By default, Madvoc action objects are created by
and they are not aware of anything else then Madvoc and servlet
context. However, for any web application actions must somehow reference
the outside world, e.g. service layer. Common need is to have
Madvoc actions to be aware of some application context, managed by
Spring or Petite, that also maintains business
Trivial solutions, such manual lookup of components from business container is out of question for serious application. The goal is to make injection automatically.
One solution is usage of interceptor that will inject bean references
from business context into action before action invocation. For that
Madvoc offers abstract
AnnotatedFieldsInterceptor. It has to be
implemented by providing custom annotation class that will be used for
annotating action's fields. Interceptor would scan action class for
such annotated fields (caching is included), performs name lookup and
injects fetched bean into the action.
It is very easy to integrate Petite* with
Madvoc, to make all actions, interceptors and results type aware of
some Petite application context (typically, the service layer). It is
just matter of using
PetiteWebApplication instead of
<web-app ...> ... <filter> <filter-name>madvoc</filter-name> <filter-class>jodd.madvoc.MadvocServletFilter</filter-class> <init-param> <param-name>madvoc.webapp</param-name> <param-value>jodd.madvoc.petite.PetiteWebApplication</param-value> </init-param> </filter> ... </web-app>
PetiteWebApplication creates and configures Petite container that is
supposed to hold application context. It also registers Petite-aware
variants of some Madvoc components, so actions, interceptors and
result type handler will be created within this application context.
Creating bean in Petite means that bean will be created, wired and
initialized within Petite context, but not registered.
Madvoc uses Petite container internally; there is no reason to use
it for application purposes.
PetiteWebApplication provides different,
separate instance, that serves as application context.
Petite container is maintained by
PetiteWebApplication. By default,
the container is created and simply auto-configured using full
available class path at that time. However, it is easy to change this
default behavior and even provide some external instance of Petite
Petite and session scope
To enable session scoped Petite beans, it is required to register the following listener:
<web-app ...> ... <listener> <listener-class> jodd.servlet.RequestContextListener </listener-class> </listener> ... </web-app>
RequestContextListener store request in the current thread and all
child threads, so it can be easily accessible. It also keep
track of sessions.