[TOC]

功能概述：

  • 每个Student 对象存储一个学生的信息
  • 查询功能：
    • 通过姓名查询（考虑重名情况）
    • 通过学号查询
  • 修改功能：
    • 修改姓名
    • 修改学号
    • 修改年龄
    • 修改班级信息
  • 增删信息：
    • 增加/删除条目
  • 展示全部：
    • 展示当前全部信息

项目结构：

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src
    └─com
        └─stu_info_manage
            ├─controller
            │      main.java
            │      UserInput.java
            │
            ├─data
            │      Add_rm.java
            │      Change_info.java
            │      Info_Stroage.java
            │      Search.java
            │      Student.java
            │
            └─service
                    Add_rm.java
                    ChangeInfo.java
                    Search.java

实现：

首先创建一个Student标准JavaBean，包含各个get，set方法：

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package com.stu_info_manage.data;

public class Student {
    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 String getId_num() {

        return this.id_num;
    }

    public void setId_num(String id_num) {
        this.id_num = id_num;
    }

    public String getClass_info() {
        return class_info;
    }

    public void setClass_info(String class_info) {
        this.class_info = class_info;
    }


    private String name;
    private int age;
    private String id_num;
    private String class_info;
    

}

然后，根据标准Java管理系统结构，分出3个package：

  • 表层：controller
  • 服务层：service
  • 数据层：dao（我写的data）

表层中，使用Userinputt类处理用户的输入输出：

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package com.stu_info_manage.controller;
import com.stu_info_manage.data.Student;
import com.stu_info_manage.service.Search;

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

public class UserInput {

    public void print_init_info(){
        while(true){
            System.out.println("Welcome,输入你的操作");
            System.out.println("1：查询\n2.修改\n3.添加\\删除\n4.列出所有");
            Scanner init_sc = new Scanner(System.in);
            int init_choice = init_sc.nextInt();

            if (init_choice ==1)
            {
                choice1_init();

            } else if (init_choice == 2) {

                choice2_init();


            } else if (init_choice == 3) {

                add_rm_stu_init();
            } else if (init_choice == 4) {

                show_all();

            } else{
                System.out.println("请重新输入");
            }
        }


    }



    public void choice1_init(){

        stu = new Student();
        System.out.println("你想通过什么查询？，输入\n1.姓名\n2.学号");
        Scanner choice1_sc = new Scanner(System.in);
        int choice1_choice = choice1_sc.nextInt();
        if(choice1_choice == 1)
        {
            System.out.println("你选择从姓名查询");
            garbage_char = choice1_sc.nextLine();
            name = choice1_sc.nextLine();
            stu_list = new ArrayList<>();
            stu_list = Search.search_form_name(name);
        }
        if(choice1_choice == 2)
        {
            System.out.println("你选择从学号查询");
            garbage_char = choice1_sc.nextLine();
            id_num = choice1_sc.nextLine();
            stu_list = new ArrayList<>();
            stu_list = Search.search_form_id_num(id_num);
        }
        System.out.println("你的查询结果：");
        for (int i = 0; i < stu_list.size(); i++) {
            stu = stu_list.get(i);
            System.out.println("name:"+stu.getName()+" id:"+stu.getId_num()+" age:"+stu.getAge()+" class:"+stu.getClass_info());
        }

    }


    public void choice2_init(){
        System.out.println("输入你想修改的人的学号");
        Scanner choice2_sc = new Scanner(System.in);
        id_num = choice2_sc.nextLine();
        System.out.println("你选择了学号为："+id_num+" 的人");
        System.out.println("请输入你想修改的信息：\n 1.姓名 \n 2.学号 \n 3.年龄 \n 4.班级");
        int choice = choice2_sc.nextInt();
        if(choice == 1){
            System.out.println("你要将姓名改成什么：");
            String trash = choice2_sc.nextLine();
            String rename = choice2_sc.nextLine();
            System.out.println("你想将姓名修改为 "+rename);

            com.stu_info_manage.service.ChangeInfo changeInfo = new com.stu_info_manage.service.ChangeInfo();

            boolean renamed = changeInfo.Rename(rename,id_num);
            if(renamed){
                System.out.println("success!");

