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{ return null; }</code><a name="wp64789"> </a>
</pre></div>
<a name="wp64790"> </a><p class="pBody">
Finally, add the code highlighted below to generate null methods for the remainder of the<code class="cCode"> XmlReader</code> interface. (Most of them are of value to a real SAX parser, but have little bearing on a data-conversion application like this one.) 
</p>
<div class="pPreformattedRelative"><pre class="pPreformattedRelative">
/** Parse an XML document from a system identifier (URI). */
<code class="cCodeBold">public void parse(String systemId)
throws IOException, SAXException 
{ }</code><a name="wp64791"> </a>
 /** Return the current DTD handler. */
<code class="cCodeBold">public DTDHandler getDTDHandler()
{ return null; }</code><a name="wp64792"> </a>
/** Return the current entity resolver. */
<code class="cCodeBold">public EntityResolver getEntityResolver()
{ return null; }</code><a name="wp64793"> </a>
/** Allow an application to register an entity resolver. */
<code class="cCodeBold">public void setEntityResolver(EntityResolver resolver)
{ }</code><a name="wp64794"> </a>
/** Allow an application to register a DTD event handler. */
<code class="cCodeBold">public void setDTDHandler(DTDHandler handler)
{ }</code><a name="wp64795"> </a>
/** Look up the value of a property. */
<code class="cCodeBold">public Object getProperty(String name)
{ return null; }</code><a name="wp64796"> </a>
/** Set the value of a property. */
<code class="cCodeBold">public void setProperty(String name, Object value)
{ }</code> <a name="wp64797"> </a>
/** Set the state of a feature. */
<code class="cCodeBold">public void setFeature(String name, boolean value)
{ }</code><a name="wp64798"> </a>
/** Look up the value of a feature. */
<code class="cCodeBold">public boolean getFeature(String name)
{ return false; }</code> <a name="wp64799"> </a>
</pre></div>
<a name="wp64800"> </a><p class="pBody">
Congratulations! You now have a parser you can use to generate SAX events. In the next section, you'll use it to construct a SAX source object that will let you transform the data into XML.
</p>
<a name="wp64802"> </a><h3 class="pHeading2">
Using the Parser as a SAXSource
</h3>
<a name="wp64803"> </a><p class="pBody">
Given a SAX parser to use as an event source, you can (easily!) construct a transformer to produce a result. In this section, you'll modify the <code class="cCode">TransformerApp</code> you've been working with to produce a stream output result, although you could just as easily produce a DOM result.
</p>
<hr>
<a name="wp64804"> </a><p class="pNote">
Note: The code discussed in this section is in <code class="cCode"><a  href="../examples/jaxp/xslt/samples/TransformationApp04.java" target="_blank">TransformationApp04.java</a></code>. The results of running it are in <code class="cCode"><a  href="../examples/jaxp/xslt/samples/TransformationLog04.txt" target="_blank">TransformationLog04.txt</a></code>.
</p>
<hr><a name="wp64805"> </a><p class="pBody">
Important!
</p>
<a name="wp68502"> </a><p class="pBody">
Make sure you put the <code class="cCode">AddressBookReader</code> aside and open up the <code class="cCode">TransformationApp</code>. The work you do in this section affects the <code class="cCode">TransformationApp</code>! (The look pretty similar, so it's easy to start working on the wrong one.)
</p>
<a name="wp64807"> </a><p class="pBody">
Start by making the changes shown below to import the classes you'll need to construct a <code class="cCode">SAXSource</code> object. (You won't be needing the DOM classes at this point, so they are discarded here, although leaving them in doesn't do any harm.)
</p>
<div class="pPreformattedRelative"><pre class="pPreformattedRelative">
import org.xml.sax.SAXException; 
import org.xml.sax.SAXParseException; 
<code class="cCodeBold">import org.xml.sax.ContentHandler;
import org.xml.sax.InputSource;
</code><code class="cCodeStruck">import org.w3c.dom.Document;
import org.w3c.dom.DOMException;
</code>...
<code class="cCodeStruck">import javax.xml.transform.dom.DOMSource; 
</code><code class="cCodeBold">import javax.xml.transform.sax.SAXSource; 
</code>import javax.xml.transform.stream.StreamResult; <a name="wp64808"> </a>
</pre></div>
<a name="wp64809"> </a><p class="pBody">
Next, remove a few other holdovers from our DOM-processing days, and add the code to create an instance of the <code class="cCode">AddressBookReader</code>:
</p>
<div class="pPreformattedRelative"><pre class="pPreformattedRelative">
public class TransformationApp 
{
<code class="cCodeStruck">&nbsp;&nbsp;// Global value so it can be ref&#39;d by the tree-adapter
&nbsp;&nbsp;static Document document; </code><a name="wp64810"> </a>
&nbsp;&nbsp; public static void main(String argv[])
&nbsp;&nbsp;{
&nbsp;&nbsp;&nbsp;&nbsp;...
&nbsp;&nbsp;&nbsp;&nbsp;<code class="cCodeStruck">DocumentBuilderFactory factory =
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;DocumentBuilderFactory.newInstance();
</code>&nbsp;&nbsp;&nbsp;&nbsp;<code class="cCodeStruck">//factory.setNamespaceAware(true);
&nbsp;&nbsp;&nbsp;&nbsp;//factory.setValidating(true); 
</code>
&nbsp;&nbsp;&nbsp;&nbsp;// Create the sax &quot;parser&quot;.
<code class="cCodeBold">&nbsp;&nbsp;&nbsp;&nbsp;AddressBookReader saxReader = new AddressBookReader();
</code>
&nbsp;&nbsp;&nbsp;&nbsp;try {
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;File f = new File(argv[0]);
&nbsp;&nbsp;&nbsp;&nbsp;<code class="cCodeStruck">&nbsp;&nbsp;DocumentBuilder builder =
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;factory.newDocumentBuilder();
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;document = builder.parse(f);</code><a name="wp64811"> </a>
</pre></div>
<a name="wp64812"> </a><p class="pBody">
Guess what! You're almost done. Just a couple of steps to go. Add the code highlighted below to construct a <code class="cCode">SAXSource</code> object: 
</p>
<div class="pPreformattedRelative"><pre class="pPreformattedRelative">
// Use a Transformer for output
...
Transformer transformer = tFactory.newTransformer();
<code class="cCodeBold">
// Use the parser as a SAX source for input
FileReader fr = new FileReader(f);
BufferedReader br = new BufferedReader(fr);
InputSource inputSource = new InputSource(br);
SAXSource source = new SAXSource(saxReader, inputSource);

