设计一个点Point类，圆类Circle继承点类，分别实现clone方法，实现一个测试类来实现Circle的自我复制。（提示：实现clone接口）


public class Point implements Cloneable
{
    private int x;
    private int y;
    public Point()
    {
    }
    public Point(int X, int Y)
    {
        x=X;
        y=Y;
    }
    public void setX(int X)
    {
        x=X;
    }
    public void setY(int Y)
    {
        y=Y;
    }
    public int getX()
    {
        return x;
    }
    public int getY()
    {
        return y;
    }
    public Object clone()
    {
        Point obj=null;
        try
        {
            obj =(Point)super.clone();
        }
        catch (CloneNotSupportedException e)
        {
            e.printStackTrace();
        }
        return obj;
    }
}

public class Circle extends Point implements Cloneable
{
    private int r;
    public Circle()
    {
    }
    public void setR(int R)
    {
        r=R;
    }
    public int getR()
    {
        return r;
    }
    public Object clone()
    {
        Circle o=null;
        try
        {
            o =(Circle)super.clone();
        }
        catch (CloneNotSupportedException e)
        {
            e.printStackTrace();
        }
        return o;
    }
}
  Point类编译成功，但Circle类失败了，显示：
在相应的try语句主体中不能抛出异常  java.lang.CloneNotSuppotedException