            }else {
                System.out.println("error!");
            }




        } else if (choice == 2) {
            System.out.println("你想将学号改成什么？");
            String trash = choice2_sc.nextLine();
            String re_id_num = choice2_sc.nextLine();
            System.out.println("你想将学号改成："+re_id_num);

            com.stu_info_manage.service.ChangeInfo changeInfo = new com.stu_info_manage.service.ChangeInfo();
            System.out.println("before: "+id_num+" after: "+re_id_num);
            boolean re_id_numed = changeInfo.Re_id_num(id_num,re_id_num);
            if(re_id_numed){
                System.out.println("success!");

            }else {
                System.out.println("error!");
            }



        } else if (choice == 3) {
            System.out.println("你想将年龄改成什么？");
            String trash = choice2_sc.nextLine();
            int reage = choice2_sc.nextInt();
            System.out.println("你想将年龄改为"+reage);
            com.stu_info_manage.service.ChangeInfo changeInfo = new com.stu_info_manage.service.ChangeInfo();
            boolean reaged = changeInfo.Reage(reage,id_num);
            if(reaged){
                System.out.println("success!");

            }else {
                System.out.println("error!");
            }


        } else if (choice == 4) {
            System.out.println("你想将班级改成什么？");
            String trash = choice2_sc.nextLine();
            String reclass= choice2_sc.nextLine();
            System.out.println("你想将班级改为"+reclass);
            com.stu_info_manage.service.ChangeInfo changeInfo = new com.stu_info_manage.service.ChangeInfo();
            boolean reclassed = changeInfo.Reclass(reclass,id_num);
            if(reclassed){
                System.out.println("success!");

            }else {
                System.out.println("error!");
            }
        }else {


        }
    }
    public void add_rm_stu_init(){
        System.out.println("加成员按1，减成员按2");
        Scanner choice3_sc = new Scanner(System.in);
        int add_or_rm = choice3_sc.nextInt();
        if(add_or_rm==1){
            System.out.println("输入姓名");
            String trush = choice3_sc.nextLine();
            String add_name = choice3_sc.nextLine();
            System.out.println("输入学号");
            String add_id = choice3_sc.nextLine();
            System.out.println("输入年龄");
            int add_age = choice3_sc.nextInt();
            System.out.println("输入班级");
            trush = choice3_sc.nextLine();
            String add_class = choice3_sc.nextLine();
            System.out.println("你想添加："+add_name+" "+add_id+" "+add_age+" "+add_class);
            com.stu_info_manage.service.Add_rm add_rm = new com.stu_info_manage.service.Add_rm();
            boolean added = add_rm.add_item(add_name,add_id,add_age,add_class);
            if(added){
                System.out.println("success!");
            }else {
                System.out.println("error!");
            }


        } else if (add_or_rm==2) {
            System.out.println("输入你要删除的学号");
            String trush = choice3_sc.nextLine();
            String rm_id = choice3_sc.nextLine();
            System.out.println("你想删除："+rm_id);
            com.stu_info_manage.service.Add_rm add_rm = new com.stu_info_manage.service.Add_rm();
            boolean rmed = add_rm.rm_item(rm_id);
            if(rmed){
                System.out.println("success!");
            }else {
                System.out.println("error!");
            }


        }


    }
    public void show_all()
    {
        com.stu_info_manage.data.Info_Stroage.show_all();
    }


    private String name;
    private int age;
    private String id_num;
    private Student stu;
    private String garbage_char;
    private ArrayList<Student> stu_list;
}

服务层中，分出 增删条目 / 修改信息 / 查找条目 三块，因为这个小系统服务层不用处理什么东西，所以基本是一个转接头的作用，不过还是写出来了框架：

  • 增删条目：
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package com.stu_info_manage.service;

public class Add_rm {
    public boolean add_item(String add_name,String add_id_num,int add_age,String add_class)
    {
        boolean added = false;
        if(add_age>30)
        {
            added = false;
        }else {
            com.stu_info_manage.data.Add_rm add_rm = new com.stu_info_manage.data.Add_rm();
            added = add_rm.add_item(add_name,add_id_num,add_age,add_class);
        }
        return added;



