如下给出抽象图形类（Graph）和坐标点类Point。 1)设计其抽象子类二维图形（TwoDGraph），添加计算面积calArea()和周长calPerimeter()两个抽象方法； 2)从TwoDGraph类派生出圆形Circle，增加圆心centerPoint和半径radius属性，增加构造方法； 3)在Circle中重写calArea、calPerimeter和toString()方法 4)从TwoDGraph类派生出长方形Rectangle，增加左上角坐标leftPoint、长length和宽width属性，增加构造方法； 5)在Rectangle中重写calArea、calPerimeter和toString()方法 6)在Rectangle新增输出4个顶点坐标方法outputPoints() 7)在main方法中，测试Circle和Rectangle类中的方法。 public abstract class Graph { private String name; public String getName() { return name; } public void setName(String name) { this.name = name; } public String toString() { return ""; } } public class Point { private double x; private double y; public Point() { this(0,0); } public Point (double x,double y) { this.x = x; this.y = y; } public double getX() { return x; } public void setX(double x) { this.x = x; } public double getY() { return y; } public void setY(double y) { this.y = y; } public String toString() { return String.format("[%.2f, %.2f]", x,y); } }

好的，我已经理解了你的问题。以下是我的回答：

1. 二维图形类（TwoDGraph）的设计如下：

public abstract class TwoDGraph extends Graph {
    public abstract double calArea();
    public abstract double calPerimeter();
}

2. 圆形类（Circle）的设计如下：

public class Circle extends TwoDGraph {
    private Point centerPoint;
    private double radius;

    public Circle(String name, Point centerPoint, double radius) {
        setName(name);
        this.centerPoint = centerPoint;
        this.radius = radius;
    }

    public Point getCenterPoint() {
        return centerPoint;
    }

    public void setCenterPoint(Point centerPoint) {
        this.centerPoint = centerPoint;
    }

    public double getRadius() {
        return radius;
    }

    public void setRadius(double radius) {
        this.radius = radius;
    }

    @Override
    public double calArea() {
        return Math.PI * radius * radius;
    }

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

    @Override
    public String toString() {
        return "Circle{" +
                "name='" + getName() + '\'' +
                ", centerPoint=" + centerPoint +
                ", radius=" + radius +
                '}';
    }
}

3. 长方形类（Rectangle）的设计如下：

public class Rectangle extends TwoDGraph {
    private Point leftPoint;
    private double length;
    private double width;

    public Rectangle(String name, Point leftPoint, double length, double width) {
        setName(name);
        this.leftPoint = leftPoint;
        this.length = length;
        this.width = width;
    }

    public Point getLeftPoint() {
        return leftPoint;
    }

    public void setLeftPoint(Point leftPoint) {
        this.leftPoint = leftPoint;
    }

    public double getLength() {
        return length;
    }

    public void setLength(double length) {
        this.length = length;
    }

    public double getWidth() {
        return width;
    }

    public void setWidth(double width) {
        this.width = width;
    }

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

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

    @Override
    public String toString() {
        return "Rectangle{" +
                "name='" + getName() + '\'' +
                ", leftPoint=" + leftPoint +
                ", length=" + length +
                ", width=" + width +
                '}';
    }

    public void outputPoints() {
        Point rightPoint = new Point(leftPoint.getX() + length, leftPoint.getY());
        Point bottomPoint = new Point(leftPoint.getX(), leftPoint.getY() - width);
        Point rightBottomPoint = new Point(rightPoint.getX(), bottomPoint.getY());

        System.out.println("The four points of the rectangle are:");
        System.out.println(leftPoint + ", " + rightPoint + ", " + rightBottomPoint + ", " + bottomPoint);
    }
}

4. 在main方法中，我们可以进行如下测试：

public static void main(String[] args) {
    Point centerPoint = new Point(0, 0);
    Circle circle = new Circle("Circle1", centerPoint, 5);
    System.out.println(circle);
    System.out.println("Area: " + circle.calArea());
    System.out.println("Perimeter: " + circle.calPerimeter());

    Point leftPoint = new Point(0, 0);
    Rectangle rectangle = new Rectangle("Rectangle1", leftPoint, 6, 4);
    System.out.println(rectangle);
    System.out.println("Area: " + rectangle.calArea());
    System.out.println("Perimeter: " + rectangle.calPerimeter());
    rectangle.outputPoints();
}

输出结果如下：

Circle{name='Circle1', centerPoint=[0.00, 0.00], radius=5.0}
Area: 78.53981633974483
Perimeter: 31.41592653589793
Rectangle{name='Rectangle1', leftPoint=[0.00, 0.00], length=6.0, width=4.0}
Area: 24.0
Perimeter: 20.0
The four points of the rectangle are:
[0.00, 0.00], [6.00, 0.00], [6.00, -4.00], [0.00, -4.00]