Re: [Springframework-developer] Reworkings and new features

[Colin S. <col...@ex...>]

jürgen höller [werk3AT] wrote:

>Everybody,
> 
>I've reworked quite significant parts in the last couple of days, and also added a few new features:
> 
>...
> 
>- I've added support for the "Open Session in View" pattern with Hibernate: OpenSessionInViewInterceptor is a HandlerInterceptor for Spring's web MVC, OpenSessionInViewFilter a generic Servlet 2.3 Filter. Both can simply be used together with HibernateTransactionManager or JtaTransactionManager: The latter will automatically detect the pre-bound Sessions and leave their lifecycle management to the original binder. In the course of implementing OpenSessionInViewFilter, I've also added generic Filter base classes, namely GenericFilterBean and OncePerRequestFilter. Those classes are now also used for MultipartFilter.
>
>  
>
Jürgen,

While I know people are always asking for the Open Session in View 
pattern support, I personally think it is a pretty dangerous pattern to 
use. As per the Hibernate docs,
  
http://www.hibernate.org/hib_docs/reference/html/manipulating-data.html#manipulating-data-s13-4
if Session throws an exception, the Session should be closed and 
discarded, as it will be inconsistent. The Open Session in View pattern 
will work ok if the view code ensures that once a Hibernate exception is 
handled no more db related code is used, but since the session handling 
is above all the other code, it does not enforce this in any way. In 
fact, if the view code is calling down to some service code that does 
the db access itself, the view code may not even know that db access is 
being done.

At a minimum, I recommend we annotate the Javadocs for these classes 
with a warning about this aspect...

Regards,
Colin