在Java中如何开发简易成绩管理系统

public class Student {
    private String id;      // 学号
    private String name;    // 姓名
    private double score;   // 成绩

    public Student(String id, String name, double score) {
        this.id = id;
        this.name = name;
        this.score = score;
    }

    // Getter 和 Setter 方法
    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 double getScore() { return score; }
    public void setScore(double score) { this.score = score; }

    @Override
    public String toString() {
        return "学号: " + id + ", 姓名: " + name + ", 成绩: " + score;
    }
}

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

public class GradeManager {
    private ArrayList<Student> students = new ArrayList<>();
    private Scanner scanner = new Scanner(System.in);

    // 添加学生
    public void addStudent() {
        System.out.print("输入学号: ");
        String id = scanner.nextLine();
        System.out.print("输入姓名: ");
        String name = scanner.nextLine();
        System.out.print("输入成绩: ");
        double score = Double.parseDouble(scanner.nextLine());

        students.add(new Student(id, name, score));
        System.out.println("学生添加成功！");
    }

    // 根据学号删除学生
    public void removeStudent() {
        System.out.print("输入要删除的学号: ");
        String id = scanner.nextLine();
        boolean removed = students.removeIf(student -> student.getId().equals(id));
        if (removed) {
            System.out.println("删除成功！");
        } else {
            System.out.println("未找到该学号的学生。");
        }
    }

    // 修改学生信息
    public void updateStudent() {
        System.out.print("输入要修改的学号: ");
        String id = scanner.nextLine();
        for (Student s : students) {
            if (s.getId().equals(id)) {
                System.out.print("新姓名: ");
                s.setName(scanner.nextLine());
                System.out.print("新成绩: ");
                s.setScore(Double.parseDouble(scanner.nextLine()));
                System.out.println("信息更新成功！");
                return;
            }
        }
        System.out.println("未找到该学生。");
    }

    // 查询学生信息
    public void findStudent() {
        System.out.print("输入学号查询: ");
        String id = scanner.nextLine();
        for (Student s : students) {
            if (s.getId().equals(id)) {
                System.out.println(s);
                return;
            }
        }
        System.out.println("未找到该学生。");
    }

    // 显示所有学生
    public void showAllStudents() {
        if (students.isEmpty()) {
            System.out.println("暂无学生信息。");
        } else {
            for (Student s : students) {
                System.out.println(s);
            }
        }
    }

    // 主菜单
    public void start() {
        while (true) {
            System.out.println("\n=== 简易成绩管理系统 ===");
            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. 查询学生");
            System.out.println("5. 显示所有学生");
            System.out.println("6. 退出");
            System.out.print("请选择操作: ");

            String choice = scanner.nextLine();

            switch (choice) {
                case "1" -> addStudent();
                case "2" -> removeStudent();
                case "3" -> updateStudent();
                case "4" -> findStudent();
                case "5" -> showAllStudents();
                case "6" -> {
                    System.out.println("退出系统。");
                    return;
                }
                default -> System.out.println("无效选择，请重试。");
            }
        }
    }
}

public class Main {
    public static void main(String[] args) {
        GradeManager manager = new GradeManager();
        manager.start();
    }
}