编辑代码

import javax.swing.*;  
import java.awt.*;  
  
public class Flower extends JFrame {  
  
    public Flower() {  
        super("小花");  
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);  
        setSize(400, 400);  
        setLocationRelativeTo(null);  
        setVisible(true);  
    }  
  
    public static void main(String[] args) {  
        new Flower();  
    }  
  
    @Override  
    public void paint(Graphics g) {  
        super.paint(g);  
        Graphics2D g2d = (Graphics2D) g;  
        g2d.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);  
        g2d.setPaint(Color.YELLOW);  
        g2d.fillOval(50, 50, 300, 300);  
        g2d.setPaint(Color.RED);  
        g2d.fillOval(150, 150, 100, 100);  
        g2d.setPaint(Color.ORANGE);  
        g2d.fillOval(250, 250, 80, 80);  
        g2d.setPaint(Color.PINK);  
        g2d.fillOval(350, 350, 60, 60);  
    }  
}