一、 实验目的：掌握类的创建，掌握对象的创建和使用
二、实验内容：
1、定义一个student类，包括属性{学号，姓名，年龄，性别，专业}； 方法{给他两个点，能够求距离，给他三个点能判断是否够构成三角形，给他若干点能够求出距离最短的两个点}
2、 编写一个测试类，测试上述内容

工程图：

second包

//Point类
package second;

public class Point {
    int x;
    int y;
    public Point() {}
    public Point(int x, int y) {
        super();
        this.x = x;
        this.y = y;
    }
    @Override
    public String toString() {
        return "Point [x=" + x + ", y=" + y + "]";
    };          
}
//Student类
package second;

public class Student {
    private String number;
    private String name;
    private String sex;
    private int age;
    private String major;
    //构造方法
    //源码->使用字段生成构造函数
    public Student() {};
    public Student(String number, String name, String sex, int age, String major) {
        super();
        this.number = number;
        this.name = name;
        this.sex = sex;
        this.age = age;
        this.major = major;
    }
    //源码->生成toString()
    @Override
    public String toString() {
        return "Student [number=" + number + ", name=" + name + ", sex=" + sex + ", age=" + age + ", major=" + major
                + "]";
    }
    //源码->生成Getter和Setter方法
    public String getNumber() {
        return number;
    }
    public void setNumber(String number) {
        this.number = number;
    }
    public String getName() {
        return name;
    }
    public void setName(String name) {
        this.name = name;
    }
    public String getSex() {
        return sex;
    }
    public void setSex(String sex) {
        this.sex = sex;
    }
    public int getAge() {
        return age;
    }
    public void setAge(int age) {
        this.age = age;
    }
    public String getMajor() {
        return major;
    }
    public void setMajor(String major) {
        this.major = major;
    }
    //两点之间的距离
    public double twoPointDistance(Point p1,Point p2) {
        return Math.sqrt((p1.x-p2.x)*(p1.x-p2.x)+(p1.y-p2.y)*(p1.y-p2.y));
    }
    //三个点构成三角形
    public boolean judgeTriangle(Point p1,Point p2,Point p3) {
        boolean flag = false;
        double c1 = twoPointDistance(p1,p2);
        double c2 = twoPointDistance(p1,p3);
        double c3 = twoPointDistance(p2,p3);
        if(c1+c2 > c3 || c1+c3 > c2 || c2+c3 > c1) flag = true;
        return flag;
    }
    //求平面内最近的两个点之间的距离
    //暴力法(分治法)
    public double minDistance(Point [] p) {
        double MinDistance = Double.MAX_VALUE;
        for (int i=0; i< p.length-1; i++) {
            for (int j=i+1; j<=p.length-1; j++) {
                double PointDistance = twoPointDistance(p[i],p[j]);
                if (PointDistance < MinDistance) 
                    MinDistance = PointDistance;
            }
        }
        return MinDistance;
    }
}
//Test类
package second;

public class Test {
    public static void main(String[] args) {
        Student stu1 = new Student("10001","张三","男",20,"计算机");
        Student stu2 = new Student();
        System.out.println(stu1);        
        stu2.setNumber("10002");
        stu2.setName("李四");
        stu2.setSex("男");
        stu2.setAge(20);
        stu2.setMajor("计算机");
        System.out.println(stu2);
        Point p1 = new Point(2,2);
        Point p2 = new Point(2,3);
        Point p3 = new Point(2,4);
        Point p4 = new Point(2,5);
        System.out.println(stu1.twoPointDistance(p1,p2));
        System.out.println( stu1.judgeTriangle(p1,p2,p3));
        Point [] p = {p1,p2,p3,p4};
        for(int i = 0;i < p.length;i++) {
            System.out.println(p[i]);
        }
        System.out.println(stu1.minDistance(p));
        /*
        stu2.number = "10002";
        stu2.name = "李四";
        stu2.sex = "男";
        stu2.age = 20;
        stu2.major = "计算机";
        */
    }

}   

//运行结果
Student [number=10001, name=张三, sex=男, age=20, major=计算机]
Student [number=10002, name=李四, sex=男, age=20, major=计算机]
1.0
true
Point [x=2, y=2]
Point [x=2, y=3]
Point [x=2, y=4]
Point [x=2, y=5]
1.0