学生管理系统Java实现

学生管理系统是一个常见的Java项目，下面简单介绍一下它的实现：

1. 创建学生类，包括学生的姓名、学号、性别、年龄等属性和对应的get/set方法。

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

    public String getName() {
        return name;
    }

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

    public String getId() {
        return id;
    }

    public void setId(String id) {
        this.id = id;
    }

    public String getGender() {
        return gender;
    }

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

    public int getAge() {
        return age;
    }

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

2. 创建学生管理类，包括添加学生、删除学生、修改学生信息、查询学生信息等操作。

public class StudentManager {
    private List<Student> studentList;

    public StudentManager() {
        studentList = new ArrayList<>();
    }

    // 添加学生
    public void addStudent(Student student) {
        studentList.add(student);
    }

    // 删除学生
    public void deleteStudent(Student student) {
        studentList.remove(student);
    }

    // 修改学生信息
    public void updateStudent(Student student) {
        for (int i = 0; i < studentList.size(); i++) {
            Student s = studentList.get(i);
            if (s.getId().equals(student.getId())) {
                studentList.set(i, student);
                break;
            }
        }
    }

    // 查询学生信息
    public Student queryStudent(String id) {
        for (Student s : studentList) {
            if (s.getId().equals(id)) {
                return s;
            }
        }
        return null;
    }
}

3. 创建学生管理系统界面，包括学生信息的录入、删除、修改和查询等操作。

import java.util.Scanner;

public class StudentManagerSystem {
    private StudentManager studentManager;

    public StudentManagerSystem() {
        studentManager = new StudentManager();
    }

    // 启动学生管理系统
    public void start() {
        Scanner scanner = new Scanner(System.in);
        while (true) {
            System.out.println("欢迎使用学生管理系统，请选择操作：");
            System.out.println("1. 录入学生信息");
            System.out.println("2. 删除学生信息");
            System.out.println("3. 修改学生信息");
            System.out.println("4. 查询学生信息");
            System.out.println("0. 退出系统");

            int choice = scanner.nextInt();
            switch (choice) {
                case 1:
                    addStudent(scanner);
                    break;
                case 2:
                    deleteStudent(scanner);
                    break;
                case 3:
                    updateStudent(scanner);
                    break;
                case 4:
                    queryStudent(scanner);
                    break;
                case 0:
                    System.out.println("已退出系统！");
                    return;
                default:
                    System.out.println("无效的操作，请重新选择！");
                    break;
            }
        }
    }

    // 录入学生信息
    private void addStudent(Scanner scanner) {
        System.out.println("请输入学生信息：");
        System.out.print("姓名：");
        String name = scanner.next();
        System.out.print("学号：");
        String id = scanner.next();
        System.out.print("性别：");
        String gender = scanner.next();
        System.out.print("年龄：");
        int age = scanner.nextInt();

        Student student = new Student();
        student.setName(name);
        student.setId(id);
        student.setGender(gender);
        student.setAge(age);
        studentManager.addStudent(student);

        System.out.println("学生信息录入成功！");
    }

    // 删除学生信息
    private void deleteStudent(Scanner scanner) {
        System.out.println("请输入要删除的学生学号：");
        String id = scanner.next();

        Student student = studentManager.queryStudent(id);
        if (student != null) {
            studentManager.deleteStudent(student);
            System.out.println("学生信息删除成功！");
        } else {
            System.out.println("学号为 " + id + " 的学生不存在！");
        }
    }

    // 修改学生信息
    private void updateStudent(Scanner scanner) {
        System.out.println("请输入要修改的学生学号：");
        String id = scanner.next();

        Student student = studentManager.queryStudent(id);
        if (student != null) {
            System.out.println("请输入学生信息：");
            System.out.print("姓名：");
            String name = scanner.next();
            System.out.print("性别：");
            String gender = scanner.next();
            System.out.print("年龄：");
            int age = scanner.nextInt();

            student.setName(name);
            student.setGender(gender);
            student.setAge(age);
            studentManager.updateStudent(student);

            System.out.println("学生信息修改成功！");
        } else {
            System.out.println("学号为 " + id + " 的学生不存在！");
        }
    }

    // 查询学生信息
    private void queryStudent(Scanner scanner) {
        System.out.println("请输入要查询的学生学号：");
        String id = scanner.next();

        Student student = studentManager.queryStudent(id);
        if (student != null) {
            System.out.println("学生信息如下：");
            System.out.println("姓名：" + student.getName());
            System.out.println("学号：" + student.getId());
            System.out.println("性别：" + student.getGender());
            System.out.println("年龄：" + student.getAge());
        } else {
            System.out.println("学号为 " + id + " 的学生不存在！");
        }
    }
}

以上就是一个简单的学生管理系统的Java实现。可以根据实际需求进行修改和扩展。