把下面的xml文件写成多个java类xml version=10catalog book id=bk101 authorGambardella Matthewauthor titleXML Developers Guidetitle genreComputergenre price4495price publish_date2000-10-01

首先，我们可以创建一个Book类，该类包含以下属性：

public class Book {
    private String id;
    private String author;
    private String title;
    private String genre;
    private double price;
    private String publishDate;
    private String description;

    // 构造函数和getter/setter方法
}

然后，我们可以创建一个Catalog类，该类包含一个Book对象的列表：

import java.util.List;

public class Catalog {
    private List<Book> books;

    // 构造函数和getter/setter方法
}

最后，我们可以创建一个Main类来解析XML文件并创建相应的Java对象：

import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import org.w3c.dom.Document;
import org.w3c.dom.Element;
import org.w3c.dom.NodeList;

public class Main {
    public static void main(String[] args) {
        try {
            DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
            DocumentBuilder builder = factory.newDocumentBuilder();
            Document doc = builder.parse("catalog.xml");
            doc.getDocumentElement().normalize();

            NodeList bookList = doc.getElementsByTagName("book");

            for (int i = 0; i < bookList.getLength(); i++) {
                Element bookElement = (Element) bookList.item(i);

                String id = bookElement.getAttribute("id");
                String author = bookElement.getElementsByTagName("author").item(0).getTextContent();
                String title = bookElement.getElementsByTagName("title").item(0).getTextContent();
                String genre = bookElement.getElementsByTagName("genre").item(0).getTextContent();
                double price = Double.parseDouble(bookElement.getElementsByTagName("price").item(0).getTextContent());
                String publishDate = bookElement.getElementsByTagName("publish_date").item(0).getTextContent();
                String description = bookElement.getElementsByTagName("description").item(0).getTextContent();

                Book book = new Book(id, author, title, genre, price, publishDate, description);
                // 将book对象添加到Catalog类中的列表中
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}

请注意，以上代码仅为示例，您可能需要根据实际情况进行适当的修改和调整