This talk is a detailed case study about the migration of a JSF-based web application from Spring 3 to Java EE 7 and CDI. It is presented at the JavaOne 2014 conference.
At first sight this didn’t seem to be too difficult. Both technologies are based on similar concepts and provide similar mechanisms for dependency injection (DI). So migrating pure annotation based bean wiring from Spring to CDI was obvious and straight forward.
But the deeper we looked into the source code the more Spring specific code we found with no direct and easy mapping in neither of JEE7, EJB3 or CDI available. Some of the problems and challenges we were confronted with were:
- How to migrate XML based bean wirings?
- How to migrate FactoryBeans?
- How to migrate AspectJ based AOP proxies?
- How to implement Spring profiles for environment based wiring?
- How to implement custom bean scopes?
- How to implement custom Spring XML schema notations and wiring?
- How to migrate code that is built against Spring APIs?
- How to migrate unit test based on Spring Test?
To answer these questions the talk will present the patterns and strategies used to map, transform and migrate the different concepts from Spring 3 to JEE7with CDI. The talk will discuss the changes and implications of the migration on the system’s architecture.