Java图书馆管理系统

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本文链接： https://blog.csdn.net/lijiangjiajun/article/details/102701279

思路：所有包都在book_manage包里
利用面向对象的多态特性去除了很多if-else的判断，不同的子类在父类所对应的方法不同。

1.首先建立一个book包
包里面有2个类，一个是Book,这个类里面包含一本书的全部信息
另外一个类是BookList，这个类是用来管理每一个书，通过这个类来寻找每一本书。
private Book[] books = new Book[100];
Book数组里面存放所有的书。

2.再建立一个包Operation 这个类里面有一个OI接口，通过对接口里面的Work方法重写，来实现管理员身份和普通用户身份的不同操作。

3.最后建立一个User包，里面有三个类，User，Admin,NormalUser
Admin和NormalUser都继承自User.
User里秒你有一个数组
protected IO[] operation;
这个数组里面包含了用户或者管理员所具备的操作。
通过对数组的索引来确定具体需要调用的操作方法。

下面来看看代码吧：
book包
Book类

package book_manager.book;

public class Book {
    private String name;
    private String id;
    private String author;
    private int price;
    private String type;
    private boolean isBorrow;

    public Book(String name, String id, String author, int price,
                String type, boolean isBorrow) {
        this.name = name;
        this.id = id;
        this.author = author;
        this.price = price;
        this.type = type;
        this.isBorrow = isBorrow;
    }

    @Override     //Object中内置的类，用来格式化打印book的信息
    public String toString() {
        return "Book{" +
                "name='" + name + '\'' +
                ", id='" + id + '\'' +
                ", author='" + author + '\'' +
                ", price=" + price +
                ", type='" + type + '\'' +
                ", isBorrow=" + isBorrow +
                '}';
    }

    public String getName(){
        return name;
    }

    public boolean isBorrow(){
        return isBorrow;
    }

    public void setBorrow(boolean bool){
        this.isBorrow=bool;
    }

    public String getId(){
        return id;
    }
}

BookList类

package book_manager.book;

import java.util.Arrays;

public class BookList {
        private Book[] books = new Book[100];
        private int size;
     public BookList(){
        books[0] = new Book("金瓶梅",
                "001", "兰陵笑笑生", 100,
                "古典名著", false);
        books[1] = new Book("水浒传",
                "002", "施耐庵", 100,
                "古典名著", false);
        books[2] = new Book("西游记",
                "003", "吴承恩", 100,
                "古典名著", false);
        size = 3;
    }

    public int getSize(){
         return size;
    }

    public void setBooks(int index,Book book){
         books[index]=book;
    }

    public void setSize(int size){
            this.size=size;
    }

    public  Book getBook(int index){
         return books[index];
    }
}

Operation包：
ADD类

package book_manager.Operation;

import book_manager.book.*;

import java.util.Scanner;

public class ADD implements IO{

    @Override
    public void work(BookList bookList) {
        Scanner scanner = new Scanner(System.in);
        System.out.println("请输入书名");
        String name =scanner.next();
        System.out.println("请输入序号");
        String id = scanner.next();
        System.out.println("请输入作者");
        String author =scanner.next();
        System.out.println("请输入价格");
        int price = scanner.nextInt();
        System.out.println("请输入类型");
        String type = scanner.next();
        Book book = new Book(name, id,
                author, price, type, false);
        bookList.setBooks(bookList.getSize(),book);
        bookList.setSize(bookList.getSize()+1);
        System.out.println("添加成功");
    }
}

Borrow类

package book_manager.Operation;

import book_manager.book.Book;
import book_manager.book.BookList;

import java.util.Scanner;

public class Borrow implements IO{
    @Override
    public void work(BookList bookList) {
        int i=0;
        int flag=0;
        Scanner scan = new Scanner(System.in);

        System.out.println("请输入需要借阅的书名");
        String name = scan.next();
        for(;i<bookList.getSize();i++){
            if(name.equals(bookList.getBook(i).getName())){
                if(bookList.getBook(i).isBorrow()==false){
                    System.out.println("借阅成功");
                    flag=1;
                    bookList.getBook(i).setBorrow(true);
                }

                }
            }
        if(flag==0){
            System.out.println("不好意思，借阅失败");
        }

    }
}

Delete类

package book_manager.Operation;

import book_manager.book.BookList;

import java.util.Scanner;

public class Delete implements IO{

    public void work(BookList bookList){
        Scanner scanner = new Scanner(System.in);
        System.out.println("请输入想要删除的编号");
        String id  = scanner.next();
        for(int i=0;i<bookList.getSize();i++){
            if(bookList.getBook(i).getId().equals(id)){
                bookList.setBooks(i,bookList.getBook(bookList.getSize()));
                bookList.setSize(bookList.getSize()-1);
                System.out.println("删除成功");
            }
            else{
                System.out.println("删除失败");
            }
        }
    }
}

