Didn't understand why somebody wants to convert XML DTD to Java classes. Ok. but this may be(may be) useful for your interest.
JAXB is used to create Java objects of the the XML elements. It needs the XML schema document (not DTD,ofcourse) as source instead of the xml document itself. The created objects are used manipulate the xml document. JAXB is faster in this process (compared to DOM/SAX !!??).
Anybody knows if JAXB is faster than DOM/SAX? Sorry harish, if I am deviating your topic.