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 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 getBooks() { return new ArrayList<>(books); } }