Java输出一个学生成绩管理系统

好的，以下是一个简单的 Java 学生成绩管理系统的代码示例：

import java.util.*;

public class Main {
    public static void main(String[] args) {
        Scanner input = new Scanner(System.in);
        List<Student> students = new ArrayList<>();

        while (true) {
            System.out.println("请选择操作：");
            System.out.println("1. 添加学生");
            System.out.println("2. 查看所有学生");
            System.out.println("3. 查看学生信息");
            System.out.println("4. 修改学生信息");
            System.out.println("5. 删除学生信息");
            System.out.println("6. 退出");

            int choice = input.nextInt();
            switch (choice) {
                case 1:
                    addStudent(students, input);
                    break;
                case 2:
                    displayAllStudents(students);
                    break;
                case 3:
                    displayStudentInfo(students, input);
                    break;
                case 4:
                    modifyStudentInfo(students, input);
                    break;
                case 5:
                    deleteStudent(students, input);
                    break;
                case 6:
                    System.out.println("谢谢使用！");
                    return;
                default:
                    System.out.println("无效的操作，请重新选择！");
                    break;
            }
        }
    }

    public static void addStudent(List<Student> students, Scanner input) {
        System.out.println("请输入学生姓名：");
        String name = input.next();
        System.out.println("请输入学生学号：");
        String id = input.next();
        System.out.println("请输入学生年龄：");
        int age = input.nextInt();
        System.out.println("请输入学生性别（男/女）：");
        String gender = input.next();
        Student student = new Student(name, id, age, gender);
        students.add(student);
        System.out.println("添加学生成功！");
    }

    public static void displayAllStudents(List<Student> students) {
        if (students.isEmpty()) {
            System.out.println("暂无学生信息！");
            return;
        }
        System.out.println("所有学生信息如下：");
        for (Student student : students) {
            System.out.println(student.toString());
        }
    }

    public static void displayStudentInfo(List<Student> students, Scanner input) {
        if (students.isEmpty()) {
            System.out.println("暂无学生信息！");
            return;
        }
        System.out.println("请输入要查看的学生学号：");
        String id = input.next();
        for (Student student : students) {
            if (student.getId().equals(id)) {
                System.out.println(student.toString());
                return;
            }
        }
        System.out.println("未找到该学生信息！");
    }

    public static void modifyStudentInfo(List<Student> students, Scanner input) {
        if (students.isEmpty()) {
            System.out.println("暂无学生信息！");
            return;
        }
        System.out.println("请输入要修改的学生学号：");
        String id = input.next();
        for (Student student : students) {
            if (student.getId().equals(id)) {
                System.out.println("请输入学生新姓名：");
                String name = input.next();
                System.out.println("请输入学生新年龄：");
                int age = input.nextInt();
                System.out.println("请输入学生新性别（男/女）：");
                String gender = input.next();
                student.setName(name);
                student.setAge(age);
                student.setGender(gender);
                System.out.println("修改学生信息成功