Lifetime Of Static Class Variables

public class Checker { static private int value1 = 0, value2 = 1; static private Activity activity; public static void init(Activity activity) { Checker.activ

Solution 1:

Based on the symptoms you are describing, what's most likely happening is that the ClassLoader for Checker is getting garbage collected but your Activity is not being garbage collected. So when the app returns from the background, Activity goes to onResume. When the call to Checker.check() is made, the Checker class is reloaded with the default values of value1 and value2.

One way to make sure that the Checker class stays around as long as the Activity is to keep a reference to a Checker instance in the Activity class. Of course, you might also consider redesigning the Checker functionality so that it doesn't depend on static member behavior.

Solution 2:

This is most likely caused by the activity not existing any more. If its in the background the os might kill it and restart it when needed, so you will need to check if it is != null before you try and finish() it :)

if (value1 != value2 && activity != null) activity.finish();