Question

首先，我知道不应该从主线程调用网络操作。这就是我在Schedulers.io（）上观察完成表的原因！

我试图连续两个完成。两个可完成的使用网络，这就是我订阅Schedulers.io（）的原因。如果我使用concatWith（或andThen）代码失败并出现NetworkOnMainThreadException。这是kotlin代码：

val singleSubject = SingleSubject.create<String>(); 
completalbe1.concatWith(completable2)
        .subscribeOn(Schedulers.io())
        .observeOn(Schedulers.io())
        .subscribe({
            singleSubject.onSuccess("ok")
        }, { error ->
            Log.e(tag, error.message, error)//here i got exception
            singleSubject.onError(error) 
        })
return singleSubject

如果我重写没有可完成链接的代码 - 一切都好。这是工作代码：

val singleSubject = SingleSubject.create<String>(); 
completable1
        .subscribeOn(Schedulers.io())
        .observeOn(Schedulers.io())
        .subscribe({
            completable2
                .subscribeOn(Schedulers.io())
                .observeOn(Schedulers.io())
                .subscribe({
                    singleSubject.onSuccess("ok")
                }, { error ->
                    Log.e(tag, error.message, error)
                    singleSubject.onError(error)
                })
        }, {error ->
            Log.e(tag, error.message, error)
            singleSubject.onError(error)
        })
return singleSubject

我想知道为什么第一个片段不起作用但是第二个呢？

UPD1：这是stacktrace：

        android.os.NetworkOnMainThreadException
 at android.os.StrictMode$AndroidBlockGuardPolicy.onNetwork(StrictMode.java:1273)
 at libcore.io.BlockGuardOs.recvfrom(BlockGuardOs.java:249)
 at libcore.io.IoBridge.recvfrom(IoBridge.java:549)
 at java.net.PlainSocketImpl.read(PlainSocketImpl.java:481)
 at java.net.PlainSocketImpl.access$000(PlainSocketImpl.java:37)
 at java.net.PlainSocketImpl$PlainSocketInputStream.read(PlainSocketImpl.java:237)
 at okio.Okio$2.read(Okio.java:139)
 at okio.AsyncTimeout$2.read(AsyncTimeout.java:237)
 at okio.RealBufferedSource.exhausted(RealBufferedSource.java:56)
 at okhttp3.internal.connection.RealConnection.isHealthy(RealConnection.java:498)
 at okhttp3.internal.connection.StreamAllocation.findHealthyConnection(StreamAllocation.java:133)
 at okhttp3.internal.connection.StreamAllocation.newStream(StreamAllocation.java:100)
 at okhttp3.internal.connection.ConnectInterceptor.intercept(ConnectInterceptor.java:42)
 at okhttp3.internal.http.RealInterceptorChain.proceed(RealInterceptorChain.java:92)
 at okhttp3.internal.http.RealInterceptorChain.proceed(RealInterceptorChain.java:67)
 at okhttp3.internal.cache.CacheInterceptor.intercept(CacheInterceptor.java:93)
 at okhttp3.internal.http.RealInterceptorChain.proceed(RealInterceptorChain.java:92)
 at okhttp3.internal.http.RealInterceptorChain.proceed(RealInterceptorChain.java:67)
 at okhttp3.internal.http.BridgeInterceptor.intercept(BridgeInterceptor.java:93)
 at okhttp3.internal.http.RealInterceptorChain.proceed(RealInterceptorChain.java:92)
 at okhttp3.internal.http.RetryAndFollowUpInterceptor.intercept(RetryAndFollowUpInterceptor.java:120)
 at okhttp3.internal.http.RealInterceptorChain.proceed(RealInterceptorChain.java:92)
 at okhttp3.internal.http.RealInterceptorChain.proceed(RealInterceptorChain.java:67)
 at okhttp3.logging.HttpLoggingInterceptor.intercept(HttpLoggingInterceptor.java:211)
 at okhttp3.internal.http.RealInterceptorChain.proceed(RealInterceptorChain.java:92)
 at okhttp3.internal.http.RealInterceptorChain.proceed(RealInterceptorChain.java:67)
 at okhttp3.RealCall.getResponseWithInterceptorChain(RealCall.java:185)
 at okhttp3.RealCall.execute(RealCall.java:69)
 at retrofit2.OkHttpCall.execute(OkHttpCall.java:180)
 at com.jakewharton.retrofit2.adapter.rxjava2.CallObservable.subscribeActual(CallObservable.java:41)
 at io.reactivex.Observable.subscribe(Observable.java:10955)
 at com.jakewharton.retrofit2.adapter.rxjava2.BodyObservable.subscribeActual(BodyObservable.java:34)
 at io.reactivex.Observable.subscribe(Observable.java:10955)
 at io.reactivex.internal.operators.observable.ObservableIgnoreElementsCompletable.subscribeActual(ObservableIgnoreElementsCompletable.java:31)
 at io.reactivex.Completable.subscribe(Completable.java:1664)
 at io.reactivex.internal.operators.completable.CompletableConcatArray$ConcatInnerObserver.next(CompletableConcatArray.java:89)
 at io.reactivex.internal.operators.completable.CompletableConcatArray$ConcatInnerObserver.onComplete(CompletableConcatArray.java:65)
 at io.reactivex.internal.operators.completable.CompletableCreate$Emitter.onComplete(CompletableCreate.java:64)
 at com.catalyst.opti.AppManager$transferImage$1$subscribe$1.onStateChanged(AppManager.kt:323)
 at com.amazonaws.mobileconnectors.s3.transferutility.TransferStatusUpdater$1.run(TransferStatusUpdater.java:172)
 at android.os.Handler.handleCallback(Handler.java:742)
 at android.os.Handler.dispatchMessage(Handler.java:95)
 at android.os.Looper.loop(Looper.java:154)
 at android.app.ActivityThread.main(ActivityThread.java:5527)
 at java.lang.reflect.Method.invoke(Native Method)
 at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:739)
 at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:629)

