Java——面向对象练习（图书管理系统的实现）

喜欢ヅ旅行 2022-10-15 12:55 188阅读 0赞

### 文章目录 ###

*  Java——面向对象练习（图书管理系统的实现）
 *  一、实现效果展示
 *   *  （1）功能简介
     *  （2）登陆界面
     *  （3）菜单界面
     *  （4）功能展示
 *  二、具体代码实现
 *   *  1.类的设计
     *  （1）创建图书相关的类
     *  （2） 创建操作相关的类
     *  1.接口的实现
     *  2.新增书籍
     *  3.删除书籍
     *  4.展示书籍
     *  5.查找书籍
     *  6.借阅书籍
     *  7.归还书籍
     *  8.退出系统
     *  （3）创建用户相关的类
     *  1.父类 用户 user 的实现
     *  2.管理员用户的实现
     *  3.普通用户类的实现
     *  Main 函数的设计
 *  完!

# Java——面向对象练习（图书管理系统的实现） #

在前面一段时间里，学习了 Java 面向对象的相关内容：包的使用、继承、多态、抽象类、接口等知识，现在为了巩固我们所学习的知识，接下来我们将从零到有实现一个简单版的图书管理系统的代码实现。

# 一、实现效果展示 #

## （1）功能简介 ##

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3JhaW42Nw_size_16_color_FFFFFF_t_70][]

## （2）登陆界面 ##

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3JhaW42Nw_size_16_color_FFFFFF_t_70 1]

## （3）菜单界面 ##

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3JhaW42Nw_size_16_color_FFFFFF_t_70 2]

## （4）功能展示 ##

1.显示图书  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3JhaW42Nw_size_16_color_FFFFFF_t_70 3]

2.新增图书

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3JhaW42Nw_size_16_color_FFFFFF_t_70 4]

3.删除图书

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3JhaW42Nw_size_16_color_FFFFFF_t_70 5]

4.查找图书

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3JhaW42Nw_size_16_color_FFFFFF_t_70 6]

5.借阅图书

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3JhaW42Nw_size_16_color_FFFFFF_t_70 7]

6.归还图书

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3JhaW42Nw_size_16_color_FFFFFF_t_70 8]

# 二、具体代码实现 #

## 1.类的设计 ##

我们通过这个管理系统的功能简介等，可以知道我们需要设计的几个类

## （1）创建图书相关的类 ##

先创建 package book

创建 Book 类, 表示一本书  
![在这里插入图片描述][20210529130315856.png]

package book;
    
    public class Book {
        
    
        private String name;
        private String author;
        private int price;
        private String type;
        private boolean isBorrowed;
    
        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=" + isBorrowed +
                    '}';
        }
    }

这个书的类中，有书的各种属性：书名、作者、价格、类别、借阅情况，同时将这些属性都封装起来。

创建 BookList 类, 用来保存 N 本书.

package book;
    
    public class BookList {
        
    
        private Book[] books = new Book[100];
        private int usedSize;
    
    
        public BookList(){
        
    
            //默认有四本书
    
            books[0] = new Book("西游记","吴承恩",10,"小说" );
            books[1] = new Book("水浒传","施耐庵",20,"小说" );
            books[2] = new Book("红楼梦","曹雪芹",10,"小说" );
            books[3] = new Book("三国演义","罗贯中",10,"小说" );
            this.usedSize  = 4;
        }
    
        public Book getBooks(int pos) {
        
            return this.books[pos];
        }
    
        public void setBooks(int pos,Book book) {
        
            //默认放到顺序表的最后
            this.books[pos] = book;
        }
    
        public int getUsedSize() {
        
            return usedSize;
        }
    
        public void setUsedSize(int usedSize) {
        
            this.usedSize = usedSize;
        }
    }

用顺序表的方式存储书籍，且在书架中默认有四本书，设置一个 现有书籍数量 usedSize的属性，在构造方法中存储四本书，usedSize = 4.

## （2） 创建操作相关的类 ##

先创建 package operation

接下来创建一组操作类, 每个类对应一个用户的动作.

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3JhaW42Nw_size_16_color_FFFFFF_t_70 9]

抽象出 Operation 的好处: 让操作和操作之间低耦合, 让操作和用户之间低耦合.

## 1.接口的实现 ##

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

## 2.新增书籍 ##

package operation;
    
    import book.Book;
    import book.BookList;
    
    import java.util.Scanner;
    
    public class AddOperation implements IOperation {
        
        @Override
        public void work(BookList bookList){
        
            Scanner scanner  = new Scanner(System.in);
            System.out.println("请输入书名：");
            String name = scanner.nextLine();
            System.out.println("请输入作者：");
            String author = scanner.nextLine();
            System.out.println("请输入类别：");
            String type = scanner.nextLine();
            System.out.println("请输入价格：");
            int price  = scanner.nextInt();
    
            for (int i = 0; i <bookList.getUsedSize() ; i++) {
        
                Book book = bookList.getBooks(i);
                if(name.equals(book.getName())){
        
                    System.out.println("书架存在这本书，不能重复添加！");
                    return;
                }
            }
    
            int currentSize = bookList.getUsedSize();
    
            Book book = new Book(name,author,price,type);
    
            bookList.setBooks(currentSize,book);
    
            bookList.setUsedSize(currentSize+1);
    
