CODEWITHSUNDEEP
javaswingnetbeanstimer
Osiris93
Osiris93

Reputation: 316

Log out of Java application after 60 seconds of inactivity?

I have developed a Java Swing Application and I want to make it so that if there is inactivity for about 60 seconds, it automatically logs out. I have tried using java timers but out of the many examples I have tried, none of them seem to work.

Here is the latest one I have tried (and the only one that did not have any errors in the code):

int seconds;
    Timer timer;
    Toolkit toolkit;
    public void AutoLogout()
    {
        toolkit = Toolkit.getDefaultToolkit();
        timer = new Timer();
        timer.schedule(null, 5000);
        if(seconds == 0)
        {
            LoginPage lp = new LoginPage();
            lp.setVisible(true);
            this.dispose();
        }
    }

However when I run the application it get the following output in the stack trace:

Exception in thread "AWT-EventQueue-0" java.lang.NullPointerException
    at java.util.Timer.sched(Timer.java:399)
    at java.util.Timer.schedule(Timer.java:193)
    at AdminMainPage.AutoLogout(AdminMainPage.java:1078)
    at AdminMainPage.<init>(AdminMainPage.java:23)
    at AdminMainPage$35.run(AdminMainPage.java:1289)
    at java.awt.event.InvocationEvent.dispatch(InvocationEvent.java:311)
    at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:756)
    at java.awt.EventQueue.access$500(EventQueue.java:97)
    at java.awt.EventQueue$3.run(EventQueue.java:709)
    at java.awt.EventQueue$3.run(EventQueue.java:703)
    at java.security.AccessController.doPrivileged(Native Method)
    at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:75)
    at java.awt.EventQueue.dispatchEvent(EventQueue.java:726)
    at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:201)
    at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:116)
    at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:105)
    at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:101)
    at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:93)
    at java.awt.EventDispatchThread.run(EventDispatchThread.java:82)

I have tried several examples from Stackoverflow but none of them work. How else can I go about getting the system to logout automatically after 60 seconds of inactivity?

Upvotes: 2

Views: 1618

Answers (2)

camickr
camickr

Reputation: 324118

Check out Application Inactiviy for a simple class that will invoke an Action after a given period of time.

The code uses an AWTEventListener to listen for events. Every time an event is generated a Swing Timer is restarted. When the Swing Timer fires the Action you specify is invoked.

Upvotes: 3

f1sh
f1sh

Reputation: 11934

If you take a look at the documentation, you will see:

throws a NullPointerException - if task is null

Which is exactly what you do in your line

timer.schedule(null, 5000);

That explains the Exception that's being thrown at you. I don't think a scheduler is the right way to go here since each user activity should reset the timer.

Upvotes: 2

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