public static void main(String[] args) {


    ArrayList<Student> list = new ArrayList();
    Scanner sc = new Scanner(System.in);
    lo:
    while (true) {
        System.out.println("~~~~~~~~欢迎来到学生管理系统~~~~~~~~");
        System.out.println("1.添加学生\t" + "\t2.删除学生");
        System.out.println("3.修改学生\t" + "\t4.查看所有学生");
        System.out.println("5.按姓名查看学生"+"\t6.退出");
        System.out.println("请输入需要操作功能的序号:");
        String index = sc.next();
        switch (index) {
            case "1":
                //添加学生
                addStudent(list);
                break;
            case "2":
                //删除学生
                deleteStudent(list);
                break;
            case "3":
                //修改学生
                updateStudent(list);
                break;
            case "4":
                //查看所有学生
                queryStudents(list);
                break;
            case "5":
                //按姓名查看学生
                nameQueryStudent(list);
                break;
            case "6":
                //退出系统
                break lo;
            default:
                System.out.println("您输入的序号有误,请检查后重试!");
                break;
        }
    }
}

//按姓名查看学生信息
private static void nameQueryStudent(ArrayList<Student> list) {
    if (list.size() == 0) {
        System.out.println("无信息,请添加后重新查询");
        return;
    }
    Scanner sc = new Scanner(System.in);
    System.out.println("请输入学生姓名:");
    String name = sc.next();
    for (int i = 0; i < list.size(); i++) {
        Student stu = list.get(i);
        if(stu.getName().equals(name)){
            System.out.println(stu.getId() + "\t" + stu.getName() + "\t" +
                    stu.getAge() + "岁" + "\t" + stu.getPlace());
        }else{
            System.out.println("查无此人!");
            return;
        }
    }
}

//查看所有学生信息
private static void queryStudents(ArrayList<Student> list) {
    if (list.size() == 0) {
        System.out.println("无信息,请添加后重新查询");
        return;
    }
    System.out.println("学号\t姓名\t年龄\t居住地");
    for (int i = 0; i < list.size(); i++) {
        Student stu = list.get(i);
        System.out.println(stu.getId() + "\t" + stu.getName() + "\t" +
                stu.getAge() + "岁" + "\t" + stu.getPlace());
    }
}

//修改学生信息
private static void updateStudent(ArrayList<Student> list) {
    if (list.size() == 0) {
        System.out.println("无信息,请添加后修改");
        return;
    }
    Scanner sc = new Scanner(System.in);
    System.out.println("请输入学号:");
    String id = sc.next();
    int index = getIndex(list, id);
    if(index==-1){
        System.out.println("该学号不存在!");
    }else{
        System.out.println("请输入学生姓名:");
        String name = sc.next();
        System.out.println("请输入学生年龄:");
        int age = sc.nextInt();
        System.out.println("请输入学生居住地:");
        String place = sc.next();

        Student stu =new Student(id,name,age,place);
        list.set(index,stu);
        System.out.println("修改成功");
    }
}

//删除学生信息
private static void deleteStudent(ArrayList<Student> list) {
    if (list.size() == 0) {
        System.out.println("无信息,请添加后删除");
        return;
    }
    Scanner sc = new Scanner(System.in);
    String id;
    while (true) {
        System.out.println("请输入学号:");
        id = sc.next();
        int index = getIndex(list, id);
        if (index == -1) {
            System.out.println("该学号不存在!");
        } else {
            list.remove(index);
            System.out.println("删除成功");
            break;
        }
    }
}

//添加学生
private static void addStudent(ArrayList<Student> list) {
    Scanner sc = new Scanner(System.in);
    String id;
    while (true) {
        System.out.println("请输入学号:");
        id = sc.next();
        int index = getIndex(list, id);
        if (index == -1) {
            break;
        }
    }

    System.out.println("请输入学生姓名:");
    String name = sc.next();
    System.out.println("请输入学生年龄:");
    int age = sc.nextInt();
    System.out.println("请输入学生居住地:");
    String place = sc.next();

    Student stu = new Student(id, name, age, place);

    list.add(stu);
    System.out.println("添加成功");
}

/***
 * getIndex : 接收一个集合对象,接收一个学生学号
 *
 * 查找这个学号,在集合中出现的索引位置
 */
private static int getIndex(ArrayList<Student> list, String id) {
    int index = -1;
    for (int i = 0; i < list.size(); i++) {
        Student stu = list.get(i);
        if (stu.getId().equals(id)) {
            index = i;
        }
    }
    return index;
}

public class Student {
    private String id;
    private String name;
    private int age;
    private String place;

    public Student() {
    }

    public Student(String id, String name, int age, String place) {
        this.id = id;
        this.name = name;
        this.age = age;
        this.place = place;
    }

    public String getId() {
        return id;
    }

    public void setId(String id) {
        this.id = id;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public int getAge() {
        return age;
    }

    public void setAge(int age) {
        this.age = age;
    }

    public String getPlace() {
        return place;
    }

    public void setPlace(String place) {
        this.place = place;
    }
}