RE: Interesting Tomcat (et al) Issue ...

From: Gentry, Michael \(Contractor\) ("Gentry,)
Date: Thu Jul 14 2005 - 09:12:40 EDT

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    Keep in mind this mixing is because I'm doing development (and want set
    breakpoints/etc in Eclipse to debug problems) on different applications
    in the same app server (Tomcat, but could be something else) at the same
    time. In a production deployment, they wouldn't be sharing the same
    project in this manner since you'd most likely make a .jar file of your
    framework and deploy it in the lib directory for each application (even
    if they hit the same database).

    Of course, this still doesn't solve the issue of needing multiple
    Cayenne projects at the same time. For example, I couldn't easily
    create a Cayenne-based user authentication/authorization framework/jar
    that gets deployed to lots of other people for use in their
    Cayenne-based application. Now you'd have two cayenne.xml files being
    needed by one application and the default class loading will only find
    the first. You'd want to keep both projects completely separate, even
    though one depends on the other.

    Just my thoughts ...

    Thanks,

    /dev/mrg

    -----Original Message-----
    From: Joshua Pyle [mailto:joshua.t.pyl..mail.com]
    Sent: Wednesday, July 13, 2005 5:27 PM
    To: cayenne-use..bjectstyle.org
    Subject: Re: Interesting Tomcat (et al) Issue ...

    Mixing your web applications at the classpath level sounds a bit
    dangerous. I have many cayenne apps running on the same tomcat
    instance with no problems. Some of them even shared mappings ( well
    copies of the same mappings ), some even hit the same database.

    The big thing is that I keep the web application classloaders seperate. 

    -- 
Joshua T. Pyle
Go has always existed.

    On 7/13/05, Gentry, Michael (Contractor) <michael_gentr..anniemae.com>
wrote:
> Well, since they are completely separate (different CVS repositories),
I
> don't think klunking together an uber-cayenne.xml is quite the ticket,
> either.
> 
> I've been stepping through the Cayenne configuration process and it
uses
> the first cayenne.xml it finds and then stops looking.  This might be
> more Java CLASSPATH related than anything -- you find the first one
and
> that has priority over all others.  I'd even be happy if you could
> specify the name of cayenne.xml (like with EOF/EOModeler -- you can
name
> the models differently), but I just tried that in Cayenne Modeler and
it
> puked an exception to my screen.
> 
> I don't think addClassPath would work since it would append to the
> CLASSPATH and my cayenne.xml #2 is already in the CLASSPATH, it is
just
> overshadowed by #1.
> 
> The more I'm thinking about this the more I think the best solution
> would be to modify the modeler to allow you to specify the filename
> (such as foo.cayenne and bar.cayenne) and then modify the Cayenne
> configuration process to load all *.cayenne XML files it finds in the
> CLASSPATH.  This would give you the most flexibility, eliminate this
> development and potential production choke point (1), and even allow
you
> to associate *.cayenne files with an application instead of just a
> generic XML file.
> 
> Any thoughts?
> 
> Thanks,
> 
> /dev/mrg
> 
> (1) Imagine you put together a Cayenne based project (free/shareware
or
> commercial) that is designed to be a standalone framework (integrated
> into other projects).  The current approach would make it difficult
for
> a customer to integrate your framework into their Cayenne-based
> application, since there are two cayenne.xml files (the framework and
> the client code).  If they had different filenames, that problem would
> be solved ...
> 
> 
> -----Original Message-----
> From: Mike Kienenberger [mailto:mkienen..laska.net]
> Sent: Wednesday, July 13, 2005 4:57 PM
> To: cayenne-use..bjectstyle.org
> Cc: cayenne-use..bjectstyle.org
> Subject: Re: Interesting Tomcat (et al) Issue ...
> 
> 
> "Gentry, Michael (Contractor)" <michael_gentr..anniemae.com> wrote:
> > Well ...
> >
> > cayenne.xml #1: 6 Domains, Sybase
> > cayenne.xml #2: 1 Domain, PostgreSQL
> >
> > They are completely unrelated.  There are three (at the moment)
> Tapestry
> > apps I have under development.  Two of them use #1, one of them uses
> #2.
> > Both are in the CLASSPATH, but #1 shows up first, and that is the
only
> > one visible to all three apps, so the third app cannot use the DB
> unless
> > I shut down the other two and remove the projects (which would be
> rather
> > inconvenient).
> 
> Yes, I was proposing
> 
> cayenne.xml #3: 7 Domains, Sybase and PostgreSQL
> 
> Or if it's just a matter of classpaths, put the files in separate
> locations
> for each app.
> 
>    public void contextInitialized(ServletContextEvent event)
>    {
>        DefaultConfiguration conf = new DefaultConfiguration();
>        conf.addClassPath("path/to/your/cayenne/config");
>        Configuration.initializeSharedConfiguration(conf);
>    }
>

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