public class CopyUtils {

    public static String[] getNullPropertyNames (Object source) {

        final BeanWrapper src = new BeanWrapperImpl(source);

        java.beans.PropertyDescriptor[] pds = src.getPropertyDescriptors();

        Set<String> emptyNames = new HashSet<String>();

        for(java.beans.PropertyDescriptor pd : pds) {

            Object srcValue = src.getPropertyValue(pd.getName());

            if (srcValue == null) emptyNames.add(pd.getName());

        }

        String[] result = new String[emptyNames.size()];

        return emptyNames.toArray(result);

    }

    public static void copyProperties(Object src, Object target) {

        BeanUtils.copyProperties(src, target, getNullPropertyNames(src));

    }

}