Android static variables are lost

Question

I am using a class with only static variables to store all constants and run-time properties. But, recently I have seen instances when I\'m referencing these variables, I ge

Answer 1

Only public static String androidId; can be null, when you want to use it you should init it in this class or in some other class in onResume()

Answer 2

Please note the following in reference to above question:

1. Garbage collector removes only unreferenced objects. Static variables will lose their values only when they are unloaded from JVM during run-time.

2. Initialization happens when app is launched via activities. If there are any services/broadcast receivers that are accessing methods within other classes and use these ids, and the app is not yet running by that time, the uninitialized values are referenced as default value. In case of string - it is null.

3. Nothing to do with low-end processors, easy to blame them often but JVM is powerful enough.

Answer 3

androidId is a reference to an string, string is a class that will get by default a null reference as intial value if you dont do it....

look at this taken from oracle's doc

So basically androidId is null because is not initialized....the fact that the variable is static or not is not relevant in this case...

see here for more details

...I SOMETIMES get null.

yes, you will get always null unless its value change at run time...