import javax.swing.*;
import java.awt.*;
import java.util.Random;
import java.awt.event.ActionListener;
import java.awt.event.ActionEvent;

public class MySwing {

    /**
     * @param args
     */
    public static void main(String[] args) {
        // TODO Auto-generated method stub

        SimpleFrame frame = new SimpleFrame();
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.setVisible(true);
    }

}

class SimpleFrame extends JFrame {
    public SimpleFrame() {
        Toolkit kit = Toolkit.getDefaultToolkit();
        setBounds(100, 100, kit.getScreenSize().width/2, kit.getScreenSize().height/2);
        setTitle("Very Cool!!!");
        setResizable(false);
        setBackground(Color.BLACK);

        Container c = getContentPane();
        final MyComponent m = new MyComponent();
        c.add(m);
        JButton button = new JButton("Repaint");
        button.addActionListener(new ActionListener(){
                @Override public void actionPerformed(ActionEvent e){
                    m.repaint();
                }
            });
        c.add(button,BorderLayout.PAGE_END);
    }
}
class MyComponent extends JPanel{

    private final Random generator = new Random();
    public void paintComponent(Graphics g) {
        // super.paintComponent(g);
        g.drawString("Very Happy", generator.nextInt(getWidth()), generator.nextInt(getHeight()));
    }
}