学生管理系统

package shf;

public class Student {
    private String sid;
    private String name;
    private String age;
    private String address;

    public Student() {
    }

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

    public String getSid() {
        return sid;
    }

    public void setSid(String sid) {
        this.sid = sid;
    }

    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;
    }

    public String getAddress() {
        return address;
    }

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

package shf;
import java.util.Scanner;
import java.util.ArrayList;
public class StudentManager {
    public static void main(String[] args) {
        ArrayList<Student> array = new ArrayList<Student>();
        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 line = sc.nextLine();

            switch (line) {
                case "1":
                    // System.out.println("添加学生");
                    addStudent(array);
                    break;
                case "2":
                    //System.out.println("删除学生");
                    deleteStudent(array);
                    break;
                case "3":
                    // System.out.println("修改学生");
                    updateStudent(array);
                    break;
                case "4":
                    //  System.out.println("查看所有学生");
                    findAllStudent(array);
                    break;
                case "5":
                    System.out.println("谢谢使用");
                    System.exit(0);
            }
        }
    }

    public static void addStudent(ArrayList<Student> array) {
        Scanner sc = new Scanner(System.in);
        String sid;
        while(true) {
            System.out.println("请输入学生学号：");
            sid = sc.nextLine();

            boolean flag = isUsed(array, sid);
            if (flag) {
                System.out.println("你输入的学号已经被使用，请重新输入");
            } else {
                break;
            }
        }
        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();
        System.out.println("请输入学生居住地：");
        String address = sc.nextLine();

        Student s = new Student();
        s.setSid(sid);
        s.setName(name);
        s.setAge(age);
        s.setAddress(address);

        array.add(s);
        System.out.println("添加学生成功");


    }

    public static boolean isUsed(ArrayList<Student> array,String sid){
        boolean flag=false;

        for(int i=0;i<array.size();i++){
         Student s=array.get(i);
         if(s.getSid().equals(sid)){
             flag=true;
             break;
         }
        }
        return flag;
    }

    public static void findAllStudent(ArrayList<Student> array) {
        if (array.size() == 0) {
            System.out.println("无信息，请添加后在查询");
            return;
        }

        System.out.println("学号\t\t姓名\t\t年龄\t\t居住地");
        for (int i = 0; i < array.size(); i++) {
            Student s = array.get(i);
            System.out.println(s.getSid() + "\t\t" + s.getName() + "\t" + s.getAge() + "岁\t" + s.getAddress());

        }
    }

    public static void deleteStudent(ArrayList<Student> array) {
        Scanner sc = new Scanner(System.in);
        System.out.println("请输入删除学生的学号：");
        String sid = sc.nextLine();
        int index = -1;

        for (int i = 0; i < array.size(); i++) {
            Student s = array.get(i);
            if (s.getSid().equals(sid)) {
                index = i;
                break;
            }
        }
        if (index == -1) {
            System.out.println("信息不存在，请重新输入");
        } else {
            array.remove(index);
            System.out.println("删除学生成功");
        }
    }

    public static void updateStudent(ArrayList<Student> array) {
        Scanner sc = new Scanner(System.in);
        System.out.println("请输入要修改的学生学号：");
        String sid = sc.nextLine();
        System.out.println("请输入学生的新姓名：");
        String name = sc.nextLine();
        System.out.println("请输入学生的新年龄：");
        String age = sc.nextLine();
        System.out.println("请输入学生的新地址：");
        String address = sc.nextLine();

        Student s = new Student();
        s.setSid(sid);
        s.setName(name);
        s.setAge(age);
        s.setAddress(address);

        int index = -1;
        for (int i = 0; i < array.size(); i++) {
            Student student = array.get(i);
            if (student.getSid().equals(sid)) {
                array.set(i, s);
                break;
            }
            System.out.println("修改学生成功");
        }
    }
}