Java-IDEA implements a simple student management system

student management system

Student class

//学生类
public class Student {
    
    
    //学号
    private String sid;
    //姓名
    private String name;
    //年龄
    private String age;
    //居住地
    private String address;

    //快捷键 Alt + Insert --> constructor
    //无参构造 
    public Student() {
    
    
    }
    //有参构造
    public Student(String sid, String name, String age, String address) {
    
    
        this.sid = sid;
        this.name = name;
        this.age = age;
        this.address = address;
    }
    //快捷键 Alt + Insert
    //Getter and Setter方法
    public String getSid() {
    
    
        return sid;
    }

    public void setSid(String sid) {
    
    
        this.sid = sid;
    }

    public String getName() {
    
    
        return name;
    }

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

    public String getAge() {
    
    
        return age;
    }

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

    public String getAddress() {
    
    
        return address;
    }

    public void setAddress(String address) {
    
    
        this.address = address;
    }
}

StudentManager class

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

public class StudentManager {
    
    
    public static void main(String[] args) {
    
    
        ArrayList<Student> array = new ArrayList<Student>();

        while (true){
    
    
        //系统界面
        System.out.println("--------欢迎来到学生管理系统--------");
        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.查看所有学生");
        System.out.println("5.退出");
        System.out.println("请输入你的选择");

        //接收选项
        Scanner sc = new Scanner(System.in);
        String line = sc.nextLine();

            switch (line) {
    
    //判断用户选择哪个选项
                case "1":
                    addStudent(array);//调用添加用户方法
                    break;
                case "2":
                    deleteStudent(array);//调用删除用户方法
                    break;
                case "3":
                    updateStudent(array);//调用更新用户方法
                    break;
                case "4":
                    findAllStudent(array);//调用查看用户方法
                    break;
                case "5":
                    System.out.println("谢谢使用");
                    System.exit(0);//JVM退出
            }

        }

    }

    //添加用户方法
    public static void addStudent(ArrayList<Student> array){
    
    

        Scanner sc = new Scanner(System.in);
        //定义学号
        String sid;

        //判断输入的学号是否已经存在
        while(true) {
    
    
            System.out.println("请输入学生学号");
            sid = sc.nextLine();
            boolean flag = isUsed(array, sid); //调用isUsed方法
            //if(flag)即if(flag==ture)
            if (flag) {
    
    
                System.out.println("你输入的学号已经被使用，请重新输入");
            }else{
    
    
                break; //结束while循环
            }
        }

        System.out.println("请输入学生姓名");
        String name = sc.nextLine();

        System.out.println("请输入学生年龄");
        String age = sc.nextLine();

        System.out.println("请输入学生居住地");
        String address = sc.nextLine();

        Student s = new Student();
        s.setSid(sid);
        s.setName(name);
        s.setAge(age);
        s.setAddress(address);

        array.add(s);
        System.out.println("添加学生成功");
    }
    //查看学生信息方法
    public static void findAllStudent(ArrayList<Student> array){
    
    
        if (array.size()==0){
    
     //判断集合中元素的个数 如果为0 则没有学生信息
            System.out.println("无学生信息，请先添加学生信息");
        }else {
    
    
            System.out.println("学号\t\t\t姓名\t\t年龄\t\t居住地");
            for (int i = 0; i < array.size(); i++) {
    
    
                Student s = array.get(i);
                System.out.println(s.getSid() + "\t" + s.getName() + "\t" + s.getAge() + "岁\t\t" + s.getAddress());
            }
        }
    }

    //删除用户信息方法
    public static void deleteStudent(ArrayList<Student> array){
    
    
        Scanner sc = new Scanner(System.in);
        System.out.println("请输入你要删除学生的学号");
        String sid = sc.nextLine();

        int index = -1;//索引，因为索引值是从0开始
        for (int i = 0; i < array.size(); i++) {
    
    
            Student s = array.get(i);
            if(s.getSid().equals(sid)){
    
    //判断输入的学号是否存在
                index = i;
                break;
            }
        }
        if (index==-1){
    
    
            System.out.println("该信息不存在，请重新输入");
        }else{
    
    
            array.remove(index);
            System.out.println("删除学生成功");
        }
    }

    //修改用户信息方法
    public static void updateStudent(ArrayList<Student> array){
    
    
        Scanner sc = new Scanner(System.in);
        String sid;

            System.out.println("请输入你要修改学生的学号");
            sid = sc.nextLine();
            boolean flag = isUsed(array, sid);//调用方法，用于判断输入的学号是否存在
            if (flag==false) {
    
    
                System.out.println("你输入的学号错误，请重新输入");
            }else {
    
    


                System.out.println("请输入学生新姓名");
                String name = sc.nextLine();
                System.out.println("请输入学生新年龄");
                String age = sc.nextLine();
                System.out.println("请输入学生新居住地");
                String address = sc.nextLine();

                Student s = new Student();
                s.setSid(sid);
                s.setName(name);
                s.setAge(age);
                s.setAddress(address);

                for (int i = 0; i < array.size(); i++) {
    
    
                    Student student = array.get(i);
                    if (student.getSid().equals(sid)) {
    
    
                        array.set(i, s);
                        break;
                    }
                }
                System.out.println("修改学生成功");
            }
    }


    public static boolean isUsed(ArrayList<Student> array,String sid){
    
    
        boolean flag = false;

        for (int i = 0; i < array.size(); i++) {
    
    
            Student s = array.get(i);
            //equals用于判断字符串是否相等
            if (s.getSid().equals(sid)){
    
    
                flag = true;
                break;
            }
        }
        return flag;
    }
}