You are right, my example is a bit confusing. lib in OtherActivity should be MainActivity.lib.
Regards, Michael A. On Aug 6, 5:11 pm, DanH <[email protected]> wrote: > I'm a little curious. A static should only be reset when a class (not > object) goes away . A class can only go away when its class loader > and all classes referencing it go away. This is independent of when > individual objects get created (except that you can't create an object > unless it's class is there, and a class can't go away while there are > existing objects). > > I suppose it's possible that Dalvik violates these rules somehow, but > if so it needs to be well-documented. > > Your example is confusing, however. Where is the "lib" in > OtherActivity defined, and how is it initialized? > > On Aug 6, 6:48 am, "Michael A." <[email protected]> wrote: > > > I am seeing a lot of NullPointerException in my code at the moment > > from public static variables. > > > I use these variables to store, e.g., my image library (used in > > Activities throughout my code). All of them are initialized in the > > OnCreate of my apps Base activity, and I check that they are > > initialized in OnResume just to be certain (and initialize them if > > they have somehow become nulled). > > > // Main APP Activity > > MainActivity { > > public static GlobalObject lib; > > > void OnCreate() { > > if (lib == null) > > lib = new GlobalObject(); > > > } > > > void OnResume() { > > if (lib == null) > > lib = new GlobalObject(); > > > } > > } > > > // Some other activity instantiated later > > OtherActivity { > > void onCreate() { > > lib.doSomething(); // This line will sometimes fail with a > > NullPointerException > > > } > > } > > > I am quite unable to recreate the situation in which this > > NullPointerException occurs. As I understand the activity lifecycle, > > it should not be possible for lib to be null when OtherActivity is > > created (if OtherActivity is in memory, MainActivity's static > > variables should also be in memory and if the app is killed, it should > > start over from MainActivity?), but that is the error I seem to be > > getting. > > > Suggestions, anyone? I suppose I am probably overlooking something > > simple, but I just can't see it. > > > Regards, > > > Michael A. -- You received this message because you are subscribed to the Google Groups "Android Developers" group. To post to this group, send email to [email protected] To unsubscribe from this group, send email to [email protected] For more options, visit this group at http://groups.google.com/group/android-developers?hl=en
