Java学生管理系统（纯练手）

Java学生管理系统（纯练手）

该系统主要功能如下：

• ​添加学生：通过键盘录入学生信息，添加到集合中
• 删除学生：通过键盘录入要删除学生的学号，将该学生对象从集合中删除
• 修改学生：通过键盘录入要修改学生的学号，将该学生对象其他信息进行修改
• 查看学生：将集合中的学生对象信息进行展示
• 退出系统：结束程序
  学生类的定义

package com.studentsystem;

public class Student {
    private  String  id;
    private  String name;
    private int age;
    private  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;
    }
}
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测试类的定义

package com.studentsystem;

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

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

        while(true){
            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.查询学生");
            System.out.println("5.退出");
            System.out.println("请输入您的选择：");
            Scanner sc = new Scanner(System.in);
            String   choose = sc.next();
            switch(choose){
                case "1"->addStudent(list);
                case "2"->deleteStudent(list);
                case "3"->updateStudent(list);
                case "4"-> queryStudent(list);
                case "5"->{
                    System.out.println("退出");
                    System.exit(0);
                }
                default->System.out.println("没有这个选项！");
            }
        }

    }
    public static  void addStudent(ArrayList<Student> list){
        Student student = new Student();
        Scanner sc = new Scanner(System.in);
        String id = null;
        while(true){
            System.out.println("请输入学生id:");
            id = sc.next();
            boolean flag = contains(list,id);
            if(flag){
                System.out.println("id已经存在，请重新输入！");
            }else{
                student.setId(id);
                break;
            }
        }
        System.out.println("请输入学生的姓名:");
        String name = sc.next();
        student.setName(name);

        System.out.println("请输入学生的年龄:");
        int age = sc.nextInt();
        student.setAge(age);

        System.out.println("请输入学生的家庭住址:");
        String address = sc.next();
        student.setAddress(address);

        list.add(student);
        System.out.println("学生信息添加成功！");
    }
    public static boolean contains(ArrayList<Student> list,String id){
        return  getIndex(list,id)>=0;
    }
    public static int getIndex(ArrayList<Student> list, String id){
        //遍历集合
        for (int i = 0; i < list.size(); i++) {
            //得到每一个学生对象
            Student stu = list.get(i);
            //得到每一个学生对象的id
            String sid = stu.getId();
            //拿着集合中的学生id跟要查询的id进行比较
            if(sid.equals(id)){
                //如果一样，那么就返回索引
                return i;
            }
        }
        //当循环结束之后还没有找到，就表示不存在，返回-1.
        return -1;
    }
    public static  void deleteStudent(ArrayList<Student> list){
        Scanner sc = new Scanner(System.in);
        System.out.println("请输入要删除的id:");
        String id = sc.next();
        int index = getIndex(list,id);
        if(index >=0){
            list.remove(index);
            System.out.println("id为："+id+"的学生删除成功！");
        }else{
            System.out.println("id不存在，删除失败！");
        }
    }
    public static  void updateStudent(ArrayList<Student> list){
        Scanner sc = new Scanner(System.in);
        System.out.println("请输入要修改的学生的id:");
        String id = sc.next();
        int index = getIndex(list,id);
        if (index ==-1) {
            System.out.println("所删除id为："+id+"的学生不存在！");
        }
        //获取要修改的学生对象
        Student stu = list.get(index);

        //输入其他的信息并修改
        System.out.println("请输入要修改的学生姓名");
        String newName = sc.next();
        stu.setName(newName);

        System.out.println("请输入要修改的学生年龄:");
        int newAge = sc.nextInt();
        stu.setAge(newAge);

        System.out.println("请输入要修改的学生家庭住址:");
        String newAddress = sc.next();
        stu.setAddress(newAddress);

        System.out.println("学生信息修改成功!");
    }
    public static  void queryStudent(ArrayList<Student> list){
        if (list.size() == 0) {
            System.out.println("当前无学生信息，请添加后再查询!");
        }
        System.out.println("id\t\t姓名\t年龄\t家庭住址");
        //当代码执行到这里，表示集合中是有数据的
        for (Student stu : list) {
            System.out.println(stu.getId() + "\t" + stu.getName() + "\t" + stu.getAge() + "\t" + stu.getAddress());
        }
    }
}

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今天就记录到这里了！