用Java实现图书管理系统-阿里云开发者社区

在这一个系统中我们会用到多态，继承，封装，接口等知识点，来综合性的设计与实现出一个简易的图书管理系统。

一、设计思路

1.首先图书管理系统缺不了的就是书类了，所以我们首先要创造一个书类

2.然后我们需要一个书架来管理图书

3.我们需要管理员和普通的用户来对书架里的图书进行相对应的操作

二、代码实现

2.1 Book类的实现

这个应该都会吧（狗头），书的应该有名字、作者、价格、还有类型、还有它是否被借出这个状态

然后用idea的生成一下就都出来了（狗头）

package library.Book;
 
public class Book {
    private String name;
    private String author;
    private int price;
    private String type;
    private boolean isBorrowed;
 
    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 ? " 已被借出 " : " 未被借出 " )+
                '}';
    }
}

2.2 BookList类的实现(书架)

书架有书，当然我们就需要一个存储书的数组了，然后还需要一个书架上书的数量

package library.Book;
 
public class BookList {
    private Book[] books = new Book[10];
    private int BookSize;//书架上书的数量
 
    public BookList() {
        books[0] = new Book("三国演义","XXX",89,"小说");
        books[1] = new Book("西游记","宋XX",100,"小说");
        books[2] = new Book("红楼梦","无名氏",200,"小说");
        this.BookSize = 3;
    }//这里用无参构造，来初始化书架
 
    public Book getBook(int pos) {
        return this.books[pos];
    }//给一个索引，来获得书架上的某一本书
 
    public void setBook(Book book){
        this.books[BookSize] = book;
    }//利用这个方法来新增图书
    public void setBook(int pos,Book book){
        this.books[pos] = book;
    }//这个方法是在给的索引位置，放置传入的book这本书
 
    public int getBookSize() {
        return BookSize;
    }
 
    public void setBookSize(int bookSize) {
        BookSize = bookSize;
    }
}

2.3 用户类的实现

用户类中，这个用户类是父类，我们不需要实现他，就定义了为抽象类，里面有抽象的menu方法，因为管理员和普通用户的菜单都是不一样的，运用dowork方法进行调用方法。IOPeration这个接口数组中存放着实现了IOPeration接口的类，配合dowork方法完成图书的管理

package library.User;
 
import library.Book.BookList;
import library.opera.IOPeration;
 
public abstract class User {
    protected String name;//姓名
    protected IOPeration[] ioPerations;//向上转型，配合下面的方法，避免使用switch
 
    public User(String name) {
        this.name = name;
    }
    public abstract int menu();
 
    public void doWork(int choice, BookList bookList){
        this.ioPerations[choice].work(bookList);
    }//运用这个进行方法的调用，比如你传入的choice为1 调用的就是数组下的1方法
 
}

2.4 操作接口的实现

我们需要执行的操作有增加，删除，显示，查找等，他们都需要遵循一定的规范，而这个规范就由接口来实现，在增删查改等操作中，他们的主要方式就是工作，即work(),故接口中提供对应的work()方法供接口的实现类，即各种操作进行重写

package library.opera;
 
import library.Book.BookList;
 
public interface IOPeration {
    void work(BookList bookList);
}

2.5 操作类的具体实现

2.5.1 AddOperation（添加）

package library.opera;
 
import library.Book.Book;
import library.Book.BookList;
 
import java.util.Scanner;
 
public class AddOperation implements IOPeration{
    @Override
    public void work(BookList bookList) {
        Scanner sc = new Scanner(System.in);
        System.out.println("新增图书");
        int size = bookList.getBookSize();
        System.out.println("请输入书名");
        String name = sc.nextLine();
        System.out.println("输入作者");
        String author = sc.nextLine();
 
        System.out.println("输入书的类型");
        String type = sc.nextLine();
 
        System.out.println("输入价格");
        int price = sc.nextInt();
 
        Book book = new Book(name,author,price,type);
        for (int i = 0; i < size; i++) {
            Book book1 = bookList.getBook(i);
            if(book1.getName().equals(name)){
                System.out.println("添加的书已存在");
                return;
            }
        }
        bookList.setBook(book);
 
        bookList.setBookSize(size+1);
        System.out.println("新增成功");
 
    }
}

2.5.2 FindOperation（查找）

package library.opera;
 
import library.Book.Book;
import library.Book.BookList;
 
import java.util.Scanner;
 
public class FindOperation implements IOPeration{
    @Override
    public void work(BookList bookList) {
        System.out.println("找到图书");
        System.out.println("请输入书名");
        Scanner sc = new Scanner(System.in);
        String name = sc.nextLine();
        int size = bookList.getBookSize();
        for (int i = 0; i < size; i++) {
            Book book = bookList.getBook(i);
            if(book.getName().equals(name)){
                System.out.println("找到此书");
                System.out.println(book);
                return;
            }
        }
        System.out.println("没找到此书");
    }
}

