16.16

import java.awt.Graphics;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;

import javax.swing.*;



public class Test_16_16 extends JFrame{
    
    public Test_16_16(){
        add(new JP());
    }
    public static void main(String[] args) {
        // TODO Auto-generated method stub
        Test_16_16 frame = new Test_16_16();        
        frame.setSize(300,220);
        frame.setTitle("Test_16_16");
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.setLocationRelativeTo(null); // Center the frame
        frame.setVisible(true); 
    }
    
    static class JP extends JPanel{
        private boolean visi = true;
        
        public JP(){
            Timer timer = new Timer(1000,new TimerListener());
            timer.start();
        }
        protected void paintComponent(Graphics g){
            super.paintComponent(g);
            if(visi == true)
                g.drawImage(new ImageIcon("image/flag4.gif").getImage(), 0, 0, this);
        }
        class TimerListener implements ActionListener{

            @Override
            public void actionPerformed(ActionEvent arg0) {
                // TODO Auto-generated method stub
                if(visi == true) visi = false;
                else visi = true;
                repaint();
            }
            
        }
    }
}