Java定义一个非公有的抽象类

我也不太会, 大概是这样吧.
abstract class shapeClass {
    String shapeType;
    abstract float 周长();
    abstract float 面积();
    void setShapeType(String type){ shapeType = type; };
    String getShapeType(){return shapeType;}
    void printShapeType(){System.out.println("shapType: " + shapeType);}
}

class rectangle extends shapeClass{
    float width;
    float height;
    String shapeType;
    public void shapeClass(){
        this.shapeType = "矩形";
    }
    public float getWidth() {
        return width;
    }
    public void setWidth(float width) {
        this.width = width;
    }
    public float getHeight() {
        return height;
    }
    public void setHeight(float height) {
        this.height = height;
    }
    public String getShapeType() {
        return shapeType;
    }
    public void setShapeType(String shapeType) {
        this.shapeType = shapeType;
    }
    float 周长() {
        return (width + height) * 2;
    };
    float 面积() {
        return (width * height);
    }
    void printShapeType(){System.out.println("shapType: " + shapeType);}
    public String toString() {
        return "\twidth: " + width + "\theight: " +height + "\tgirth: " + 周长() + "\tarea: " + 面积();
    }
    void print() {
        System.out.println(this);
    }
}

public class 文件名{
    public static void main(String[] args) {
        //如果需要运行时输入, 则使用System.in.read();函数有几个原型, 可以自己写一个read函数
        循环:{
            打印菜单: 1. 矩形, 2退出
            输入选择: menuId;  
            如果ID==1{
                实例化rectangle类,
                打印输入长,宽;
                获取输入, 判断是否合法, 如果合法{
                    输出形状, 长,宽,
                    调用 周长和面积函数,并打印结果
                }
            }else if ID==2 {
                退出;
            }
        }
    }
}