Работаем с ХМЛ - DOM и SAX

import java.io.ByteArrayInputStream;
import java.io.StringWriter;
import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.parsers.SAXParser;
import javax.xml.parsers.SAXParserFactory;
import javax.xml.transform.Transformer;
import javax.xml.transform.TransformerFactory;
import javax.xml.transform.dom.DOMSource;
import javax.xml.transform.stream.StreamResult;
import org.w3c.dom.Comment;
import org.w3c.dom.Document;
import org.w3c.dom.Element;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;
import org.w3c.dom.Text;
import org.xml.sax.Attributes;
import org.xml.sax.InputSource;
import org.xml.sax.SAXException;
import org.xml.sax.ext.DefaultHandler2;
 
/**
 * @author mutagen
 */
public class XMLComment {
 
    /**
     * @param args the command line arguments
     */
    public static void main(String[] args) throws Exception {
        DocumentBuilderFactory builderFactory = DocumentBuilderFactory.newInstance();
        DocumentBuilder builder = builderFactory.newDocumentBuilder();
        Document doc = builder.newDocument();
 
 
        DOMSource dOMSource = new DOMSource(doc);
        Element rootElement = doc.createElement("iRoot");
        doc.appendChild(rootElement);
        Comment comment = doc.createComment(" it is comment ");
        rootElement.appendChild(comment);
        Element inside = doc.createElement("inside");
        inside.setAttribute("iAttribute", "attrValue");
        Element subElement = doc.createElement("iSub");
        inside.appendChild(subElement);
        Text text1 = doc.createTextNode("sub1");
        subElement.appendChild(text1);
        subElement = doc.createElement("iSub");
        inside.appendChild(subElement);
        Text text2 = doc.createTextNode("sub2");
        subElement.appendChild(text2);
 
        rootElement.appendChild(inside);
 
        StringWriter sw = new StringWriter();
        TransformerFactory transformerFactory = TransformerFactory.newInstance();
        Transformer transformer = transformerFactory.newTransformer();
        DOMSource source = new DOMSource(doc);
        StreamResult result = new StreamResult(sw);
        transformer.transform(source, result);
 
        System.out.println("Source XML =====>");
        System.out.println(sw.toString());
        
        System.out.println("DOM parser ======>");
        Document newDoc = builder.parse(new ByteArrayInputStream(sw.toString().getBytes()));
        Node rootNode = newDoc.getFirstChild();
        
        printComment(rootNode);
        NodeList nl = doc.getElementsByTagName("iSub");
        for (int i = 0; i < nl.getLength(); i++) {
            System.out.println("tag iSub: " + nl.item(i).getTextContent());
        }
 
        System.out.println("SAX parser ========>");
        
        CustomHandler mp = new CustomHandler();
        SAXParserFactory factory = SAXParserFactory.newInstance();
        factory.setValidating(true);
        factory.setNamespaceAware(false);
        SAXParser parser = factory.newSAXParser();
        InputSource is = new InputSource(new ByteArrayInputStream(sw.toString().getBytes()));
        parser.setProperty ("http://xml.org/sax/properties/lexical-handler", mp);
        parser.parse(is, mp);
    }
 
    public static void printComment(Node node) {
        NodeList list = node.getChildNodes();
        for (int i = 0; i < list.getLength(); i++) {
            Node subnode = list.item(i);
            if (subnode.getNodeType() == Node.COMMENT_NODE) {
                String comment = subnode.getTextContent();
                System.out.println("dom comment: " + comment);
            }
        }
    }
 
    static class CustomHandler extends DefaultHandler2 {
 
        @Override
        public void characters(char[] ch, int start, int length) throws SAXException {
            System.out.println("sax chars: " + new String(ch, start, length));
        }
 
 
        @Override
        public void comment(char[] ch, int start, int length) throws SAXException {
            System.out.println("sax comment: " + new String(ch, start, length));
        }
    }
}