Java中如何实现班级学生管理系统

public class Student {
    private int id;
    private String name;
    private int age;
    private double score;
<pre class='brush:java;toolbar:false;'>public Student(int id, String name, int age, double score) {
    this.id = id;
    this.name = name;
    this.age = age;
    this.score = score;
}

// getter 和 setter 方法
public int getId() { return id; }
public void setId(int 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 double getScore() { return score; }
public void setScore(double score) { this.score = score; }

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

import java.util.ArrayList;
import java.util.Scanner;
<p>public class StudentManager {
private ArrayList<Student> students = new ArrayList<>();
private Scanner scanner = new Scanner(System.in);</p><pre class='brush:java;toolbar:false;'>// 添加学生
public void addStudent() {
    System.out.print("输入学号：");
    int id = scanner.nextInt();
    if (findStudentById(id) != null) {
        System.out.println("该学号已存在！");
        return;
    }
    System.out.print("输入姓名：");
    String name = scanner.next();
    System.out.print("输入年龄：");
    int age = scanner.nextInt();
    System.out.print("输入成绩：");
    double score = scanner.nextDouble();

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

// 根据学号查找学生
private Student findStudentById(int id) {
    for (Student s : students) {
        if (s.getId() == id) {
            return s;
        }
    }
    return null;
}

// 删除学生
public void deleteStudent() {
    System.out.print("输入要删除的学号：");
    int id = scanner.nextInt();
    Student s = findStudentById(id);
    if (s != null) {
        students.remove(s);
        System.out.println("删除成功！");
    } else {
        System.out.println("未找到该学生！");
    }
}

// 修改学生信息
public void updateStudent() {
    System.out.print("输入要修改的学号：");
    int id = scanner.nextInt();
    Student s = findStudentById(id);
    if (s == null) {
        System.out.println("未找到该学生！");
        return;
    }
    System.out.print("输入新姓名：");
    s.setName(scanner.next());
    System.out.print("输入新年龄：");
    s.setAge(scanner.nextInt());
    System.out.print("输入新成绩：");
    s.setScore(scanner.nextDouble());
    System.out.println("修改成功！");
}

// 查询学生
public void findStudent() {
    System.out.print("输入学生姓名或学号（-1表示按学号）：");
    String keyword = scanner.next();
    try {
        int id = Integer.parseInt(keyword);
        Student s = findStudentById(id);
        if (s != null) {
            System.out.println(s);
        } else {
            System.out.println("未找到该学生！");
        }
    } catch (NumberFormatException e) {
        // 按姓名查找
        boolean found = false;
        for (Student s : students) {
            if (s.getName().contains(keyword)) {
                System.out.println(s);
                found = true;
            }
        }
        if (!found) {
            System.out.println("未找到匹配的学生！");
        }
    }
}

// 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);
        }
    }
}

public class Main {
    public static void main(String[] args) {
        StudentManager manager = new StudentManager();
        Scanner scanner = new Scanner(System.in);
        while (true) {
            System.out.println("\n--- 班级学生管理系统 ---");
            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：");
<pre class='brush:java;toolbar:false;'>        int choice = scanner.nextInt();
        switch (choice) {
            case 1 -> manager.addStudent();
            case 2 -> manager.deleteStudent();
            case 3 -> manager.updateStudent();
            case 4 -> manager.findStudent();
            case 5 -> manager.showAllStudents();
            case 6 -> {
                System.out.println("退出系统！");
                return;
            }
            default -> System.out.println("无效选择，请重试！");
        }
    }
}