You can also use transfer objects with your DAOs, or turn lazy loading off for certain classes or collections that you are using as transfer objects. Either approach will eliminate the need for OpenSessionInView-like things and enable you to switch DAO implemenations. The right choice depends on how much work you are willing to do in order to be able to switch DAO implementations.
> -----Original Message----- > From: news [mailto:[EMAIL PROTECTED] On Behalf Of Werner Punz > Sent: Wednesday, August 31, 2005 1:52 PM > To: [email protected] > Subject: Re: JSF + Spring + Hibernate > > well OpenSessionInView... is one of those rare circumstances > where it actually makes sense, because it eases the > portability and implementation... > > I would not say it reall is dependend on the view layer, more > on the control layer of the server... > It is one of those border cases... > > > Larry Meadors wrote: > > Heheh, are you suggesting that making your DAO layer depend > upon your > > view layer is a bad idea? > > > > I would have to agree.... > > > > Larry > > > > > > On 8/31/05, Ken Weiner <[EMAIL PROTECTED]> wrote: > > > >>I have a question about designing a webapp to use a DAO > layer, lazily loaded > >>objects, Hibernate, and the OpenSessionInView technique. > >> > >> Doesn't this strategy make it very difficult to > reimplement the DAO layer > >>sometime in the future? If you switched a DAO > implementation from Hibernate > >>to let's say, Spring JDBC, then how would all the lazy > loading work? There > >>would be no equivalent OpenSessionInView technique for > Spring JDBC. For > >>this reason, I have been shying away from designing my > domain objects such > >>that the rest of the app expects them to lazily load data. > >> > >> So, instead of a Company class having a getEmployees() > method, I would > >>choose, instead, to have a CompanyDao.getEmployees(Company > company) method > >>that must be called at the point my webapp needs all the > Employees for a > >>Company. > >> > >> Have any of you had the same concerns? Or am I missing > how a webapp that > >>relies on lazy-loaded object graphs can change DAO > implementations easily? > >> > >> -Ken > >> > > > > > >
