Java Cookbook

Transforming XML with XSLT

Problem

You need to make significant changes to the output format.

Solution

Use XSLT; it is fairly easy to use and does not require writing much Java.

Discussion

XSLT, or Extensible Style Language for Transformations, allows you a great deal of control over the output format. It can be used to change an XML file from one DTD into another, as might be needed in a business-to-business (B2B) application where information is passed from one industry-standard DTD to a site that uses another. It can also be used to render XML into another format such as HTML. Think of XSLT as a scripting language for transforming XML.

You need a set of classes called an XSLT processor . One freely available XSLT processor is the Apache project’s Xalan (formerly available from Lotus/IBM as the Lotus XSL processor). To use this, you create an XSL processor by calling the factory method getProcessor( ) , then call its parse method passing in two XSLTInputSources (one for the XML document and one for the XSL stylesheet) and one XSLTResultTarget for the output file.

Assume you have a file of people’s names, addresses, and so on, stored in an XML document such as the file people.xml, shown in Example 21-1.

Example 21-1. people.xml

<?xml version="1.0"?>
<people>
<person>
    <name>Ian Darwin</name>
    <email>[e-mail]</email>
    <country>Canada</country>
</person>
<person>
    <name>Another Darwin</name>
    <email type="intranet">ad</email>
    <country>Canada</country>
</person>
</people>

You ...