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
