I'm getting a list of installed apps on the device. It's a costly operation, so I'm using Rx for that:
Observable<List> observable = Observable.create(subscriber -> {
List result = getUserApps();
subscriber.onNext(result);
subscriber.onError(new Throwable());
subscriber.onCompleted();
});
observable
.map(s -> {
ArrayList<String> list = new ArrayList<>();
ArrayList<Application> applist = new ArrayList<>();
for (Application p : (ArrayList<Application>) s) {
list.add(p.getAppName());
applist.add(p);
}
return applist;
})
.subscribeOn(Schedulers.newThread())
.observeOn(AndroidSchedulers.mainThread())
.doOnError(throwable -> L.e(TAG, "Throwable " + throwable.getMessage()))
.subscribe(s -> createListView(s, view));
However, my problem is with handling errors.
Normally, user launches this screen, waits for apps to load, selects what is best and goes to next page. However, when user quickly changes the UI - app crashes with NullPointer.
Okay, so I implemented this onError. However it still doesn't work, and with above usecase it throws me this:
04-15 18:12:42.530 22388-22388/pl.digitalvirgo.safemob E/AndroidRuntime﹕ FATAL EXCEPTION: main
java.lang.IllegalStateException: Exception thrown on Scheduler.Worker thread. Add `onError` handling.
at rx.internal.schedulers.ScheduledAction.run(ScheduledAction.java:52)
at android.os.Handler.handleCallback(Handler.java:730)
at android.os.Handler.dispatchMessage(Handler.java:92)
at android.os.Looper.loop(Looper.java:176)
at android.app.ActivityThread.main(ActivityThread.java:5419)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:525)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1046)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:862)
at dalvik.system.NativeStart.main(Native Method)
Caused by: rx.exceptions.OnErrorNotImplementedException
at rx.Observable$31.onError(Observable.java:7134)
at rx.observers.SafeSubscriber._onError(SafeSubscriber.java:154)
at rx.observers.SafeSubscriber.onError(SafeSubscriber.java:111)
at rx.internal.operators.OperatorDoOnEach$1.onError(OperatorDoOnEach.java:70)
at rx.internal.operators.NotificationLite.accept(NotificationLite.java:147)
at rx.internal.operators.OperatorObserveOn$ObserveOnSubscriber.pollQueue(OperatorObserveOn.java:177)
at rx.internal.operators.OperatorObserveOn$ObserveOnSubscriber.access$000(OperatorObserveOn.java:65)
at rx.internal.operators.OperatorObserveOn$ObserveOnSubscriber$2.call(OperatorObserveOn.java:153)
at rx.internal.schedulers.ScheduledAction.run(ScheduledAction.java:47)
at android.os.Handler.handleCallback(Handler.java:730)
at android.os.Handler.dispatchMessage(Handler.java:92)
at android.os.Looper.loop(Looper.java:176)
at android.app.ActivityThread.main(ActivityThread.java:5419)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:525)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1046)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:862)
at dalvik.system.NativeStart.main(Native Method)
Caused by: java.lang.Throwable
at pl.digitalvirgo.safemob.fragments.wizard.ApplicationsFragment.lambda$getAppList$25(ApplicationsFragment.java:267)
at pl.digitalvirgo.safemob.fragments.wizard.ApplicationsFragment.access$lambda$2(ApplicationsFragment.java)
at pl.digitalvirgo.safemob.fragments.wizard.ApplicationsFragment$$Lambda$3.call(Unknown Source)
at rx.Observable$1.call(Observable.java:145)
at rx.Observable$1.call(Observable.java:137)
at rx.Observable.unsafeSubscribe(Observable.java:7304)
at rx.internal.operators.OperatorSubscribeOn$1$1.call(OperatorSubscribeOn.java:62)
at rx.internal.schedulers.ScheduledAction.run(ScheduledAction.java:47)
at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:390)
at java.util.concurrent.FutureTask.run(FutureTask.java:234)
at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.access$201(ScheduledThreadPoolExecutor.java:153)
at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(ScheduledThreadPoolExecutor.java:267)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1080)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:573)
at java.lang.Thread.run(Thread.java:841)
How should I properly handle this problem?
.doOnError() is an operator, and is not as such a part of the Subscriber.
Therefore, having a .doOnError() does not count as an implemented onError().
About the question in one of the comments, of course it is possible to use lambdas.
In this case simply replace
.doOnError(throwable -> L.e(TAG, "Throwable " + throwable.getMessage()))
.subscribe(s -> createListView(s, view))
with
.subscribe(s -> createListView(s, view),
throwable -> L.e(TAG, "Throwable " + throwable.getMessage()))
My take is: you are probably using Action1 in
.subscribe(s -> createListView(s, view));
You will need to replace it with Subscriber or Observer which has abstract method onError. This method will be called from subscriber.onError(new Throwable());
EDIT: This is how I would do it. Upon closer look I think the main problem in your code is the early part where you call subscriber.onError even when there's no error. You probably don't need map either because you are technically passing data as-is without manipulation. But I left it in case it is needed later.
