在线急等!!!!
如何将一个3D画布加载到一个JPANEL里面
class   SanWeiTuXingGUI   extends   JPanel   implements   ActionListener
  {
protected   Canvas3D   canvas;
JButton   back;
public   SanWeiTuXingGUI()
{
back=new   JButton( "返回 ");
GraphicsConfigTemplate3D   template   =   new   GraphicsConfigTemplate3D();
                template.setDoubleBuffer(template.REQUIRED);
                GraphicsEnvironment   env   =GraphicsEnvironment.getLocalGraphicsEnvironment();
                GraphicsDevice   dev   =   env.getDefaultScreenDevice();
                canvas   =   new   Canvas3D(dev.getBestConfiguration(template));
                canvas.setStereoEnable(false);
                canvas.setDoubleBufferEnable(true);
                canvas.setVisible(true);
                this.setLayout(new   BorderLayout());
                this.add(canvas, "Center ");
                this.add(back, "South ");
               
}
public   void   actionPerformed(ActionEvent   e)
{
layout.show(pCenter, "WELCOME   MODE ");
}

    }
}
这么做为什么画布显示不出来??????

------解决方案--------------------
class bb
{
public static void main(String [] args)
{

int x=-7,y=9;
int sum = getArea(x,y);
System.out.println(sum);

}
static int getArea(int x,int y)
{
if(x <0 || y <0)
{
System.out.println( "有负数！ ");

}
int z;
z=x*y;
return z;
}
}
这样就行啦！！