Re: [Hibernate] Road Map

[Mark W. <mor...@SM...>]

Christian Bauer wrote:

>While I'm at it: Another rework, or at least a discussion about it, for
>2.0 would be the automatic reconnect of Sessions. You once mentioned
>that in a forum post, but didn't like it. 
>
>My two cents:
>
>If you've learned the basic concepts of O/R mapping, it's easy to produce 
>a real, working and maintainable two-tiered application with Hibernate.
>
>Just use lazy collections and disconnect/reconnect the Session which is
>stored in the HttpSession. At least for web applications, that is. If
>you don't require the lazy loaded collection in a Servlet call or JSP,
>you could even just close it and reopen it at the next call.
>
>In a three-tiered architecture, the recommended approach we currently
>propagate is to just open new Sessions and close them with each
>transaction. Some people realized that their JSP pages at the top of the
>system can also start transactions (by calling transactional methods on
>the Business Facade) and therefore open/close Hibernate Sessions in the
>Persistence Layer somewhere further down in the system.
>
>They immediately face the problem of lazy loaded collections: Loading an
>object at the "top" of the JSP page (results in open/retrieval/close or
>reconnect/retrieval/disconnect of a Hibernate Session) and using the 
>accessors further "down" in the JSP will fail. So they have to either
>
>a) Delay the closing of the Session until the JSP is rendered
>b) Delay the disconnection of the Session until the JSP is rendered
>
>Of course this can't happen in the JSP itself, the ViewController (the
>handler of Views) should somehow send a notify which will magically
>close/disconnect the Hibernate Session after the read and the whole 
>rendering is finished.
>

Have you considered using a filter to close the Session after everything 
is rendered?


-Mark