学生管理系统

import java.util.ArrayList;
import java.util.Scanner;
 
public class StudentGL {
public static void main(String[] args) {
ArrayList<Student> al = new ArrayList(); //创建集合对象用来装学生
 
 
while (true){
System.out.println("----学生管理系统----");
System.out.println("输入1添加学生");
System.out.println("输入2删除学生");
System.out.println("输入3修改学生");
System.out.println("输入4查询学生");
System.out.println("输入5退出系统");
System.out.println("请输入：");
Scanner sc = new Scanner(System.in);
String line = sc.nextLine(); //录入用户选择
 
//Student s =new Student();
 
switch (line){
//输入1添加学生
case "1":
System.out.println("请输入学生编号：");
String id = sc.nextLine();
 
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();
 
Student s =new Student(); //创建学生对象
s.setId(id);
s.setName(name);
s.setAge(age);
 
al.add(s);
break;
//输入2删除学生
case "2":
System.out.println("请输入学生编号：");
String id2 = sc.nextLine();
for (int i = 0; i < al.size(); i++) {
Student ss = al.get(i);
if (id2.equals(ss.getId())) {
al.remove(i);
}
}
break;
//输入3修改学生
case "3":
System.out.println("请输入学生编号：");
String num = sc.nextLine();
for (int i = 0; i < al.size(); i++) {
Student ss = al.get(i);
if (num.equals(ss.getId())){
System.out.println("输入0撤销；输入1修改编号；输入2修改姓名；输入3修改年龄。" +"
"+ "请输入要修改的项号：");
String xiang = sc.nextLine();
switch (xiang){
case "0":
break;
 
case "1":
System.out.println("请输入学生编号：");
String id3 = sc.nextLine();
ss.setId(id3);
break;
 
case "2":
System.out.println("请输入学生姓名：");
String name3 = sc.nextLine();
ss.setName(name3);
break;
 
case "3":
System.out.println("请输入学生年龄：");
String age3 = sc.nextLine();
ss.setAge(age3);
break;
 
}
al.set(i, ss);
}
}
break;
//输入4查询学生
case "4":
for (int i = 0; i < al.size(); i++) {
Student ss = al.get(i);
System.out.println(ss.getId() + ss.getName() + ss.getAge());
}
break;
//输入5退出系统
case "5":
System.out.println("谢谢使用！");
System.exit(0);
break;
}
}
}
}
 
class Student{
private String id;
private String name;
private String age;
 
public Student() {
}
 
public Student(String id, String name, String age) {
this.id = id;
this.name = name;
this.age = age;
}
 
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 String getAge() {
return age;
}
 
public void setAge(String age) {
this.age = age;
}
}