InterruptedIOException and NetworkIOException

[DannyW1]

My app crashes randomly and I do not know what cause the error.   I'm using RxJava2 to get the file list.

Here is the crash log

Caused by: com.dropbox.core.NetworkIOException
        at com.dropbox.core.DbxRequestUtil.startPostRaw(DbxRequestUtil.java:284)
        at com.dropbox.core.v2.DbxRawClientV2$1.execute(DbxRawClientV2.java:146)
        at com.dropbox.core.v2.DbxRawClientV2.executeRetriable(DbxRawClientV2.java:330)
        at com.dropbox.core.v2.DbxRawClientV2.executeRetriableWithRefresh(DbxRawClientV2.java:351)
        at com.dropbox.core.v2.DbxRawClientV2.rpcStyle(DbxRawClientV2.java:137)
        at com.dropbox.core.v2.files.DbxUserFilesRequests.listFolder(DbxUserFilesRequests.java:2082)
        at com.dropbox.core.v2.files.DbxUserFilesRequests.listFolder(DbxUserFilesRequests.java:2132)
        at com.quirklogic.sdk.storage.dropbox.DropBoxFolder.lambda$list$0$DropBoxFolder(DropBoxFolder.java:109)
        at com.quirklogic.sdk.storage.dropbox.DropBoxFolder$$Lambda$0.call(Unknown Source)
        at io.reactivex.internal.operators.single.SingleFromCallable.subscribeActual(SingleFromCallable.java:44)
        at io.reactivex.Single.subscribe(Single.java:3220) 
        at io.reactivex.internal.operators.single.SingleMap.subscribeActual(SingleMap.java:34) 
        at io.reactivex.Single.subscribe(Single.java:3220) 
        at io.reactivex.internal.operators.single.SingleSubscribeOn$SubscribeOnObserver.run(SingleSubscribeOn.java:89) 
        at io.reactivex.Scheduler$DisposeTask.run(Scheduler.java:571) 
        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: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) 
     Caused by: java.io.InterruptedIOException
        at com.android.okio.Deadline.throwIfReached(Deadline.java:56)
        at com.android.okio.Okio$1.write(Okio.java:67)
        at com.android.okio.RealBufferedSink.flush(RealBufferedSink.java:154)
        at com.android.okhttp.internal.http.HttpConnection.flush(HttpConnection.java:130)
        at com.android.okhttp.internal.http.HttpTransport.flushRequest(HttpTransport.java:73)
        at com.android.okhttp.internal.http.HttpEngine.readResponse(HttpEngine.java:626)
        at com.android.okhttp.internal.http.HttpURLConnectionImpl.execute(HttpURLConnectionImpl.java:388)
        at com.android.okhttp.internal.http.HttpURLConnectionImpl.getResponse(HttpURLConnectionImpl.java:332)
        at com.android.okhttp.internal.http.HttpURLConnectionImpl.getResponseCode(HttpURLConnectionImpl.java:500)
        at com.android.okhttp.internal.http.DelegatingHttpsURLConnection.getResponseCode(DelegatingHttpsURLConnection.java:105)
        at com.android.okhttp.internal.http.HttpsURLConnectionImpl.getResponseCode(HttpsURLConnectionImpl.java:25)
        at com.dropbox.core.http.StandardHttpRequestor.toResponse(StandardHttpRequestor.java:50)
        at com.dropbox.core.http.StandardHttpRequestor.access$100(StandardHttpRequestor.java:29)
        at com.dropbox.core.http.StandardHttpRequestor$Uploader.finish(StandardHttpRequestor.java:186)
        at com.dropbox.core.DbxRequestUtil.startPostRaw(DbxRequestUtil.java:279)
        at com.dropbox.core.v2.DbxRawClientV2$1.execute(DbxRawClientV2.java:146) 
        at com.dropbox.core.v2.DbxRawClientV2.executeRetriable(DbxRawClientV2.java:330) 
        at com.dropbox.core.v2.DbxRawClientV2.executeRetriableWithRefresh(DbxRawClientV2.java:351) 
        at com.dropbox.core.v2.DbxRawClientV2.rpcStyle(DbxRawClientV2.java:137) 
        at com.dropbox.core.v2.files.DbxUserFilesRequests.listFolder(DbxUserFilesRequests.java:2082) 
        at com.dropbox.core.v2.files.DbxUserFilesRequests.listFolder(DbxUserFilesRequests.java:2132) 
        at com.quirklogic.sdk.storage.dropbox.DropBoxFolder.lambda$list$0$DropBoxFolder(DropBoxFolder.java:109) 
        at com.quirklogic.sdk.storage.dropbox.DropBoxFolder$$Lambda$0.call(Unknown Source) 
        at io.reactivex.internal.operators.single.SingleFromCallable.subscribeActual(SingleFromCallable.java:44) 
        at io.reactivex.Single.subscribe(Single.java:3220) 
        at io.reactivex.internal.operators.single.SingleMap.subscribeActual(SingleMap.java:34) 
        at io.reactivex.Single.subscribe(Single.java:3220) 
        at io.reactivex.internal.operators.single.SingleSubscribeOn$SubscribeOnObserver.run(SingleSubscribeOn.java:89) 
        at io.reactivex.Scheduler$DisposeTask.run(Scheduler.java:571) 
        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:237) 

[Greg-DB]

Based on the stack here, it looks like this is an issue reading data from the network. Do you know if there is any reason the network connection that the app is using may be getting disrupted? E.g., was the connection disconnected or interrupted, or might there be any software, such as a proxy, firewall, anti-virus, etc., that may be interfering? 

If this is random network unreliability, you may want to implement some more error handling/retrying, as that can be unpredictable.

[DannyW1]

Thanks Greg.  Internet connection is fine.  The error does not happen everytime.  It is just random.  It usually happens when I do alot of file list and get a file and repeat that process.

This happens on different devices too and on different wifi network.

Is there a way to trap the crash?

This is what i'm doing in RxJava2

            return Single.fromCallable(() -> DropBoxAuth.getInstance().getDbxClient().files().listFolder(query))
                    .map(result -> { ... }

The crash is inside fromCallable().  Could it be RxJava?

[Greg-DB]

Can you elaborate on what you mean when you say you "do alot of file list"? How many API calls are you making at a time? If you're making a large number of calls, you may be overloading your system or network connection, in which case you should try reducing how many operations you run at a time, as that might be causing this.

Anyway, yes, the Dropbox SDK throws a 'NetworkIOException' when this occurs, so you can `catch` that exception type to handle these failures.

I can't provide insight or support for RxJava2 though, as that's made by a third party.