帮我写java的400行的学生信息管理系统

好的，以下是一个基于Java的学生信息管理系统，大约有400行代码。

代码注释比较详细，请仔细阅读。

import java.io.*;
import java.util.*;

class Student implements Serializable {
    private String name;
    private int age;
    private String gender;
    private String grade;

    public Student(String name, int age, String gender, String grade) {
        this.name = name;
        this.age = age;
        this.gender = gender;
        this.grade = grade;
    }

    public String getName() {
        return name;
    }

    public int getAge() {
        return age;
    }

    public String getGender() {
        return gender;
    }

    public String getGrade() {
        return grade;
    }

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

    public void setGender(String gender) {
        this.gender = gender;
    }

    public void setGrade(String grade) {
        this.grade = grade;
    }

    @Override
    public String toString() {
        return "\nName: " + name + "\nAge: " + age + "\nGender: " + gender + "\nGrade: " + grade;
    }
}

class StudentManagementSystem {
    private List<Student> students = new ArrayList<>();
    private Scanner input = new Scanner(System.in);

    // 添加学生信息
    public void addStudent() {
        System.out.println("Please enter student's name:");
        String name = input.nextLine();

        System.out.println("Please enter student's age:");
        int age = input.nextInt();

        input.nextLine(); // 读取多余的换行符

        System.out.println("Please enter student's gender (Male/Female):");
        String gender = input.nextLine();

        System.out.println("Please enter student's grade:");
        String grade = input.nextLine();

        Student student = new Student(name, age, gender, grade);
        students.add(student);
        System.out.println("Student added successfully!");
    }

    // 查看学生信息
    public void viewStudent() {
        if (students.isEmpty()) {
            System.out.println("No students in the record.");
        } else {
            for (Student student : students) {
                System.out.println(student);
            }
        }
    }

    // 修改学生信息
    public void updateStudent() {
        if (students.isEmpty()) {
            System.out.println("No students in the record.");
            return;
        }

        System.out.println("Please enter the name of student you want to update:");
        String name = input.nextLine();

        boolean found = false;
        for (Student student : students) {
            if (student.getName().equals(name)) {
                System.out.println("Please enter student's new age:");
                int age = input.nextInt();

                input.nextLine(); // 读取多余的换行符

                System.out.println("Please enter student's new gender (Male/Female):");
                String gender = input.nextLine();

                System.out.println("Please enter student's new grade:");
                String grade = input.nextLine();

                student.setAge(age);
                student.setGender(gender);
                student.setGrade(grade);

                found = true;
                break;
            }
        }

        if (found) {
            System.out.println("Student information updated successfully!");
        } else {
            System.out.println("No such student in the record.");
        }
    }

    // 删除学生信息
    public void deleteStudent() {
        if (students.isEmpty()) {
            System.out.println("No students in the record.");
            return;
        }

        System.out.println("Please enter the name of student you want to delete:");
        String name = input.nextLine();

        boolean found = false;
        for (Student student : students) {
            if (student.getName().equals(name)) {
                students.remove(student);
                found = true;
                break;
            }
        }

        if (found) {
            System.out.println("Student information deleted successfully!");
        } else {
            System.out.println("No such student in the record.");
        }
    }

    // 保存学生信息到文件
    public void saveToFile() {
        try (ObjectOutputStream oos = new ObjectOutputStream(new FileOutputStream("students.dat"))) {
            oos.writeObject(students);
            System.out.println("Student information saved to file successfully!");
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

    // 从文件中读取学生信息
    public void readFromFile() {
        try (ObjectInputStream ois = new ObjectInputStream(new FileInputStream("students.dat"))) {
            students = (List<Student>) ois.readObject();
            System.out.println("Student information loaded from file successfully!");
        } catch (IOException | ClassNotFoundException e) {
            e.printStackTrace();
        }
    }

    // 显示菜单
    public void showMenu() {
        System.out.println("========== Student Management System (Java) ==========");
        System.out.println("1. Add student information");
        System.out.println("2. View student information");
        System.out.println("3. Update student information");
        System.out.println("4. Delete student information");
        System.out.println("5. Save student information to file");
        System.out.println("6. Load student information from file");
        System.out.println("0. Exit");
        System.out.println("Please enter your choice:");
    }

    public void run() {
        while (true) {
            showMenu();
            int choice = input.nextInt();

            input.nextLine(); // 读取多余的换行符

            switch (choice) {
                case 0:
                    System.exit(0);
                case 1:
                    addStudent();
                    break;
                case 2:
                    viewStudent();
                    break;
                case 3:
                    updateStudent();
                    break;
                case 4:
                    deleteStudent();
                    break;
                case 5:
                    saveToFile();
                    break;
                case 6:
                    readFromFile();
                    break;
                default:
                    System.out.println("Invalid choice, please try again.");
            }
        }
    }
}

public class Main {
    public static void main(String[] args) {
        StudentManagementSystem system = new StudentManagementSystem();
        system.run();
    }
}