Persistence with Vaadin

Question

I'm trying to learn vaadin. I'm really confused how to do any kind of application development with persistence because if I have a reference to my service layer objects, they get stored in session and I really don't want that. Persistence stuff just isn't serializable.

My case is that I have an already made application that uses Spring and I'm creating a new UI for it with Vaadin. I can inject the spring stuff to my Vaadin application but that gets stored in the session. Any tips?

By the way how do you post in the Vaadin forums? I can't find a post button or way to register :)

Answer 1

My suggestions:

• Define your containers as only containing presentation data. Don't keep any direct references from your presentation objects to your persistent objects.
• Define a "load" operation that, within a transaction, loads the persistent data objects and converts them into the corresponding presentation objects that back your container.
• Make all your containers read-only (following the model-view-controller pattern: the container is the model)
• Set up notifications/triggers as necessary to reload your containers when the underlying persistent data changes.
• For scalability, design or use containers that know how to lazy load, etc., so you don't populate the entire container at once (note: difficult with TreeTable - see issue #9516)

Answer 2

Have you tried this http://vaadin.com/directory#addon/enterprise-app. This add-on use spring and hibernate.