UPD2：

completable1是将文件上传到AWS S3的函数：

private fun transferImage(imageName: String, image: File): Completable {
    return Completable.create(object : CompletableOnSubscribe {
        override fun subscribe(e: CompletableEmitter) {
            val transferObserver = transferUtility.upload("some", imageName, image)
            transferObserver.setTransferListener(object : TransferListener {
                override fun onProgressChanged(id: Int, bytesCurrent: Long, bytesTotal: Long) {
                    Log.i(tag, "bytesCurrent: $bytesCurrent, bytesTotal: $bytesTotal")
                }

                override fun onStateChanged(id: Int, state: TransferState?) {
                    if (state == TransferState.COMPLETED) {
                        e.onComplete()
                    }
                }

                override fun onError(id: Int, ex: java.lang.Exception) {
                    Log.d(tag, "error transfer s3: ${ex.message}", ex)
                    e.onError(ex)
                }
            })
        }
    });
}

completable2是retrofit2电话：

@POST("some")
    fun verifyLocation(@Header(AUTH_TOKEN_HEADER) authToken: String, @Body 
verifyLocation: VerifyLocation): Completable

Answer 1

我猜transferObserver.setTransferListener调用主线程上的回调，然后主线程上也会订阅completable2。您必须将subscribeOn(Schedulers.io())应用于completable2，就像在其他示例中一样。

val singleSubject = SingleSubject.create<String>(); 
completalbe1.subscribeOn(Schedulers.io())
    .concatWith(completable2.subscribeOn(Schedulers.io())) // <-----------------------
    .observeOn(Schedulers.io())
    .subscribe({
        singleSubject.onSuccess("ok")
    }, { error ->
        Log.e(tag, error.message, error)//here i got exception
        singleSubject.onError(error) 
    })

return singleSubject

subscribeOn会影响订阅（旁边）效果，但是当completalbe1在主线程上调用onComplete时会产生观察效果。

rxjava2：使用连接的补充表并在IO线程中观察它们

1 个答案: