定义Shape类表示一般二维图形。Shape具有抽象方法area和perimeter，分别计算形状的面积和周长。试定义二维形状类矩形、三角形、圆形，这些均为Shape类的子类，并计算出这些形状的面积和周长，打印输出相关信息。用JAVA写

首先，我们定义一个名为`Shape`的抽象类，包含两个抽象方法`area()`和`perimeter()`，代表通用的面积和周长计算：

import java.util.Random;

abstract class Shape {
    abstract double area();
    abstract double perimeter();

    public void printInfo() {
        System.out.println("Shape Information:");
        System.out.println("Area: " + area());
        System.out.println("Perimeter: " + perimeter());
    }
}

接下来，我们会创建三个具体的形状子类：`Rectangle`, `Triangle`, 和 `Circle`，它们分别覆盖`Shape`的抽象方法：

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

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

    @Override
    double area() {
        return length * width;
    }

    @Override
    double perimeter() {
        return 2 * (length + width);
    }

    @Override
    public void printInfo() {
        super.printInfo();
        System.out.println("Rectangle: Length = " + length + ", Width = " + width);
    }
}

class Triangle extends Shape {
    private double base;
    private double height;

    public Triangle(double base, double height) {
        this.base = base;
        this.height = height;
    }

    @Override
    double area() {
        return 0.5 * base * height;
    }

    @Override
    double perimeter() {
        // 这里假设是等腰三角形，如果有不同类型三角形需要提供对应方法
        double side = Math.random(); // 假设边长为随机数
        return side + base + side;
    }

    @Override
    public void printInfo() {
        super.printInfo();
        System.out.println("Triangle: Base = " + base + ", Height = " + height);
    }
}

class Circle extends Shape {
    private double radius;

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

    @Override
    double area() {
        return Math.PI * Math.pow(radius, 2);
    }

    @Override
    double perimeter() {
        return 2 * Math.PI * radius;
    }

    @Override
    public void printInfo() {
        super.printInfo();
        System.out.println("Circle: Radius = " + radius);
    }
}

public class Main {
    public static void main(String[] args) {
        Random random = new Random();

        Shape rectangle = new Rectangle(5, 7);
        Shape triangle = new Triangle(random.nextDouble(), random.nextDouble());
        Shape circle = new Circle(random.nextDouble());

        rectangle.printInfo();
        triangle.printInfo();
        circle.printInfo();
    }
}

这个程序会生成并打印每个形状的面积和周长，以及其特定属性，如矩形的长度和宽度、三角形的底和高、以及圆的半径。