Exit类

package book_manager.Operation;

import book_manager.book.BookList;

public class Exit implements IO{
    @Override
    public void work(BookList bookList) {
        System.out.println("退出成功");
        System.exit(0);
    }
}

Find类

package book_manager.Operation;

import book_manager.book.BookList;

import java.util.Scanner;

public class Find implements IO{
    @Override
    public void work(BookList bookList) {
        int i=0;
        int count=0;
        Scanner scan = new Scanner(System.in);

        System.out.println("请输入需要查找的书名");
        String name = scan.next();
        for(;i<bookList.getSize();i++){
            if(name.equals(bookList.getBook(i).getName())){
                count++;
            }
        }
        if(count==0){
            System.out.println("不好意思，没有找到");
        }
        else{
            System.out.println("找到了，共计"+count+"本");
        }
    }
}

IO接口

package book_manager.Operation;

import book_manager.book.BookList;

public interface IO {
    abstract public void work(BookList bookList);
}

PrintAll类

package book_manager.Operation;

import book_manager.book.BookList;

public class PrintAll implements IO{
    @Override
    public void work(BookList bookList) {
        for(int i=0;i<bookList.getSize();i++){
            System.out.println(bookList.getBook(i));
        }
    }

}

Return类

package book_manager.Operation;

import book_manager.book.BookList;

import java.util.Scanner;

public class Return implements IO{
    @Override
    public void work(BookList bookList) {
        int i=0;
        int flag=0;
        Scanner scan = new Scanner(System.in);

        System.out.println("请输入需要归还的ID");
        String id = scan.next();
        for(;i<bookList.getSize();i++){
            if(id.equals(bookList.getBook(i).getId())){
                if(bookList.getBook(i).isBorrow()==true){
                    System.out.println("归还成功");
                    bookList.getBook(i).setBorrow(false);
                    flag=1;
                }
                else{
                    System.out.println("归还失败");
                }
            }

        }
        if(flag==0){
            System.out.println("不好意思，没有此书");
        }

    }
}

user包:
User类

package book_manager.user;

import book_manager.Operation.*;
import book_manager.Operation.IO;
import book_manager.book.BookList;

abstract public class User {
    String name;
    protected IO[] operation;

    public User(String name){
        this.name=name;
    }

    abstract public int menu();//该方法被重写
    public void doOperation(int choice, BookList bookList) {
        operation[choice].work(bookList);
    }
}

Admin类

package book_manager.user;

import book_manager.Operation.*;

import java.util.Scanner;

public class Admin extends User{
    public Admin(String name){
        super(name);
        operation=new IO[]{
                new Exit(),
                new Find(),
                new ADD(),
                new Delete(),
                new PrintAll(),
        };

    }



    public int menu() {
        System.out.println("============");
        System.out.println("hello " + name);
        System.out.println("1. 查找书籍");
        System.out.println("2. 增加书籍");
        System.out.println("3. 删除书籍");
        System.out.println("4. 打印所有信息");
        System.out.println("0. 退出");
        System.out.println("============");
        System.out.println("请输入您的选择: ");
        Scanner scanner = new Scanner(System.in);
        int choice = scanner.nextInt();
        return choice;
    }
    
}

NormalUser

package book_manager.user;

import book_manager.Operation.*;

import java.util.Scanner;

public class NormalUser extends User{
    public NormalUser(String name){
        super(name);
        operation=new IO[]{
                new Exit(),
                new Find(),
                new Borrow(),
                new Return(),
                new PrintAll()
        };
    }
    public int menu() {
        System.out.println("============");
        System.out.println("hello " + name);
        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("4. 查看全部书籍");
        System.out.println("0. 退出");
        System.out.println("============");
        System.out.println("请输入您的选择: ");
        Scanner scanner = new Scanner(System.in);
        int choice = scanner.nextInt();
        // close 本质上是在关闭 System.in
        // 由于后面还需要用到 System.in, 此处不能盲目关闭.
        // scanner.close();
        return choice;
    }

}

最后还有一个Test类，里面放了main函数

package book_manager;

import book_manager.book.BookList;
import book_manager.user.Admin;
import book_manager.user.NormalUser;
import book_manager.user.User;

import java.util.Scanner;

public class Test {
    public static void main(String[] args) {
        BookList list = new BookList();
        User user = login();
        //通过不同的choice和身份调用不同的Operation方法
            while(true){
            int choice = user.menu();
            user.doOperation(choice, list);
        }
    }

    public static User login(){
        Scanner scanner = new Scanner(System.in);
        System.out.println("请输入你的姓名");
        String name = scanner.next();
        System.out.println("请输入你的身份");
        System.out.println("1.普通用户 2.管理员");
        int role= scanner.nextInt();
        if(role==1){
            return new NormalUser(name);
        }
        else{
            return new Admin(name);
        }

    }
}