Third-party Object Models: DOM, JDOM, XOM, and DOM4J
This section is relevant to the Java platform only.
Saxon allows various third-party object models to be used to supply the input to a transformation or query.
Specifically, it supports DOM, JDOM, XOM, and DOM4J. For each of these models there is a support module in its own
JAR file: saxon8-dom.jar, saxon8-jdom.jar, saxon8-xom.jar, or saxon8-dom4j.jar.
The relevant object model is not recognized unless the appropriate support module is on the classpath.
For DOM input, the source can be supplied by wrapping a
DOMSource around the DOM
Document node. For JDOM, XOM, and DOM4J the approach is similar, except that the wrapper classes are supplied
by Saxon itself: they are
respectively. These wrapper classes implement
NodeInfo interface (which means that they also implement
None of these models is likely to be as efficient as using Saxon's native tree model. For best performance,
you should avoid using a DOM, JDOM, XOM, or DOM4J source. These models should only be used if your application
needs to construct them for other reasons.
Saxon supports these models by wrapping each DOM, JDOM, XOM, or DOM4J node in a wrapper that implements
NodeInfo interface. When nodes are returned by the XQuery or XPath API, these
wrappers are removed and the original node is returned. Similarly, the wrappers are generally removed when
extension functions expecting a node are called.
In the case of DOM only, Saxon also supports a wrapping the other way around: an object implementing
the DOM interface may be wrapped around a Saxon NodeInfo. This is done when Java methods expecting a
DOM Node are called as extension functions, if the NodeInfo is not itself a wrapper for a DOM Node.
You can also send output to a DOM by using a
DOMResult, or to a JDOM tree by
JDOMResult. In such cases it is a good idea to set
xsl:output to ensure that the
transformation or query result is a well-formed document (for example, that it does not contain
several elements at the top level).