Editing XML Files with Java

edit-xml-file.java

import javax.xml.parsers.*;
import org.w3c.dom.*;
import java.io.*;
import javax.xml.transform.*;
import javax.xml.transform.dom.DOMSource;
import javax.xml.transform.stream.StreamResult;

public class EditXML {
    public static void main(String[] args) throws Exception {
        File inputFile = new File("books.xml");
        DocumentBuilderFactory dbFactory = DocumentBuilderFactory.newInstance();
        DocumentBuilder dBuilder = dbFactory.newDocumentBuilder();
        Document doc = dBuilder.parse(inputFile);
        doc.getDocumentElement().normalize();

        NodeList nodeList = doc.getElementsByTagName("book");
        for (int i = 0; i < nodeList.getLength(); i++) {
            Node node = nodeList.item(i);
            if (node.getNodeType() == Node.ELEMENT_NODE) {
                Element element = (Element) node;
                if (element.getAttribute("id").equals("1")) {
                    element.getElementsByTagName("price").item(0).setTextContent("24.99");
                }
            }
        }

        TransformerFactory transformerFactory = TransformerFactory.newInstance();
        Transformer transformer = transformerFactory.newTransformer();
        DOMSource source = new DOMSource(doc);
        StreamResult result = new StreamResult(new File("books.xml"));
        transformer.transform(source, result);
    }
}