维的拼音怎么读:[菜鸟求助]java编程：关于Applet窗口画矩形

按照一本编程教材的做法，有一下代码：
import java.awt.*;
import java.applet.Applet;
public class RectDemo extends Applet
{public void paint(Graphics g)
{g.drawRect(20,20,60,60);
g.fillRect(120,20,60,60);
g.setColor(Color.red);
g.drawRoundRect(220,20,60,60,20,20);
g.fillRoundRect(320,20,60,60,20,20);
g.setColor(Color.pink);
g.fill3DRect(420,20,60,60,true);
g.fill3DRect(520,20,60,60,false);
}
}

可它就是通不过编译，出现如下错误提示：
RectDemo.java:7: cannot resolve symbol
symbol : method drawRect (int,int,int,int)
location: class Graphics
{g.drawRect(20,20,60,60);
^
RectDemo.java:8: cannot resolve symbol
symbol : method fillRect (int,int,int,int)
location: class Graphics
g.fillRect(120,20,60,60);
^
RectDemo.java:9: cannot resolve symbol
symbol : method setColor (java.awt.Color)
location: class Graphics
g.setColor(Color.red);
^
RectDemo.java:10: cannot resolve symbol
symbol : method drawRoundRect (int,int,int,int,int,i
location: class Graphics
g.drawRoundRect(220,20,60,60,20,20);
^
RectDemo.java:11: cannot resolve symbol
symbol : method fillRoundRect (int,int,int,int,int,i
location: class Graphics
g.fillRoundRect(320,20,60,60,20,20);
^
RectDemo.java:12: cannot resolve symbol
symbol : method setColor (java.awt.Color)
location: class Graphics
g.setColor(Color.pink);
^
RectDemo.java:13: cannot resolve symbol
symbol : method fill3DRect (int,int,int,int,boolean)
location: class Graphics
g.fill3DRect(420,20,60,60,true);
^
RectDemo.java:14: cannot resolve symbol
symbol : method fill3DRect (int,int,int,int,boolean)
location: class Graphics
g.fill3DRect(520,20,60,60,false);
^
8 errors

请各位高手看看，问题出在哪啊？先谢了！