Spring: OpenSessionInViewInterceptor vs. OpenSessionInViewFilter

(url: http://mikenereson.blogspot.com/2007/02/spring-opensessioninviewinterceptor-vs.html)

Problem: Assuming you're using an ORM, such as Hibernate, rendering the view with business objects that have many-to-one or one-to-one relationships might try to access a detached object with a lazy property and throw a LazyInitializationException. For this reason, we're provided with the Open Session In View pattern.

Solution: The Open Session In View pattern binds a Hibernate session to the thread to be used throughout the life of the request and closes any transactions when the response is sent. This is what allows your view to access model objects with lazily loaded properties after a transaction has been closed. This is nothing new and this is not what this post is about.

To setup the Open Session In View in your Spring application, you have two options. The OpenSessionInViewInterceptor and the OpenSessionInViewFilter. You can use either solution because the two classes serve the very same function. Well if this is the case, then why do they both exist? Why is there a filter option and an interceptor option? This is what I set to find out.

I've been searching Google all night. I've read through forums, I've read docs, and I've read blogs. Why? Because I want to use the better of the two options on my application. I want to ensure I am getting the best performance and the most reliability for my clients as I can. Anyway, the only thing that I could dig up was that they are equal in almost every way. The only consideration that you really need to make is what servlet spec you are using. If your servlet container support version 2.3 or later, you can use either one. If it's 2.2 or earlier, you'll need to go with the OpenSessionInViewInterceptor.

Surely there are other considerations. Maybe you want to keep your filters down to a bare minimum, or you think interceptors are confusing or messy. Or perhaps you like to keep your configuration files as small as possible. If you use annotations, you might want to go with the OpenSessionInViewInterceptor.

I hope I answered any questions you had about why there were two classes for implementing this pattern.


My tiny little blog here has been getting tons of hits because of my post titled OpenSessionInViewInterceptor vs. OpenSessionInViewFilter so I guess people are interested in these. I don't know why you all are comming here. I do know that I'd hate for you to come here looking for an example and then have to go looking elsewhere for it, so here is an example of each.

Interceptor Configuration (action-servlet.xml)




class="org.springframework.web.servlet.handler.SimpleUrlHandlerMapping">









...



...

class="org.springframework.orm.hibernate3.support.OpenSessionInViewInterceptor">








Filter Configuration (web.xml)




...



openSessionInViewFilter


org.springframework.orm.hibernate3.support.OpenSessionInViewFilter



...


openSessionInViewFilter
*.do


...





I hope this is what you were looking for.