How is it possible that fragment's onActivityResult will be triggered during activity resuming

Question

Normally, this is how my fragment's onActivityResult being triggered.

public void onActivityResult(final int requestCode, final int resultCode, final Intent data)

(1) Starting an intent through startActivityForResult from fragment

Intent intent = new Intent(this.getActivity(), NewBuyPortfolioFragmentActivity.class);
startActivityForResult(intent, RequestCode.REQUEST_NEW_BUY_PORTFOLIO_FRAGMENT_ACTIVITY);

(2) Set result and finish from the launched activity

setResult(RESULT_OK, resultIntent);
finish();

(3) Fragment's onActivityResult will be triggered

However, under very rare case (I'm not able to reproduce), I will receive such crash report.

It seems that during activity resuming, my fragment onActivityResult will be triggered, with its requestCode matched to my application requestCode (RequestCode.REQUEST_NEW_BUY_PORTFOLIO_FRAGMENT_ACTIVITY).

Any idea why fragment's onActivityResult will be triggered during activity resuming?

java.lang.RuntimeException: Unable to resume activity {org.yccheok.jstock.gui/org.yccheok.jstock.gui.JStockFragmentActivity}: java.lang.RuntimeException: Failure delivering result ResultInfo{who=null, request=196615, result=-1, data=Intent { (has extras) }} to activity {org.yccheok.jstock.gui/org.yccheok.jstock.gui.JStockFragmentActivity}: java.lang.NullPointerException
at android.app.ActivityThread.performResumeActivity(ActivityThread.java:2124)
at android.app.ActivityThread.handleResumeActivity(ActivityThread.java:2139)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:1672)
at android.app.ActivityThread.handleRelaunchActivity(ActivityThread.java:2836)
at android.app.ActivityThread.access$1600(ActivityThread.java:117)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:939)
at android.os.Handler.dispatchMessage(Handler.java:99)
at android.os.Looper.loop(Looper.java:130)
at android.app.ActivityThread.main(ActivityThread.java:3687)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:507)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:867)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:625)
at dalvik.system.NativeStart.main(Native Method)
Caused by: java.lang.RuntimeException: Failure delivering result ResultInfo{who=null, request=196615, result=-1, data=Intent { (has extras) }} to activity {org.yccheok.jstock.gui/org.yccheok.jstock.gui.JStockFragmentActivity}: java.lang.NullPointerException
at android.app.ActivityThread.deliverResults(ActivityThread.java:2536)
at android.app.ActivityThread.performResumeActivity(ActivityThread.java:2111)
... 13 more
Caused by: java.lang.NullPointerException
at org.yccheok.jstock.gui.portfolio.BuyPortfolioFragment.void addTransaction(org.yccheok.jstock.portfolio.Transaction)(SourceFile:733)
at org.yccheok.jstock.gui.portfolio.PortfolioFragment.void onActivityResult(int,int,android.content.Intent)(SourceFile:661)
at android.support.v4.app.FragmentActivity.void onActivityResult(int,int,android.content.Intent)(SourceFile:161)
at org.yccheok.jstock.gui.JStockFragmentActivity.void onActivityResult(int,int,android.content.Intent)(SourceFile:988)
at android.app.Activity.dispatchActivityResult(Activity.java:3908)
at android.app.ActivityThread.deliverResults(ActivityThread.java:2532)
... 14 more

Note, if NPE is being thrown in onActivityResult during the 3 steps normal flow I mention above, I will be getting the below stack trace, without Unable to resume activity message.

Crash report produced from normal onActivityResult flow.

FATAL EXCEPTION: main
java.lang.RuntimeException: Failure delivering result ResultInfo{who=null, request=196615, result=-1, data=Intent { (has extras) }} to activity {org.yccheok.jstock.gui/org.yccheok.jstock.gui.JStockFragmentActivity}: java.lang.NullPointerException
    at android.app.ActivityThread.deliverResults(ActivityThread.java:3141)
    at android.app.ActivityThread.handleSendResult(ActivityThread.java:3184)
    at android.app.ActivityThread.access$1100(ActivityThread.java:130)
    at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1243)
    at android.os.Handler.dispatchMessage(Handler.java:99)
    at android.os.Looper.loop(Looper.java:137)
    at android.app.ActivityThread.main(ActivityThread.java:4745)
    at java.lang.reflect.Method.invokeNative(Native Method)
    at java.lang.reflect.Method.invoke(Method.java:511)
    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:786)
    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:553)
    at dalvik.system.NativeStart.main(Native Method)
Caused by: java.lang.NullPointerException
    at org.yccheok.jstock.gui.portfolio.BuyPortfolioFragment.addTransaction(BuyPortfolioFragment.java:734)
    at org.yccheok.jstock.gui.portfolio.PortfolioFragment.onActivityResult(PortfolioFragment.java:661)
    at android.support.v4.app.FragmentActivity.onActivityResult(FragmentActivity.java:161)
    at org.yccheok.jstock.gui.JStockFragmentActivity.onActivityResult(JStockFragmentActivity.java:988)
    at android.app.Activity.dispatchActivityResult(Activity.java:5192)
    at android.app.ActivityThread.deliverResults(ActivityThread.java:3137)
    ... 11 more

Answer 1

It possible that fragment's onActivityResult will be triggered during activity resuming by doing this-

Actually i am not getting how u have managed your fragment but i am providing u two solutions... on the basis of above code.

1. In your case it is null pointer exception so u can check null before super.onActivityResult of your fragment activity.

2. Just put ur code "Intent intent = new Intent(this.getActivity(), NewBuyPortfolioFragmentActivity.class); startActivityForResult(intent, RequestCode.REQUEST_NEW_BUY_PORTFOLIO_FRAGMENT_ACTIVITY);" on click of fragment item or any where from where u want to switch on NewBuyPortfolioFragmentActivity and from there just "Intent resultIntent; resultIntent = new Intent(this, ImageFragment.class); setResult(RESULT_OK, resultIntent); finish();"