RaffaeleSgarro/DomParser.java

## DomParser.java
package stackoverflow;

import org.w3c.dom.*;

import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import java.io.File;

public class DomParser {

    public static void main(String... args) throws Exception {
        // File in current JVM directory
        File file = new File("template.html");
        DocumentBuilderFactory dbFactory = DocumentBuilderFactory.newInstance();
        // Don't try to fetch the DTD over internet
        dbFactory.setFeature("http://apache.org/xml/features/nonvalidating/load-external-dtd", false);
        DocumentBuilder dBuilder = dbFactory.newDocumentBuilder();
        Document doc = dBuilder.parse(file);
        Finder finder = new Finder();
        finder.findById(doc.getDocumentElement());
        System.out.println(finder.el.getTextContent());
    }

    private static class Finder {

        public boolean found;

        public Element el;

        private void findById(Node node) {
            if (found)
                return;

            NamedNodeMap attrs = node.getAttributes();

            if (attrs != null)  {
                Node id = attrs.getNamedItem("id");
                if (id != null) {
                    el = (Element) node;
                    found = true;
                }
            }

            NodeList childNodes = node.getChildNodes();
            for (int i = 0; i < childNodes.getLength(); i++) {
                if (found)
                    return;

                Node child = childNodes.item(i);
                findById(child);
            }
        }
    }
}

## template.html
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE html
        PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN"
        "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
<html>
<head>
    <title>TEST</title>
</head>
<body>
<h1 id="hey">Hello, World!</h1>
</body>
</html>
	package stackoverflow;

	import org.w3c.dom.*;

	import javax.xml.parsers.DocumentBuilder;
	import javax.xml.parsers.DocumentBuilderFactory;
	import java.io.File;

	public class DomParser {

	public static void main(String... args) throws Exception {
	// File in current JVM directory
	File file = new File("template.html");
	DocumentBuilderFactory dbFactory = DocumentBuilderFactory.newInstance();
	// Don't try to fetch the DTD over internet
	dbFactory.setFeature("http://apache.org/xml/features/nonvalidating/load-external-dtd", false);
	DocumentBuilder dBuilder = dbFactory.newDocumentBuilder();
	Document doc = dBuilder.parse(file);
	Finder finder = new Finder();
	finder.findById(doc.getDocumentElement());
	System.out.println(finder.el.getTextContent());
	}

	private static class Finder {

	public boolean found;

	public Element el;

	private void findById(Node node) {
	if (found)
	return;

	NamedNodeMap attrs = node.getAttributes();

	if (attrs != null) {
	Node id = attrs.getNamedItem("id");
	if (id != null) {
	el = (Element) node;
	found = true;
	}
	}

	NodeList childNodes = node.getChildNodes();
	for (int i = 0; i < childNodes.getLength(); i++) {
	if (found)
	return;

	Node child = childNodes.item(i);
	findById(child);
	}
	}
	}
	}
	<?xml version="1.0" encoding="UTF-8"?>
	<!DOCTYPE html
	PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN"
	"http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
	<html>
	<head>
	<title>TEST</title>
	</head>
	<body>
	<h1 id="hey">Hello, World!</h1>
	</body>
	</html>