Two questions: 1) We are investigating sending JPA entities through WS. When the entity defines mappedBy, WS fails because mappedBy cause recursive when the engine tried to generate the XML. The most obvious way to resolve the problem, is to remove mappedBy, but is that the best way, any other ways? 2) A larger question, is it the best practice to send JPA entity over WS? Is there any risk of troubles? I see an logical argument against it: sending data object over WS is not the best practice, what should be send over is the business object.