Observable.create(new Observable.OnSubscribe<Application>() {
#Override
public void call(Subscriber<? super Application> subscriber) {
List result = getUserApps();
if (result != null){
for (Application app : result){
subscriber.onNext(app);
}
subscriber.onComplete();
}else{
subscriber.onError(new IOException("no permission / no internet / etc"));
//or if this is a try catch event you can pass the exception
}
}
})
.subscribeOn(Schedulers.io())//the thread *observer* runs in
.observeOn(AndroidSchedulers.mainThread())//the thread *subscriber* runs in
.map(new Func1<Application, String>() {
// Mapping methods are where data are manipulated.
// You can simply skip this and
//do the same thing in Subscriber implementation
#Override
public String call(Application application) {
return application.getName();
}
}).subscribe(new Subscriber<String>() {
#Override
public void onCompleted() {
Toast.makeText(context, "completed", Toast.LENGTH_SHORT).show();
//because subscriber runs in main UI thread it's ok to do UI stuff
//raise Toast, play sound, etc
}
#Override
public void onError(Throwable e) {
Log.e("getAppsError", e.getMessage());
//raise Toast, play sound, etc
}
#Override
public void onNext(String s) {
listAdapter.add(s);
}
});
Here is the newbie response (because I am new in javarx and finally fix this issue) :
Here is your implementation :
Observable.create(new Observable.OnSubscribe<RegionItem>() {
#Override
public void call(Subscriber<? super RegionItem> subscriber) {
subscriber.onError(new Exception("TADA !"));
}
})
.doOnNext(actionNext)
.doOnError(actionError)
.doOnCompleted(actionCompleted)
.subscribe();
In this previous implementation, when I subscribe I trigger the error flow ... and I get an application crash.
The problem is that you HAVE TO manage the error from the subscribe() call. The "doOnError(...)" is just a kind of helper that clone the error and give you a new place to do some action after an error. But it doesn't Handle the error.
So you have to change your code with that :
Observable.create(new Observable.OnSubscribe<RegionItem>() {
#Override
public void call(Subscriber<? super RegionItem> subscriber) {
subscriber.onError(new Exception("TADA !"));
}
})
.subscribe(actionNext, actionError, actionCompleted);
Not sure about the real explanation, but this is how I fix it. Hope it will help.
Related
I am using the following (out of date) libraries:
Retrofit: 1.9.0
OkHTTP: 2.3.0
RxAndroid: 0.24.0
I noticed that every once in a while I get the following stack trace for my POST request:
D/Retrofit: ---> HTTP POST https:xxxxx
D/Retrofit: Content-Type: application/x-www-form-urlencoded; charset=UTF-8
D/Retrofit: Content-Length: 396
D/Retrofit: ---> END HTTP (396-byte body)
D/Retrofit: ---- ERROR https:xxxxx
I/Choreographer: Skipped 33 frames! The application may be doing too much work on its main thread.
D/Retrofit: java.io.InterruptedIOException
at okio.Timeout.throwIfReached(Timeout.java:146)
at okio.Okio$1.write(Okio.java:75)
at okio.AsyncTimeout$1.write(AsyncTimeout.java:155)
at okio.RealBufferedSink.flush(RealBufferedSink.java:201)
at com.squareup.okhttp.internal.http.HttpConnection.flush(HttpConnection.java:140)
at com.squareup.okhttp.Connection.makeTunnel(Connection.java:399)
at com.squareup.okhttp.Connection.upgradeToTls(Connection.java:229)
at com.squareup.okhttp.Connection.connect(Connection.java:159)
at com.squareup.okhttp.Connection.connectAndSetOwner(Connection.java:175)
at com.squareup.okhttp.OkHttpClient$1.connectAndSetOwner(OkHttpClient.java:120)
at com.squareup.okhttp.internal.http.HttpEngine.nextConnection(HttpEngine.java:330)
at com.squareup.okhttp.internal.http.HttpEngine.connect(HttpEngine.java:319)
at com.squareup.okhttp.internal.http.HttpEngine.sendRequest(HttpEngine.java:241)
at com.squareup.okhttp.Call.getResponse(Call.java:271)
at com.squareup.okhttp.Call$ApplicationInterceptorChain.proceed(Call.java:228)
at com.squareup.okhttp.Call.getResponseWithInterceptorChain(Call.java:199)
at com.squareup.okhttp.Call.execute(Call.java:79)
at retrofit.client.OkClient.execute(OkClient.java:53)
at retrofit.RestAdapter$RestHandler.invokeRequest(RestAdapter.java:326)
at retrofit.RestAdapter$RestHandler.invoke(RestAdapter.java:240)
at java.lang.reflect.Proxy.invoke(Proxy.java:913)
at $Proxy1.replyTransaction(Unknown Source)
< App Specific Trace >
at rx.Observable$1.call(Observable.java:145)
at rx.Observable$1.call(Observable.java:137)
