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Posted to users@felix.apache.org by Matt Clark <ma...@clarknet.cc> on 2007/08/30 05:54:46 UTC
osgi.parentClassLoader
Hi all,
Does Felix support the property osgi.parentClassLoader, or is that an
Equinox-specific configuration setting? I am embedding Felix in a webapp to
register extensions to our application, and would like to be able to use the
'fwk' setting to expose all packages known by the classloader that loaded
the Felix framework to bundles. I've read that this could also be done
through extension bundles, but 1) I've read about some recent bugs with
those (http://www.mail-archive.com/dev@felix.apache.org/msg01283.html), and
2) the thought of having to maintain a list of all packages which we would
like to be available to the bundles scares me.
FWIW, our use case is pretty simple. We would like to be able to hot-deploy
extensions (classes and resources) to our application, and these will all
follow the 'extender' model rather than the 'service' model. As such, I
really don't care about the bundles being isolated from the classpath.
Any help is appreciated :-)
Thanks,
Matt Clark
Re: Use log4j & commons-logging in bundle
Posted by Stuart McCulloch <st...@jayway.net>.
On 02/09/07, Felix Meschberger <fm...@gmail.com> wrote:
>
> Hi Thierry,
>
> First of all, a bundle can only specify a single host bundle. So you
> would have to decide which Bundle you want to attach to.
>
> Rather - in the case of Log4J - I suggest you call the Log4J
> configuration mechanism to control the configuration of Log4J.
> Alternatively you might create your own Log4J bundle, where you control
> the first use of Log4J and have the oportunity to configure Log4J
> correctly.
shameless plug... you could also try Pax Logging :)
http://wiki.ops4j.org/confluence/x/F
for v0.9.5 and later you only need these two bundles:
http://repository.ops4j.org/maven2/org/ops4j/pax/logging/api
http://repository.ops4j.org/maven2/org/ops4j/pax/logging/service
and you can configure log4j using config admin
Hope this helps.
>
> Regards
> Felix
>
>
> Am Freitag, den 31.08.2007, 17:11 +0200 schrieb Thierry Templier:
> > Hello,
> >
> > I use some bundles that I haven't developped and use
> > log4j & commons-logging for tracing. By default, I
> > have the following message in the console:
> > log4j:WARN No appenders could be found for logger
> > (log4jdemo.Activator).
> > log4j:WARN Please initialize the log4j system
> > properly.
> >
> > I want to configure log4j & commons-logging with
> > custom property files in order to activate the traces
> > I need. I see that it's possible using Fragment-Host
> > in the manifest.mf file.
> >
> > So, I create a bundle containing my log4j.properties
> > and commons-logging.properties files and the following
> > manifest.mf file:
> > Bundle-SymbolicName: LogProperties
> > Fragment-Host:
> > org.apache.log4j,org.apache.commons.logging
> >
> > After the installation and the start of the bundle, I
> > always have the same warning.
> >
> > Is it the correct way to activate trace?
> > Thanks for your help.
> > Thierry
> >
> > Take a look at my blog:
> > http://jroller.com/page/Templth/
> > (old: http://templth.blogspot.com/)
> >
> >
> >
> _____________________________________________________________________________
> > Ne gardez plus qu'une seule adresse mail ! Copiez vos mails vers Yahoo!
> Mail
> >
> > ---------------------------------------------------------------------
> > To unsubscribe, e-mail: users-unsubscribe@felix.apache.org
> > For additional commands, e-mail: users-help@felix.apache.org
> >
>
>
> ---------------------------------------------------------------------
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>
>
--
Cheers, Stuart
Re: Use log4j & commons-logging in bundle
Posted by Felix Meschberger <fm...@gmail.com>.
Hi Thierry,
First of all, a bundle can only specify a single host bundle. So you
would have to decide which Bundle you want to attach to.
Rather - in the case of Log4J - I suggest you call the Log4J
configuration mechanism to control the configuration of Log4J.
Alternatively you might create your own Log4J bundle, where you control
the first use of Log4J and have the oportunity to configure Log4J
correctly.
