The J2EE™ Tutorial Second Edition

The JAXP APIs

The main JAXP APIs are defined in the javax.xml.parsers package. That package contains vendor-neutral factory classes—SAXParserFactory, DocumentBuilderFactory, and TransformerFactory—which give you a SAXParser, a DocumentBuilder, and an XSLT transformer, respectively. DocumentBuilder, in turn, creates a DOM-compliant Document object.

The factory APIs let you plug in an XML implementation offered by another vendor without changing your source code. The implementation you get depends on the setting of the javax.xml.parsers.SAXParserFactory, javax.xml.parsers.DocumentBuilderFactory, and javax.xml.transform.TransformerFactory system properties, using System.setProperties() in the code, <sysproperty key="..." value="..."/> in an Ant ...