java - Why throw CannotResolveClassException on XStream? -

i using follow code:

@xstreamalias("listofmbdo")  public class xmllistofmbdo {    	@xstreamimplicit(itemfieldname = "mbdo")  	public list<modifybetriebsortdataobject> items = new linkedlist<modifybetriebsortdataobject>();    }    public class modifybetriebsortdataobject {    	@xstreamalias("pk")  	public integer pk;    	@xstreamalias("name")  	public string name;    	public modifybetriebsortdataobject(final integer pk, final string name) {  		this.pk = pk;  		this.name = name;  	}  }      public void loadthis() {    final string test = "<listofmbdo><mbdo><pk>123456</pk><name>test</name></mbdo></listofmbdo>";    final xstream _xstream = new xstream(new domdriver());    _xstream.processannotations(xmllistofmbdo.class);    _xstream.processannotations(modifybetriebsortdataobject.class);    final xmllistofmbdo testlist = (xmllistofmbdo) _xstream.fromxml(test);  }

the serializationto xml works fine. deserialization throws an

com.thoughtworks.xstream.mapper.cannotresolveclassexception: ....data.xmllistofmbdo : ....data.xmllistofmbdo     @ com.thoughtworks.xstream.mapper.defaultmapper.realclass(defaultmapper.java:68)     @ com.thoughtworks.xstream.mapper.mapperwrapper.realclass(mapperwrapper.java:38)     @ com.thoughtworks.xstream.mapper.dynamicproxymapper.realclass(dynamicproxymapper.java:71) ... 

why?

you can try solving deserialization error adding

    _xstream.alias("listofmbdo", xmllistofmbdo.class);