Java中处理XML数据的方法

<bookstore>
  <book category="cooking">
    <title lang="en">Everyday Italian</title>
    <author>Giada De Laurentiis</author>
    <year>2005</year>
    <price>30.00</price>
  </book>
  <book category="children">
    <title lang="en">Harry Potter</title>
    <author>J.K. Rowling</author>
    <year>2005</year>
    <price>29.99</price>
  </book>
</bookstore>

package cn.juwatech.xml;
import org.w3c.dom.Document;
import org.w3c.dom.Element;
import org.w3c.dom.NodeList;
import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import java.io.File;
public class DomParserExample {
    public static void main(String[] args) {
        try {
            File xmlFile = new File("books.xml");
            DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
            DocumentBuilder builder = factory.newDocumentBuilder();
            Document doc = builder.parse(xmlFile);
            // 获取根元素
            Element root = doc.getDocumentElement();
            // 获取所有book元素
            NodeList bookList = root.getElementsByTagName("book");
            // 遍历book元素
            for (int i = 0; i < bookList.getLength(); i++) {
                Element book = (Element) bookList.item(i);
                String category = book.getAttribute("category");
                String title = book.getElementsByTagName("title").item(0).getTextContent();
                String author = book.getElementsByTagName("author").item(0).getTextContent();
                int year = Integer.parseInt(book.getElementsByTagName("year").item(0).getTextContent());
                double price = Double.parseDouble(book.getElementsByTagName("price").item(0).getTextContent());
                System.out.println("Book: " + title);
                System.out.println("  Category: " + category);
                System.out.println("  Author: " + author);
                System.out.println("  Year: " + year);
                System.out.println("  Price: $" + price);
                System.out.println();
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}

package cn.juwatech.xml;
import org.xml.sax.Attributes;
import org.xml.sax.SAXException;
import org.xml.sax.helpers.DefaultHandler;
import javax.xml.parsers.SAXParser;
import javax.xml.parsers.SAXParserFactory;
import java.io.File;
public class SaxParserExample {
    public static void main(String[] args) {
        try {
            File xmlFile = new File("books.xml");
            SAXParserFactory factory = SAXParserFactory.newInstance();
            SAXParser saxParser = factory.newSAXParser();
            DefaultHandler handler = new DefaultHandler() {
                boolean bTitle = false;
                boolean bAuthor = false;
                boolean bYear = false;
                boolean bPrice = false;
                public void startElement(String uri, String localName, String qName, Attributes attributes) throws SAXException {
                    if (qName.equalsIgnoreCase("title")) {
                        bTitle = true;
                    } else if (qName.equalsIgnoreCase("author")) {
                        bAuthor = true;
                    } else if (qName.equalsIgnoreCase("year")) {
                        bYear = true;
                    } else if (qName.equalsIgnoreCase("price")) {
                        bPrice = true;
                    }
                }
                public void characters(char[] ch, int start, int length) throws SAXException {
                    if (bTitle) {
                        System.out.println("Book: " + new String(ch, start, length));
                        bTitle = false;
                    } else if (bAuthor) {
                        System.out.println("  Author: " + new String(ch, start, length));
                        bAuthor = false;
                    } else if (bYear) {
                        System.out.println("  Year: " + new String(ch, start, length));
                        bYear = false;
                    } else if (bPrice) {
                        System.out.println("  Price: $" + new String(ch, start, length));
                        bPrice = false;
                    }
                }
            };
            saxParser.parse(xmlFile, handler);
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}

package cn.juwatech.xml;
import javax.xml.bind.annotation.XmlElement;
import javax.xml.bind.annotation.XmlRootElement;
import javax.xml.bind.annotation.XmlType;
import javax.xml.bind.JAXBContext;
import javax.xml.bind.JAXBException;
import javax.xml.bind.Unmarshaller;
import java.io.File;
@XmlRootElement(name = "book")
@XmlType(propOrder = {"title", "author", "year", "price"})
public class Book {
    private String title;
    private String author;
    private int year;
    private double price;
    @XmlElement(name = "title")
    public String getTitle() {
        return title;
    }
    public void setTitle(String title) {
        this.title = title;
    }
    @XmlElement(name = "author")
    public String getAuthor() {
        return author;
    }
    public void setAuthor(String author) {
        this.author = author;
    }
    @XmlElement(name = "year")
    public int getYear() {
        return year;
    }
    public void setYear(int year) {
        this.year = year;
    }
    @XmlElement(name = "price")
    public double getPrice() {
        return price;
    }
    public void setPrice(double price) {
        this.price = price;
    }
    public static void main(String[] args) {
        try {
            File xmlFile = new File("book.xml");
            JAXBContext context = JAXBContext.newInstance(Book.class);
            Unmarshaller unmarshaller = context.createUnmarshaller();
            Book book = (Book) unmarshaller.unmarshal(xmlFile);
            System.out.println("Book: " + book.getTitle());
            System.out.println("  Author: " + book.getAuthor());
            System.out.println("  Year: " + book.getYear());
            System.out.println("  Price: $" + book.getPrice());
        } catch (JAXBException e) {
            e.printStackTrace();
        }
    }
}