servlet problem: hibernate-validator (requestValidator.getInvalidValues(data) fails)

This section of code fails (data is the bean object):

InvalidValue[] validationMessages;
ClassValidator requestValidator = new ClassValidator(data.getClass());
validationMessages = requestValidator.getInvalidValues(data); //fails here!

Don’t know why but this works (“hobby” is one of the fields of the data bean):
requestValidator.getInvalidValues(data, “hobby”)

So, I modified the whole section to use request’s getParameterMap to traverse each bean property:
    InvalidValue[] validationMessages;
    List<InvalidValue[]> validationMsgList = new ArrayList<InvalidValue[]>();
    ClassValidator requestValidator = new ClassValidator(data.getClass());
    Map pMap = request.getParameterMap();
    Iterator ParIt = pMap.entrySet().iterator();
    while (ParIt.hasNext()) {
            Map.Entry pairs = (Map.Entry) ParIt.next();
            String key = “” + pairs.getKey();
            validationMessages = requestValidator.getInvalidValues(data, key);
            validationMsgList.add(validationMessages);
    }

App finally runs.