java202302java学习笔记第十六天-学生管理系统设计8代码

package StudentSys;
public class Student {
    private String Id;
    private String Name;
    private Number age;
    private  String address;
    public Student(String id, String name, Number age, String address) {
        Id = id;
        Name = name;
        this.age = age;
        this.address = address;
    }
    public String getId() {
        return Id;
    }
    public void setId(String id) {
        Id = id;
    }
    public String getName() {
        return Name;
    }
    public void setName(String name) {
        Name = name;
    }
    public Number getAge() {
        return age;
    }
    public void setAge(Number age) {
        this.age = age;
    }
    public String getAddress() {
        return address;
    }
    public void setAddress(String address) {
        this.address = address;
    }
    public Student() {
    }
}

package StudentSys;
import java.util.ArrayList;
import java.util.Scanner;
public class StudentSys {
    public static void main(String[] args) {
        ArrayList<Student> list = new ArrayList<>();
        loop:
        while (true) {
            System.out.println("-----欢迎来到歌谣的学生系统------");
            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退出学生");
            Scanner sc = new Scanner(System.in);
            String choose = sc.next();
            switch (choose) {
                case "1": {
                    addStudent(list);
                    break;
                }
                case "2": {
                    deleteStudent(list);
                    break;
                }
                case "3": {
                    updateStudent(list);
                    break;
                }
                case "4": {
                    getQueryStudent(list);
                    break;
                }
                case "5": {
                    System.out.println("5退出学生");
                    break loop;
                }
                default:
                    System.out.println("没有这个选项");
            }
        }
    }
    public static void addStudent(ArrayList<Student> list) {
        Scanner sc = new Scanner(System.in);
        Student s = new Student();
        while (true) {
            System.out.println("请输入学生的id");
            String Id = sc.next();
            boolean flag = container(list, Id);
            if (flag) {
                System.out.println("id已经存在 请重新录入");
            } else {
                s.setId(Id);
                break;
            }
        }
        System.out.println("请输入学生的姓名");
        String Name = sc.next();
        s.setName(Name);
        System.out.println("请输入学生的年龄");
        int Age = sc.nextInt();
        s.setAge(Age);
        System.out.println("请输入学生的地址");
        String Address = sc.next();
        s.setAddress(Address);
        list.add(s);
        System.out.println("学生信息添加成功");
    }
    public static void updateStudent(ArrayList<Student> list) {
        Scanner sc = new Scanner(System.in);
        System.out.println("请输入需要修改学生信息的id");
        String id = sc.next();
        int index = getIndex(list, id);
        if (index == -1) {
            System.out.println("当前学生的id不存在,请重新输入");
            return;
        }
        Student stu = list.get(index);
        System.out.println("请输入学生的姓名");
        String Name = sc.next();
        stu.setName(Name);
        System.out.println("请输入学生的年龄");
        int Age = sc.nextInt();
        stu.setAge(Age);
        System.out.println("请输入学生的地址");
        String Address = sc.next();
        stu.setAddress(Address);
        System.out.println("id为" + id + "的学生已经被修改成功");
    }
    public static void deleteStudent(ArrayList<Student> list) {
        Scanner sc = new Scanner(System.in);
        System.out.println("请选择你要删除的id");
        String id = sc.next();
        int index = getIndex(list, id);
        if (index >= 0) {
            list.remove(index);
            System.out.println("id为" + id + "的学生已经被删除成功");
        } else {
            System.out.println("删除失败");
        }
    }
    public static void getQueryStudent(ArrayList<Student> list) {
        if (list.size() == 0) {
            System.out.println("当前学生信息不存在，请添加后再进行查询");
            return;
        }
        System.out.println("id\t姓名\t年龄\t家庭住址");
        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());
        }
    }
    //寻找下表索引
    public static boolean container(ArrayList<Student> list, String id) {
//        for (int i = 0; i < list.size(); i++) {
//            Student stu=list.get(i);
//            String sid=stu.getId();
//            if(sid.equals(id)){
//                return true;
//            }
//        }
//        return  false;
        return getIndex(list, id) >= 0;
    }
    public static int getIndex(ArrayList<Student> list, String id) {
        for (int i = 0; i < list.size(); i++) {
            Student stu = list.get(i);
            String sid = stu.getId();
            if (sid.equals(id)) {
                return i;
            }
        }
        return -1;
    }
}