Hope this helps.
Regards
Felix
Am Freitag, den 31.08.2007, 17:11 +0200 schrieb Thierry Templier:
> Hello,
>
> I use some bundles that I haven't developped and use
> log4j & commons-logging for tracing. By default, I
> have the following message in the console:
> log4j:WARN No appenders could be found for logger
> (log4jdemo.Activator).
> log4j:WARN Please initialize the log4j system
> properly.
>
> I want to configure log4j & commons-logging with
> custom property files in order to activate the traces
> I need. I see that it's possible using Fragment-Host
> in the manifest.mf file.
>
> So, I create a bundle containing my log4j.properties
> and commons-logging.properties files and the following
> manifest.mf file:
> Bundle-SymbolicName: LogProperties
> Fragment-Host:
> org.apache.log4j,org.apache.commons.logging
>
> After the installation and the start of the bundle, I
> always have the same warning.
>
> Is it the correct way to activate trace?
> Thanks for your help.
> Thierry
>
> Take a look at my blog:
> http://jroller.com/page/Templth/
> (old: http://templth.blogspot.com/)
>
>
> _____________________________________________________________________________
> Ne gardez plus qu'une seule adresse mail ! Copiez vos mails vers Yahoo! Mail
>
> ---------------------------------------------------------------------
> To unsubscribe, e-mail: users-unsubscribe@felix.apache.org
> For additional commands, e-mail: users-help@felix.apache.org
>
---------------------------------------------------------------------
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Use log4j & commons-logging in bundle
Posted by Thierry Templier <te...@yahoo.fr>.
Hello,
I use some bundles that I haven't developped and use
log4j & commons-logging for tracing. By default, I
have the following message in the console:
log4j:WARN No appenders could be found for logger
(log4jdemo.Activator).
log4j:WARN Please initialize the log4j system
properly.
I want to configure log4j & commons-logging with
custom property files in order to activate the traces
I need. I see that it's possible using Fragment-Host
in the manifest.mf file.
So, I create a bundle containing my log4j.properties
and commons-logging.properties files and the following
manifest.mf file:
Bundle-SymbolicName: LogProperties
Fragment-Host:
org.apache.log4j,org.apache.commons.logging
After the installation and the start of the bundle, I
always have the same warning.
Is it the correct way to activate trace?
Thanks for your help.
Thierry
Take a look at my blog:
http://jroller.com/page/Templth/
(old: http://templth.blogspot.com/)
_____________________________________________________________________________
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RE: osgi.parentClassLoader
Posted by Matt Clark <mc...@voyence.com>.
Thanks for the quick response, Richard.
I'll clarify my 'extender model' comment a little more. We're writing a
web application which is sold as an installable software product. There
are two use cases right now, and maybe more in the feature, where there
are bundles which we would like to deliver to customers as a
subscription service. These bundles don't provide new versions of
existing services, or completely new services, they only provide
additional implementations of existing interfaces (where the interfaces
already exist in the classpath).
One of these use cases is deploying new reports to the server, where the
bundle for the report would contain some proprietary files related to
our report engine, a POJO implementing an interface in the classpath,
some resources such as images. As these bundles are deployed, we'll be
listening for their deployment and maintaining a registry of their
availability, so that when users go to find which reports are available
the newly deployed reports will show up. We'll also be extracting the
report-engine files and resources to a location on disk, which is
required for the report engine.
The report POJO might need access to any number of packages which may or
may not already be on the classpath. When I write the code (which lives
in the classpath) to instantiate Felix, I don't want to have to
predetermine which packages future report bundles will and will not need
access to. I also don't want to export packages A and B to the system
classpath, and end up with the unforeseen dependency on package C in
future bundles. I could always include package C in those bundles, but
then I would run into the problem where there were two instances of
package C running.
If I'm thinking incorrectly about this, please let me know. I think the
answer you gave me (setting boot delegation to *) gives me the answer I
need, but I at least wanted to talk through the use case in case it
gives you an additional use case for Felix.
Again, thanks for your help!