    }

    public  boolean rm_item(String rm_id_num){
        boolean rmed = false;
        com.stu_info_manage.data.Add_rm add_rm = new com.stu_info_manage.data.Add_rm();
        rmed = add_rm.rm_item(rm_id_num);

        return rmed;
    }

}

  • 修改信息：
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package com.stu_info_manage.service;

public class ChangeInfo {
    public boolean Rename(String rename,String id_num)
    {
        this.rename = rename;
        this.id_num = id_num;
        com.stu_info_manage.data.Change_info change_info = new com.stu_info_manage.data.Change_info();
        boolean renamed = change_info.Rename(this.id_num,this.rename);

        return renamed;

    }

    public boolean Re_id_num(String id_num,String id_num_aft)
    {
        this.id_num = id_num;
        this.id_num_aft = id_num_aft;
        com.stu_info_manage.data.Change_info change_info = new com.stu_info_manage.data.Change_info();
        boolean re_id_numed = change_info.Re_id_numed(this.id_num,this.id_num_aft);

        return re_id_numed;

    }
    public boolean Reage(int reage,String id_num)
    {
        this.reage = reage;
        this.id_num = id_num;
        com.stu_info_manage.data.Change_info change_info = new com.stu_info_manage.data.Change_info();
        boolean reaged = change_info.Reage(this.id_num,this.reage);

        return reaged;

    }
    public boolean Reclass(String reclass,String id_num)
    {
        this.reclass = reclass;
        this.id_num = id_num;
        com.stu_info_manage.data.Change_info change_info = new com.stu_info_manage.data.Change_info();
        boolean reclassed = change_info.Reclass(this.id_num,this.reclass);

        return reclassed;

    }

    private String rename;
    private String reclass;
    private int reage;
    private String id_num;
    private String id_num_aft;

}




  • 查找条目：
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package com.stu_info_manage.service;
import com.stu_info_manage.data.Student;

import java.util.ArrayList;

public class Search {
    public static ArrayList<Student> search_form_name(String name)
    {
        Search sh = new Search();
        sh.name = name;
        com.stu_info_manage.data.Search sh_data = new com.stu_info_manage.data.Search();
        sh.stu_list = new ArrayList<>();
        sh.stu_list = sh_data.search_form_name(sh.name);

        return  sh.stu_list;

    }
    public static ArrayList<Student> search_form_id_num(String id_num)
    {
        Search sh = new Search();
        sh.id_num = id_num;
        com.stu_info_manage.data.Search sh_data = new com.stu_info_manage.data.Search();
        sh.stu_list = new ArrayList<>();
        sh.stu_list = sh_data.search_form_id_num(sh.id_num);

        return sh.stu_list;

    }
    private String name;
    private String id_num ;
    private int age;
    static private Student stu;
    private ArrayList<Student> stu_list;
}

数据层同样分出三层，也相当于转接头，不予列出

最终数据处理在Info_stroage类中：

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package com.stu_info_manage.data;
import java.util.ArrayList;
import java.util.Arrays;

public class Info_Stroage {
    public static void init_example()
    {
        stu_null = new Student();
        stu_null .setName("null");
        stu_null.setAge(000);
        stu_null.setId_num("000");

        students = new Student[100];
        for (int i = 0; i < students.length; i++) {
            students[i] = new Student();
        }
        students[0].setName("ctx");
        students[0].setAge(20);
        students[0].setId_num("2023211949");
        students[0].setClass_info("23dx0211");

        students[2].setName("ctx");
        students[2].setAge(21);
        students[2].setId_num("2023211950");
        students[2].setClass_info("23dx0211");

        students[1].setName("zwc");
        students[1].setAge(20);
        students[1].setId_num("2023211940");
        students[1].setClass_info("23dx0210");

        stu_num = 3;
    }

    public static ArrayList<Student> getStudents_name(String name) {
        stu_list = new ArrayList<>();
        int stu_num  = 0;
        for (int i = 0; i < students.length; i++) {

            if (students[i].getName()!=null&&students[i].getName().equals(name))
            {
                System.out.println("find the studrent:"+i);
                stu_list.add(students[i]);
                stu_num ++ ;
            }

