DOMToXML.java - Converting DOM Documents to XML Files

JDK Tutorials - Herong's Tutorial Examples

∟DOM (Document Object Model) - API for XML Files

∟DOMToXML.java - Converting DOM Documents to XML Files

This section provides a tutorial example on how to write a program to convert a DOM document object into an XML file using the default XML transformer, org.apache.xalan.transformer, provided in the JDK.

Once you have a DOM document in memory, for sure you want to know how to write it out into an XML file. One way to do this is to use the XML transform package offered in J2SDK.

The main class in the XML transform package is called Transformer, which can be used process XML from a variety of sources and write the transformation output to a variety of sinks.

Here is a program to illustrate how to use Transformer to convert a DOM document into a XML file:

/* DOMToXML.java
 * Copyright (c) HerongYang.com. All Rights Reserved.
 */
import java.io.*;
import javax.xml.parsers.*;
import org.w3c.dom.*;
import javax.xml.transform.*;
import javax.xml.transform.dom.*;
import javax.xml.transform.stream.*;
class DOMToXML {
   public static void main(String[] args) {
      try {
         File x = new File(args[0]);
         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"));
         TransformerFactory tf = TransformerFactory.newInstance();
         Transformer m = tf.newTransformer();
         System.out.println(m.toString());
         DOMSource source = new DOMSource(d);
         StreamResult result = new StreamResult(x);
         m.transform(source, result);
      } catch (ParserConfigurationException e) {
         System.out.println(e.toString());
      } catch (TransformerConfigurationException e) {
         System.out.println(e.toString());
      } catch (TransformerException e) {
         System.out.println(e.toString());
      }
   }
}

Run this program with "java DOMToXML word.xml, you will get the following on the Java console window:

com.sun.org.apache.xalan.internal.xsltc.trax.TransformerImpl@52e922

This tells us that the factory pickup an implementation of Transformer from the com.sun.org.apache.xalan.internal.xsltc.trax package.

word.xml, the XML file generated by the program, looks very good:

<?xml version="1.0" encoding="UTF-8"?>
<dictionary><word><update date="2002-12-24"/>
<name is_acronym="true">DTD</name>
<definition>Document Type Definition</definition></word>
</dictionary>