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简单的图书管理系统

二、各个类的实现

1.book类

（1）Book

package book;
public class Book {
    private String name;//书名
    private String author;//作者
    private int price;//价格
    private String type;//类型
    private boolean isBorrowed;//是否借出

    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 isBorrowed() {
        return isBorrowed;
    }

    public void setBorrowed(boolean borrowed) {
        isBorrowed = borrowed;
    }

    @Override
    public String toString() {
        return "Book{" +
                "name='" + name + '\'' +
                ", author='" + author + '\'' +
                ", price=" + price +
                ", type='" + type + '\'' +
                ((isBorrowed == true) ? " 已经被借出 " : " 未被借出 ") +
                '}';
    }
}

（2）BookList

package book;

public class BookList {
    private Book[] books = new Book[10];
    private int usedSize;

    public BookList() {
        books[0] = new Book("三国演义","罗贯中",17,"小说");
        books[1] = new Book("西游记","吴承恩",47,"小说");
        books[2] = new Book("水浒传","施耐庵",37,"小说");
        this.usedSize = 3;
    }

    public int getUsedSize() {
        return usedSize;
    }

    public void setUsedSize(int usedSize) {
        this.usedSize = usedSize;
    }

    //获取到pos位置的一本书
    public Book getPos(int pos) {
        return this.books[pos];
    }

    //设置Pos下标为一本书->[添加一本书]
    public void setBook(int pos,Book book) {
        this.books[pos] = book;
    }

}

2.operation类

（1）IOperation

因为Operation包中各个操作都需要用到book,所以创建一个接口IOperation，以便提高程序运行的效率.

package operation;
import book.BookList;
import java.util.Scanner;

public interface IOperation {
    Scanner scanner=new Scanner(System.in);
    void work(BookList bookList);
}

（2）AddOperation

package operation;

import book.Book;
import book.BookList;

public class AddOperation implements IOperation{
       public void work(BookList bookList){
           System.out.println("新增图书！");
           System.out.println("新增图书的名字：");
           String name =scanner.nextLine();
           System.out.println("请输入图书的作者：");
           String author = scanner.nextLine();
           System.out.println("请输入图书的价格：");
           int price = scanner.nextInt();
           System.out.println("请输入图书的类型：");
           String type = scanner.nextLine();

           Book book =new Book(name,author,price,type);
           int size=bookList.getUsedSize();
           bookList.setBook(size,book);
           bookList.setUsedSize(size+1);
           System.out.println("新增图书成功！");
       }
}

（3）BorrowOperation

package operation;

import book.BookList;
import book.Book;

public class BorrowOperation implements IOperation{
    public void work(BookList bookList){
        System.out.println("借阅图书！");
        System.out.println("请输入你想借阅图书的名字：");
        String name = scanner.nextLine();
        int size=bookList.getUsedSize();
        for (int i=0;i<size;i++){
            Book book=bookList.getPos(i);
            if(name.equals(book.getName())){
                book.setBorrowed(true);
                System.out.println("借阅成功！");
                System.out.println(book);
                return;
            }
        }
        System.out.println("不存在你需要借阅的书籍！");
    }
}

（4）DelOperation

package operation;

import book.Book;
import book.BookList;

public class DelOperation implements IOperation{
    public void work(BookList bookList){
        System.out.println("删除图书！");
        //1.根据书名找到书的位置 index
        System.out.println("请输入你要删除的书的名字：");
        String name = scanner.nextLine();
        int currentSize = bookList.getUsedSize();
        int index = 0;//存储找到的下标
        int i=0;
        for (;i<currentSize;i++){
            Book book=bookList.getPos(i);
            if(book.getName().equals(name)){
                index=i;
                break;
            }
        }
        if (i>=currentSize){
            System.out.println("没有你要删除的这本书！");
            return;
        }
        //2.进行删除
        for (int j=0;j<currentSize-1;j++){
            Book book=bookList.getPos(j+1);
            bookList.setBook(j,book);
        }
        bookList.setBook(currentSize,null);
        bookList.setUsedSize(currentSize-1);
        System.out.println("删除成功！");
    }
}

（5）DisplayOperation

package operation;

import book.BookList;
import book.Book;

public class DisplayOperation implements IOperation {
    public void work(BookList bookList){
        System.out.println("打印图书！");
        int size=bookList.getUsedSize();
        for (int i=0;i<size;i++){
            Book book=bookList.getPos(i);
            System.out.println(book);
        }
    }
}

（6）ExitOperation

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);
    }
}

（7）FindOperation

package operation;

import book.BookList;
import book.Book;

public class FindOperation implements IOperation{
    public void work(BookList bookList) {
        System.out.println("查找图书：");
        String name=scanner.nextLine();
        int size=bookList.getUsedSize();
        for (int i=0;i<size;i++){
            Book book=bookList.getPos(i);
            if(name.equals(book.getName())){
                System.out.println("找到了这本书，信息如下：");
                System.out.println(book);
                return;
            }
        }
        System.out.println("没有找到这本书！");
    }
}

（8）ReturnOperation

package operation;

import book.Book;
import book.BookList;

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的名字：");
        String name=scanner.nextLine();
        int size=bookList.getUsedSize();
        for (int i=0;i<size;i++){
            Book book=bookList.getPos(i);
            if (name.equals(book.getName())){
                book.setBorrowed(false);
                System.out.println("归还成功！");
                System.out.println(book);
                return;
            }
        }
        System.out.println("没有你要归还的书！");
    }
}

3.user类

（1）AdminUser

package user;

import book.BookList;
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 DisplayOperation()
        };
    }

    public int menu() {
        System.out.println("===========管理员菜单===========");
        System.out.println("hello " + this.name +" 欢迎来到这里！");
        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("==============================");
        Scanner scanner = new Scanner(System.in);
        int choice = scanner.nextInt();
        return choice;
    }
}

（2）NormalUser

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("===========普通用户的菜单===========");
        System.out.println("hello " + this.name +" 欢迎来到这里！");
        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("==============================");
        Scanner scanner = new Scanner(System.in);
        int choice = scanner.nextInt();
        return choice;
    }
}

（3）User

package user;

import book.BookList;
import operation.IOperation;

public abstract class User {
    protected String name;

    protected IOperation[] iOperations;

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

    public void dowork(int choice, BookList bookList) {
        iOperations[choice].work(bookList);
    }
}

main函数

import book.BookList;
import user.AdminUser;
import user.NormalUser;
import user.User;
import java.util.Scanner;

public class Main {

    public static User login(){
        System.out.println("请输入你的姓名：");
        Scanner scanner=new Scanner(System.in);
        String name=scanner.nextLine();
        System.out.println("请输入你的身份：1->管理员，0->普通用户");
        int choice=scanner.nextInt();

        if (choice==1){
            return new AdminUser(name);
        }else {
            return new NormalUser(name);
        }
    }

    public static void main(String[] args) {
        BookList bookList=new BookList();
        User user=login();//向上转型
        while (true){
            int choice=user.menu();//发生了动态绑定->多态
            //根据你的choice调用合适的操作
            user.dowork(choice,bookList);
        }
    }
}

总结

提示：以上是一个简单的图书管理系统代码实现，后续还将有更多的功能添加其中。