How to find source of crashes of type java.lang.RuntimeException: Parcel android.os.Parcel@####: Unmarshalling unknown type code XXXX at offset YYY

Question

Our crash reporting system is logging crashes of this type:

Caused by java.lang.RuntimeException: Parcel android.os.Parcel@8bf0d1f: Unmarshalling unknown type code 6881391 at offset 356
   at android.os.Parcel.readValue(Parcel.java:2779)
   at android.os.Parcel.readSparseArrayInternal(Parcel.java:3148)
   at android.os.Parcel.readSparseArray(Parcel.java:2362)
   at android.os.Parcel.readValue(Parcel.java:2757)
   at android.os.Parcel.readArrayMapInternal(Parcel.java:3067)
   at android.os.BaseBundle.unparcel(BaseBundle.java:257)
   at android.os.Bundle.getSparseParcelableArray(Bundle.java:958)
   at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:1329)
   at android.support.v4.app.FragmentManagerImpl.moveFragmentToExpectedState(FragmentManager.java:1759)
   at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:1827)
   at android.support.v4.app.FragmentManagerImpl.dispatchStateChange(FragmentManager.java:3244)
   at android.support.v4.app.FragmentManagerImpl.dispatchCreate(FragmentManager.java:3194)
   at android.support.v4.app.Fragment.restoreChildFragmentState(Fragment.java:1444)
   at android.support.v4.app.Fragment.onCreate(Fragment.java:1415)
   at com.payments.base.BaseFragment.onCreate(BaseFragment.java:68)
   at com.payments.app.fragments.TopLevelFragment.onCreate(TopLevelFragment.java:422)
   at android.support.v4.app.Fragment.performCreate(Fragment.java:2331)
   at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:1386)
   at android.support.v4.app.FragmentManagerImpl.moveFragmentToExpectedState(FragmentManager.java:1759)
   at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:1827)
   at android.support.v4.app.FragmentManagerImpl.dispatchStateChange(FragmentManager.java:3244)
   at android.support.v4.app.FragmentManagerImpl.dispatchCreate(FragmentManager.java:3194)
   at android.support.v4.app.Fragment.restoreChildFragmentState(Fragment.java:1444)
   at android.support.v4.app.Fragment.onCreate(Fragment.java:1415)

What I know: This occurs when app is restored from background, and onCreate is called. Our app is a Single-Activity app, with all UI managed by fragments. This crash is infrequent, and very hard to reproduced in our dev environment.

Also - I don't believe the cause is some parcelable object we created, rather Android component reloading, but not sure.

What I'd like to know: how to analyze these stacktraces to pinpoint the cause? how to make use of the little data given?

Note that the stacktrace hardly points to any particular line in our app, and where it does - only to the onCreate methods of our activity and fragments base classes

Answer 1

我刚刚了解到您可以阻止测试设备保持活动。开发者选项的“应用程序”部分中有一个选项，打开该选项后，每次用户离开活动时都会销毁活动。

打开此选项后，我只需关闭并重新打开我的应用程序即可重现该错误。正如您所说，这是 onCreate() 方法中的错误。就我而言，原因是从保存的实例状态解组自定义 Parcelable 时出现 ClassNotFoundException。这可能无法解决您的问题，但至少可以帮助您重现并确定错误。狩猎快乐！