problem in refreshing JPanels

[partha phukan]

Hi everyone! i need to refresh my JPanel with new data, but i could not able to do it....

package com.ws.ui;

import java.awt.*;
import java.awt.event.*;
import javax.swing.*;

public class WeatherDelegator implements ActionListener {
	static JFrame frame;
    JPanel mainPanel; //a panel that uses CardLayout
    JMenu forecastMenu;
    JMenuItem fItem1,fItem2,fItem3;
    CurrentPanel c=new CurrentPanel();
    HoursPanel h=new HoursPanel();
    DaysPanel d=new DaysPanel();
 
    CardLayout cl;
    Timer timer;
    
    public void addComponentToPane(Container pane) {
				forecastMenu=new JMenu("Forecast");
				forecastMenu.setMnemonic(KeyEvent.VK_F);

				fItem1=new JMenuItem("Current");
				fItem1.setAccelerator(KeyStroke.getKeyStroke(KeyEvent.VK_W,ActionEvent.CTRL_MASK));
				fItem2=new JMenuItem("Next 3 Hours");
				fItem2.add(new JSeparator());
				fItem3=new JMenuItem("Next 3 Days");
				fItem3.add(new JSeparator());
				forecastMenu.add(fItem1);
				forecastMenu.add(fItem2);
				forecastMenu.add(fItem3);
           
				
		//create the JMenuBar
				JMenuBar menuBar = new JMenuBar();
	//Add menu items in the Menu Bar         
				menuBar.add(forecastMenu);
						
				fItem1.addActionListener(this);
				fItem2.addActionListener(this);
				fItem3.addActionListener(this);
        
        //Create the panel that contains the "cards".
        mainPanel = new JPanel(new CardLayout());
        mainPanel.setBackground(Color.BLACK);
        
        int delay = 60000; // 1000 ms is 1sec
			timer = new Timer(delay, new ActionListener(){
			     public void actionPerformed(ActionEvent e){
			    	 c.currentPanel().invalidate();
			    	 c.currentPanel().revalidate();			    	 
			    	 c.currentPanel().repaint();
			    	 mainPanel.add(c.currentPanel(), "p1");
	 			     //cl.show(mainPanel,"p1");
	 			      
	 			   h.hoursPanel().invalidate();
	 			   h.hoursPanel().revalidate();			    	 
	 			   h.hoursPanel().repaint();
	 			   mainPanel.add(h.hoursPanel(), "p2");
     			              //cl.show(mainPanel,"p2");
     			        
     			       d.daysPanel().invalidate();
     			       d.daysPanel().revalidate();			    	 
     			       d.daysPanel().repaint();
    			    	mainPanel.add(d.daysPanel(), "p3");
    			       //cl.show(mainPanel,"p3");
    			  
			     	}
			     });
				timer.start();  
        pane.add(mainPanel);
    }
    
    public void actionPerformed(ActionEvent e){
        cl = (CardLayout)(mainPanel.getLayout());
        Object obj=e.getSource();
        	if(obj==fItem1){
        		mainPanel.revalidate();
        		mainPanel.add(c.currentPanel(), "p1");
	        	cl.show(mainPanel,"p1");
	        	   				
        	}else if(obj==fItem2){
        		
        		mainPanel.revalidate();
        		mainPanel.add(h.hoursPanel(), "p2");
	        	cl.show(mainPanel,"p2");  		
	        	
        	}else if(obj==fItem3){
        		
        		mainPanel.revalidate();
        		mainPanel.add(d.daysPanel(), "p3");
	        	cl.show(mainPanel,"p3"); 
	       }
	}
    
    /**
     * Create the GUI and show it.  For thread safety,
     * this method should be invoked from the
     * event dispatch thread.
     */
    private static void createAndShowGUI() {
        //Create and set up the window.
        frame = new JFrame("Weather Report");
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        
        //Create and set up the content pane.
       WeatherDelegator weathDel = new WeatherDelegator();
       weathDel.addComponentToPane(frame.getContentPane());
        
        //Display the window.
        frame.pack();
        frame.setSize(930,630);
		frame.setResizable(false);
		frame.setVisible(true);
    }
   
    public static void main(String[] args) {   
        //Schedule a job for the event dispatch thread:
        //creating and showing this application's GUI.
        javax.swing.SwingUtilities.invokeLater(new Runnable() {
            public void run() {
                createAndShowGUI();
            }
        });
    }
}

Here this is the main class of my project. Above CurrentPanel, HoursPanel, DaysPanel are 3 separate classes where i displayed some JLabels and Graphs and JTables, and the corresponding values for them are taken from the database by executing some queries..... In all the classes i performed all the operations and returned the JPanels. i have used a cardlayout and added the 3 (returned) JPanels in the cardlayout panel( i.e mainPanel) All my queries are running properly everything is fine. But i don't know how to refresh the JLabel, JTable and Graphs values with time. I am maintaining a database table with time as a field. As time changes the queries must take the new time values and displayed in the correspnding places of JLabels, JTable and Graphs.....

I don't know how to use timers. i searched in google and tried to apply myself but no any success.... Please guide me. Please give me some suggestion for this. please.... thank you in advance......