Java1.设计一个Point类表示平面坐标系中的点。该类包括私有的double型的x和y属性。两个构造方法，一个是无参的构造方法，该方法中x和y的值为0；另外一个构造方法包含两个参数，分别为x和y赋值。为x和y属性提供setter和getter方法，重写Object类的hashcode和equals方法。最后重写Object类的toString（）方法。编写一个类，包含如下功能：（1）定义一个数组，数组的长度是50，数组元素是Point的对象。Point对象的x和y值随机赋值。（2）判断数组中是否有两个相等的点（点的x和y的值相等）（3）指定一个点，求该点到其他点的距离（两种理解）（4）求距离最近的两个点。

Point类的实现：

import java.util.Objects;

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

    public Point() {
        this.x = 0;
        this.y = 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;
    }

    @Override
    public int hashCode() {
        return Objects.hash(x, y);
    }

    @Override
    public boolean equals(Object obj) {
        if (this == obj) return true;
        if (obj == null || getClass() != obj.getClass()) return false;
        Point point = (Point) obj;
        return Double.compare(point.x, x) == 0 && Double.compare(point.y, y) == 0;
    }

    @Override
    public String toString() {
        return "Point{" +
                "x=" + x +
                ", y=" + y +
                '}';
    }
}

使用Point类的类的实现：

import java.util.Arrays;
import java.util.Random;

public class PointTest {
    public static void main(String[] args) {
        Point[] points = new Point[50];
        Random random = new Random();
        for (int i = 0; i < points.length; i++) {
            double x = random.nextDouble() * 100;
            double y = random.nextDouble() * 100;
            points[i] = new Point(x, y);
        }

        // 判断数组中是否有两个相等的点
        boolean hasEqualPoints = false;
        for (int i = 0; i < points.length - 1; i++) {
            for (int j = i + 1; j < points.length; j++) {
                if (points[i].equals(points[j])) {
                    hasEqualPoints = true;
                    System.out.println("数组中有两个相等的点：" + points[i] + "，" + points[j]);
                    break;
                }
            }
            if (hasEqualPoints) {
                break;
            }
        }
        if (!hasEqualPoints) {
            System.out.println("数组中没有两个相等的点。");
        }

        // 指定一个点，求该点到其他点的距离
        Point p = new Point(50, 50);
        System.out.println("点" + p + "到其他点的距离：");
        for (Point point : points) {
            double distance = getDistance(p, point);
            System.out.println("  " + point + "：" + distance);
        }

        // 求距离最近的两个点
        double minDistance = Double.MAX_VALUE;
        Point minPoint1 = null;
        Point minPoint2 = null;
        for (int i = 0; i < points.length - 1; i++) {
            for (int j = i + 1; j < points.length; j++) {
                double distance = getDistance(points[i], points[j]);
                if (distance < minDistance) {
                    minDistance = distance;
                    minPoint1 = points[i];
                    minPoint2 = points[j];
                }
            }
        }
        System.out.println("距离最近的两个点：" + minPoint1 + "，" + minPoint2);
    }

    /**
     * 计算两个点之间的距离
     *
     * @param p1 点1
     * @param p2 点2
     * @return 距离
     */
    private static double getDistance(Point p1, Point p2) {
        double dx = p1.getX() - p2.getX();
        double dy = p1.getY() - p2.getY();
        return Math.sqrt(dx * dx + dy * dy);
    }
}