Matt
-----Original Message-----
From: Richard S. Hall [mailto:heavy@ungoverned.org]
Sent: Thursday, August 30, 2007 8:52 AM
To: users@felix.apache.org
Subject: Re: osgi.parentClassLoader
That is Equinox-specific...we had talked briefly about allowing a class
loader to be passed into the Felix constructor for delegation purposes,
but didn't really have a compelling reason to do so.
Anyhow, Felix doesn't separate the framework classes from the
application class loader, like Equinox does. So, if you want to expose
everything on the class path to your bundles, then I am pretty sure it
is sufficient to just set boot delegation to "*".
I do not really understand your comment about using the extender model
instead of the service model and therefore isolation is not necessary.
Use of the extender model is orthogonal to isolation. It is probably
still better to set the framework system packages property to explicitly
list the packages to expose from the class path, that way your bundles
can explicitly import them so you know their dependencies. The system
packages list only needs to be maintained in a single place in the
framework for all bundles and most bundle development tools will
automatically calculate your bundle imports, so you don't have to do
anything there...
-> richard
Matt Clark wrote:
> Hi all,
>
>
>
> Does Felix support the property osgi.parentClassLoader, or is that an
> Equinox-specific configuration setting? I am embedding Felix in a
webapp to
> register extensions to our application, and would like to be able to
use the
> 'fwk' setting to expose all packages known by the classloader that
loaded
> the Felix framework to bundles. I've read that this could also be
done
> through extension bundles, but 1) I've read about some recent bugs
with
> those
(http://www.mail-archive.com/dev@felix.apache.org/msg01283.html), and
> 2) the thought of having to maintain a list of all packages which we
would
> like to be available to the bundles scares me.
>
>
>
> FWIW, our use case is pretty simple. We would like to be able to
hot-deploy
> extensions (classes and resources) to our application, and these will
all
> follow the 'extender' model rather than the 'service' model. As such,
I
> really don't care about the bundles being isolated from the classpath.
>
>
>
> Any help is appreciated :-)
>
>
>
> Thanks,
>
> Matt Clark
>
>
>
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Re: osgi.parentClassLoader
Posted by "Richard S. Hall" <he...@ungoverned.org>.
That is Equinox-specific...we had talked briefly about allowing a class
loader to be passed into the Felix constructor for delegation purposes,
but didn't really have a compelling reason to do so.
Anyhow, Felix doesn't separate the framework classes from the
application class loader, like Equinox does. So, if you want to expose
everything on the class path to your bundles, then I am pretty sure it
is sufficient to just set boot delegation to "*".
I do not really understand your comment about using the extender model
instead of the service model and therefore isolation is not necessary.
Use of the extender model is orthogonal to isolation. It is probably
still better to set the framework system packages property to explicitly
list the packages to expose from the class path, that way your bundles
can explicitly import them so you know their dependencies. The system
packages list only needs to be maintained in a single place in the
framework for all bundles and most bundle development tools will
automatically calculate your bundle imports, so you don't have to do
anything there...
-> richard
Matt Clark wrote:
> Hi all,
>
>
>
> Does Felix support the property osgi.parentClassLoader, or is that an
> Equinox-specific configuration setting? I am embedding Felix in a webapp to
> register extensions to our application, and would like to be able to use the
> 'fwk' setting to expose all packages known by the classloader that loaded
> the Felix framework to bundles. I've read that this could also be done
> through extension bundles, but 1) I've read about some recent bugs with
> those (http://www.mail-archive.com/dev@felix.apache.org/msg01283.html), and
> 2) the thought of having to maintain a list of all packages which we would
> like to be available to the bundles scares me.
>
>
>
> FWIW, our use case is pretty simple. We would like to be able to hot-deploy
> extensions (classes and resources) to our application, and these will all
> follow the 'extender' model rather than the 'service' model. As such, I
> really don't care about the bundles being isolated from the classpath.
>
>
>
> Any help is appreciated :-)
>
>
>
> Thanks,
>
> Matt Clark
>
>
>
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