用Java分别编写两个类Point2D,Point3D来表示二维空间和三维空间的点，使之满足以下要求

1.类的定义

Point2D类：

public class Point2D {
    private double x;
    private double y;

    public Point2D(double x, double y) {
        this.x = x;
        this.y = y;
    }

    public double getX() {
        return x;
    }

    public double getY() {
        return y;
    }

    public void setX(double x) {
        this.x = x;
    }

    public void setY(double y) {
        this.y = y;
    }

    public String toString() {
        return "(" + x + ", " + y + ")";
    }
}

Point3D类：

public class Point3D {
    private double x;
    private double y;
    private double z;

    public Point3D(double x, double y, double z) {
        this.x = x;
        this.y = y;
        this.z = z;
    }

    public double getX() {
        return x;
    }

    public double getY() {
        return y;
    }

    public double getZ() {
        return z;
    }

    public void setX(double x) {
        this.x = x;
    }

    public void setY(double y) {
        this.y = y;
    }

    public void setZ(double z) {
        this.z = z;
    }

    public String toString() {
        return "(" + x + ", " + y + ", " + z + ")";
    }
}

2.测试代码

Point2D测试代码：

public class Point2DTest {
    public static void main(String[] args) {
        Point2D p = new Point2D(3.0, 4.0);
        System.out.println(p);  // 输出 (3.0, 4.0)
        p.setX(5.0);
        System.out.println(p);  // 输出 (5.0, 4.0)
    }
}

Point3D测试代码：

public class Point3DTest {
    public static void main(String[] args) {
        Point3D p = new Point3D(3.0, 4.0, 5.0);
        System.out.println(p);  // 输出 (3.0, 4.0, 5.0)
        p.setX(6.0);
        System.out.println(p);  // 输出 (6.0, 4.0, 5.0)
    }
}

以上代码分别实现了二维空间和三维空间的点的表示，并且满足了题目要求。