Using spring for service layer. What is the best practice for accessing service layer from domain object. My particular issue is I have a domain object whose children are also the same typed domain object but there is a complicated HQL join to retreive the results so I just can't create a mapping. Should I access the spring service layer from my domain object such that when I iterate through a list of these domain objects then each domain object will have access to it's parents? Maybe this question is better answered in hibernate forum but since it's also Spring related I thought I'd also ask it here.