This is how I would make a countdown timer:
Timer timer = new Timer(1000, new TimerListener());
class TimerListener implements ActionListener{
int elapsedSeconds = 30;
public void actionPerformed(ActionEvent evt){
elapsedSeconds--;
timerLabel.setText(elapsedSeconds)
if(elapsedSeconds <= 0){
timer.stop();
wrong()
// fill'er up here...
}
}
}