长方形和圆形都属于几何图形，都有周长和面积，并且它们都有自己的周长和面积计算公式。使用抽象类的知识设计一个程序，可以计算不同图形的面积和周长。（自用方便版）

import java.util.Scanner;
public class driver{
    public static void main(String[] args) {
        ShapeCalculate s=new ShapeCalculate();
        s.circle();
        s.rectangle();
    }
}
abstract class Shape{
    abstract void zhouchang();
    abstract void mianji();
}
class circle extends Shape{
    double r;
    public double getR(){
        return r;
    }
    public void setR(double r){
        this.r=r;
    }
    double PI=3.14;
    void zhouchang() {
        double zhouchang=2*r*PI;
        System.out.println("圆的周长为"+zhouchang);
    }
    void mianji() {
        double mianji=PI*r*r;
        System.out.println("圆的面积为"+mianji);
    }
    public circle(double r){
        this.r=r;
    }
}
class rectangle extends Shape{
    int chang;
    int kuan;
    public int getChang(){
        return chang;
    }
    public void setChang(int chang){
        this.chang=chang;
    }
    public int getKuan(){
        return kuan;
    }
    public void setKuan(int kuan){
        this.kuan=kuan;
    }
    void zhouchang() {
        int zhouchang=(chang+kuan)*2;
        System.out.println("长方形周长为"+zhouchang);
    }
    void mianji() {
        int mianji=chang*kuan;
        System.out.println("长方形面积为"+mianji);
    }
    public rectangle(int chang,int kuan){
        this.chang=chang;
        this.kuan=kuan;
    }
}
class ShapeCalculate{
    Scanner sc=new Scanner(System.in);
    void circle() {
        System.out.println("输入圆的半径");
        int x=sc.nextInt();
           circle c=new circle(x);
           c.mianji();
           c.zhouchang();
    }
    void rectangle(){
        System.out.println("输入长方形的长");
        int x=sc.nextInt();
        System.out.println("输入长方形的宽");
        int y=sc.nextInt();
        rectangle r=new rectangle(x,y);
        r.zhouchang();
        r.mianji();
    }

}