图书管理系统

目录

前言：

需求分析

核心分析

包的设计

代码实现 

user包

book包

operation包

小结：

---

前言：

    面向对象编程，首先分析需求，抽象出来对象。对具体的对象在进行细分，比如对象之间的分类，用不同的包去维护不同类别的对象，具体类别的对象还可以进行共性的抽取，后期开发也好进行一些操作。

需求分析

🎈图书管理系统，有管理员和普通用户，书籍的信息，对书籍的查看，添加，修改等等一些操作。

🎈首先把普通用户和管理员，和书抽象出来对象。前两者和书可以分为两个类别。普通用户和管理员都是对系统的使用者，可以进行共性的抽取。对于书来说，只是一个单纯的对象，而对于图书管理系统来说需要对大量书籍进行管理，因此可以用这个对象设置一个书架，也就是数组，我们只需要对这个数组进行操作。对于书籍的一些操作，可以认为是一些标准的行为，可以实现一个接口，让每一个操作去实现这些接口。

核心分析

🪖最后需要我们把，各种对象，各种操作整合起来。根据用户选择来实例化管理员对象或者普通用户对象，用它们的父类引用类型接收（向上提升）。根据用户选择进行相应操作，那么就需要调用各种操作类里面的方法，管理员或者普通用户实例化对象时，将各种操作的对象存储起来，我们只需要选择不同对象去调用不同操作方法即可。

包的设计

代码实现 

user包

AdminUser类

package user;
 
import operation.*;
 
import java.util.Scanner;
 
public class AdminUser extends User{
    public AdminUser(String name) {
        super(name);
        this.iOperations = new IOperation[]{
                new ExitOperation(),
                new FindOperation(),
                new AddOperation(),
                new DelOperation(),
                new ShowOperation(),
        };
    }
    public int menu() {
        System.out.println("欢迎" + this.name + "来到图书小练习");
        System.out.println("1. 查找图书");
        System.out.println("2. 新增图书");
        System.out.println("3. 删除图书");
        System.out.println("4. 显示图书");
        System.out.println("0. 退出系统");
        System.out.println("请选择你的操作：");
        Scanner scan = new Scanner(System.in);
        int choose = scan.nextInt();
        return choose;
    }
 
}

NormalUser类

package user;
 
import operation.*;
 
import java.util.Scanner;
 
public class NormalUser extends User{
    public NormalUser(String name) {
        super(name);
        this.iOperations = new IOperation[]{
                new ExitOperation(),
                new FindOperation(),
                new BorrowOperation(),
                new ReturnOperation()
        };
    }
    public int menu() {
        System.out.println("欢迎" + this.name + "来到图书小练习");
        System.out.println("1. 查找图书");
        System.out.println("2. 借阅图书");
        System.out.println("3. 归还图书");
        System.out.println("0. 退出系统");
        System.out.println("请选择你的操作：");
        Scanner scan = new Scanner(System.in);
        int choose = scan.nextInt();
        return choose;
    }
}

User抽象类

package user;
 
import book.BookList;
import operation.IOperation;
 
public abstract class User {
    protected String name;
 
    IOperation[] iOperations;
    public User(String name) {
        this.name = name;
    }
    public abstract int menu();
    public void doOpeation(int choose, BookList bookList) {
        iOperations[choose].work(bookList);
    }
}

Main类（主类）

import book.BookList;
import user.AdminUser;
import user.NormalUser;
import user.User;
 
import java.util.Scanner;
 
public class Main {
    private static User login() {
 
        System.out.println("请输入你的姓名：");
        Scanner scan = new Scanner(System.in);
        String name = scan.nextLine();
        System.out.println("请输入你的身份  1. 管理员  0. 普通用户");
        int choose = scan.nextInt();
        if(choose == 1){
            return new AdminUser(name);
        }else {
            return new NormalUser(name);
        }
 
    }
    public static void main(String[] args) {
        BookList bookList = new BookList();
 
 
        User user = login();
        while(true) {
            int choose = user.menu();
            user.doOpeation(choose,bookList);
        }
 
    }
}

book包

Book类

package book;
 
public class Book {
    private String name;
    private String author;
    private int price;
    private String type;
    private boolean isBorrow;
 
    public Book(String name, String author, int price, String type) {
        this.name = name;
        this.author = author;
        this.price = price;
        this.type = type;
    }
 
    public String getName() {
        return name;
    }
 
    public void setName(String name) {
        this.name = name;
    }
 
    public String getAuthor() {
        return author;
    }
 
    public void setAuthor(String author) {
        this.author = author;
    }
 
    public int getPrice() {
        return price;
    }
 
    public void setPrice(int price) {
        this.price = price;
    }
 
    public String getType() {
        return type;
    }
 
    public void setType(String type) {
        this.type = type;
    }
 
    public Boolean getBorrow() {
        return isBorrow;
    }
 
    public void setBorrow(Boolean borrow) {
        isBorrow = borrow;
    }
 
    @Override
    public String toString() {
        return "Book{" +
                "name='" + name + '\'' +
                ", author='" + author + '\'' +
                ", price=" + price +
                ", type='" + type + '\'' +
                ", isBorrow=" + (isBorrow == true ? " 已借出" :" 未借出")+
                '}';
    }
}