at rx.Observable.unsafeSubscribe(Observable.java:7304)
at rx.internal.operators.OperatorSubscribeOn$1$1.call(OperatorSubscribeOn.java:62)
at rx.internal.schedulers.ScheduledAction.run(ScheduledAction.java:47)
at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:457)
at java.util.concurrent.FutureTask.run(FutureTask.java:266)
at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(ScheduledThreadPoolExecutor.java:301)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1162)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:636)
at java.lang.Thread.run(Thread.java:764)
D/Retrofit: ---- END ERROR
retrofit.RetrofitError
at retrofit.RestAdapter$RestHandler.invokeRequest(RestAdapter.java:395)
at retrofit.RestAdapter$RestHandler.invoke(RestAdapter.java:240)
at java.lang.reflect.Proxy.invoke(Proxy.java:913)
at $Proxy1.replyTransaction(Unknown Source)
< App Specific Trace >
at rx.Observable$1.call(Observable.java:145)
at rx.Observable$1.call(Observable.java:137)
at rx.Observable.unsafeSubscribe(Observable.java:7304)
at rx.internal.operators.OperatorSubscribeOn$1$1.call(OperatorSubscribeOn.java:62)
at rx.internal.schedulers.ScheduledAction.run(ScheduledAction.java:47)
at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:457)
at java.util.concurrent.FutureTask.run(FutureTask.java:266)
at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(ScheduledThreadPoolExecutor.java:301)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1162)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:636)
at java.lang.Thread.run(Thread.java:764)
Caused by: java.io.InterruptedIOException
at okio.Timeout.throwIfReached(Timeout.java:146)
at okio.Okio$1.write(Okio.java:75)
at okio.AsyncTimeout$1.write(AsyncTimeout.java:155)
at okio.RealBufferedSink.flush(RealBufferedSink.java:201)
at com.squareup.okhttp.internal.http.HttpConnection.flush(HttpConnection.java:140)
at com.squareup.okhttp.Connection.makeTunnel(Connection.java:399)
at com.squareup.okhttp.Connection.upgradeToTls(Connection.java:229)
at com.squareup.okhttp.Connection.connect(Connection.java:159)
at com.squareup.okhttp.Connection.connectAndSetOwner(Connection.java:175)
at com.squareup.okhttp.OkHttpClient$1.connectAndSetOwner(OkHttpClient.java:120)
at com.squareup.okhttp.internal.http.HttpEngine.nextConnection(HttpEngine.java:330)
at com.squareup.okhttp.internal.http.HttpEngine.connect(HttpEngine.java:319)
at com.squareup.okhttp.internal.http.HttpEngine.sendRequest(HttpEngine.java:241)
at com.squareup.okhttp.Call.getResponse(Call.java:271)
at com.squareup.okhttp.Call$ApplicationInterceptorChain.proceed(Call.java:228)
at com.squareup.okhttp.Call.getResponseWithInterceptorChain(Call.java:199)
at com.squareup.okhttp.Call.execute(Call.java:79)
at retrofit.client.OkClient.execute(OkClient.java:53)
at retrofit.RestAdapter$RestHandler.invokeRequest(RestAdapter.java:326)
at retrofit.RestAdapter$RestHandler.invoke(RestAdapter.java:240)
at java.lang.reflect.Proxy.invoke(Proxy.java:913)
at $Proxy1.replyTransaction(Unknown Source)
< App Specific Trace >
at rx.Observable$1.call(Observable.java:145)
at rx.Observable$1.call(Observable.java:137)
at rx.Observable.unsafeSubscribe(Observable.java:7304)
at rx.internal.operators.OperatorSubscribeOn$1$1.call(OperatorSubscribeOn.java:62)
at rx.internal.schedulers.ScheduledAction.run(ScheduledAction.java:47)
at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:457)
at java.util.concurrent.FutureTask.run(FutureTask.java:266)
at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(ScheduledThreadPoolExecutor.java:301)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1162)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:636)
at java.lang.Thread.run(Thread.java:764)
My code for this is as follows:
Network call:
return Observable.create(new Observable.OnSubscribe<Object>() {
#Override public void call(Subscriber<? super Object> subscriber) {
try {
subscriber.onNext(/* Sync network call here. */);
} catch (Exception e) {
subscriber.onError(e);
}
subscriber.onCompleted();
}
})
.onBackpressureBuffer()
// singleton for Schedulers.io()
.subscribeOn(ioScheduler)
// singleton for AndroidSchedulers.mainThread()
.observeOn(mainThreadScheduler);
Which is called like so:
subscription = makeNetworkCall()
.subscribe(new Observer<Object>() {
#Override public void onNext(Object object) {
// close and finish activity
}
#Override public void onError(Throwable e) {
// whoops!
