使用JAVA GUI画一个椭圆的代码

下面是使用JAVA GUI画一个椭圆的代码：

import java.awt.Color;
import java.awt.Graphics;
import javax.swing.JFrame;
import javax.swing.JPanel;

public class Oval extends JPanel {

public void paintComponent(Graphics g) {
super.paintComponent(g);
g.setColor(Color.RED);
g.drawOval(50, 50, 100, 200);
}

public static void main(String[] args) {
JFrame frame = new JFrame("Oval");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
Oval oval = new Oval();
frame.add(oval);
frame.setSize(300, 300);
frame.setVisible(true);
}
}