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From "Jacek Laskowski" <ja...@laskowski.net.pl>
Subject Re: Significance of writing an additional Descriptor file
Date Tue, 04 Mar 2008 20:14:10 GMT
On Mon, Mar 3, 2008 at 10:37 PM, Ch Praveena <ps050202@gmail.com> wrote:

>    May i know the significance of writing geronimo-web.xml in WEB-INF, along
> with web.xml, while deploying war files.

In short...

web.xml is a java ee thingy. web.xml is mandatory in Java Servlets
2.5. Without it the war would be incorrect. You use web.xml to declare
your *logical* resource names. You declare your requirements a runtime
environment.

geronimo-web.xml is a Geronimo thingy and is optional, but helps
mapping *logical* names to their runtime counterparts. The runtime
resources are managed by application server and their access is
application server-specific. When names are the same and Geronimo can
compute their runtime representations you don't need geronimo-web.xml
at all.

Application assembler maps the *logical* names to runtime counterparts
with geronimo-web.xml. I'd say you should never use geronimo-web.xml
in war. Why? Because it's not in a developer role to  do the mapping,
but it's only him/her able to change the war (the war should be sealed
and untouched by anyone but developer, right?). It's an application
assembler's or a application deployer's job. They can use a separate,
external plan (geronimo-web.xml, geronimo-plan.xml, name it whatever
you want) and not change anything in your war or ear. That's one of
the goodies you can find in Geronimo (there're more, but since you've
not asked about them I won't list them here ;-)). No need to include
the runtime configuration *inside* an application since it could
eventually be deployed to different Geronimo runtime environments
where resources are named differently depending on administrator's
mood (or expertise).

Jacek

-- 
Jacek Laskowski
http://www.JacekLaskowski.pl

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