}
});
and is unsubscribed from in the Activity like so:
#Override
protected void onPause() {
super.onPause();
if (subscription != null) {
subscription.unsubscribe();
subscription = null;
if (condition) {
finish();
}
}
}
My understanding of this is that I am getting an InterruptedException because I am unsubscribe()ing from the Subscription in onPause(). We do this for other requests though so I am not sure why I am only seeing it here and why exactly it is happening.
To provide a bit more info on this, the network call happens from an Activity that is launched from the lock screen via a notification action to force the user to unlock their device in order to take action.
My question here is why is this happening and is there a good way to remediate this? According to a few articles, onPause() is where you should unsubscribe from Observables.
More info on this can be see In okHTTP's github issues
Thanks!
This is a guess, but it may be that you are not checking if the subscriber is still there before emitting the interrupted exception.
Try this:
return Observable.create(new Observable.OnSubscribe<Object>() {
#Override public void call(Subscriber<? super Object> subscriber) {
try {
subscriber.onNext(/* Sync network call here. */);
subscriber.onCompleted();
} catch (Exception e) {
if (!subscriber.isUnsubscribed()) { // <-- check before emitting error
subscriber.onError(e);
}
}
}
})
Upon unsubscription the chain need not do any more work as we don't care about the output anymore. We could just let the current operation complete, and stop the work cleanly when we reach the next operator, but why waste any resources we don't have to? If there's an ongoing network request we want to cancel it. We do this by interrupting the thread. If/when the code on this thread checks if it is interrupted then no more work need be done, and InterruptedIOException can be thrown.
Depending on exactly when unsubscribe is called you may or may not see the error. If unsubscribe is called well before the request has started loading or after it has finished then you may not see this error.
So the reason for this Exception is OkHttp wants to give up as soon as it knows you're not interested in its results and RxJava doesn't want to swallow it in-case it was important for you.
You can add a default error handler to suppress undeliverable InterruptedExceptions and InterruptedIOExceptions which are rarely useful. See RxJava 2 Error Handling, I believe RxJava 1 has a similar construct, but you should consider migrating to RxJava 2. It's really not much of a departure, and RxBinding has been updated to RxJava 2.
onPause() is not necessarily where you should unsubscribe. You should unsubscribe where the logic of your app demands it and where it will prevent memory leaks.
try this:
return Observable.create(e -> {
try {
e.onNext(...);
} catch (Exception ex) {
e.tryOnError(ex);
}
e.onComplete();
});
tryOnError() checks is the Observer is disposed or not when sending error.
reference: https://github.com/ReactiveX/RxJava/issues/4863
I am new to using RxAndroid and RxJava. I am using RxJava + Retrofit2 to make GET requests. I am doing approximately 1500 GET requests using the following code and getting Out of memory error. However the same code this time with only retrofit, NO RxAndroid and it works. So my conclusion was I am doing something wrong in RxAndroid. Can you please help with what I am missing?
Code Sample:
Subject<Story> mStoryEmitter = PublishSubject.create();
private void getStory(int storyID) {
HNApi.Factory.getInstance().getStory(storyID).subscribeOn(Schedulers.io())
.observeOn(AndroidSchedulers.mainThread())
.subscribe(getStoryObserver());
}
mStoryListEmitter.subscribe(new Observer<List<Integer>>() {
#Override
public void onSubscribe(Disposable d) {}
#Override
public void onNext(List<Integer> value) {
if(mRecyclerView != null) {
mRecyclerView.setAdapter(null);
if(mAdapter != null) {
mAdapter.clear();
mAdapter = null;
}
}
mAdapter = new SimpleRecyclerViewAdapter();
mRecyclerView.setAdapter(mAdapter);
for(Integer storyID : value) {
getStory(storyID);
}
}
#Override
public void onError(Throwable e) {}
#Override
public void onComplete() {}
});
private DisposableObserver<Story> getStoryObserver() {
DisposableObserver<Story> observer = new DisposableObserver<Story>() {
#Override
public void onNext(Story value) {
mStoryEmitter.onNext(value);
dispose();
}
#Override
public void onError(Throwable e) {
}
#Override
public void onComplete() {
}
};
return observer;
}
Error:
Throwing OutOfMemoryError "Could not allocate JNI Env"
java.lang.IllegalStateException: Fatal Exception thrown on Scheduler.
