Building a New DOM Document Object

XML Tutorials - Herong's Tutorial Examples

∟DOM (Document Object Model) Programming Interface

∟Building a New DOM Document Object

This section provides a tutorial example on how to build a new DOM Document object and print it out as DOM Node tree.

DOM document objects can also be created from scratch instead of parsed from an XML file. This can be easily done by using the following methods:

DocumentBuilder.newDocument(): Create an empty DOM document.
Document.createElement(): Create a new Element.
Document.createTextNode(): Create a new TextNode.
Node.appendChild(): Insert a sub Node into the current Node.
Element.setAttribute(): Add new attribute into an element.

The following program shows how to create a simple DOM document object with these methods:

/* DOMNewDoc.java
 - Copyright (c) 2002-2018 HerongYang.com. All Rights Reserved.
 */
import java.io.*;
import javax.xml.parsers.*;
import org.w3c.dom.*;
class DOMNewDoc {
   public static void main(String[] args) {
      try {
         DocumentBuilderFactory f
            = DocumentBuilderFactory.newInstance();
         DocumentBuilder b = f.newDocumentBuilder();
         Document d = b.newDocument();
         Element r = d.createElement("dictionary");
         d.appendChild(r);
         Element w = d.createElement("word");
         r.appendChild(w);
         Element e = d.createElement("update");
         w.appendChild(e);
         e.setAttribute("date","2002-12-24");
         e = d.createElement("name");
         w.appendChild(e);
         e.setAttribute("is_acronym","true");
         e.appendChild(d.createTextNode("DTD"));
         e = d.createElement("definition");
         w.appendChild(e);
         e.appendChild(d.createTextNode("Document Type Definition"));
         printNode(d, "");
      } catch (ParserConfigurationException e) {
         System.out.println(e.toString());
      }
   }
   static void printNode(Node n, String p) {
      NodeList l = n.getChildNodes();
      NamedNodeMap m = n.getAttributes();
      int ml = -1;
      if (m!=null) ml = m.getLength();
      System.out.println(p+n.getNodeName()+": "+n.getNodeType()+", "
         +l.getLength()+", "+ml+", "+n.getNodeValue());
      for (int i=0; i<ml; i++) {
         Node c = m.item(i);
         printNode(c,p+" |-");
      }
      for (int i=0; i<l.getLength(); i++) {
         Node c = l.item(i);
         printNode(c,p+" ");
      }
   }
}

Run this sample Java program in JDK, you should get:

herong> java DOMNewDoc

#document: 9, 1, -1, null
 dictionary: 1, 1, 0, null
  word: 1, 3, 0, null
   update: 1, 0, 1, null
    |-date: 2, 0, -1, 2002-12-24
   name: 1, 1, 1, null
    |-is_acronym: 2, 0, -1, true
    #text: 3, 0, -1, DTD
   definition: 1, 1, 0, null
    #text: 3, 0, -1, Document Type Definition