It is hard to configure XStream in an OSGI environment.

    protected synchronized XmlPullParser createParser() throws XmlPullParserException {
        if (factory == null) {
        	try {
        		factory = XmlPullParserFactory.newInstance(null, XppDriver.class);
        	} catch (final XmlPullParserException ex) {
        		// fall-back for OSGi environment
        		factory = XmlPullParserFactory.newInstance();
        	}
        }
        return factory.newPullParser();
    }