From reading Rod Johnson's books I am sold on the benefits of Spring. I'd like to take a medium-size application we've developed and migrate it to Spring but I'm struggling with the best approach to take.
The application consists of a dozen or so webapp screens and a remote java client application. We use a mixture of entity bean and homebrew JDBC wrappers for data access. The app is currently run under WebLogic 6.1 and makes use of a dozen stateless session beans and 25 entity beans. Other then the remotre client, the rest of the system is co-located. The system uses a single database so no JTA is required.
One goal is to eliminate the use of session beans **except for the stateless session bean that serves as the communications endpoint for the java client **.
I'd also like to eventually replace the entity beans and homebrew JDBC junk with something else: either Spring's JdbcTemplate or maybe hibernate.
With those changes in place I think we could run this app under a simple servlet container like tomcat, which would be cool. I can live with our struts-based webapp for now but I'd love to look at Spring's MVC webapp framework someday.
Where to start? I need to introduce a DAO layer for sure. I'd like the initial implementation to be the code currently in existence but using Spring's DataAccess exception heirarchy to hide the impl details.
Our session beans serve as the typical pointless "facade" of functions -- mainly the methods are data acess oriented, but some are pure business logic. The data access methods need to migrate into my new DataAccess layer. This will leave the existing session beans with just some business logic methods. Where to "migrate" these -- into POJOs?
I know this is a bit of a ramble. Do I sound like I'm at least in the neighborhood?