at io.reactivex.android.schedulers.HandlerScheduler$ScheduledRunnable.run(HandlerScheduler.java:111)
at android.os.Handler.handleCallback(Handler.java:739)
at android.os.Handler.dispatchMessage(Handler.java:95)
at android.os.Looper.loop(Looper.java:148)
at android.app.ActivityThread.main(ActivityThread.java:5417)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:726)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:616)
Caused by: java.lang.OutOfMemoryError: Could not allocate JNI Env
at java.lang.Thread.nativeCreate(Native Method)
at java.lang.Thread.start(Thread.java:1063)
at java.util.concurrent.ThreadPoolExecutor.addWorker(ThreadPoolExecutor.java:921)
at java.util.concurrent.ThreadPoolExecutor.ensurePrestart(ThreadPoolExecutor.java:1556)
at java.util.concurrent.ScheduledThreadPoolExecutor.delayedExecute(ScheduledThreadPoolExecutor.java:310)
at java.util.concurrent.ScheduledThreadPoolExecutor.schedule(ScheduledThreadPoolExecutor.java:543)
at java.util.concurrent.ScheduledThreadPoolExecutor.submit(ScheduledThreadPoolExecutor.java:642)
at io.reactivex.internal.schedulers.NewThreadWorker.scheduleActual(NewThreadWorker.java:120)
at io.reactivex.internal.schedulers.IoScheduler$EventLoopWorker.schedule(IoScheduler.java:221)
at io.reactivex.Scheduler.scheduleDirect(Scheduler.java:130)
at io.reactivex.Scheduler.scheduleDirect(Scheduler.java:109)
AppData::create pipe(2) failed: Too many open files
at io.reactivex.internal.operators.observable.ObservableSubscribeOn.subscribeActual(ObservableSubscribeOn.java:36)
at io.reactivex.Observable.subscribe(Observable.java:10514)
at io.reactivex.internal.operators.observable.ObservableObserveOn.subscribeActual(ObservableObserveOn.java:44)
at io.reactivex.Observable.subscribe(Observable.java:10514)
at com.example.MainActivity.getStory(MainActivity.java:100)
at com.example.MainActivity.access$300(MainActivity.java:25)
at com.example.MainActivity$2.onNext(MainActivity.java:67)
at com.example.MainActivity$2.onNext(MainActivity.java:49)
at io.reactivex.subjects.PublishSubject$PublishDisposable.onNext(PublishSubject.java:263)
at io.reactivex.subjects.PublishSubject.onNext(PublishSubject.java:182)
at com.example.MainActivity$5.onNext(MainActivity.java:147)
at com.example.MainActivity$5.onNext(MainActivity.java:138)
at io.reactivex.internal.operators.observable.ObservableObserveOn$ObserveOnObserver.drainNormal(ObservableObserveOn.java:198)
at io.reactivex.internal.operators.observable.ObservableObserveOn$ObserveOnObserver.run(ObservableObserveOn.java:250)
at io.reactivex.android.schedulers.HandlerScheduler$ScheduledRunnable.run(HandlerScheduler.java:109)
... 7 more
AppData::create pipe(2) failed: Too many open files
FATAL EXCEPTION: main
Process: com.example, PID: 15857
java.lang.IllegalStateException: Fatal Exception thrown on Scheduler.
at io.reactivex.android.schedulers.HandlerScheduler$ScheduledRunnable.run(HandlerScheduler.java:111)
at android.os.Handler.handleCallback(Handler.java:739)
at android.os.Handler.dispatchMessage(Handler.java:95)
at android.os.Looper.loop(Looper.java:148)
at android.app.ActivityThread.main(ActivityThread.java:5417)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:726)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:616)
Caused by: java.lang.OutOfMemoryError: Could not allocate JNI Env
at java.lang.Thread.nativeCreate(Native Method)
at java.lang.Thread.start(Thread.java:1063)
at java.util.concurrent.ThreadPoolExecutor.addWorker(ThreadPoolExecutor.java:921)
at java.util.concurrent.ThreadPoolExecutor.ensurePrestart(ThreadPoolExecutor.java:1556)
at java.util.concurrent.ScheduledThreadPoolExecutor.delayedExecute(ScheduledThreadPoolExecutor.java:310)
at java.util.concurrent.ScheduledThreadPoolExecutor.schedule(ScheduledThreadPoolExecutor.java:543)
at java.util.concurrent.ScheduledThreadPoolExecutor.submit(ScheduledThreadPoolExecutor.java:642)
at io.reactivex.internal.schedulers.NewThreadWorker.scheduleActual(NewThreadWorker.java:120)
at io.reactivex.internal.schedulers.IoScheduler$EventLoopWorker.schedule(IoScheduler.java:221)
at io.reactivex.Scheduler.scheduleDirect(Scheduler.java:130)
at io.reactivex.Scheduler.scheduleDirect(Scheduler.java:109)
at io.reactivex.internal.operators.observable.ObservableSubscribeOn.subscribeActual(ObservableSubscribeOn.java:36)
at io.reactivex.Observable.subscribe(Observable.java:10514)
at io.reactivex.internal.operators.observable.ObservableObserveOn.subscribeActual(ObservableObserveOn.java:44)
at io.reactivex.Observable.subscribe(Observable.java:10514)
at com.example.MainActivity.getStory(MainActivity.java:100)
at com.example.MainActivity.access$300(MainActivity.java:25)
at com.example.MainActivity$2.onNext(MainActivity.java:67)
at com.example.MainActivity$2.onNext(MainActivity.java:49)
at io.reactivex.subjects.PublishSubject$PublishDisposable.onNext(PublishSubject.java:263)
at io.reactivex.subjects.PublishSubject.onNext(PublishSubject.java:182)
at com.example.MainActivity$5.onNext(MainActivity.java:147)
at com.example.MainActivity$5.onNext(MainActivity.java:138)
at io.reactivex.internal.operators.observable.ObservableObserveOn$ObserveOnObserver.drainNormal(ObservableObserveOn.java:198)
at io.reactivex.internal.operators.observable.ObservableObserveOn$ObserveOnObserver.run(ObservableObserveOn.java:250)
at io.reactivex.android.schedulers.HandlerScheduler$ScheduledRunnable.run(HandlerScheduler.java:109)
... 7 more
Posted the same question at RxAndroid github.
