hhhhhhhh/BookCategory.java

package jichuti1;

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

/**
 * 图书类别类，与图书建立聚合关系
 */
public class BookCategory {
    private String categoryId;    // 类别ID
    private String categoryName;  // 类别名称
    private List<Book> books;     // 聚合的图书列表

    public BookCategory(String categoryId, String categoryName) {
        this.categoryId = categoryId;
        this.categoryName = categoryName;
        this.books = new ArrayList<>();
    }

    // 添加图书到类别
    public void addBook(Book book) {
        if (!books.contains(book)) {
            books.add(book);
        }
    }

    // 移除类别中的图书
    public void removeBook(Book book) {
        books.remove(book);
    }

    // getter和setter
    public String getCategoryId() { return categoryId; }
    public String getCategoryName() { return categoryName; }
    public List<Book> getBooks() { return new ArrayList<>(books); }
}