2.5.3 DelOperation（删除）

package library.opera;
 
import library.Book.Book;
import library.Book.BookList;
 
import java.util.Scanner;
 
public class DelOperation implements IOPeration{
    @Override
    public void work(BookList bookList) {
        System.out.println("删除图书");
        System.out.println("请输入删除图书的名字");
        Scanner sc = new Scanner(System.in);
        String name = sc.nextLine();
        int size = bookList.getBookSize();
        int index = -1;
        for (int i = 0; i < size; i++) {
            Book book = bookList.getBook(i);
            if(book.getName().equals(name)){
                index = i;//找到要删除图书的索引
                break;
            }
        }
        if(index != -1){//如果不等于-1说明找到要删除的书籍
            for (int i = index; i < size - 1; i++) {
                Book book = bookList.getBook(i + 1);// 可以理解取出索引为i+1的元素
                bookList.setBook(i,book);// 理解为a[i] = a[i+1]
            }
            bookList.setBookSize(size-1);
            //因为删除的是对象，所以 吧最后一个赋值为null
            bookList.setBook(size-1,null);
            System.out.println("删除成功");
 
        }else {
            System.out.println("未找到");
        }
 
    }
}

2.5.4 ShowOperation（显示）

package library.opera;
 
import library.Book.BookList;
 
public class ShowOperation implements IOPeration{
    @Override
    public void work(BookList bookList) {
        System.out.println("找到图书");
        int size = bookList.getBookSize();
        for (int i = 0; i < size; i++) {
            System.out.println(bookList.getBook(i));
        }
    }
}

2.5.5 BorrowOperation（借书）

package library.opera;
 
import library.Book.Book;
import library.Book.BookList;
 
import java.util.Scanner;
 
public class BorrowOperation implements IOPeration{
    @Override
    public void work(BookList bookList) {
        System.out.println("借阅图书");
        System.out.println("输入你要借阅的图书");
        Scanner sc = new Scanner(System.in);
        int size = bookList.getBookSize();
        String name = sc.nextLine();
        for (int i = 0; i < size; i++) {
            Book book = bookList.getBook(i);
            if(book.getName().equals(name) && book.isBorrowed() == false){//要存在书籍 且 书籍的状态为false
                book.setBorrowed(true);//借出后要将书籍的状态弄为true,表示已被借出
                System.out.println("借阅成功");
                return;
            }
        }
        System.out.println("借阅失败");
    }
}

2.5.6 RutrunOperation（还书）

package library.opera;
 
import library.Book.Book;
import library.Book.BookList;
 
import java.util.Scanner;
 
public class RutrunOperation implements IOPeration{
    @Override
    public void work(BookList bookList) {
        System.out.println("归还图书");
        System.out.println("输入你要归还的图书");
        Scanner sc = new Scanner(System.in);
        int size = bookList.getBookSize();
        String name = sc.nextLine();
        for (int i = 0; i < size; i++) {
            Book book = bookList.getBook(i);
            if(book.getName().equals(name) && book.isBorrowed()){
                book.setBorrowed(false);//归还后要将book的状态还原成false
                System.out.println("归还成功");
                return;
            }
        }
        System.out.println("归还失败");
    }
}

2.5.7 ExitOperation（退出）

package library.opera;
 
import library.Book.BookList;
 
public class ExitOperation implements IOPeration{
    @Override
    public void work(BookList bookList) {
        System.out.println("退出系统");
        System.exit(0);
    }
}

2.6 管理员类的实现

首先，管理员类需要继承于用户类，同时实现用户类中的抽象方法menu()，同时继承了work方法，这里利用接口的多态性来进行实现的。

package library.User;
 
import library.opera.*;
 
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()};
    }//这里就是运用了接口的多态
    //调用0方法就是退出系统 调用1方法就是找图书的方法依次类推，避免使用switch
 
    public int menu(){
        System.out.println("-----------------");
        System.out.println("hello"+name+"欢迎来到图书");
        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("-----------------");
        System.out.println("请输入您的操作:");
        Scanner sc = new Scanner(System.in);
        int choice = sc.nextInt();
        return choice;
    }
}

2.7 读者类的实现

同理

package library.User;
 
import library.opera.*;
 
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 RutrunOperation()};
    }
    public int menu(){
        System.out.println("-----------------");
        System.out.println("hello"+name+"欢迎来到图书");
        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("-----------------");
        System.out.println("请输入您的操作:");
        Scanner sc = new Scanner(System.in);
        int choice = sc.nextInt();
        return choice;
    }
}

2.8 Test运行

package library;
 
import library.Book.BookList;
import library.User.AdminUser;
import library.User.NormalUser;
import library.User.User;
 
import java.util.Scanner;
 
public class Test {
    public static User login(){
        System.out.println("请输入您的姓名");
        Scanner sc = new Scanner(System.in);
        String name = sc.nextLine();
        System.out.println("请输入您的身份:1->管理员 0->普通用户");
        int choice = sc.nextInt();
        if(choice == 1){//也相当于向上转型，多态的使用
            return new AdminUser(name);
        }else {
            return new NormalUser(name);
        }
    }
    public static void main(String[] args) {
        BookList bookList = new BookList();
        User user = login();//相当于User user = new AdminUser(name)或者User user = new NormalUser(name)
        while (true) {
            int choice = user.menu();
            user.doWork(choice,bookList);
        }
 
 
 
    }
}

用Java实现图书管理系统