And JakeWharton reply acually heped
The problem is that Schedulers.io() uses a cached thread pool without a limit and thus is trying to create 1500 threads. You should consider using a Scheduler that has a fixed limit of threads, or using RxJava 2.x's parallel() operator to parallelize the operation to a fixed number of workers.
If you're using raw Retrofit by default it uses OkHttp's dispatcher which limits the threads to something like 64 (with a max of 5 per host). That's why you aren't seeing it fail.
If you use createAsync() when creating the RxJava2CallAdapterFactory it will create fully-async Observable instances that don't require a subscribeOn and which use OkHttp's Dispatcher just like Retrofit would otherwise. Then you only need observeOn to move back to the main thread, and you avoid all additional thread creation.
Add all your Disposables to CompositeDisposable and dispose it for every cycle
CompositeDisposable disposable = new CompositeDisposable();
mStoryListEmitter.subscribe(new Observer<List<Integer>>() {
#Override
public void onSubscribe(Disposable d) {
disposable.add(d); // adding disposable
}
#Override
public void onNext(List<Integer> value) {
if(mRecyclerView != null) {
mRecyclerView.setAdapter(null);
if(mAdapter != null) {
mAdapter.clear();
mAdapter = null;
}
}
mAdapter = new SimpleRecyclerViewAdapter();
mRecyclerView.setAdapter(mAdapter);
for(Integer storyID : value) {
getStory(storyID);
}
}
#Override
public void onError(Throwable e) {}
#Override
public void onComplete() {
diposable.dispose(); // <--- Disposing on complete
}
})
;
I'm working on a large codebase with a lot of network calls. It currently works with Retrofit 1.9 and RxJava 1.x. But, we're trying to go to RxJava 2.x.
I currently keep getting a NetworkOnMainThreadException on our RxJava 2 code. I'm using RxJava 2.x and Retrofit 1.9. The plan is to go to Retrofit 2.x later. But, for now, we need to make this work with RxJava 2 + Retrofit 1.9.
The code in question is:
observable
.subscribeOn(Schedulers.io())
.observeOn(AndroidSchedulers.mainThread())
.subscribeWith(new DisposableObserver<Void>() {
#Override
public void onNext(Void response) {
if (listener != null) {
listener.onSuccess(response);
}
}
#Override
public void onError(Throwable e) {
if (listener != null) {
listener.onError(e);
}
}
#Override
public void onComplete() {
//do nothing for now
}
});
Any ideas how the network operation is ending up on the UI thread when I told it to subscribeOn(Schedulers.io())?
Edit: by request here's the stacktrace. I genericized filenames and such because I'm not allowed to divulge those details...
retrofit.RetrofitError
at retrofit.RestAdapter$RestHandler.invokeRequest(RestAdapter.java:400)
at retrofit.RestAdapter$RestHandler.invoke(RestAdapter.java:240)
at java.lang.reflect.Proxy.invoke(Proxy.java:913)
at <package-name>.network.api.$Proxy40.someApiMethod(Unknown Source)
at <package-name>.SomeApi.someApiMethod(SomeApi.java:30)
Caused by: android.os.NetworkOnMainThreadException
at android.os.StrictMode$AndroidBlockGuardPolicy.onNetwork(StrictMode.java:1425)
at java.net.Inet6AddressImpl.lookupHostByName(Inet6AddressImpl.java:102)
at java.net.Inet6AddressImpl.lookupAllHostAddr(Inet6AddressImpl.java:90)
at java.net.InetAddress.getAllByName(InetAddress.java:787)
at com.squareup.okhttp.internal.Network$1.resolveInetAddresses(Network.java:29)
at com.squareup.okhttp.internal.http.RouteSelector.resetNextInetSocketAddress(RouteSelector.java:224)
at com.squareup.okhttp.internal.http.RouteSelector.nextProxy(RouteSelector.java:193)
at com.squareup.okhttp.internal.http.RouteSelector.next(RouteSelector.java:113)
at com.squareup.okhttp.internal.http.HttpEngine.createNextConnection(HttpEngine.java:344)
at com.squareup.okhttp.internal.http.HttpEngine.nextConnection(HttpEngine.java:329)
at com.squareup.okhttp.internal.http.HttpEngine.connect(HttpEngine.java:319)
at com.squareup.okhttp.internal.http.HttpEngine.sendRequest(HttpEngine.java:241)
at com.squareup.okhttp.Call.getResponse(Call.java:271)
at com.squareup.okhttp.Call$ApplicationInterceptorChain.proceed(Call.java:228)
