Create a name node filer and traverse DOM tree in Java

import java.io.StringReader;
//from www  .j  a v a  2  s.  co  m
import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;

import org.w3c.dom.Document;
import org.w3c.dom.Element;
import org.w3c.dom.Node;
import org.w3c.dom.traversal.DocumentTraversal;
import org.w3c.dom.traversal.NodeFilter;
import org.w3c.dom.traversal.NodeIterator;
import org.xml.sax.InputSource;

public class Main {
  
  public static void main(String[] argv) throws Exception {
    StringReader sr = new StringReader("<tag>java2s.com</tag>");
    DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
    DocumentBuilder loader = factory.newDocumentBuilder();

    Document document = loader.parse(new InputSource(sr));

    DocumentTraversal traversal = (DocumentTraversal) document;

    NodeIterator iterator = traversal.createNodeIterator(document.getDocumentElement(),
        NodeFilter.SHOW_ALL, new ItemFilter(), true);

    for (Node n = iterator.nextNode(); n != null; n = iterator.nextNode()) {
      System.out.println("Element: " + ((Element) n).getTagName());
    }

  }
  
}
class ItemFilter implements NodeFilter {
  public short acceptNode(Node n) {
    if (n instanceof Element) {
      if (((Element) n).getTagName().equals("tag")) {
        return NodeFilter.FILTER_ACCEPT;
      }
    }
    return NodeFilter.FILTER_REJECT;
  }
}