How to find an error when Logcat doesn't show any of your classes?

Question

Developing my app with Android Studio, I'm having a runtime error but Logcat doesn't show the error in any of my classes.

How to determine where is the problem / what piece of code is failing when this happens?

Example:

09-17 13:29:23.420  17656-17656/com.mycompany.android.app E/AndroidRuntime﹕ FATAL EXCEPTION: main
java.lang.NullPointerException
        at android.support.v4.app.Fragment.setUserVisibleHint(Fragment.java:860)
        at android.support.v4.app.FragmentStatePagerAdapter.setPrimaryItem(FragmentStatePagerAdapter.java:152)
        at android.support.v4.view.ViewPager.populate(ViewPager.java:1103)
        at android.support.v4.view.ViewPager.populate(ViewPager.java:951)
        at android.support.v4.view.ViewPager.onTouchEvent(ViewPager.java:2041)
        at android.view.View.dispatchTouchEvent(View.java:7320)
        at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2179)
        at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:1914)
        at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2185)
        at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:1886)
        at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2185)
        at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:1886)
        at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2185)
        at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:1886)
        at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2185)
        at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:1886)
        at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2185)
        at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:1886)
        at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2185)
        at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:1886)
        at com.android.internal.policy.impl.PhoneWindow$DecorView.superDispatchTouchEvent(PhoneWindow.java:2038)
        at com.android.internal.policy.impl.PhoneWindow.superDispatchTouchEvent(PhoneWindow.java:1490)
        at android.app.Activity.dispatchTouchEvent(Activity.java:2471)
        at android.support.v7.internal.view.WindowCallbackWrapper.dispatchTouchEvent(WindowCallbackWrapper.java:59)
        at android.support.v7.internal.view.WindowCallbackWrapper.dispatchTouchEvent(WindowCallbackWrapper.java:59)
        at com.android.internal.policy.impl.PhoneWindow$DecorView.dispatchTouchEvent(PhoneWindow.java:1986)
        at android.view.View.dispatchPointerEvent(View.java:7514)
        at android.view.ViewRootImpl.deliverPointerEvent(ViewRootImpl.java:3679)
        at android.view.ViewRootImpl.deliverInputEvent(ViewRootImpl.java:3623)
        at android.view.ViewRootImpl.doProcessInputEvents(ViewRootImpl.java:4798)
        at android.view.ViewRootImpl.enqueueInputEvent(ViewRootImpl.java:4777)
        at android.view.ViewRootImpl$WindowInputEventReceiver.onInputEvent(ViewRootImpl.java:4873)
        at android.view.InputEventReceiver.dispatchInputEvent(InputEventReceiver.java:208)
        at android.os.MessageQueue.nativePollOnce(Native Method)
        at android.os.MessageQueue.next(MessageQueue.java:125)
        at android.os.Looper.loop(Looper.java:135)
        at android.app.ActivityThread.main(ActivityThread.java:5751)
        at java.lang.reflect.Method.invokeNative(Native Method)
        at java.lang.reflect.Method.invoke(Method.java:511)
        at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1083)
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:850)
        at dalvik.system.NativeStart.main(Native Method)

Fragment.setUserVisibleHint(Fragment.java:860) this is the problem — Syed Nazar Muhammad, Sep 17 '15 at 12:15
check this: http://stackoverflow.com/questions/20893000/android-support-v4-app-fragment-setuservisiblehint-null-pointer-on-app-resuming — Opiatefuchs, Sep 17 '15 at 12:45
@Opiatefuchs I tried that solution before to ask. Thanks anyway! — kike, Sep 17 '15 at 13:01
I agree with Syed, that you should post the code where you're messing with visibility. My guess is you're trying to change visible properties of something that doesn't technically exist yet — Riot Goes Woof, Sep 17 '15 at 14:18

score 1 · Answer 1 · answered Sep 18 '15 at 07:51

1

I'd suggest to encapsulate the code in your fragment within the isVisible() method. For example,

//do something

to

if(isVisible()) {
    //do something
}

answered Sep 18 '15 at 07:51

darthvading

809
2
10
23

I'm already doing something like that. I've changed "getActivity!=null" for "isVisible()" because I feel it's an improvement of the code. Thanks for that. – kike Sep 18 '15 at 08:04
I would like to add that I'm doing the stack trace of the app and seems that the error is in this piece of code. – kike Sep 18 '15 at 08:10

How to find an error when Logcat doesn't show any of your classes?

1 Answers1