不能导入自己建立的package有关问题

package Moolgu;import Mooly.*;public class Main {    public static void main(String args[]){    Rectangle circle = new Rectangle(1.0,2.0);    }}---------------------------------------package Mooly;public class GetClass{    }abstract class Graph{     abstract void Area();}class Circle extends Graph{    double R;    Circle (double r){R=r;}    void Area(){        double Pi=3.1415;         System.out.println("圆的周长为:"+2*Pi*R);        System.out.println("圆的面积为:"+Pi*R*R);    }}class Triangle extends Graph{    double s;    double X,Y,Z;    Triangle(double x,double y,double z){X=x;Y=y;Z=z;}        void Area(){                s=(X+Y+Z);        System.out.println("三角形的周长为:"+(X+Y+Z));        System.out.println("圆的面积为:"+Math.sqrt(s*(s-X)*(s-Y)*(s-Z)));    }}class Rectangle extends Graph{    double X,Y;    Rectangle(double x,double y){X=x;Y=y;}    void Area(){        System.out.println("圆的周长为:"+X*Y);    }}