java定义一个图书类 java创建一个图书类

转载

mob64ca13f7ecc9 2023-09-23 11:51:46

文章标签 java定义一个图书类 java idea System ide 文章分类 Java 后端开发

文章目录

前言
思维导图
一、创建图书相关的类
二、创建操作相关的类

1.新增图书
2.借阅图书
3.删除图书
4显示所有图书
5.退出系统
6.查找图书
7.归还图书

三、创建用户相关的类

普通用户类
管理员用户类

四、进行整合
五、运行结果

前言

最近了解到世界上公认的最有效率的学习方法“费曼学习法”，其中非常重要的一步叫做传授，就是检测知识的最终的途径是你有能力把它传播给另一个人。

下面是学习了Java后，实现图书管理系统简单的练习，包含了类和对象，继承，封装，多态，抽象类，接口和顺序表。

思维导图

java定义一个图书类 java创建一个图书类_ide

一、创建图书相关的类

先创建 package book

创建 Book 类, 表示一本书

public class Book {
    private String name;
    private String author;
    private int price;
    private String type;
    private boolean isBorrowed = false;

    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=" + isBorrowed +
                '}';
    }
}

创建 BookList 类, 用来保存 N 本书.

public class BookList {
    private final Book[] books = new Book[100];

    private int size = 0;

    public BookList() {
        books[0] = new Book("三国演义", "罗贯中", 100, "小说");
        books[1] = new Book("水浒传", "施耐庵", 100, "小说");
        books[2] = new Book("西游记", "吴承恩", 100, "小说");
        this.size = 3;
    }

    public int getSize() {
        return size;
    }

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

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

    public Book getBook(int pos) {
        return this.books[pos];
    }

}

二、创建操作相关的类

先创建 package operation

public interface IOperation {
    void work(BookList bookList);
}

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。

接下来创建一组操作类, 每个类对应一个用户的动作.

1.新增图书

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("请输入图书的价格：");
        int price = scanner.nextInt();
        System.out.println("请输入图书的类型：");
        String type = scanner.next();

        Book book = new Book(name,author,price,type);
        int curSize = bookList.getSize();
        bookList.setBooks(curSize,book);
        bookList.setSize(curSize+1);
        System.out.println("新增成功！");
    }
}

2.借阅图书

public class BorrowOperation implements IOperation {


    @Override
    public void work(BookList bookList) {
        System.out.println("借阅图书");
        Scanner scanner = new Scanner(System.in);
        System.out.println("请输入图书的名字：");
        String name = scanner.nextLine();

        for (int i =0; i < bookList.getSize(); i++) {
            Book book = bookList.getBook(i);
            if (book.getName().equals(name)) {
                book.setBorrowed(true);
                System.out.println("借阅成功！");
                return;
            }
        }
        System.out.println("没有你要借阅的那本书");

    }
}

3.删除图书

public class DelOperation implements IOperation {
    @Override
    public void work(BookList bookList) {
        System.out.println("删除图书");
        Scanner scanner = new Scanner(System.in);
        System.out.println("请输入图书的名字：");
        String name = scanner.nextLine();

        int i = 0;
        for (; i < bookList.getSize(); i++) {
            Book book = bookList.getBook(i);
            if (book.getName().equals(name)) {
                break;
            }
        }
        if (i == bookList.getSize()) {
            System.out.println("没有这本书！");
            return;
        }
        for (int pos = i; pos < bookList.getSize()-1;pos++) {
            Book book = bookList.getBook(pos+1);
            bookList.setBooks(pos,book);
        }
        bookList.setSize(bookList.getSize()-1);
        System.out.println("删除成功！");

    }
}

4显示所有图书

public class DisplayOperation implements IOperation {
    @Override
    public void work(BookList bookList) {
        System.out.println("显示所有图书");
        for (int i =0; i < bookList.getSize(); i++) {
            Book book = bookList.getBook(i);
            System.out.println(book);
        }
    }
}

5.退出系统

public class ExitOperation implements IOperation{

    @Override
    public void work(BookList bookList) {
        System.out.println("退出系统");
        System.exit(1);

    }
}

6.查找图书

public class FindOperation implements IOperation {

    @Override
    public void work(BookList bookList) {
        System.out.println("查找图书");
        Scanner scanner = new Scanner(System.in);
        System.out.println("请输入图书的名字：");
        String name = scanner.nextLine();

        for (int i = 0; i < bookList.getSize(); i++) {
            Book book = bookList.getBook(i);
            if (book.getName().equals(name)) {
                System.out.println(book);
                System.out.println("查找成功！");
                return;
            }
        }
    }
}

7.归还图书

public class ReturnOperation implements IOperation {
    @Override
    public void work(BookList bookList) {
        System.out.println("归还图书");
        Scanner scanner = new Scanner(System.in);
        System.out.println("请输入图书的名字：");
        String name = scanner.nextLine();

        for (int i = 0; i < bookList.getSize(); i++) {
            Book book = bookList.getBook(i);
            if (book.getName().equals(name)) {
                book.setBorrowed(false);
                System.out.println("归还成功！");
            }
        }
        System.out.println("没有你要归还的图书！");

    }
}

三、创建用户相关的类

先创建 package user
创建 User 类, 这是一个抽象类

public abstract class User {
    protected String name;
    protected IOperation[] operations;

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

    public abstract int menu();

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

普通用户类

public class NormalUser extends User {

    public NormalUser(String name) {
        super(name);
        this.operations = new IOperation[] {
                new ExitOperation(),
                new FindOperation(),
                new BorrowOperation(),
                new ReturnOperation()

        };
    }

    @Override
    public int menu() {
        System.out.println("=============================");
        System.out.println("Hello " + this.name + ", 欢迎使用图书管理系统!");
        System.out.println("1. 查找图书");
        System.out.println("2. 借阅图书");
        System.out.println("3. 归还图书");
        System.out.println("0. 退出系统");
        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;
    }
}

管理员用户类

public class Admin extends User {
    public Admin(String name) {
        super(name);
        this.operations = new IOperation[] {
                new ExitOperation(),
                new FindOperation(),
                new AddOperation(),
                new DelOperation(),
                new DisplayOperation()
        };
    }

    @Override
    public int menu() {
        System.out.println("=============================");
        System.out.println("Hello " + this.name + ", 欢迎使用图书管理系统!");
        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. 显示所有图书");
        System.out.println("0. 退出系统");
        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;

    }

}

四、进行整合

创建 Main 类和 main 方法, 搭建整体逻辑

public class TextMain {
    public static User login() {
        Scanner scanner = new Scanner(System.in);
        System.out.println("请输入姓名：");
        String name = scanner.nextLine();
        System.out.println("请输入您的身份：1——》管理员，2——》普通用户");
        int choice = scanner.nextInt();

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

    }
    public static void main(String[] args) {
        BookList bookList = new BookList();
        User user = login();
        while(true) {
            int choice = user.menu();
            user.doOperation(choice, bookList);
        }
    }
}