        }

        if(stu_num==0){
            System.out.println("stu_name_is_null");
            stu_list.add(stu_null);
        }

        return stu_list;
    }

    public static ArrayList<Student> getStudents_id_num(String id_num) {
        stu_list = new ArrayList<>();
        int stu_num = 0;
        for (int i = 0; i < students.length; i++) {

            if (students[i].getId_num()!=null && students[i].getId_num().equals(id_num))
            {
                System.out.println("find the studrent:"+i);
                stu_list.add(students[i]);
                stu_num++;
            }

        }
        if(stu_num == 0)
        {
            System.out.println("the student is null");
            stu_list.add(stu_null);
        }

        return stu_list;
    }

    public static boolean Rename(String id_num,String rename)
    {
        boolean renamed = false;
        for (int i = 0; i < students.length; i++) {
            if(students[i].getId_num()!=null&&students[i].getId_num().equals(id_num))
            {
                students[i].setName(rename);
                renamed = true;

            }

        }
        return renamed;
    }
    public static boolean Re_id_num(String id_num_pre,String id_num_aft)
    {
        boolean re_id_numed = false;
        for (int i = 0; i < students.length; i++) {
            if(students[i].getId_num()!=null&&students[i].getId_num().equals(id_num_pre))
            {
                System.out.println("find_stu"+i);
                students[i].setId_num(id_num_aft);
                re_id_numed = true;

            }

        }
        System.out.println(re_id_numed);
        return re_id_numed;
    }
    public static boolean Reage(String id_num,int reage)
    {
        boolean reaged = false;
        for (int i = 0; i < students.length; i++) {
            if(students[i].getId_num()!=null&&students[i].getId_num().equals(id_num))
            {
                students[i].setAge(reage);
                reaged = true;

            }

        }
        return reaged;
    }
    public static boolean Reclass(String id_num,String reclass)
    {
        boolean reclassed = false;
        for (int i = 0; i < students.length; i++) {
            if(students[i].getId_num()!=null&&students[i].getId_num().equals(id_num))
            {
                students[i].setClass_info(reclass);
                reclassed = true;

            }

        }
        return reclassed;
    }

    public static boolean add_item(String add_name,String add_id_num,int add_age,String add_class)
    {
        boolean added = false;
        students[stu_num].setName(add_name);
        students[stu_num].setId_num(add_id_num);
        students[stu_num].setAge(add_age);
        students[stu_num].setClass_info(add_class);
        stu_num++;
        added = true;
        return added;
    }

    public static boolean rm_item(String rm_id_num){
        boolean rmed = false;
        int loc = 0;
        for (int i = 0; i < students.length; i++) {
            if(students[i].getId_num().equals(rm_id_num)) {
                loc = i;
                break;
            }

        }
        for (int i = loc; i < stu_num; i++) {
            students[i] = students[i+1];
        }

        stu_num--;
        rmed = true;
        return rmed;
    }

    public static void show_all()
    {
        System.out.println("total: "+stu_num);
        for (int i = 0; i < stu_num; i++) {
            System.out.println("name: "+students[i].getName()+" age: "+students[i].getAge()+" id: "+students[i].getId_num()+" class: "+students[i].getClass_info());
        }
    }
    private static Student[] students;
    private static Student stu_null;
    private static ArrayList<Student> stu_list;
    private static int stu_num;

}

开发记录

1.ArrayList 的使用

在存储对象的时候，一开始想把对象存储在数组中，也就是对象数组，当然最后也是这么存的，但在查找类的构建过程中，意识到可能存在重名情况，因此不能固定返回一个Student对象，而应该返回一个数组

然而，数组的长度是不确定的，所以引入ArrayList可变长数组来进行对象的动态数目存储

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// new ArrayList 对象：
ArrayList<Student> stu_list = new ArrayList();

//增加元素：
stu_list.add(stu_example);

//作为函数返回值：
public ArrayList<stduent> method()
{
    
}