Traverse the DOM tree using TreeWalker in Java
Description
The following code shows how to traverse the DOM tree using TreeWalker.
Example
//from ww w. j a v a 2s . c o m
import java.io.StringReader;
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.TreeWalker;
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;
TreeWalker walker = traversal.createTreeWalker(document.getDocumentElement(),
NodeFilter.SHOW_ELEMENT, null, true);
traverseLevel(walker, "");
}
private static final void traverseLevel(TreeWalker walker, String indent) {
Node parend = walker.getCurrentNode();
System.out.println(indent + "- " + ((Element) parend).getTagName());
for (Node n = walker.firstChild(); n != null; n = walker.nextSibling()) {
traverseLevel(walker, indent + '\t');
}
walker.setCurrentNode(parend);
}
}
The code above generates the following result.