Applet中的一个绘图问题

一下代码为何只绘出了圆弧，没有绘出矩形,感谢兄台赐教!
import javax.swing.JApplet;
import javax.swing.JComponent;
import java.awt.Color;
import java.awt.Graphics2D;
import java.awt.Container;
import java.awt.Graphics;
import java.awt.Rectangle;
import java.awt.geom.Rectangle2D;
import java.awt.geom.QuadCurve2D;public class ttt extends JApplet {
  // Initialize the applet
  public void init() {
                          // Create pane containing curves
    Container content = getContentPane();         // Get the content pane
    // Add the pane displaying the curves to the content pane for the applet
    content.add(new cPane());                  // BorderLayout.CENTER is default position
  }
  // Class defining a pane on which to draw
  class cPane extends JComponent {
    // Constructor
    public cPane() {
      quadCurve = new QuadCurve2D.Double(50,75,80,25,150,75);               // Create quadratic curve                         
    rect=new Rectangle2D.Double(50,50,50,50);//Create rectangle           
    }    public void paint(Graphics g) {
      Graphics2D g2D = (Graphics2D)g;                   // Get a 2D device context      // Draw the curves and rect
      g2D.setPaint(Color.BLUE);
      g2D.draw(rect);
      g2D.draw(quadCurve);
      
     
    }
  }
  // Points for quadratic curve
   // Points for cubic curve
   QuadCurve2D.Double quadCurve;    
  Rectangle2D.Double rect;                      // Quadratic curve
                       // Cubic curve
                     // Pane to contain curves
}