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From David Jencks <david_jen...@yahoo.com>
Subject Re: Library Packaging for Geronimo 1.1
Date Thu, 06 Jul 2006 16:52:04 GMT

On Jul 6, 2006, at 8:47 AM, Dennis Cartier wrote:

> I would like to refactor some of my monolithic applications into
> smaller chunks. With the new features in Geronimo 1.1, I am wondering
> what deployment plan would be best suited for this?
>
> For example to package my DAO classes into a jar that can be deployed
> into Geronimo to be shared amongst multiple web applications. I looked
> through the schemas and found that geronimo-module.xsd would be the
> type most suited?
>
> I am assuming that if I include a geronimo-module.xml file in the
> JAR's META-INF directory that Geronimo will be able to use it during
> deployment and I will be able to specify the dependencies for the
> particular module in it.

The file should be named geronimo-service.xml.

> Is this even necessary (or desirable) if I
> deploy the JAR file into Geronimo as a Common Lib?
>
> I am also wondering where the plugins and CAR type fit into the scheme
> of things as well.
>
> If anyone could provide more info or point me to where this
> information is online I would appreciate it. All the examples I found
> seemed to be pretty thin on content or were still for  Geronimo 1.0.

There are several dimensions to what is going on here, lets see if I  
can explain.

1. classloaders.
a. if you include the geronimo-service.xml file and _deploy_ the jar  
either using the packaging plugin or on the command line or (I think)  
through the console, you will get a module (in a car file).  This  
will basically represent a classloader.  If you then include a  
dependency on this car file in your other modules (such as j2ee  
applications) each such module will have the classloader for your  
classes as a parent: in other words only ONE copy of your classes  
will be loaded, shared by every module that uses them.

b. if you do not include the geronimo-service.xml (or forget to  
deploy it) and put the jar in the geronimo repository directly, you  
can use a jar dependency in each module.  In this case your jar will  
be included in each module classloader, in other words each module  
gets a separate copy of your classes.  No car file is generated for  
your jar.

2. plugins are basically a way to package up one or more car files so  
they can be easily installed and transported between servers.  IIUC a  
plugin can also package all its dependencies, but I'm not sure of the  
details.

Hope this helps,
david jencks


>
> Dennis
>
>
> --
>
> "The music business is a cruel and shallow money trench, a long
> plastic hallway where thieves and pimps run free, and good men die
> like dogs. There's also a negative side. "
>
> Hunter S. Thompson, US journalist (1939 – 2005)


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