problem in refreshing automatically with time

[tultul]

i have a problem. i don't know where i am making the mistake.... i need to refreshed my JPanels automatically with time..... i have used timers for this. i used in the constructor of the class...

public class HoursPanel{
//....
//.....
   public HoursPanel(){
    int delay = 60000;
    Timer timer = new Timer(delay, new ActionListener(){
         public void actionPerformed(ActionEvent e){
             hrPanel.invalidate();
             hrPanel.revalidate();                   
             hrPanel.repaint();
         }
    });
    timer.start();
     }

//....
//.....
//.....

i am posting only my timer portion. I need to refresh my JPanel which contain values from database. i need to refresh at a regular interval of 1 min automatically, but i got my JPanel refreshed only when i minimize the JFrame or if i switch to different JPanel(which are in cardlayout) and coming back to that JPanel...

in above hrPanel is an object of JPanel, where i put all my JLabel and graphs.... please give me suggestion that where i am doing wrong. Thank you in advance.....

[JamesCherrill]

Where's the code that updates the data from the database?
Your structure should be:
timer actionPerformed updates data objects and calls repaint() for the GUI
paintComponent(...) does the minimum needed to keep the GUI in step with the data objects.

[tultul]

Thank you for your reply. Actually i have 3 classes...

(1) a main class....

(2) a database class where i did all the queries and connections and returned the queries....

(3) another class where i used the returned queries and did all the calculation and added to respective JLabels in a JPanel and returned the JPanel (with those database values in JLabels) to the main class and added to the main JPanel, which is in cardlayout....

Now what should i do...? what should be used in actionPerformed method of timer? i am getting the desired answer, but only when i minimize the JFrame or when i switch to different JPanel and again coming back to that JPanel..... do i need to follow different approach?

[JamesCherrill]

Can't say without the whole picture. But like I said before, update the queries and calculations in a method (whatever class it may be in) from the Timer, and update the contents of the JPanel (by querying the previously-retrieved data & calcs) in the paintComponent. You should only need to set up the JPanel once.

[tultul]

Yaaa!!! I have done it. I just used the above code which i have posted but in a method not in the constructor... Thank you...