On Fri, 25 Feb 2005 17:53:08 -0500, James Carman
<[EMAIL PROTECTED]> wrote:
>
>
>
> Ok, I'm trying to make sure I understand how bean services have been
> implemented. From what I understand (could be way off base, though)â
>
>
>
> The proxy returned to the client is a subclass of the bean service
> implementation class.
Yes; it adds the sematics to delegate all behavior to the service
implementation (including any interceptors, etc.). It fulfils the
role of an "outer proxy". It also understands Registry shutdown
semantics.
> It also implements some sort of dynamically generated
> interface (we'll call it bean interface) which has all of the public methods
> of the bean class in it.
Yep, we generate a synthetic service interface from the public methods
of the bean.
> The proxy returned to the client doesn't call any of the superclass
> implementations of the methods. It overrides the methods, forwarding calls
> to the InterceptorStack (which also uses the bean interface).
Yep, though its not the InterceptorStack, its the inner proxy that
gets replaced by the service or the outermost interceptor.
>
>
>
> I do have some questionsâ
>
>
>
> We can't put service interceptors on non-public (or protected) methods,
> correct?
Correct; just the public methods.
> What type of object is at the end of the interceptor stack?
The service implementation is left alone, a bridge class is created
that implements the synthetic service interface and delegates to the
service implementation.
So, we can end up with something like:
bean subclass as outer proxy
+--> interceptor (implementing service interface)
+--> bridge (implementating service interface)
+--> service implementation
But in actuallity, the bridge is only needed if there aren't any
interceptors (because the delegate of the outer proxy must implement
the service interface; the bridge and interceptors do, the service
implementation doesn't).
Head spinning yet?
--
Howard M. Lewis Ship
Independent J2EE / Open-Source Java Consultant
Creator, Jakarta Tapestry
Creator, Jakarta HiveMind
Professional Tapestry training, mentoring, support
and project work. http://howardlewisship.com
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