</code>StreamResult result = new StreamResult(System.out);
transformer.transform(source, result);<a name="wp64813"> </a>
</pre></div>
<a name="wp64814"> </a><p class="pBody">
Here, you constructed a buffered reader (as mentioned earlier) and encapsulated it in an input source object. You then created a <code class="cCode">SAXSource</code> object, passing it the reader and the <code class="cCode">InputSource</code> object, and passed that to the transformer.
</p>
<a name="wp64815"> </a><p class="pBody">
When the application runs, the transformer will configure itself as the <code class="cCode">ContentHandler</code> for the SAX parser (the <code class="cCode">AddressBookReader</code>) and tell the parser to operate on the <code class="cCode">inputSource</code> object. Events generated by the parser will then go to the transformer, which will do the appropriate thing and pass the data on to the result object. 
</p>
<a name="wp64816"> </a><p class="pBody">
Finally, remove the exceptions you no longer need to worry about, since the <code class="cCode">TransformationApp</code> no longer generates them:
</p>
<div class="pPreformattedRelative"><pre class="pPreformattedRelative">
<code class="cCodeStruck">catch (SAXParseException spe) {
&nbsp;&nbsp;// Error generated by the parser
&nbsp;&nbsp;System.out.println(&quot;\n** Parsing error&quot;
&nbsp;&nbsp;&nbsp;&nbsp;+ &quot;, line &quot; + spe.getLineNumber()
&nbsp;&nbsp;&nbsp;&nbsp;+ &quot;, uri &quot; + spe.getSystemId());
&nbsp;&nbsp;System.out.println(&quot;   &quot; + spe.getMessage() );
&nbsp;&nbsp;
&nbsp;&nbsp;// Use the contained exception, if any
&nbsp;&nbsp;Exception  x = spe;
&nbsp;&nbsp;if (spe.getException() != null)
&nbsp;&nbsp;&nbsp;&nbsp;x = spe.getException();
&nbsp;&nbsp;x.printStackTrace();

} catch (SAXException sxe) {
&nbsp;&nbsp;// Error generated by this application
&nbsp;&nbsp;// (or a parser-initialization error)
&nbsp;&nbsp;Exception  x = sxe;
&nbsp;&nbsp;if (sxe.getException() != null)
&nbsp;&nbsp;&nbsp;&nbsp;x = sxe.getException();
&nbsp;&nbsp;x.printStackTrace();

} catch (ParserConfigurationException pce) {
&nbsp;&nbsp;// Parser with specified options can&#39;t be built
&nbsp;&nbsp;pce.printStackTrace();
</code>
} catch (IOException ioe) {
&nbsp;&nbsp;...<a name="wp64817"> </a>
</pre></div>
<a name="wp64818"> </a><p class="pBody">
You're done! You have now created a transformer which will use a <code class="cCode">SAXSource</code> as input, and produce a <code class="cCode">StreamResult</code> as output. 
</p>
<a name="wp64820"> </a><h3 class="pHeading2">
Doing the Conversion
</h3>
<a name="wp64821"> </a><p class="pBody">
Now run the application on the address book file. Your output should look like this:
</p>
<div class="pPreformattedRelative"><pre class="pPreformattedRelative">
&lt;?xml version=&quot;1.0&quot; encoding=&quot;UTF-8&quot;?&gt;
&lt;addressbook&gt;
&nbsp;&nbsp;&lt;nickname&gt;Fred&lt;/nickname&gt;
&nbsp;&nbsp;&lt;email&gt;[e-mail]&lt;/email&gt;
&nbsp;&nbsp;&lt;html&gt;TRUE&lt;/html&gt;
&nbsp;&nbsp;&lt;firstname&gt;Fred&lt;/firstname&gt;
&nbsp;&nbsp;&lt;lastname&gt;Flintstone&lt;/lastname&gt;
&nbsp;&nbsp;&lt;work&gt;999-Quarry&lt;/work&gt;
&nbsp;&nbsp;&lt;home&gt;999-BedrockLane&lt;/home&gt;
&nbsp;&nbsp;&lt;fax&gt;888-Squawk&lt;/fax&gt;
&nbsp;&nbsp;&lt;pager&gt;777-pager&lt;/pager&gt;
&nbsp;&nbsp;&lt;cell&gt;555-cell&lt;/cell&gt;
&lt;/addressbook&gt;<a name="wp64822"> </a>
</pre></div>
<a name="wp64823"> </a><p class="pBody">
You have now successfully converted an existing data structure to XML. And it wasn't even that hard. Congratulations! 
</p>
    </blockquote>

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