studio 2.4 Preview 6).
You can read more here .

Answer 2

Thanks yosriz . I use: https://github.com/aNNiMON/Lightweight-Stream-API . My code was looking like that:

 couponsCode.forEach(value -> couponsCodes.add(new CouponsCode(value)));

And my code looking like that now:

 Stream.of(couponsCode).forEach(value -> couponsCodes.add(new CouponsCode(value)));

All errors are gone.