From: Felipe Gaúcho <fgaucho_at_gmail.com>
Date: Thu, 12 Mar 2009 14:19:22 +0100

pay special attention to the wsimport options:

                <wsimport debug="true" verbose="${verbose}" keep="true"
extension="false" destdir="${generated.dir}"
wsdl="${service.admin.wsdl}"
wsdllocation="${service.admin.wsdllocation}">
                        <produces dir="${generated.dir}" includes="${generated.dir}/**/*.java" />
                        <xjcarg value="-Xcollection-setter-injector" />
                </wsimport>

* you can remove this Xcollection.. element, it is just for the FLEX
integration....

here it is the wsimport docs:
https://jax-ws.dev.java.net/jax-ws-ea3/docs/wsimport.html