HomeXML Page 2 - XML Parsing With DOM and Xerces (part 1)
Float Like A Butterfly... - XML
The Simple API for XML (SAX) is just one approach to parsing XML. An alternative approach is the Document Object Model (DOM), which builds a data tree in memory for easier, non-sequential access to XML data fragments. In this article, find out how to combine the Java-based Xerces parser with the DOM to create simple Java/XML applications.
The Xerces Java Parser (version 1.4.4) has been developed by the same people who created Apache, the Web server that is standard on most UNIX systems. Though it's named after a butterfly, this parser is anything but lightweight; it supports the latest version of the DOM standard (Level 2) in addition to the SAX 1.0 standard and the newer SAX 2.0 specification. Note, however, that since XML standards are constantly evolving, using Xerces can sometimes produce unexpected results; take a look at the documentation provided with the parser, and at the information available on its official Web site, for errata and updates.
With the introductions out of the way, let's put together the tools you'll need to get started with Xerces. Here's a quick list of the software you'll need:
1. The Java Development Kit (JDK), available from the Sun Microsystems Web site (http://java.sun.com)
2. The Apache Web server, available from the Apache Software Foundation's Web site (http://httpd.apache.org)
3. The Tomcat Application Server, available from the Apache Software Foundation's Web site (http://httpd.apache.org)
4. The Xerces parser, available from the Apache XML Project's Web site (http://xml.apache.org)
5. The mod_jk extension for Apache-Tomcat communication, available from the Jakarta Project's Web site (http://httpd.apache.org)
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