Android "Global Variables" Not Persisting

Question

I have created a class that extends Application to store variables I want to access from multiple activities

public class MyApplication extends Application 
{
private String fbId, firstName;
private long expires;

@Override
public void onCreate() 
{
    super.onCreate();
}

public String getFbId() 
{
    return fbId;
}

public void setFbId(String fbId) 
{
    this.fbId = fbId;
}

public String getFirstName()
{
    return firstName;
}

public void setFirstName(String firstName) 
{
    this.firstName = firstName;
}

I am able to access these variables and set these variables the first time I am running the app. Once I quit out and restart the application it sets my values to null, any suggestions for why this may be happening?

Answer 1

If you don't store your data in storage (that doesn't need to be a database, could be a flat file, SharedPreferences, or whatever) then it is not persistent.

You should be using SharedPreferences to save this kind of persistent data.

The SharedPreferences class provides a general framework that allows you to save and retrieve persistent key-value pairs of primitive data types. You can use SharedPreferences to save any primitive data: booleans, floats, ints, longs, and strings. This data will persist across user sessions (even if your application is killed).