[jboss-user] [JBoss Seam] - Hotel Booking sample and Conversation - Why merge?

The HotelBookingAction (SFSB) has an method that begins the long-running conversation (@Begin) called selectHotel(Hotel selectedHotel) . See below: | @Stateful | @Name("hotelBooking") | @Restrict("#{identity.loggedIn}") | public class HotelBookingAction implements HotelBooking | { | | @PersistenceContext(type=EXTENDED) | private EntityManager em; | | ... | | @In(required=false) @Out | private Hotel hotel; | | @In(required=false) | @Out(required=false) | private Booking booking; | | ... | | @Begin | public void selectHotel(Hotel selectedHotel) | { | hotel = em.merge(selectedHotel); | } | | | @End | public void confirm() | { | em.persist(booking); | facesMessages.add("Thank you, #{user.name}, your confimation number for #{hotel.name} is #{booking.id}"); | log.info("New booking: #{booking.id} for #{user.username}"); | events.raiseTransactionSuccessEvent("bookingConfirmed"); | } | | ... | } | The question is: why does use em.merge on 'selectedHotel'? What about em.find(Hotel.class, selectedHotel.getId())? View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4086920#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...