JAVA学习历程记录（五）

JAVA学习历程记录（五）

使用ArrayList和while循环实现一个学生管理系统。包含增加学生，删除学生，查看学生以及修改学生信息功能。在内存中实现即可，不需要做本地持久化

package studentsystem;

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

public class MangerSystem {
    public static void main(String[] args) {
        Scanner sc = new Scanner(java.lang.System.in);
        ArrayList<Student> array = new ArrayList<>();
        int i = -1;
        int k = -1;


        while (i == -1 ){
            add(array);
            System.out.println("输入-1继续输入，输入任意正整数退出添加");
            i = sc.nextInt();
        }
        while ( k == -1){
        System.out.println("请选择您接下来的操作");
        System.out.println("若要退出系统，输入1,否则输入其他整数继续");
        k = sc.nextInt();
        if (k==1)
            return;
        System.out.println("1.增加学生信息");
        System.out.println("2.删除学生信息");
        System.out.println("3.查看全部学生信息");
        System.out.println("4.搜索学生信息");
        System.out.println("5.修改学生信息");
        String a = sc.next();
        switch (a) {
            case "1":
                int b =-1;
                while (b == -1 ){
                    add(array);
                    System.out.println("输入-1继续输入，输入任意正整数退出添加");
                    b = sc.nextInt();
                }
                break;
            case "2":
                System.out.println("请输入要删除学生信息的学号");
                int num = sc.nextInt();
                ad2(array,num);
                break;
            case "3":
                ad3(array);
                break;
            case "4":
                System.out.println("请输入要搜索学生信息的学号");
                int num1 = sc.nextInt();
                ad4(array,num1);
                break;
            case "5":
                System.out.println("请输入要修改学生信息的学号");
                int num2 = sc.nextInt();
                ad5(array,num2);
                break;
        }
        k = -1;

        }

    }




    private static void ad1(ArrayList<Student> student, String na) {
            add(student);
    }


    private static void ad2(ArrayList<Student> array,int num){
        for (int i = 0;i < array.size();i++){
            Student s = array.get(i);
            if (s.getNum() == num){
                array.remove(i);
                break;
            }
            else if (i == array.size() - 1)
                System.out.println("没有找到");
        }
    }

    private static void ad3(ArrayList<Student> array){
        if (array.size() == 0) {
            System.out.println("集合中没有元素");
            return;
        }
        for (int i = 0;i < array.size();i++){
            Student s = array.get(i);
            System.out.println( s.num + "\t" + s.name + "\t" + s.sex + "\t" +  s.age + "\t" + s.grade);
        }
    }
    private static void ad4(ArrayList<Student> array,int num){
        if (array.size() == 0) {
            System.out.println("集合中没有元素");
            return;
        }
        for (int i = 0;i < array.size();i++){

            Student s = array.get(i);
            if (s.num == num)
            System.out.println( s.num + "\t" + s.name + "\t" + s.sex + "\t" +  s.age + "\t" + s.grade);
        }
    }
    private static void ad5(ArrayList<Student> array,int num){
        Scanner sc = new Scanner(System.in);
        if (array.size() == 0) {
            System.out.println("集合中没有元素");
            return;
        }
        for (int i = 0;i < array.size();i++){
            Student s = array.get(i);
            if (s.num == num) {
                System.out.println("1.修改姓名");
                System.out.println("2.修改性别");
                System.out.println("3.修改年龄");
                System.out.println("4.修改成绩");
                System.out.println("请输入要修改的内容");
                int a = sc.nextInt();
                System.out.println("请输入修改后的内容");
                String str = sc.next();
                switch (a){
                    case 1:
                        s.setName(str);
                        break;
                    case 2:
                        s.setSex(str);
                        break;
                    case 3:
                        s.setAge(str);
                        break;
                    case 4:
                        s.setGrade(str);
                        break;
                }

            }
            else if (i == array.size() - 1)
                System.out.println("没有该学生");
        }

    }


    private static void  add(ArrayList<Student> array) {
        Scanner sc = new Scanner(System.in);
        Student s = new Student();
        System.out.println("接下来输入学生信息");
        System.out.println("输入学号");
        s.num = sc.nextInt();
        for (int i = 0;i < array.size();i++){
            Student stu = array.get(i);
            while (stu.num == s.num){
                System.out.println("学号重复，请重新输入");
                s.num = sc.nextInt();}
        }
            System.out.println("输入学生姓名，名字中不能包含数字");
            s.name = sc.next();
            while(s.name.matches(".*\\d.*")){
                System.out.println("姓名输入错误，请重新输入");
                s.name = sc.next();
            }
            System.out.println("输入学生年龄，年龄不能超过三位数");
            s.age = sc.next();
            while(!s.age.matches("[\\d]{1,2}")){
                System.out.println("年龄输入错误，请重新输入");
                s.age = sc.next();
            }

            System.out.println("输入学生性别，男或者女");
            s.sex = sc.next();
            while (!(s.sex.equals("男") || s.sex.equals("女"))){
                System.out.println( "性别输入错误，请重新输入");
                s.sex = sc.next();
            }

            System.out.println("输入学生成绩，成绩不能超过三位数");
            s.grade = sc.next();
            while (!s.grade.matches("[\\d]{1,2}")){
                System.out.println("成绩输入错误，请重新输入");
                s.grade = sc.next();
            }
            Student stu = new Student(s.num,s.name,s.sex,s.age,s.grade);
            array.add(s);

    }
    static class Student {
        int num;
        String name;
        String sex;
        String age;
        String grade;
        public Student(){

        }

        public Student(int num,String name, String sex, String age, String grade) {
            this.age = age;
            this.grade = grade;
            this.name = name;
            this.sex = sex;
            this.num = num;
        }

        public int getNum() {
            return num;
        }

        public void setNum(int num) {
            this.num = num;
        }

        public String getName() {
            return name;
        }

        public void setName(String name) {
            this.name = name;
        }

        public String getSex() {
            return sex;
        }

        public void setSex(String sex) {
            this.sex = sex;
        }

        public String getAge() {
            return age;
        }

        public void setAge(String age) {
            this.age = age;
        }

        public String getGrade() {
            return grade;
        }

        public void setGrade(String grade) {
            this.grade = grade;
        }
    }}