            System.out.println("增加成功！");
        }
    }

## 3.删除书籍 ##

package operation;
    
    import book.Book;
    import book.BookList;
    
    import java.util.Scanner;
    
    
    public class DelOperation implements IOperation{
        
        @Override
        public void work(BookList bookList) {
        
            System.out.println("删除书籍！ ");
            Scanner scanner = new Scanner(System.in);
            System.out.println("请输入要删除的图书的名字:");
            String name = scanner.nextLine();
    
            int currentSize = bookList.getUsedSize();
    
            int index = -1;
    
            for (int i = 0; i < currentSize; i++) {
        
    
                Book book = bookList.getBooks(i);
    
                if(name.equals(book.getName())) {
        
                    //找到了这本书
                    index = i;
                }
    
            }
            if(index == -1) {
        
                System.out.println("没有你要删除的书！");
                return;
            }
    
            for (int i = index; i < currentSize-1; i++) {
        
                Book book1 = bookList.getBooks(i+1);
                bookList.setBooks(i,book1);
                //bookList[i] = bookList[i+1];
            }
    
            //防止内存泄漏
            bookList.setBooks(currentSize-1,null);
            //控制usedSize
            bookList.setUsedSize(currentSize-1);
    
            System.out.println("删除成功！");
        }
    }

## 4.展示书籍 ##

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

## 5.查找书籍 ##

package operation;
    
    import book.Book;
    import book.BookList;
    
    import java.util.Scanner;
    
    public class FindOperation implements IOperation{
        
        @Override
        public void work(BookList booklist){
        
            System.out.println("请输入要查找的书名：");
            Scanner scanner = new Scanner(System.in);
            String name = scanner.nextLine();
    
            for (int i = 0; i <booklist.getUsedSize() ; i++) {
        
                Book book = booklist.getBooks(i);
                if(name.equals(book.getName())){
        
                    System.out.println("找到此书入下：");
                    System.out.println(book);
                    return ;
                }
            }
    
            System.out.println("没有这本书！");
        }
    }

## 6.借阅书籍 ##

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("借阅书籍");
            System.out.println("请输入要借阅的图书的名字:");
            Scanner scanner = new Scanner(System.in);
            String name = scanner.nextLine();
    
    
            for (int i = 0; i <bookList.getUsedSize(); i++) {
        
    
                Book book = bookList.getBooks(i);
    
                if(name.equals(book.getName()) && book.isBorrowed()==false) {
        
                    //找到了就借阅
                  book.setBorrowed(true);
                  return ;
                }
            }
            System.out.println("借阅失败，没有此书 ，或此书已被借出");
        }
    }

## 7.归还书籍 ##

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("归还书籍");
            System.out.println("请输入要归还的图书的名字:");
            Scanner scanner = new Scanner(System.in);
            String name = scanner.nextLine();
    
    
            for (int i = 0; i <bookList.getUsedSize(); i++) {
        
    
                Book book = bookList.getBooks(i);
    
                if(name.equals(book.getName())) {
        
                    //找到了就归还
                    book.setBorrowed(false);
                    System.out.println("归还成功！");
                    return ;
                }
            }
            System.out.println("归还失败，没有此书！");
        }
    }

## 8.退出系统 ##

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);
        }
    }

## （3）创建用户相关的类 ##

## 1.父类 用户 user 的实现 ##

package users;
    
    import book.BookList;
    import operation.*;
    
    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);
        }
    }

## 2.管理员用户的实现 ##

package users;
    
    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(){
        
            Scanner scanner = new Scanner(System.in);
            System.out.println("hello"+this.name+" "+"欢迎来到图书小练习!");
            System.out.println("=========管理员菜单=========");
            System.out.println("=========0.退出系统=========");
            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=========");
    
            int choice = scanner.nextInt();
            return choice;
        }
    
        @Override
        public void doOperation(int choice, BookList bookList) {
        
            super.doOperation(choice, bookList);
        }
    }

## 3.普通用户类的实现 ##

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(){
        
                Scanner scanner = new Scanner(System.in);
                System.out.println("hello"+this.name+" "+"欢迎来到图书小练习!");
                System.out.println("========普通用户菜单=========");
                System.out.println("=========0.退出系统=========");
                System.out.println("=========1.查找图书=========");
                System.out.println("=========2.借阅图书=========");
                System.out.println("=========3.归还图书=========");
    
                int choice = scanner.nextInt();
                return choice;
            }
    
        @Override
        public void doOperation(int choice, BookList bookList) {
        
            super.doOperation(choice, bookList);
        }
    }

## Main 函数的设计 ##

import book.Book;
    import book.BookList;
    import users.AdminUser;
    import users.NormalUser;
    import users.User;
    
    import java.util.Scanner;
    
    public class Main {
        
    
        public static User login(){
        
            System.out.println("请输入姓名：");
            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 who  = scanner.nextInt();
            if(who == 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) {
        
              // 根据菜单的选项 调用合适的方法
              int choice = user.menu();
              user.doOperation(choice, bookList);
          }
    
        }
    
    }

本次练习的目的只是为了熟悉 Java面向对象的特性,在实现具体功能的业务逻辑时并没有那么严谨,希望大家多多指正!

好了今天的分享到这里就结束了,感谢大家的观看.

感谢关注!!

# 完! #

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