The Java XML package

Interface play an important role in the implementation of plugable appliation platform.

The W3C Document Object Model (DOM) is a platform- and language-neutral interface that will allow programs and scripts to dynamically access and update the content, structure and style of documents (XML). The org.w3c.dom is the corresponding interface definition for Java. The interface allows any conformance DOM parser to be “plug-and-play” into an application. (Also see the javax.xml.parser)

javax.xml.parsers.DocumentBuilderFactory bf = 
    DocumentBuilderFactory.newInstance();
javax.xml.parsers.DoucumentBuilder b = 
    bf.newDocumentBuilder();
org.w3c.dom.Document document = b.parse(...);
org.w3c.dom.Element root = document.getDocumentElement();