Booking example question

[lawrieg]

Hi,

I've just been re-reading the Seam tutorial and I just wanted to check if my understanding is correct regarding the Booking example code...

In the HotelBookingAction class the selectHotel method reads as follows:

@Begin
public String selectHotel(Hotel selectedHotel) {
 hotel = em.merge(selectedHotel);
 return "hotel";
}

Am I correct that the reason the line hotel = em.merge(selectedHotel) is necessary is because the selectedHotel object was obtained by a different entity manager?

And, if so, does this mean that you always need to use em.merge when an object that was loaded in one class is passed as a parameter to a method in another class?

Thanks,

Lawrie

[lawrieg]

Also, is there any reason why you couldn't / wouldn't code the method as follows instead???

@Begin
public String selectHotel(Hotel selectedHotel) {
 hotel = em.find(Hotel.class, selectedHotel.getId());
 return "hotel";
}