BookList类

package book;
 
public class BookList {
    //引用数组
    private Book[] books = new Book[10];
    private int usedSize;
 
    public BookList() {
        books[0] = new Book("三国演义","罗贯中", 89,"小说");
        books[1] = new Book("红楼梦","曹雪芹",78,"小说");
        books[2] = new Book("西游记","吴承恩",99,"小说");
       this.usedSize = 3;
    }
 
    public int getUsedSize() {
        return usedSize;
    }
 
    public void setUsedSize(int usedSize) {
        this.usedSize = usedSize;
    }
 
    public Book getPos(int i){
        return books[i];
    }
    public void setBook(Book book, int pos) {
        books[pos] = book;
    }
 
}

operation包

AddOperation类

package operation;
 
import book.Book;
import book.BookList;
 
import java.util.Scanner;
 
public class AddOperation implements IOperation{
    public void work(BookList bookList) {
        System.out.println("请输入你要增加的书名：");
        Scanner scan = new Scanner(System.in);
        String bookName = scan.nextLine();
        System.out.println("请输入作者：");
        String author = scan.nextLine();
 
        System.out.println("请输入类型");
        String type = scan.nextLine();
        //防止nextInt读取回车
        System.out.println("请输入价格：");
        int price = scan.nextInt();
 
        Book book = new Book(bookName,author,price,type);
        bookList.setBook(book,bookList.getUsedSize());
 
        bookList.setUsedSize(bookList.getUsedSize() + 1);
    }
}

BorrowOperation类

package operation;
 
import book.BookList;
 
import java.util.Scanner;
 
public class BorrowOperation implements IOperation{
    public void work(BookList bookList) {
        System.out.println("借阅图书");
        System.out.println("请输入你要借阅的图书");
        Scanner scan = new Scanner(System.in);
        String name = scan.nextLine();
        for (int i = 0; i < bookList.getUsedSize(); i++) {
            if(name.equals(bookList.getPos(i).getName())) {
                if(bookList.getPos(i).getBorrow()) {
                    System.out.println("抱歉你要借阅的图书以借出");
                    return;
                } else {
                    bookList.getPos(i).setBorrow(true);
                    System.out.println("借阅成功");
                    return;
                }
            }
        }
        System.out.println("抱歉，没有你要借阅的图书");
    }
}

DelOperation类

package operation;
 
import book.BookList;
 
import java.util.Scanner;
 
public class DelOperation implements IOperation{
    public void work(BookList bookList) {
        System.out.println("删除图书");
        System.out.println("请输入你要删除图书的名字：");
        Scanner scan = new Scanner(System.in);
        String name = scan.nextLine();
        for(int i = 0; i < bookList.getUsedSize(); i++) {
            if(name.equals(bookList.getPos(i).getName())){
                for(int j = i; j < bookList.getUsedSize() - 1; j++) {
                    bookList.setBook(bookList.getPos(j + 1), j);
                }
                //防止内存泄漏，删除后数组最后一位数据还引用着对象
                bookList.setBook(null,bookList.getUsedSize() - 1);
                bookList.setUsedSize(bookList.getUsedSize() - 1);
                System.out.println("删除成功");
                return;
            }
        }
        System.out.println("抱歉，没有你要删除的图书");
 
    }
 
}

ExitOperation类

package operation;
 
import book.BookList;
 
public class ExitOperation implements IOperation{
    public void work(BookList bookList) {
        System.out.println("退出系统");
        System.exit(0);
    }
 
}

FindOperation类

package operation;
 
import book.BookList;
 
import java.util.Scanner;
 
public class FindOperation implements IOperation{
    public void work(BookList bookList) {
        System.out.println("查找图书");
        System.out.println("请输入你要查找的书名");
        Scanner scan = new Scanner(System.in);
        String bookName = scan.nextLine();
        for(int i = 0; i < bookList.getUsedSize(); i++){
            if(bookName.equals(bookList.getPos(i).getName())){
                System.out.println("你要查找图书的信息");
                System.out.println(bookList.getPos(i));
                return;
            }
        }
        System.out.println("抱歉，没有你要查找的图书");
    }
}

ReturnOperation类

package operation;
 
import book.BookList;
 
import java.util.Scanner;
 
public class ReturnOperation implements IOperation{
    public void work(BookList bookList) {
        System.out.println("归还图书");
        System.out.println("请输入你要归还的书名：");
        Scanner scan = new Scanner(System.in);
        String name = scan.nextLine();
        for(int i = 0; i < bookList.getUsedSize(); i++) {
            if(name.equals(bookList.getPos(i).getName())) {
                if(bookList.getPos(i).getBorrow()) {
                    bookList.getPos(i).setBorrow(false);
                    System.out.println("归还成功");
                    return;
                }else {
                    System.out.println("你的书已经归还，无需再次归还");
                    return;
                }
 
            }
        }
        System.out.println("没有你要归还的图书");
    }
}

ShowOperation类

package operation;
 
import book.BookList;
 
public class ShowOperation implements IOperation{
    public void work(BookList bookList) {
        for(int i = 0; i < bookList.getUsedSize(); i++){
            System.out.println(bookList.getPos(i));
        }
    }
}

IOperation接口

package operation;
 
import book.BookList;
 
public interface IOperation {
    void work(BookList bookList);
}

小结：

🐵面向对象编程，需求分析，框架搭建，然后才是核心代码的编写，需要大量去思考，锻炼自己的这种思维。