Why static variable of my android application sometimes return null?

Question

I am trying to get value from SharedPreferences and storing it inside of an static variable. The problem is sometimes I am getting null value from static variable but SharedPreferences has value. I have stored value via this process:

 SharedPreferences sp = u.returnShare();
    SharedPreferences.Editor editor = sp.edit();

    StaticVariables.userId = sp.getString("UserId", "default");

smith324 · Accepted Answer · 2013-01-11 06:47:16Z

3

Don't use static variables, its bad practice. Android can destroy you application's process at any time and later recreate it by recreating activities as necessary. If you're creating your static variable in the "first" activity then it wont get initialized when the 2nd or 3rd are started first.

answered Jan 11, 2013 at 6:47

smith324

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2 Comments

TKumar Over a year ago

Then what can I do? Shall I get value every times from sharedPreference or any other better idea?

smith324 Over a year ago

Treat the static variable as a cache, if it is null you need to get if from shared preferences again.

Henry · Accepted Answer · 2013-01-11 06:47:24Z

3

Static variables are not a good long term storage in android. The system may kill your application at any time when it is in background (for example when the memory is needed for other tasks). All your values stored in static variables are then gone when the app is restarted.

answered Jan 11, 2013 at 6:47

Henry

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1 Comment

TKumar Over a year ago

Then what can I do? Shall I get value every times from sharedPreference or any other better idea?

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