Question

我正在使用以下（过时）库：

Retrofit: 1.9.0
OkHTTP: 2.3.0
RxAndroid: 0.24.0

我注意到每隔一段时间我就会收到以下用于POST请求的堆栈跟踪：

 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)

我的代码如下：

网络电话：

    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);

这样称呼：

subscription = makeNetworkCall()
            .subscribe(new Observer<Object>() {
              @Override public void onNext(Object object) {
                // close and finish activity
              }
              @Override public void onError(Throwable e) {
                // whoops!
              }
            });

并且在活动中取消订阅如下：

  @Override
  protected void onPause() {
    super.onPause();
    if (subscription != null) {
      subscription.unsubscribe();
      subscription = null;
      if (condition) {
        finish();
      }
    }
  }

我对此的理解是，我收到了InterruptedException，因为我unsubscribe()来自Subscription onPause()。我们这样做是为了其他请求，所以我不确定为什么我只在这里看到它以及为什么会发生这种情况。

为了提供更多相关信息，网络呼叫从通过通知操作从锁定屏幕启动的活动发生，以强制用户解锁其设备以采取行动。

我的问题是为什么会发生这种情况并且有一个很好的方法来修复它？根据一些文章，onPause()是您应该取消订阅Observables的地方。

有关这方面的更多信息，请参阅In okHTTP's github issues

谢谢！

Answer 1

取消订阅后，链条不再需要做任何工作，因为我们不再关心输出。我们可以让当前的操作完成，当我们到达下一个操作员时干净地停止工作，但为什么要浪费我们不需要的任何资源？如果有正在进行的网络请求，我们要取消它。我们通过中断线程来做到这一点。如果/当此线程上的代码检查它是否被中断时，则不需要再进行任何工作，并且可以抛出InterruptedIOException。

根据确切调用取消订阅的时间，您可能会看到错误，也可能看不到错误。如果在请求开始加载之前或者在完成请求之后调用取消订阅，那么您可能看不到此错误。

所以这个例外的原因是OkHttp想要一旦知道你对它的结果不感兴趣就放弃了，而RxJava并不想吞下它，以防它对你很重要。

您可以添加默认错误处理程序来抑制无法传递的InterruptedException和InterruptedIOException，这些很少有用。请参阅RxJava 2 Error Handling，我相信RxJava 1有一个类似的构造，但你应该考虑迁移到RxJava 2.它真的不是很大的离开，并且RxBinding已经更新为RxJava 2。

onPause()不一定是取消订阅的地方。您应该取消订阅应用程序逻辑所需的位置以及防止内存泄漏的位置。

Answer 2

这是猜测，但可能是您在发出中断的异常之前没有检查订户是否仍在那里。

试试这个：

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);
          }
        }
      }
    })

Answer 3

试试这个：

return Observable.create(e -> {
           try {
               e.onNext(...);
           } catch (Exception ex) {
               e.tryOnError(ex);
           }
           e.onComplete();
       });

tryOnError（）检查是发送错误时是否处置Observer。

参考：https://github.com/ReactiveX/RxJava/issues/4863

Retrofit / OkHTTP / RxJava间歇性InterruptedIOException

3 个答案: