Java Graphics - 如何绘制立方曲线CubicCurve2D.Float

import java.awt.Frame;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.geom.CubicCurve2D;

public class MainClass extends Frame {
  public static void main(String[] args) {
    (new MainClass()).setVisible(true);
  }

  public MainClass() {
    super("Shape Sampler");
    setSize(400, 550);
  }

  public void paint(Graphics g) {
    Graphics2D g2d = (Graphics2D) g;

    CubicCurve2D cubcurve = new CubicCurve2D.Float(30, 400, 150, 400, 200, 500, 350, 450);
    g2d.draw(cubcurve);
  }
}