JAXB 和抽象类

JAXB（Java Architecture for XML Binding）是一种用于将XML文档和Java对象之间进行映射的技术。它提供了一种简单易用的方式，使开发人员能够在Java应用程序中使用XML数据。JAXB通过将XML文档转换为Java对象，以及将Java对象转换为XML文档，实现了Java对象和XML文档之间的相互转换。

java
import javax.xml.bind.annotation.XmlElement;
import javax.xml.bind.annotation.XmlRootElement;
@XmlRootElement
public class Book {
    private String title;
    private String author;
    private String publicationDate;
    public String getTitle() {
        return title;
    }
    @XmlElement
    public void setTitle(String title) {
        this.title = title;
    }
    public String getAuthor() {
        return author;
    }
    @XmlElement
    public void setAuthor(String author) {
        this.author = author;
    }
    public String getPublicationDate() {
        return publicationDate;
    }
    @XmlElement
    public void setPublicationDate(String publicationDate) {
        this.publicationDate = publicationDate;
    }
}

java
import javax.xml.bind.JAXBContext;
import javax.xml.bind.JAXBException;
import javax.xml.bind.Unmarshaller;
import javax.xml.bind.Marshaller;
public class JAXBExample {
    public static void main(String[] args) {
        try {
            // 创建JAXBContext对象
            JAXBContext jaxbContext = JAXBContext.newInstance(Book.class);
            // 创建Unmarshaller对象
            Unmarshaller unmarshaller = jaxbContext.createUnmarshaller();
            // 将XML数据转换为Java对象
            Book book = (Book) unmarshaller.unmarshal(new File("book.xml"));
            // 将Java对象转换为XML数据
            Marshaller marshaller = jaxbContext.createMarshaller();
            marshaller.setProperty(Marshaller.JAXB_FORMATTED_OUTPUT, true);
            marshaller.marshal(book, System.out);
        } catch (JAXBException e) {
            e.printStackTrace();
        }
    }
}