Choose Your Java XML Parser

he XML parser world is a dynamic one. As standards change, the parsers change as well--XML parsers are becoming more sophisticated. For most programming projects, the parser, at minimum, must support DOM Level 2, SAX 2, XSLT, and Namespaces. All the parsers discussed here provide these capabilities; however, there are distinct differences in performance, reliability, and conformance to standards. In this article, I'll compare the latest parsers from Sun, Oracle, and the Apache Software Foundation.

Apache parser
The Apache parser version 1.2.3 (commonly known as Xerces) is an open-source effort based on IBM's XML4J parser. Xerces has full support for the W3C Document Object Model (DOM) Level 1 and the Simple API for XML (SAX) 1.0 and 2.0; however it currently has only limited support for XML Schemas, DOM Level 2 (version 1). Add the xerces.jar file to your CLASSPATH to use the parser. You can use Xalan, also available from Apache's Web site, for XSLT processing. You can configure both the DOM and SAX parsers. Xerces uses the SAX2 method getFeature() and setFeature() to query and set various parser features. For example, to create a validating DOM parser instance, you would write:

DOMParser domp = new DOMParser();
try {
domp.setFeature ("http://xml.org/dom/features/validation", true);
} catch (SAXExcepton ex) {
System.out.println(ex);
}
 

Other modifiable features include support for Schemas and namespaces.