用java写学生信息管理系统

好的，下面是一个简单的 Java 学生信息管理系统的示例代码：

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

public class StudentManagementSystem {

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

    public void start() {
        boolean quit = false;
        while (!quit) {
            System.out.println("请选择操作：");
            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. 退出系统");

            int choice = scanner.nextInt();

            switch (choice) {
                case 1:
                    addStudent();
                    break;
                case 2:
                    deleteStudent();
                    break;
                case 3:
                    updateStudent();
                    break;
                case 4:
                    queryStudent();
                    break;
                case 5:
                    displayStudents();
                    break;
                case 6:
                    quit = true;
                    break;
                default:
                    System.out.println("输入有误，请重新选择。");
            }
        }
    }

    private void addStudent() {
        System.out.println("请输入学生姓名：");
        String name = scanner.next();
        System.out.println("请输入学生年龄：");
        int age = scanner.nextInt();
        System.out.println("请输入学生性别：");
        String gender = scanner.next();

        Student student = new Student(name, age, gender);
        students.add(student);
        System.out.println("学生添加成功。");
    }

    private void deleteStudent() {
        System.out.println("请输入要删除的学生姓名：");
        String name = scanner.next();

        boolean found = false;
        for (int i = 0; i < students.size(); i++) {
            Student student = students.get(i);
            if (student.getName().equals(name)) {
                students.remove(i);
                found = true;
                System.out.println("学生删除成功。");
                break;
            }
        }

        if (!found) {
            System.out.println("未找到该学生。");
        }
    }

    private void updateStudent() {
        System.out.println("请输入要修改的学生姓名：");
        String name = scanner.next();

        boolean found = false;
        for (int i = 0; i < students.size(); i++) {
            Student student = students.get(i);
            if (student.getName().equals(name)) {
                System.out.println("请输入学生年龄：");
                int age = scanner.nextInt();
                System.out.println("请输入学生性别：");
                String gender = scanner.next();

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

                found = true;
                System.out.println("学生修改成功。");
                break;
            }
        }

        if (!found) {
            System.out.println("未找到该学生。");
        }
    }

    private void queryStudent() {
        System.out.println("请输入要查询的学生姓名：");
        String name = scanner.next();

        boolean found = false;
        for (int i = 0; i < students.size(); i++) {
            Student student = students.get(i);
            if (student.getName().equals(name)) {
                System.out.println(student);
                found = true;
                break;
            }
        }

        if (!found) {
            System.out.println("未找到该学生。");
        }
    }

    private void displayStudents() {
        for (int i = 0; i < students.size(); i++) {
            System.out.println(students.get(i));
        }
    }

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

class Student {
    private String name;
    private int age;
    private String gender;

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

    public String getName() {
        return name;
    }

    public int getAge() {
        return age;
    }

    public String getGender() {
        return gender;
    }

    public void setName(String name) {
        this.name = name;
    }

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

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

    @Override
    public String toString() {
        return "姓名：" + name + "，年龄：" + age + "，性别：" + gender;
    }
}

这个示例代码实现了一个简单的学生信息管理系统，包括添加、删除、修改、查询和显示所有学生等功能。您可以根据自己的需求进行修改和扩展。