写一个使用类，测试接口中的所有方法,方法如下void addBook(Book b); //添加图书 void deleteByIsbn(String ibsn); // void deleteByAuthor(String author); // void updateBook(Book b); //附加题 int size(); //统计书的数量 void clear(); //清空所有图书 Book selectByIsbn(String isbn); Book[] getAllBooks(); //获取所有图书

public class Library {
    private List<Book> books;

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

    public void addBook(Book b) {
        books.add(b);
        System.out.println("成功添加一本书：" + b.getTitle());
    }

    public void deleteByIsbn(String isbn) {
        for (Book b : books) {
            if (b.getIsbn().equals(isbn)) {
                books.remove(b);
                System.out.println("成功删除一本书：" + b.getTitle());
                return;
            }
        }
        System.out.println("找不到该ISBN号对应的书籍");
    }

    public void deleteByAuthor(String author) {
        int count = 0;
        Iterator<Book> it = books.iterator();
        while (it.hasNext()) {
            Book b = it.next();
            if (b.getAuthor().equals(author)) {
                it.remove();
                count++;
            }
        }
        if (count == 0) {
            System.out.println("找不到该作者对应的书籍");
        } else {
            System.out.println("成功删除" + count + "本书");
        }
    }

    public void updateBook(Book b) {
        for (int i = 0; i < books.size(); i++) {
            if (books.get(i).getIsbn().equals(b.getIsbn())) {
                books.set(i, b);
                System.out.println("成功更新一本书：" + b.getTitle());
                return;
            }
        }
        System.out.println("找不到该ISBN号对应的书籍");
    }

    public int size() {
        return books.size();
    }

    public void clear() {
        books.clear();
        System.out.println("已清空所有图书");
    }

    public Book selectByIsbn(String isbn) {
        for (Book b : books) {
            if (b.getIsbn().equals(isbn)) {
                return b;
            }
        }
        System.out.println("找不到该ISBN号对应的书籍");
        return null;
    }

    public Book[] getAllBooks() {
        return books.toArray(new Book[books.size()]);
    }

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

        // 添加图书
        Book b1 = new Book("9787121332379", "Java编程思想", "Bruce Eckel");
        Book b2 = new Book("9787111128069", "Java核心技术", "Cay S. Horstmann, Gary Cornell");
        Book b3 = new Book("9787508353937", "八分钟演讲", "许倩");
        library.addBook(b1);
        library.addBook(b2);
        library.addBook(b3);

        // 获取所有图书
        Book[] allBooks = library.getAllBooks();
        for (Book b : allBooks) {
            System.out.println(b.getTitle());
        }

        // 更新图书信息
        b2.setAuthor("Cay S. Horstmann, Gary Cornell, Alvin Alexander");
        library.updateBook(b2);

        // 删除图书（ISBN号）
        library.deleteByIsbn("1234567890");
        library.deleteByIsbn("9787121332379");

        // 删除图书（作者）
        library.deleteByAuthor("abc");
        library.deleteByAuthor("Cay S. Horstmann, Gary Cornell, Alvin Alexander");

        // 清空所有图书
        library.clear();

        // 统计书的数量
        System.out.println("图书馆共有" + library.size() + "本书");

        // 查询图书（ISBN号）
        Book b4 = library.selectByIsbn("1234567890");
        if (b4 != null) {
            System.out.println("《" + b4.getTitle() + "》的作者是" + b4.getAuthor());
        }

        // 查询图书（不存在的ISBN号）
        library.selectByIsbn("1111111111");
    }
}