Java实现学生管理系统

package CCTest.StudentSystem;

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

public class StudentSystemDemo {
    public static void main(String[] args) {
        ArrayList list=new ArrayList<>();
       xunhuan:while (true) {//因为break只能跳出单层循环，要跳出switch语句的同时需要跳出外层循环，要给循环加上名字
            Scanner scan=new Scanner(System.in);
            System.out.println("------------------欢迎来到学生学习系统------------------");
            System.out.println("请按照提示选择要进行的功能：");
            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:退出");
            System.out.println("请输入您的选择：");
            String input= scan.next();
            switch (input){
                case "1":
                    System.out.println("添加学生");
                    addStudent(list);
                    break;
                case "2":
                    System.out.println("删除学生");
                    deleteStudent(list);
                    break;
                case "3":
                    System.out.println("修改学生");
                    updateStudent(list);
                    break;
                case "4":
                    System.out.println("查询学生");
                    queryStudent(list);
                    break;
                case "5":
                    System.out.println("退出");
                    break xunhuan;
                default:
                    System.out.println("没有这个功能");

            }
        }
    }

    //添加学生
    public static void addStudent(ArrayList list){
        Student stu=new Student();
        Scanner scan=new Scanner(System.in);
        while (true) {
            System.out.println("请输入学生的id：");
            String id = scan.next();

            boolean f = contain(list, id);
            if (f){
                //表示id已存在
                System.out.println("录入失败，id已存在");
            }else {
                System.out.println("录入成功");
                stu.setId(id);
                break;
            }
        }
        System.out.println("请输入学生的姓名：");
        String name = scan.next();
        stu.setName(name);
        System.out.println("请输入学生的年龄：");
        int age=scan.nextInt();
        stu.setAge(age);
        System.out.println("请输入学生的家庭住址：");
        String address = scan.next();
        stu.setAddress(address);
        list.add(stu);
        System.out.println("添加成功,学生总数："+list.size());

    }
    //删除学生
    public static void deleteStudent(ArrayList list){
        Scanner scan=new Scanner(System.in);
        System.out.println("请输入要删除的学生id：");
        String input= scan.next();
        for (int i = 0; i < list.size(); i++) {
            Student st = list.get(i);
            if (st.getId().equals(input)){
                list.remove(i);
                System.out.println("id已删除");
                break;
            }else {
                System.out.println("id不存在");
            }
        }


    }
    //修改学生
    public static void updateStudent(ArrayList list){
        Student stu=new Student();
        Scanner scan=new Scanner(System.in);
        System.out.println("请输入要修改的id:");
        String id = scan.next();
        for (int i = 0; i < list.size(); i++) {
            Student s = list.get(i);
            boolean fl = contain(list, id);
            if (fl){
                System.out.println("id存在,可以修改");
                System.out.println("请输入新的id：");
                s.setId(scan.next());
                System.out.println("请输入新的名字：");
                s.setName(scan.next());
                System.out.println("请输入新的年龄：");
                s.setAge(scan.nextInt());
                System.out.println("请输入新的家庭地址：");
                s.setAddress(scan.next());

            }else {
                System.out.println("id不存在");
            }
    }
    }
    //查询学生
    public static void queryStudent(ArrayList list){
        if (list.size()==0){
            System.out.println("当前无学生信息，请添加后再查询");
            return;
        }
        //表头
        System.out.println("id\t\t姓名\t\t年龄\t\t家庭住址");
        //集合里有数据
        for (int i = 0; i < list.size(); i++) {
            Student stu=list.get(i);
            System.out.println(stu.getId()+"\t"+stu.getName()+"\t"+stu.getAge()+"\t"+stu.getAddress());
        }
    }

    //判断集合中是否存在id
    public static boolean contain(ArrayList list,String id) {
        //循环便利集合得到每一个学生对象
        //得到后获取id并进行判断
        //存在，true  不存在false
        for (int i = 0; i < list.size(); i++) {
            Student stu = list.get(i);
            String Id = stu.getId();
            if (Id.equals(id)) {
                return true;
            }
        }return false;
    }

}




创建Student的对象

package CCTest.StudentSystem;

public class Student {
    String id;
    String name;
    int age;
    String address;

    public Student() {
    }

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

    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 getAddress() {
        return address;
    }

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