package 绘制图形;
//画二次曲线
import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.Toolkit;
import java.awt.geom.QuadCurve2D;

import javax.swing.JFrame;
import javax.swing.JPanel;



public class hyperbola extends JFrame{
    public static void main(String args[]) {
        new hyperbola();
    }
    public hyperbola() {
        Toolkit kit = Toolkit.getDefaultToolkit();
        Dimension screen = kit.getScreenSize();
        
        int wight = screen.width;
        int hight = screen.height;
        this.add(new DrawQuadCurve());
        this.setBounds(wight/4, hight/4, 400, 300);
        this.setDefaultCloseOperation(3);
        this.setVisible(true);
        
    }
    

}
class DrawQuadCurve extends JPanel{
    public void paint(Graphics g) {
        Graphics2D g2 = (Graphics2D)g;
//      对应的坐标分别为起始的x,y位置,控制点的x,y位置,结束点x,y位置
//      QuadCurve2D.Double与QuadCurve2D.Float都是画二次曲线的类,QuadCurve2D.Float更节省空间
        QuadCurve2D.Double quadCurve1 = new QuadCurve2D.Double(60,20,120,100,40,120);
        g2.draw(quadCurve1);
        QuadCurve2D.Double quadCurve2 = new QuadCurve2D.Double(180,20,120,100,180,120);
        g2.draw(quadCurve2);
        
    }
}

画二次曲线.png