① 定义一个Point类，它包含两个属性：横坐标x和纵坐标y，和一个构造函数Point(double x, double y)； ② 定义一个接口Shape，它包含两个抽象方法：计算面积的方法double computeArea()和计算周长的方法double computeDiameter()；定义一个矩形Rectangle，它实现了接口Shape，并包含四个Point类型的私有属性A、B、C、D。分别为这四个属性定义getter和setter方法。定义Rectangle的一个构造函数Rectangle(Point A, Point B, Point C, Point D), 并验证这四个点是否能构成矩形（AB=CD, AD=BC, AB垂直于BC），如果不能构成矩形，为用户输出提示信息。另外，Rectangle中包含一个公有实例方法draw（），它负责在控制台打印信息“这是一个矩形”；定义一个公有类型ShapeTest，包含main方法。在main方法中，初始化一个矩、，并输出它的面积和周长。

好的，我理解了你的问题。以下是对应的Java代码：

public class Point {
    private double x;
    private double y;
    
    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 interface Shape {
    public abstract double computeArea();
    public abstract double computeDiameter();
}

public class Rectangle implements Shape {
    private Point A;
    private Point B;
    private Point C;
    private Point D;
    
    public Rectangle(Point A, Point B, Point C, Point D) {
        if (checkRectangle(A, B, C, D)) {
            this.A = A;
            this.B = B;
            this.C = C;
            this.D = D;
        } else {
            System.out.println("这四个点不能构成矩形！");
        }
    }
    
    private boolean checkRectangle(Point A, Point B, Point C, Point D) {
        double AB = Math.sqrt(Math.pow(A.getX() - B.getX(), 2) + Math.pow(A.getY() - B.getY(), 2));
        double CD = Math.sqrt(Math.pow(C.getX() - D.getX(), 2) + Math.pow(C.getY() - D.getY(), 2));
        double AD = Math.sqrt(Math.pow(A.getX() - D.getX(), 2) + Math.pow(A.getY() - D.getY(), 2));
        double BC = Math.sqrt(Math.pow(B.getX() - C.getX(), 2) + Math.pow(B.getY() - C.getY(), 2));
        double AB_CD = Math.abs(AB - CD);
        double AD_BC = Math.abs(AD - BC);
        double cos = (A.getX() - B.getX()) * (C.getX() - B.getX()) + (A.getY() - B.getY()) * (C.getY() - B.getY());
        if (AB_CD < 0.0001 && AD_BC < 0.0001 && cos < 0.0001) {
            return true;
        } else {
            return false;
        }
    }
    
    public Point getA() {
        return A;
    }
    
    public void setA(Point A) {
        this.A = A;
    }
    
    public Point getB() {
        return B;
    }
    
    public void setB(Point B) {
        this.B = B;
    }
    
    public Point getC() {
        return C;
    }
    
    public void setC(Point C) {
        this.C = C;
    }
    
    public Point getD() {
        return D;
    }
    
    public void setD(Point D) {
        this.D = D;
    }
    
    @Override
    public double computeArea() {
        double AB = Math.sqrt(Math.pow(A.getX() - B.getX(), 2) + Math.pow(A.getY() - B.getY(), 2));
        double BC = Math.sqrt(Math.pow(B.getX() - C.getX(), 2) + Math.pow(B.getY() - C.getY(), 2));
        return AB * BC;
    }
    
    @Override
    public double computeDiameter() {
        double AB = Math.sqrt(Math.pow(A.getX() - B.getX(), 2) + Math.pow(A.getY() - B.getY(), 2));
        double BC = Math.sqrt(Math.pow(B.getX() - C.getX(), 2) + Math.pow(B.getY() - C.getY(), 2));
        double CD = Math.sqrt(Math.pow(C.getX() - D.getX(), 2) + Math.pow(C.getY() - D.getY(), 2));
        double AD = Math.sqrt(Math.pow(A.getX() - D.getX(), 2) + Math.pow(A.getY() - D.getY(), 2));
        return AB + BC + CD + AD;
    }
    
    public void draw() {
        System.out.println("这是一个矩形");
    }
}

public class ShapeTest {
    public static void main(String[] args) {
        Point A = new Point(0, 0);
        Point B = new Point(0, 2);
        Point C = new Point(3, 2);
        Point D = new Point(3, 0);
        
        Rectangle rectangle = new Rectangle(A, B, C, D);
        if (rectangle.getA() != null) {
            System.out.println("矩形的面积为：" + rectangle.computeArea());
            System.out.println("矩形的周长为：" + rectangle.computeDiameter());
            rectangle.draw();
        }
    }
}

希望这个代码能够解决你的问题！