#64 App crashes due to network issue

at org.notabug.lifeuser.moviedb.activity.DetailActivity$2.onScrollChanged(DetailActivity.java:174)
at org.notabug.lifeuser.moviedb.NotifyingScrollView.onScrollChanged(NotifyingScrollView.java:51)
at android.view.View.scrollTo(View.java:12415)
at android.widget.ScrollView.scrollTo(ScrollView.java:1649)
at android.view.View.scrollBy(View.java:12430)
at android.widget.ScrollView.smoothScrollBy(ScrollView.java:1211)
at android.widget.ScrollView.scrollToChildRect(ScrollView.java:1374)
at android.widget.ScrollView.requestChildRectangleOnScreen(ScrollView.java:1500)
at android.view.View.requestRectangleOnScreen(View.java:5539)
at android.view.View.requestRectangleOnScreen(View.java:5505)
at android.widget.TextView.bringPointIntoView(TextView.java:7445)
at android.widget.TextView.onPreDraw(TextView.java:5228)
at android.view.ViewTreeObserver.dispatchOnPreDraw(ViewTreeObserver.java:944)
at android.view.ViewRootImpl.performTraversals(ViewRootImpl.java:2055)
at android.view.ViewRootImpl.doTraversal(ViewRootImpl.java:1107)
at android.view.ViewRootImpl$TraversalRunnable.run(ViewRootImpl.java:6013)
at android.view.Choreographer$CallbackRecord.run(Choreographer.java:858)
at android.view.Choreographer.doCallbacks(Choreographer.java:670)
at android.view.Choreographer.doFrame(Choreographer.java:606)
at android.view.Choreographer$FrameDisplayEventReceiver.run(Choreographer.java:844)
at android.os.Handler.handleCallback(Handler.java:739)
at android.os.Handler.dispatchMessage(Handler.java:95)
at android.os.Looper.loop(Looper.java:148)
at android.app.ActivityThread.main(ActivityThread.java:5417)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:726)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:616)

at java.lang.Integer.invalidInt(Integer.java:138)
at java.lang.Integer.parse(Integer.java:410)
at java.lang.Integer.parseInt(Integer.java:367)
at java.lang.Integer.parseInt(Integer.java:334)
at org.notabug.lifeuser.moviedb.activity.CastActivity.setActorData(CastActivity.java:280)
at org.notabug.lifeuser.moviedb.activity.CastActivity.access$1500(CastActivity.java:62)
at org.notabug.lifeuser.moviedb.activity.CastActivity$ActorDetails.onPostExecute(CastActivity.java:513)
at org.notabug.lifeuser.moviedb.activity.CastActivity$ActorDetails.onPostExecute(CastActivity.java:450)
at android.os.AsyncTask.finish(AsyncTask.java:651)
at android.os.AsyncTask.-wrap1(AsyncTask.java)
at android.os.AsyncTask$InternalHandler.handleMessage(AsyncTask.java:668)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:148)
at android.app.ActivityThread.main(ActivityThread.java:5417)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:726)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:616)

Studies have shown that mobile apps are prone to crashes due to a network issue, mainly because successful network calls return unexpected or no data. And we found that when this app (version 2.1.1)'s network returned data is null or some fields are null (JSON format), the app has crashed. the specific crash information is as follows: 1. java.lang.NullPointerException: Attempt to invoke virtual method 'void org.notabug.lifeuser.moviedb.activity.DetailActivity$AlphaForegroundColorSpan.setAlpha(float)' on a null object reference at org.notabug.lifeuser.moviedb.activity.DetailActivity$2.onScrollChanged(DetailActivity.java:174) at org.notabug.lifeuser.moviedb.NotifyingScrollView.onScrollChanged(NotifyingScrollView.java:51) at android.view.View.scrollTo(View.java:12415) at android.widget.ScrollView.scrollTo(ScrollView.java:1649) at android.view.View.scrollBy(View.java:12430) at android.widget.ScrollView.smoothScrollBy(ScrollView.java:1211) at android.widget.ScrollView.scrollToChildRect(ScrollView.java:1374) at android.widget.ScrollView.requestChildRectangleOnScreen(ScrollView.java:1500) at android.view.View.requestRectangleOnScreen(View.java:5539) at android.view.View.requestRectangleOnScreen(View.java:5505) at android.widget.TextView.bringPointIntoView(TextView.java:7445) at android.widget.TextView.onPreDraw(TextView.java:5228) at android.view.ViewTreeObserver.dispatchOnPreDraw(ViewTreeObserver.java:944) at android.view.ViewRootImpl.performTraversals(ViewRootImpl.java:2055) at android.view.ViewRootImpl.doTraversal(ViewRootImpl.java:1107) at android.view.ViewRootImpl$TraversalRunnable.run(ViewRootImpl.java:6013) at android.view.Choreographer$CallbackRecord.run(Choreographer.java:858) at android.view.Choreographer.doCallbacks(Choreographer.java:670) at android.view.Choreographer.doFrame(Choreographer.java:606) at android.view.Choreographer$FrameDisplayEventReceiver.run(Choreographer.java:844) at android.os.Handler.handleCallback(Handler.java:739) at android.os.Handler.dispatchMessage(Handler.java:95) at android.os.Looper.loop(Looper.java:148) at android.app.ActivityThread.main(ActivityThread.java:5417) at java.lang.reflect.Method.invoke(Native Method) at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:726) at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:616) 2. java.lang.NumberFormatException: Invalid int: "null" at java.lang.Integer.invalidInt(Integer.java:138) at java.lang.Integer.parse(Integer.java:410) at java.lang.Integer.parseInt(Integer.java:367) at java.lang.Integer.parseInt(Integer.java:334) at org.notabug.lifeuser.moviedb.activity.CastActivity.setActorData(CastActivity.java:280) at org.notabug.lifeuser.moviedb.activity.CastActivity.access$1500(CastActivity.java:62) at org.notabug.lifeuser.moviedb.activity.CastActivity$ActorDetails.onPostExecute(CastActivity.java:513) at org.notabug.lifeuser.moviedb.activity.CastActivity$ActorDetails.onPostExecute(CastActivity.java:450) at android.os.AsyncTask.finish(AsyncTask.java:651) at android.os.AsyncTask.-wrap1(AsyncTask.java) at android.os.AsyncTask$InternalHandler.handleMessage(AsyncTask.java:668) at android.os.Handler.dispatchMessage(Handler.java:102) at android.os.Looper.loop(Looper.java:148) at android.app.ActivityThread.main(ActivityThread.java:5417) at java.lang.reflect.Method.invoke(Native Method) at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:726) at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:616)