java热度怎么实现的?实现的?

解决问题：如何实现一个简单的图书管理系统

1. 引言

随着互联网的飞速发展，人们对于图书阅读的需求也越来越大。而作为一名Java开发人员，我们可以利用Java的热度来实现一个简单的图书管理系统。本文将详细介绍如何使用Java编写一个基于控制台的图书管理系统，以满足用户的图书借阅、归还和查询等需求。

2. 功能需求

在开始编写代码之前，我们需要明确系统的功能需求:

• 用户登录和注册功能
• 图书的添加、删除和修改功能
• 图书的借阅和归还功能
• 图书的查询功能（按图书名称、作者、分类等进行查询）

3. 系统设计

3.1 类图

下面给出系统的类图，使用Mermaid语法进行标识：

classDiagram
    class User
    class Book
    class Library
    class BookManager
    class UserManager
    class Main
    
    User <|-- UserManager
    Book <|-- BookManager
    Library --> BookManager
    User --> Library
    Main --> Library

3.2 业务流程图

下面给出系统的业务流程图，使用Mermaid语法进行标识：

journey
    title 图书管理系统业务流程
    section 用户登录和注册
        Main -> UserManager: 用户登录/注册
        UserManager -> Library: 验证用户信息
        Library --> Main: 登录/注册成功
    section 图书管理
        Main -> Library: 添加/删除/修改图书
        Library -> BookManager: 处理图书管理请求
        BookManager -> Library: 更新图书数据
        Library --> Main: 操作成功
    section 图书借阅和归还
        Main -> Library: 借阅/归还图书
        Library -> BookManager: 处理借阅/归还请求
        BookManager -> Library: 更新图书状态
        Library --> Main: 操作成功
    section 图书查询
        Main -> Library: 查询图书
        Library -> BookManager: 处理查询请求
        BookManager --> Main: 返回查询结果

4. 代码实现

4.1 User类

public class User {
    private String username;
    private String password;
    
    public User(String username, String password) {
        this.username = username;
        this.password = password;
    }
    
    // getter and setter methods
}

4.2 Book类

public class Book {
    private String title;
    private String author;
    private String category;
    private boolean isBorrowed;
    
    public Book(String title, String author, String category) {
        this.title = title;
        this.author = author;
        this.category = category;
        this.isBorrowed = false;
    }
    
    // getter and setter methods
}

4.3 Library类

import java.util.ArrayList;
import java.util.List;

public class Library {
    private List<Book> books;
    private User currentUser;
    
    public Library() {
        this.books = new ArrayList<>();
        this.currentUser = null;
    }
    
    public void addBook(Book book) {
        books.add(book);
    }
    
    public void removeBook(Book book) {
        books.remove(book);
    }
    
    public void borrowBook(Book book) {
        if (!book.isBorrowed()) {
            book.setBorrowed(true);
        }
    }
    
    public void returnBook(Book book) {
        if (book.isBorrowed()) {
            book.setBorrowed(false);
        }
    }
    
    public List<Book> searchBooksByTitle(String title) {
        List<Book> result = new ArrayList<>();
        for (Book book : books) {
            if (book.getTitle().contains(title)) {
                result.add(book);
            }
        }
        return result;
    }
    
    // other search methods
    
    public void setCurrentUser(User user) {
        this.currentUser = user;
    }
    
    // other methods
}

4.4 BookManager类

public class BookManager {
    private Library library;
    
    public BookManager(Library library) {
        this.library = library;
    }
    
    public void addBook(String title, String author, String category) {
        Book book = new Book(title, author, category);
        library.addBook(book);
    }
    
    public void removeBook(String title) {
        List<Book> books = library.searchBooksByTitle(title);
        if (books.size() > 0) {
            library.removeBook(books.get