Creating a global variable

Question

I'm trying to implement a basic login in my app. What I want to do is set a "Global" variable as true / false if user is logged in.

I've followed this tutorial. So this is my code now:

import android.app.Application;

public class GlobalParameters extends Application{
    private boolean loggedIn;

    public boolean isLoggedIn() {
    return loggedIn;
    }

    public void setLoggedIn(boolean loggedIn) {
    this.loggedIn = loggedIn;
    }
}

And this is on my onCreate:

GlobalParameters gp = ((GlobalParameters)getApplicationContext());
gp.setLoggedIn(false);

But GlobalParameters gp = ... throws this exception:

ClassCastException

I've added this too in my manifest:

<application android:name=".GlobalParameters" 
   android:icon="@drawable/ic_launcher" 
   android:label="@string/app_name">
</application>

Any idea?

Thanks.

I would rather use shared prefs for storing the login token. — Dhruv Gairola, Mar 25 '13 at 22:30

chopchop · Accepted Answer · 2013-03-25T22:53:12.877

1

Use this.getApplication() to get the Application associated with your Activity. But I think in your case, going to the Application is a bit overkill. You could just use a static field in a class.

However, if you want the state to be retained when your Activity is discarded then you can use SharedPreferences, a good guide to get started with those is here https://developer.android.com/guide/topics/data/data-storage.html#pref

edited Mar 25 '13 at 22:53

answered Mar 25 '13 at 22:26

chopchop

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Static fields in Android do not retain state when an activity is discarded. That is the whole point of the (ugly) solution with the application. – Hauke Ingmar Schmidt Mar 25 '13 at 22:46

score 0 · Answer 2 · answered Mar 25 '13 at 22:58

0

If your variable is just to login and logout, is better you use a static variable and set it true on login and set it false on logout.

public static boolean loggedIn;

and use it as below:

myApplication.loggedIn = true;

myApplication.loggedIn = false;

answered Mar 25 '13 at 22:58

Victor Laerte

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Creating a global variable

2 Answers2