import java.io.File;
import javax.xml.parsers.DocumentBuilderFactory;
import org.w3c.dom.Document;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;
public class Main {
public static void main(String[] argv) throws Exception{
DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
factory.setValidating(true);
factory.setExpandEntityReferences(false);
Document doc = factory.newDocumentBuilder().parse(new File("filename"));
visit(doc, 0);
}
public static void visit(Node node, int level) {
NodeList list = node.getChildNodes();
for (int i = 0; i < list.getLength(); i++) {
Node childNode = list.item(i);
visit(childNode, level + 1);
}
}
}