import java.awt.*;import java.awt.geom.*;import javax.swing.*;import java.net.*;public class RoundButton extends JButton {        public RoundButton(String label) {        super(label);        // These statements enlarge the button so that it        // becomes a circle rather than an oval.        Dimension size = getPreferredSize();//        size.width = size.height = Math.max(size.width, size.height);        setPreferredSize(size);        // This call causes the JButton not to paint the background.        // This allows us to paint a round background.        setContentAreaFilled(false);    }    // Paint the round background and label.    protected void paintComponent(Graphics g) {	if (getModel().isArmed()) {            // You might want to make the highlight color            // a property of the RoundButton class.            g.setColor(Color.lightGray);        } else {            g.setColor(getBackground());        }	g.fillOval(0, 0, getSize().width-1, getSize().height-1);        // This call will paint the label and the focus rectangle.	super.paintComponent(g);    }    // Paint the border of the button using a simple stroke.    protected void paintBorder(Graphics g) {        g.setColor(getForeground());        g.drawOval(0, 0, getSize().width-1, getSize().height-1);    }    // Hit detection.    Shape shape;    public boolean contains(int x, int y) {        // If the button has changed size, make a new shape object.        if (shape == null || !shape.getBounds().equals(getBounds())) {            shape = new Ellipse2D.Float(0, 0, getWidth(), getHeight());        }        return shape.contains(x, y);    }            // Test routine.    public static void main(String[] args) {        // Create a button with the label.	JButton button = new RoundButton("圓形按鈕");        JButton b2;	ImageIcon ic;	button.setBackground(Color.green);                // Create a frame in which to show the button.        ic = new ImageIcon("Red.GIF");	b2=new JButton(ic);	JFrame frame = new JFrame();		frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);        frame.getContentPane().setBackground(Color.yellow);        frame.getContentPane().add(button);        frame.getContentPane().setLayout(new FlowLayout());        frame.getContentPane().add(b2);	frame.setSize(300, 200);        frame.setVisible(true);    }}