http://www.infoq.com/articles/converting-struts-2-part1
http://www.infoq.com/articles/migrating-struts-2-part2
Summary of points:
- Dispatcher has been changed from servlet to filter
- Action class is not singleton. So no thread-safety issues for Action class
- Action class can be a simple POJO with a signature public String methodName
- No tight coupling to container in Action class code.
- Injected dependencies with DI/IoC
- Concept of Interceptors
- Simplified Unit testing of action classes
