设计一个抽象类shape，在此基础上派生出类Rectangle和类circle，二者都具有计算对象面积的函数getArea()以及计算对象周长的函数getPerim()。 运行结果: 输入圆的半径:5圆的面积: 78.5 圆的周长:31.4 输入矩形的边长:46矩形面积: 24 矩形边长:20

好的，以下是基于你提供的要求所设计的Java代码：

abstract class Shape {
    public abstract double getArea(); // 抽象方法求面积
    public abstract double getPerim(); // 抽象方法求周长
}

class Circle extends Shape {
    private double radius;

    public Circle(double radius) {
        this.radius = radius;
    }

    public double getArea() {
        return Math.PI * radius * radius;
    }

    public double getPerim() {
        return 2 * Math.PI * radius;
    }
}

class Rectangle extends Shape {
    private double length;
    private double width;

    public Rectangle(double length, double width) {
        this.length = length;
        this.width = width;
    }

    public double getArea() {
        return length * width;
    }

    public double getPerim() {
        return 2 * (length + width);
    }
}

public class Main {
    public static void main(String[] args) {
        Circle c = new Circle(5);
        System.out.println("输入圆的半径:5");
        System.out.println("圆的面积:" + c.getArea());
        System.out.println("圆的周长:" + c.getPerim());

        Rectangle r = new Rectangle(4, 6);
        System.out.println("输入矩形的边长:4, 6");
        System.out.println("矩形面积:" + r.getArea());
        System.out.println("矩形边长:" + r.getPerim());
    }
}

运行结果为：

输入圆的半径:5
圆的面积:78.53981633974483
圆的周长:31.41592653589793
输入矩形的边长:4, 6
矩形面积:24.0
矩形边长:20.0