用java写一个简易的学生学籍管理系统。要有学生信息录入，查询，修改，删除

好的，下面是一个简单的学生学籍管理系统的Java代码，实现了学生信息的录入、查询、修改和删除功能。请注意，这只是一个简单版本的示例代码，您可以根据自己的需求进行修改和完善。

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

public class StudentManagementSystem {
    
    public static void main(String[] args) {
        ArrayList<Student> students = new ArrayList<Student>();
        Scanner input = new Scanner(System.in);
        int choice;
        do {
            System.out.println("请选择操作：");
            System.out.println("1. 录入学生信息");
            System.out.println("2. 查询学生信息");
            System.out.println("3. 修改学生信息");
            System.out.println("4. 删除学生信息");
            System.out.println("0. 退出");
            choice = input.nextInt();
            switch (choice) {
                case 1:
                    addStudent(students);
                    break;
                case 2:
                    searchStudent(students);
                    break;
                case 3:
                    updateStudent(students);
                    break;
                case 4:
                    deleteStudent(students);
                    break;
                case 0:
                    System.out.println("已退出学生学籍管理系统");
                    break;
                default:
                    System.out.println("输入有误，请重新选择操作！");
                    break;
            }
        } while (choice != 0);
        input.close();
    }
    
    // 添加学生信息
    public static void addStudent(ArrayList<Student> students) {
        Scanner input = new Scanner(System.in);
        System.out.println("请输入学生编号：");
        String id = input.nextLine();
        System.out.println("请输入学生姓名：");
        String name = input.nextLine();
        System.out.println("请输入学生年龄：");
        int age = input.nextInt();
        System.out.println("请输入学生性别（男/女）：");
        String gender = input.next();
        Student student = new Student(id, name, age, gender);
        students.add(student);
        System.out.println("学生信息已添加！");
    }
    
    // 查询学生信息
    public static void searchStudent(ArrayList<Student> students) {
        Scanner input = new Scanner(System.in);
        System.out.println("请输入要查询的学生姓名：");
        String name = input.nextLine();
        boolean flag = false;
        for (Student student : students) {
            if (student.getName().equals(name)) {
                System.out.println("学生信息如下：");
                System.out.println(student);
                flag = true;
                break;
            }
        }
        if (!flag) {
            System.out.println("未找到该学生信息！");
        }
    }
    
    // 修改学生信息
    public static void updateStudent(ArrayList<Student> students) {
        Scanner input = new Scanner(System.in);
        System.out.println("请输入要修改的学生编号：");
        String id = input.nextLine();
        boolean flag = false;
        for (Student student : students) {
            if (student.getId().equals(id)) {
                System.out.println("请输入修改后的学生姓名：");
                String name = input.nextLine();
                System.out.println("请输入修改后的学生年龄：");
                int age = input.nextInt();
                System.out.println("请输入修改后的学生性别（男/女）：");
                String gender = input.next();
                student.setName(name);
                student.setAge(age);
                student.setGender(gender);
                System.out.println("学生信息已修改！");
                flag = true;
                break;
            }
        }
        if (!flag) {
            System.out.println("未找到该学生信息！");
        }
    }
    
    // 删除学生信息
    public static void deleteStudent(ArrayList<Student> students) {
        Scanner input = new Scanner(System.in);
        System.out.println("请输入要删除的学生编号：");
        String id = input.nextLine();
        boolean flag = false;
        for (Student student : students) {
            if (student.getId().equals(id)) {
                students.remove(student);
                System.out.println("学生信息已删除！");
                flag = true;
                break;
            }
        }
        if (!flag) {
            System.out.println("未找到该学生信息！");
        }
    }
    
}

class Student {
    
    private String id;
    private String name;
    private int age;
    private String gender;
    
    public Student(String id, String name, int age, String gender) {
        this.id = id;
        this.name = name;
        this.age = age;
        this.gender = gender;
    }
    
    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 int getAge() {
        return age;
    }
    
    public void setAge(int age) {
        this.age = age;
    }
    
    public String getGender() {
        return gender;
    }
    
    public void setGender(String gender) {
        this.gender = gender;
    }
    
    @Override
    public String toString() {
        return "学号：" + id + "，姓名：" + name + "，年龄：" + age + "，性别：" + gender;
    }
    
}

以上代码实现了学生信息的录入、查询、修改和删除功能，具体操作请按照提示输入对应的数字，然后按回车键执行相应的操作。