List  ids   = ...
Query query = pSession.createQuery("select from BOCustomer as customer " +
                                   "where customer.id in (:ids)");
query.setParameterList("ids", ids);
List results= query.list();

List  ids   = ...
Query query = pSession.createQuery("select from BOCustomer as customer " +
                                   "where customer.id in (:ids)");
query.setParameterList("ids", ids);
List results= query.list();

// sync the order of the result list with the order of the keys list
int  n   = results.size();
List back= new ArrayList(n);
Map  map = new HashMap  (n); // key= id, value= customer
for (int i = 0; i < n; i++)
{
    BOCustomer customer= (BOCustomer) results.get(i);
    Long       id      = new Long(customer.getId());
    map.put(id, customer);
}
for (int i = 0, n = ids.size(); i < n; i++)
{
    Long       id      = (Long)ids.get(i);
    BOCustomer customer= (BOCustomer) map.get(id);
    back.add(customer);
}