GWT RPC, Spring, JPA/Hibernate - null on callback method -

this first app. have problem between gwt (rpc) , db (mysql). junit tests run great. here code: https://github.com/sutakjakub/game

client package:

userservice.util.getinstance().adduser("kuba","tajne", new asynccallback<long>() {  @override public void onfailure(throwable arg0) { window.alert("get se nezdaril" + arg0);  }  @override public void onsuccess(long id) { if(id == null){ window.alert("null"); }else{ window.alert("zapsano db; id=" + id); }  }  }); 

this method must return id of new user return null (in method onsuccess(long id)).

i dont have error logs. tried everything. thank idea or solution.

an updated entity isn't returned saveorupdate method (generichibernatejpadao):

@override public <entity extends abstractbussinessobject> entity saveorupdate(entity o) {   if(o.getid() == null){     getentitymanager().persist(o);   }else{     getentitymanager().merge(o);   } return o; } 

should become:

return getentitymanager().merge(o); 

if want use persist(), should read this well.