用Java写一个小图书管理系统

创建一个简单的图书管理系统，我们可以使用Java的基本控制结构、集合框架以及一些基本的数据库操作。以下是一个简化的例子，使用了命令行界面作为用户交互：

import java.util.*;

class Book {
    String title;
    String author;
    int quantity;

    // constructor and getters/setters
}

class Library {
    private Map<String, Book> books;

    public Library() {
        this.books = new HashMap<>();
    }

    public void addBook(Book book) {
        books.put(book.getTitle(), book);
    }

    public void removeBook(String title) {
        books.remove(title);
    }

    public Book findBook(String title) {
        return books.get(title);
    }
}

public class Main {
    public static void main(String[] args) {
        Library library = new Library();

        Scanner scanner = new Scanner(System.in);

        while (true) {
            System.out.println("1. 添加书籍");
            System.out.println("2. 删除书籍");
            System.out.println("3. 查找书籍");
            System.out.print("请输入选项（1-3）: ");
            int choice = scanner.nextInt();
            switch (choice) {
                case 1:
                    System.out.print("输入书名: ");
                    String title = scanner.next();
                    System.out.print("作者: ");
                    String author = scanner.next();
                    System.out.print("库存量: ");
                    int quantity = scanner.nextInt();
                    Book book = new Book();
                    book.setTitle(title);
                    book.setAuthor(author);
                    book.setQuantity(quantity);
                    library.addBook(book);
                    break;
                case 2:
                    System.out.print("输入要删除的书名: ");
                    title = scanner.next();
                    library.removeBook(title);
                    break;
                case 3:
                    System.out.print("输入查找的书名: ");
                    title = scanner.next();
                    Book foundBook = library.findBook(title);
                    if (foundBook != null) {
                        System.out.println("找到的书籍信息: " + foundBook);
                    } else {
                        System.out.println("未找到该书籍");
                    }
                    break;
                default:
                    System.out.println("无效的选择");
            }
            scanner.nextLine(); // 清理输入缓冲区
        }
    }
}