From: Felipe Gaúcho <fgaucho_at_gmail.com>
Date: Fri, 12 Jun 2009 14:21:08 +0200

my old ANT file:

        <target name="compile.schema">
                <xjc removeOldOutput="no" readonly="yes" header="true"
stackSize="2mb" extension="true" classpath="${project.classpath}"
destdir="${xjc.target}">
                        <schema dir="${basedir}/resources/schema" includes="**/*.xsd" />
                        <produces dir="${xjc.target}" includes="**/**/*.class" />
                </xjc>
        </target>

I am not sure how it performs with DTD, but in schema you can use
annotations of "JAXB
Customization"..

if you can change your DTD to a XSD schema, perhaps I can help more...