at com.squareup.okhttp.Call.getResponseWithInterceptorChain(Call.java:199)
at com.squareup.okhttp.Call.execute(Call.java:79)
at retrofit.client.OkClient.execute(OkClient.java:53)
I'm having tons of ConcurrentModificationException when doing some update operations with my database using ORMlite. I'm wrapping the code that does the actual update into rx.Observables to make it asynchronously. Looks like this:
#Override
public void setFavoriteTeams(List<Team> teams) {
final Iterator<Team> it = teams.iterator();
Observable.create(new Observable.OnSubscribe<Object>() {
#Override
public void call(final Subscriber<? super Object> subscriber) {
try {
List<String> teamIds = new ArrayList<>();
while (it.hasNext()) {
Team team = it.next();
teamIds.add(team.getmSipId());
}
setFavoriteTeamsSql(teamIds);
} catch (Exception e) {
handleException(e);
} finally {
subscriber.onNext(null);
subscriber.onCompleted();
}
}
}).subscribeOn(Schedulers.computation()).subscribe();
}
Ironically, a while ago I started using Interator instead of a for-loop to avoid any ConcurrenceModificationException that may happen, but instead they increased a lot. The setFavoriteTeamsSql(List<String>) method simply uses ORMlite's UpdateBuilder class to update the table. The exception is being thrown at the Team team = it.next(); line.
Any idea about how to fix this? Right now I'm rolling back the changes and going back to the for-loop. But I'd like doing this the right way.
UPDATE:
This is how the Stacktrace looks like:
Non-fatal Exception: java.util.ConcurrentModificationException
at java.util.ArrayList$ArrayListIterator.next(ArrayList.java:573)
at com.siplay.android_siplay.data.cache.db.DBTeamCache$4.call(DBTeamCache.java:164)
at com.siplay.android_siplay.data.cache.db.DBTeamCache$4.call(DBTeamCache.java:157)
at rx.Observable.unsafeSubscribe(Observable.java:10150)
at rx.internal.operators.OperatorSubscribeOn$1.call(OperatorSubscribeOn.java:94)
at rx.internal.schedulers.EventLoopsScheduler$EventLoopWorker$1.call(EventLoopsScheduler.java:172)
at rx.internal.schedulers.ScheduledAction.run(ScheduledAction.java:55)
at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:423)
at java.util.concurrent.FutureTask.run(FutureTask.java:237)
at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.access$201(ScheduledThreadPoolExecutor.java:154)
at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(ScheduledThreadPoolExecutor.java:269)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1113)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:588)
at java.lang.Thread.run(Thread.java:818)
UPDATE 2:
...
mNetworkTeamRepository
.subscribeOn(Schedulers.io())
.obseveOn(AndroidSchedulers.mainThread())
.subscribe(new DefaultSubscriber<List<Teams>>() {
#Override
public void onSuccess(List<Team> teams) {
mTeamsCache.setFavoriteTeams(teams);
}
public void onResult(List<Team> teams) {
callback.showTeams(teams);
}
});
...
The TeamRepository internally uses a Retrofit service to get the server-side response.
Your code is equivalent to
public void setFavoriteTeams(List<Team> teams) {
Observable
.fromIterable(teams)
.map(Team::getmSipId)
.toList()
.doOnNext(this::setFavoriteTeamsSql)
.subscribeOn(Schedulers.computation())
.subscribe();
}
But I still can't see how your code emits ConcurrentModificationException - maybe a stack trace will help?
Many RxJava tutorials with RxTextView.textChanges examples and debounce, use 'live search'. For example: Improving UX with RxJava. So I've implemented this example and I tried to play around:
RxTextView.textChanges(searchView)
.observeOn(Schedulers.io())
.skip(1)
.debounce(DELAY_BEFORE_REQUEST_MS, TimeUnit.MILLISECONDS)
.map(new Func1<CharSequence, String>() {
#Override public String call(CharSequence charSequence) {
return charSequence.toString();
}
})
.switchMap(new Func1<String, Observable<Response>>() {
#Override public Observable<Response> call(String query) {
return retrofitService.search(query);
}
})
.subscribe();
Everything looked good, until I decided to simulate GPRS network type on Android emulator.
