If an application makes extensive use of Spring, it can be convenient to manage all the classes in one location – the Spring configuration. Remember, Actions do not need to implement a special interface. Actions can also be POJOs that are not tied to Struts or the web-layer in any fashion.

We might also want to apply more complex AOP or Spring-enabled technologies, such as Acegi, to our Action objects.

For more, see Initializing Actions from Spring.