用ArrayList实现简单的学生管理系统

package xuesheng;

public class Student {
    //学号
    private String id;
    //姓名
    private String name;
    //年龄
    private  int age;
    //班级
    private  int  clas;

    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 int getClas() {
        return clas;
    }

    public void setClas(int clas) {
        this.clas = clas;
    }

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

    public Student() {
    }
}



//
package xuesheng;

import com.sun.deploy.net.MessageHeader;

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

public class StudentMannger {
    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 查看所有学生");
            System.out.println("5 退出");
            System.out.println("请输入你的选择");
            Scanner sc = new Scanner(System.in);
            String x = sc.nextLine();
            switch (x) {
                case "1":
                    addstudent(list);
                    break;
                case "2":
                    deletestudent(list);
                    break;
                case "3":
                    Revisestudent(list);
                    break;
                case "4":
                    checkall(list);
                    break;
                case "5":
                    System.exit(0);




            }
        }
    }

    public static void addstudent(ArrayList<Student> list) {
          Scanner sc = new Scanner(System.in);
            String s ;
        while(true) {

            System.out.println("请输入学号");
          s= sc.nextLine();
            boolean flag = isused(list, s);
            if (flag == true) {
                System.out.println("该学号已经添加,请重新输入");
            }
            else {
                break;
            }
        }
        System.out.println("请输入名字");
        String s1 = sc.nextLine();
        System.out.println("请输入年龄");
        int a = sc.nextInt();
        System.out.println("请输入班级");
        int b = sc.nextInt();
        Student st = new Student();
        st.setId(s);
        st.setName(s1);
        st.setAge(a);
        st.setClas(b);

        list.add(st);
        System.out.println("添加学生成功");
    }

    public  static boolean isused(ArrayList<Student> list,String id){
        boolean flag=false;
        for (int i=0;i< list.size();i++){
            Student s=list.get( i);
            if (s.getId().equals(id)){
                flag=true;
                break;
            }

        }
        return flag;
    }
    public static void deletestudent(ArrayList<Student> list) {
        if (list.isEmpty()) {
            System.out.println("没有内容不能删除");
        } else {
            System.out.println("请输入要删除学生的学号");
            Scanner sc = new Scanner(System.in);
            String s = sc.nextLine();
            int index=-1;
            for (int i=0;i< list.size();i++){
                Student st=list.get(i);
                if (st.getId().equals(s)){
                   index=i;
                    break;
                }
            }
            if (index==-1){
                System.out.println("没有该学生");
            }
            else{
                list.remove(index) ;
                System.out.println("删除成功");
            }
        }
    }
    public static void Revisestudent(ArrayList<Student>list){
        Scanner scanner=new Scanner(System.in);
        System.out.println("请输入要修改学生的学号");
        String id = scanner.nextLine();
        System.out.println("请输入新名字");
        String name = scanner.nextLine();
        System.out.println("请输入新年龄");
        int age=scanner.nextInt();
        System.out.println("请输入新班级");
        int cla = scanner.nextInt();

        Student student=new Student();
        student.setId(id);
        student.setName(name);
        student.setAge(age);
        student.setClas(cla);
        for (int i = 0; i < list.size(); i++) {
            Student s=list.get(i);
            if (s.getId().equals(id)){
                list.set(i,student);
            }

        }
        System.out.println("修改成功");
    }
    public static void checkall(ArrayList<Student> list){
        if(list.size()==0){
            System.out.println("请先添加信息再查询");
            return;
        }
        System.out.println("学号：   姓名：   年龄：  班级");
        for (int i=0;i< list.size();i++){
            Student s=list.get(i);
            System.out.println(s.getId()+"   "+s.getName()+"         "+s.getAge()+"         "+s.getClas());
        }

    }
}