XStreamMarshaller uses the class CompositeClassLoader here, but it is not part of the public API. xstream is an OSGi bundle and does not export the package com.thoughtworks.xstream.core.util. This results in a ClassNotFoundException when using Spring oxm + xstream in an OSGi environment since that package is not exported.

I've asked explicitly here about this. Could Spring oxm use the same classloader which loaded the xstream classes (XStream.class.getClassLoader()) to lookup the CompositeClassLoader and create a new instance to avoid this issue?