Gridview onClickListerener nullpointer

Question

the problem: When you click an item in the gridview, OCLGenre (OnItemClickListener for Genre view) fires an nullPointer at line 123. I'm trying to understand where the nullPointer comes from but can't find it.

The stack:

ERROR/AndroidRuntime(10511): FATAL EXCEPTION: main
 java.lang.NullPointerException
 at com.MMWeb.MMWeb$browse$1.onItemClick(MMWeb.java:123)
 at android.widget.AdapterView.performItemClick(AdapterView.java:284)
 at android.widget.AbsListView$PerformClick.run(AbsListView.java:1812)
 at android.os.Handler.handleCallback(Handler.java:587)
 at android.os.Handler.dispatchMessage(Handler.java:92)
 at android.os.Looper.loop(Looper.java:123)
 at android.app.ActivityThread.main(ActivityThread.java:3683)
 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:839)
 at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:597)
 at dalvik.system.NativeStart.main(Native Method)

Anyone got a pointer to where to find the source of this nullPointer?

found the cause: at this point the ArrayList> items is null... now figure out why :( — Peter Elzinga, Oct 06 '11 at 14:37
Oke i found my problem By moving the ImageAdapter out of the "browse" class, the "browse" class did not have any reference to the ArrayList 'items'. I could find the problem because, after all, i defined the ArrayList at line 112. However, showGenres() uses a local ArrayList, and the ImageAdapter would put it in "browser.items". Fixed it by removing the local decleration of items on line 145, 154 and 162 — Peter Elzinga, Oct 06 '11 at 14:44
Possible duplicate of [What is a NullPointerException, and how do I fix it?](https://stackoverflow.com/questions/218384/what-is-a-nullpointerexception-and-how-do-i-fix-it) — Paul Karam, Mar 09 '18 at 07:13

score 1 · Answer 1 · edited Mar 09 '18 at 07:27

1

If you try to access an object which is null. Like the below example.

ClassA  objA;

At this time you have just declared this object but you have not initialized or instantiated it.

When you try to access any property or method in it, it will throw
NullPointerException.

edited Mar 09 '18 at 07:27

johnashu

2,167
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answered Mar 09 '18 at 06:49

kundan kamal

674
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score 0 · Accepted Answer · answered Oct 12 '11 at 08:03

Oke i found my problem By moving the ImageAdapter out of the "browse" class, the "browse" class did not have any reference to the ArrayList 'items'. I could find the problem because, after all, i defined the ArrayList at line 112. However, showGenres() uses a local ArrayList, and the ImageAdapter would put it in "browser.items". Fixed it by removing the local decleration of items on line 145, 154 and 162

Gridview onClickListerener nullpointer

2 Answers2