First api call was triggered, and when I added next letter to 'searchView', app crashed with InterruptedIOException:
java.lang.IllegalStateException: Exception thrown on Scheduler.Worker thread. Add `onError` handling.
at rx.internal.schedulers.ScheduledAction.run(ScheduledAction.java:60)
at java.util.concurrent.Executors$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: rx.exceptions.OnErrorNotImplementedException: thread interrupted
at rx.Observable$27.onError(Observable.java:7923)
at rx.observers.SafeSubscriber._onError(SafeSubscriber.java:159)
at rx.observers.SafeSubscriber.onError(SafeSubscriber.java:120)
at rx.internal.operators.OperatorSubscribeOn$1$1$1.onError(OperatorSubscribeOn.java:71)
at rx.observers.SerializedObserver.onError(SerializedObserver.java:159)
at rx.observers.SerializedSubscriber.onError(SerializedSubscriber.java:79)
at rx.internal.operators.OperatorSwitch$SwitchSubscriber.error(OperatorSwitch.java:223)
at rx.internal.operators.OperatorSwitch$InnerSubscriber.onError(OperatorSwitch.java:282)
at rx.internal.operators.OperatorMerge$MergeSubscriber.reportError(OperatorMerge.java:240)
at rx.internal.operators.OperatorMerge$MergeSubscriber.checkTerminate(OperatorMerge.java:776)
at rx.internal.operators.OperatorMerge$MergeSubscriber.emitLoop(OperatorMerge.java:537)
at rx.internal.operators.OperatorMerge$MergeSubscriber.emit(OperatorMerge.java:526)
at rx.internal.operators.OperatorMerge$MergeSubscriber.onError(OperatorMerge.java:250)
at rx.internal.operators.OperatorMap$1.onError(OperatorMap.java:48)
at retrofit2.RxJavaCallAdapterFactory$CallOnSubscribe.call(RxJavaCallAdapterFactory.java:114)
at retrofit2.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$2.call(Observable.java:154)
at rx.Observable.unsafeSubscribe(Observable.java:8098)
at rx.internal.operators.OperatorSwitch$SwitchSubscriber.onNext(OperatorSwitch.java:105)
at rx.internal.operators.OperatorSwitch$SwitchSubscriber.onNext(OperatorSwitch.java:60)
at rx.internal.operators.OperatorMap$1.onNext(OperatorMap.java:54)
at rx.internal.operators.OperatorDoOnEach$1.onNext(OperatorDoOnEach.java:85)
at rx.internal.operators.OperatorMap$1.onNext(OperatorMap.java:54)
at rx.observers.SerializedObserver.onNext(SerializedObserver.java:95)
at rx.observers.SerializedSubscriber.onNext(SerializedSubscriber.java:95)
at rx.internal.operators.OperatorDebounceWithTime$DebounceState.emit(OperatorDebounceWithTime.java:132)
at rx.internal.operators.OperatorDebounceWithTime$1$1.call(OperatorDebounceWithTime.java:79)
at rx.internal.schedulers.ScheduledAction.run(ScheduledAction.java:55)
at java.util.concurrent.Executors$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.io.InterruptedIOException: thread interrupted
at okio.Timeout.throwIfReached(Timeout.java:145)
at okio.Okio$2.read(Okio.java:136)
at okio.AsyncTimeout$2.read(AsyncTimeout.java:211)
at okio.RealBufferedSource.indexOf(RealBufferedSource.java:306)
at okio.RealBufferedSource.indexOf(RealBufferedSource.java:300)
at okio.RealBufferedSource.readUtf8LineStrict(RealBufferedSource.java:196)
at okhttp3.internal.http.Http1xStream.readResponse(Http1xStream.java:184)
at okhttp3.internal.http.Http1xStream.readResponseHeaders(Http1xStream.java:125)
at okhttp3.internal.http.HttpEngine.readNetworkResponse(HttpEngine.java:723)
at okhttp3.internal.http.HttpEngine.access$200(HttpEngine.java:81)
at okhttp3.internal.http.HttpEngine$NetworkInterceptorChain.proceed(HttpEngine.java:708)
at okhttp3.internal.http.HttpEngine.readResponse(HttpEngine.java:563)
at okhttp3.RealCall.ge
I have searched a little, and it looks like I'm not alone: first and second.
Author of that first question solved this problem this by wrapping retrofit request with try-catch block.
For me it is attempt of covering bad architecture. And I'm looking for cleaner solution.
Is there a way of ignoring first API call result, and starting new one using RxJava? Or I should try to switch over new Retrofit Call API, and try to cancel previous request (and break a reactive approach)?
I have using Retrofit 2 beta 3, with newest Okio and OkHttp.
Well, the error is pretty explicit, you should add onError handling. It could look something like this:
.subscribe(new Observer<Response>() {
#Override
public void onCompleted() {
}
#Override
public void onError(Throwable e) {
}
#Override
public void onNext(Response response) {
}
});
However, your subscription will be terminated once an error is emitted, but you can avoid this by handling the errors of the API call like this:
.switchMap(new Func1<String, Observable<Response>>() {
#Override public Observable<Response> call(String query) {
return retrofitService.search(query)
.onErrorResumeNext(Observable.<Response>empty());
}
})