前言

显然，此异常是由在主线程上运行网络操作引起的。但是，正如您从堆栈跟踪中看到的，此错误源自doInBackground的{{1}}！在那之后我也没有转换到主线程。

有趣的是，我无法在我的设备上复制此问题。对于绝大多数用户而言，这也不是一个问题。因此，它不能是一般的实现错误。

步骤

主线
某些东西导致频道列表刷新（无论是手动还是初始加载）
我的API库被调用（附录1）
背景线程
AsyncTask调用API库以获取URL的主体（附录2）
我的缓存库会检查正文是否已保存，但不会更改AsyncTask。
API库调用必要的Thread方法来提取URL的主体（附录3）

堆栈跟踪

OkHttp

附录1

Fatal Exception: java.lang.RuntimeException: An error occurred while executing doInBackground()
       at android.os.AsyncTask$3.done(AsyncTask.java:309)
       at java.util.concurrent.FutureTask.finishCompletion(FutureTask.java:354)
       at java.util.concurrent.FutureTask.setException(FutureTask.java:223)
       at java.util.concurrent.FutureTask.run(FutureTask.java:242)
       at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1113)
       at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:588)
       at java.lang.Thread.run(Thread.java:818)
Caused by 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(SourceFile:139)
       at okio.AsyncTimeout$2.read(SourceFile:211)
       at okio.RealBufferedSource.indexOf(SourceFile:306)
       at okio.RealBufferedSource.indexOf(SourceFile:300)
       at okio.RealBufferedSource.readUtf8LineStrict(SourceFile:196)
       at okhttp3.internal.http.Http1xStream.readResponse(SourceFile:184)
       at okhttp3.internal.http.Http1xStream.readResponseHeaders(SourceFile:125)
       at okhttp3.internal.http.HttpEngine.readNetworkResponse(SourceFile:723)
       at okhttp3.internal.http.HttpEngine.access$200(SourceFile:81)
       at okhttp3.internal.http.HttpEngine$NetworkInterceptorChain.proceed(SourceFile:708)
       at okhttp3.internal.http.HttpEngine.readResponse(SourceFile:563)
       at okhttp3.RealCall.getResponse(SourceFile:241)
       at okhttp3.RealCall$ApplicationInterceptorChain.proceed(SourceFile:198)
       at okhttp3.RealCall.getResponseWithInterceptorChain(SourceFile:160)
       at okhttp3.RealCall.execute(SourceFile:57)
       at com.mypackagename.app.http.Api.getBody(SourceFile:1472)
       at com.mypackagename.app.tasks.GetChannelListTask$2.renewCache(SourceFile:72)
       at com.mypackagename.app.utils.Cache.get(SourceFile:27)
       at com.mypackagename.app.tasks.GetChannelListTask.doInBackground(SourceFile:69)
       at com.mypackagename.app.tasks.GetChannelListTask.doInBackground(SourceFile:24)
       at android.os.AsyncTask$2.call(AsyncTask.java:295)
       at java.util.concurrent.FutureTask.run(FutureTask.java:237)
       at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1113)
       at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:588)
       at java.lang.Thread.run(Thread.java:818)

附录2

public void getChannelList(final IGetChannelListCallback callback) {
    try {
        GetChannelListTask task = new GetChannelListTask(mContext.get(), callback);
        AsyncTaskCompat.executeParallel(task);
    } catch (RejectedExecutionException e) {
        Crashlytics.logException(e);
    }
}

附录3

protected ArrayList<Channel> doInBackground(String... urls) {
    final ArrayList<Channel> channelList = new ArrayList<Channel>();

    // ...

    String json = Cache.get(context, GET_CHANNELS_CACHE, GET_CHANNELS_CACHE_TIME, new IBadCache() {
        public String renewCache() {
            return Api.getInstance(context).getBody(GET_CHANNELS_URL);
        }
    });

    // ...

    return channelList;
}

更新1

检查线程导致了预期的结果：

@WorkerThread
@NonNull
public String getBody(@NonNull final String url) {
    try {
        Request request = new Request.Builder()
                .url(logUrl(url))
                .build();

        Response response = mClient.newCall(request).execute();

        return response.body().string();
    } catch (IOException e) {
        Utils.log("API", "E::"+e.toString());
    } catch (SecurityException e) {
        reportNoInternetPermission();
    }

    return "";
}

移至refreshChannelList: MainThread: true getChannelList: MainThread: true onPreExecute: MainThread: true doInBackground: MainThread: false renewCache: MainThread: false getBody: MainThread: false onPostExecute: MainThread: true后台线程并继续doInBackground来电，在OkHttp返回主线程。

Answer 1

嗯，看起来像你在doInbackground方法中做某事（用上下文用法调用一些操作）的问题。如果Activity / Fragment等的上下文实例（取自UI组件）表示使用上下文的操作使用MainThread执行。这就是为什么你会得到这样的例外。尝试执行此

String json = Cache.get(context, GET_CHANNELS_CACHE, GET_CHANNELS_CACHE_TIME, new IBadCache() {
    public String renewCache() {
        return Api.getInstance(context).getBody(GET_CHANNELS_URL);
    }
});

on

@Override
protected void onProgressUpdate(Object... values) {
  super.onProgressUpdate(values);

}

使用publishProgress（Object obj）;在doInbackground方法上。它必须帮助

这个NetworkOnMainThreadException的原因是什么

前言

步骤

堆栈跟踪

附录1

附录2

附录3

更新1

1 个答案: