创建学生类

/**
 * 学生类
 * @author DS_xiao_jian
 * @date 2023.04.09 下午 03:19:00
 */
public class Student {
    /**
     * 学号
     */
    private String id;
    /**
     *姓名
     */
    private String name;
    /**
     * 年龄
     */
    private int age;
    /**
     * 生日
     */
    private String birth;

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

    public Student() {
    }

    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 getBirth() {
        return birth;
    }

    public void setBirth(String birth) {
        this.birth = birth;
    }

    @Override
    public String toString() {
        return "Student{" +
                "id='" + id + '\'' +
                ", name='" + name + '\'' +
                ", age=" + age +
                ", birth='" + birth + '\'' +
                '}';
    }
}

管理员类

/**
 * 管理员类
 * @author DS_xiao_jian
 * @date 2023.04.09 下午 03:35:53
 */
public class Admin {
    /**
     * 用户名
     */
    private String username = "root";
    /**
     * 密码
     */
    private String passworld = "root";

    public String getUsername() {
        return username;
    }

    public String getPassworld() {
        return passworld;
    }
}

输出菜单与功能

import java.util.ArrayList;
import java.util.Scanner;

/**
 * 学生管理系统
 *
 * @author DS_xiao_jian
 * @date 2023.04.09 下午 03:39:15
 */
public class StuManagement {
    public static void main(String[] args) {
        //创建管理员对象
        Admin admin = new Admin();
        Scanner scanner = new Scanner(System.in);
        System.out.println("请输入用户名：");
        String username = scanner.next().trim();
        if (!username.equals(admin.getUsername())) {
            System.out.println("用户名错误");
            return;
        }
        System.out.println("请输入密码：");
        String password = scanner.next().trim();
        if (!password.equals(admin.getPassworld())) {
            System.out.println("密码错误");
            return;
        }
        ArrayList<Student> list = new ArrayList<>();
        boolean flag = true;
        while (flag) {
            // 1. 搭建主界面菜单
            System.out.println("--------欢迎来到学生管理系统--------");
            System.out.println("1 添加学生");
            System.out.println("2 删除学生");
            System.out.println("3 修改学生");
            System.out.println("4 查看学生");
            System.out.println("5 退出");
            System.out.println("请输入您的选择:");
            int choice = scanner.nextInt();
            switch (choice) {
                case 1:
                    System.out.println("添加学生");
                    addStu(list);
                    System.out.println("本次添加完后，系统共有" + list.size() + "个学生");
                    break;
                case 2:
                    System.out.println("删除学生");
                    removeStu(list);
                    break;
                case 3:
                    System.out.println("修改学生");
                    updateStu(list);
                    break;
                case 4:
                    System.out.println("查看学生");
                    viewAllStu(list);
                    break;
                case 5:
                    System.out.println("退出");
                    flag = false;
                    break;
                default:
                    System.out.println("没有此功能");
                    break;
            }

        }
    }

    /**
     * 修改学生信息
     *
     * @param list 要修改的集合
     */
    public static void updateStu(ArrayList<Student> list) {
        Scanner scanner = new Scanner(System.in);
        System.out.println("请输入要删除学生的学号");
        String id = scanner.next();
        for (int i = 0; i < list.size(); i++) {
            Student student = list.get(i);
            if (id.equals(student.getId())) {
                System.out.println("请修改学生的姓名");
                student.setName(scanner.next());
                System.out.println("请修改学生的年龄");
                student.setAge(scanner.nextInt());
                System.out.println("请修改学生的生日");
                student.setBirth(scanner.next());
                list.set(i, student);
            }
        }
    }

    /**
     * 删除学生
     *
     * @param list 要删除的集合
     */
    public static void removeStu(ArrayList<Student> list) {
        Scanner scanner = new Scanner(System.in);
        System.out.println("请输入要删除学生的学号");
        String id = scanner.next();
        for (int i = 0; i < list.size(); i++) {
            Student student = list.get(i);
            if (id.equals(student.getId())) {
                list.remove(i);
            }

        }
    }

    /**
     * 查看所有学生
     *
     * @param list 要查看的集合
     */
    public static void viewAllStu(ArrayList<Student> list) {
        for (int i = 0; i < list.size(); i++) {
            System.out.println(list.get(i));
        }
    }

    /**
     * 添加学生
     *
     * @param list 要添加到的集合
     */
    public static void addStu(ArrayList<Student> list) {
        Scanner scanner = new Scanner(System.in);
        Student student = new Student();
        System.out.println("请录入学生的学号");
        student.setId(scanner.next());
        System.out.println("请录入学生的姓名");
        student.setName(scanner.next());
        System.out.println("请录入学生的年龄");
        student.setAge(scanner.nextInt());
        System.out.println("请录入学生的生日");
        student.setBirth(scanner.next());
        list.add(student);
    }
}