【Java】实现简易的图书管理系统（继承，封装，多态）-阿里云开发者社区

前言

本篇文章我们来学习一个综合案例——图书管理系统，是对继承，封装和多态的一个小练习，通过这个案例可以加深我们对语法的理解。

一、实现的功能

实现对图书的管理，我们登录时有两个身份，一个是图书管理员，一个是普通用户，这两个实现的功能各不一样。

二、具体的代码

有三个包和一个main函数。

book包（书的信息和书架）

book包：

book类：

package book;
public class book {
    private  String name; //书名
    private  String  author;//作者
    private  int price;//价格
    private  String type;//类型如小说散文等
    private  boolean  isBorrowed;//是否被借出
    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;
    }
    public book(String name, String author, int price, String type) {
        this.name = name;
        this.author = author;
        this.price = price;
        this.type = type;
    }
    @Override
    public String toString() {
        return "book{" +
                "name='" + name + '\'' +
                ", author='" + author + '\'' +
                ", price=" + price +
                ", type='" + type + '\'' +
                ((isBorrowed==true)?"已经借出":"未借出")+'}';
    }
}

booklist类：

package book;
public class booklist {
    private book[]books=new book[10]; //最多可以放十本书
    private int usedSize;//实时记录，当前books这个数组中有多少本书。
   public booklist(){
       books[0]=new book("三国演义","罗贯中",19,"小说");
       books[1]=new book("西游记","吴承恩",19,"小说");
       books[2]=new book("红楼梦","曹雪芹",19,"小说");
        usedSize=3;
   }
   public book  getBook(int pos){
       return books[pos];     //找书
   }
   public void setBook(int pos,book Book){
       books[pos]=Book;   //增加书
   }
   public void  setUsedSize(int size){
       usedSize=size;        //实时修改当前书架上书的个数
   }
   public int  getUsedSize(){
//实时获取当前书的个数
       return usedSize;
   }
}

operation包（实现具体的功能）

AddOperation:

package operation;
import book.book;
import book.booklist;
import java.util.Scanner;
public class AddOperation implements IOperation {
    @Override
    public void work(booklist Booklist) {
        System.out.println("新增图书");
        Scanner scanner = new Scanner(System.in);
        System.out.println("请输入图书的名字：");
        String name=scanner.nextLine();
        System.out.println("请输入图书的作者：");
        String author=scanner.nextLine();
        System.out.println("请输入图书的类型：");
        String type=scanner.nextLine();
        System.out.println("请输入图书的价格：");
        int price=scanner.nextInt();
        book Book=new book(name,author,price,type);
        int currentSize=Booklist.getUsedSize();
        Booklist.setBook(currentSize,Book);
        Booklist.setUsedSize(currentSize+1);
        System.out.println("新增图书成功");
    }
}

BorrowOperation :

package operation;
import book.book;
import book.booklist;
import java.util.Scanner;
public class BorrowOperation implements  IOperation {
    @Override
    public void work(booklist Booklist) {
        System.out.println("请输入借阅图书的名字");
        Scanner scanner = new Scanner(System.in);
        String name = scanner.nextLine();
        int currentSize = Booklist.getUsedSize();
        for (int i = 0; i < currentSize; i++) {
            book Book = Booklist.getBook(i);
            if (Book.getName().equals(name)) {
              Book.setBorrowed(true);
                System.out.println("借阅成功");
                return;
            }
        }
    }
}

DelOperation:

package operation;
import book.book;
import book.booklist;
import sun.security.provider.certpath.CertId;
import java.util.Scanner;
public class DelOperation implements  IOperation{
    @Override
    public void work(booklist Booklist) {
        System.out.println("请输入删除图书的名字");
        Scanner scanner = new Scanner(System.in);
        String name = scanner.nextLine();
        int currentSize = Booklist.getUsedSize();
        int SIZE=0;
        for (int i = 0; i < currentSize; i++) {
            book Book = Booklist.getBook(i);
            if (Book.getName().equals(name)) {
                SIZE=i;
                break;
            }
        }
  for(int i=SIZE;i<currentSize-1;i++){
      book  Book= Booklist.getBook(i+1);
      Booklist.setBook(i,Book);
      Booklist.setUsedSize(currentSize-1);
      System.out.println("删除成功");
  }
    }
}

DisplayOperation:

package operation;
import book.book;
import book.booklist;
public class DisplayOperation implements IOperation{
    @Override
    public void work(booklist Booklist) {
        int currentSize = Booklist.getUsedSize();
        for (int i = 0; i < currentSize; i++) {
            book Book = Booklist.getBook(i);
                System.out.println(Booklist.getBook(i));
        }
    }
}

ExitOperation:

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

FindOperation:

import java.util.Scanner;
public class FindOperation implements IOperation{
    @Override
    public void work(booklist Booklist) {
        System.out.println("查找图书");
        int currentSize = Booklist.getUsedSize();
        System.out.println("请输入图书的名字");
        Scanner scanner = new Scanner(System.in);
        String name = scanner.nextLine();
        for (int i = 0; i < currentSize; i++) {
            book Book = Booklist.getBook(i);
            if (Book.getName().equals(name)) {
                System.out.println("找到了这本书");
                System.out.println(Book);
                return;
            }
        }
        System.out.println("没有你要找的这本书");
    }
}

ReturnOperation:

package operation;
import book.book;
import book.booklist;
import java.util.Scanner;
public class ReturnOperation implements IOperation {
    @Override
    public void work(booklist Booklist) {
        System.out.println("归还图书");
        System.out.println("请输入归还图书的名字");
        Scanner scanner = new Scanner(System.in);
        String name = scanner.nextLine();
        int currentSize = Booklist.getUsedSize();
        for (int i = 0; i < currentSize; i++) {
            book Book = Booklist.getBook(i);
            if (Book.getName().equals(name)) {
                Book.setBorrowed(false);
                System.out.println("归还成功");
                return;
            }
        }
    }
}

接口： IOperation

package operation;
import book.booklist;
public interface IOperation {
    void work(booklist Booklist);
}

user包（管理员用户 main方法）

AdminUser：

package user;
import book.*;
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("hello"+this.name+"欢迎来到图书小练习");
        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("请输入你的操作");
        Scanner scanner=new Scanner(System.in);
        int choice= scanner.nextInt();
        return choice;
    }
}

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("hello"+this.name+"欢迎来到图书小练习");
        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("请输入你的操作");
        Scanner scanner=new Scanner(System.in);
        int choice= scanner.nextInt();
        return choice;
    }
}

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 doOperation(int choice, booklist Booklist){
        this.iOperations[choice].work(Booklist);
    }
}

main方法：

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 2.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();//登录
        while(true) {
            int choice = user.menu(); //动态绑定
            user.doOperation(choice, Booklist);
        }
    }
}

总结

这个小程序可以加深我们对继承封装和多态的理解，可以让我们更熟悉语法。

本篇文章内容结束，感谢大家观看。如果意见或建议，可以在评论区留言，您的点赞是我更新的动力。我们下篇文章再见。

【Java】实现简易的图书管理系统（继承，封装，多态）

前言

一、实现的功能

二、具体的代码

book包（书的信息和书架）

operation包（实现具体的功能）

user包（管理员用户 main方法）

总结

热门文章

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相关电子书

相关实验场景

【Java】实现简易的图书管理系统（继承，封装，多态）

前言

一、实现的功能

二、具体的代码

book包（书的信息和书架）

operation包（实现具体的功能）

user包（管理员 用户 main方法）

总结

热门文章

最新文章

相关课程

相关电子书

相关实验场景

user包（管理员用户 main方法）