[Opensource] porting an existing framework to Expresso

[Steve Crossan]

Hello,

I have a question about whether, and how, Expresso might help to solve a
problem.

We have developed a framework of java application objects for content
management, elearning, user management yadda yadda the usual
suspects. It's built on top of Struts and open source though we haven't
really started to talk about it yet (it's only 1 year old) and AFAIK
no-one other than us (15 person UK OS web engineers) and our clients are
using it. If interested:

http://share.runtime-collective.com/~java/community

So, we have a new client who requires us to deploy on clustered Weblogic. 

Since Struts doesn't have a database link layer we implemented our own. I
know, I know, we shouldn't have done. We did look at the options, honest
(Castor, JBoss, Expresso) but for whatever reason (IMO wrong) we didn't.

Briefly, the architecture involves an interface called EntityBeanStore
that handles initialisation of beans from the db and also works as a cache
based on application-unique IDs.

There's a factory for these things so we can adopt different policies for
exactly how this works, but our default is to have the beans themselves
have save() and create() methods that know how to persist their state
etc. So you call something like EntityBeanStore.save(beanID) and the
default implementation calls back to the bean to save itself.

Simple to implement but not the most sophisticated db layer in the
world. Works fine in our standard lightweight single server environments.

So now we've got to go clustered weblogic. We'd like to preserver our
lightweightness but be EJB compatible so we can go distributed where
necessary. Sound familiar? One idea is to just implement a new
EntityBeanStore implementation that sits in the servlet container and
delegates to peer DAO objects that live in ejb space. Gotta write a bunch
of new objects, but we get to keep all our existing code.

I'd be very grateful to hear how Expresso Enterprise tackles this problem,
whether you think ('course you do) porting to it would be our best bet,
and a breif idea of the steps we'd need to go through (assuming some
familiarity with the documentation and architecture of Expresso - though
not Enterprise, and not hands-on).

Thanks very much in advance for any help

Steve Crossan

http://www.runtime-collective.com
Runtime Collective - Strange Contractors

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