[slf4j-dev] OSGi support in slf4j

Wed Nov 3 16:12:07 CET 2010

Did it and sent pull request to Ceki.

Heiko

On 2 November 2010 23:27, Hugues Malphettes <hmalphettes at intalio.com> wrote:

>
>
> On Tue, Nov 2, 2010 at 2:43 PM, Heiko Seeberger <
> heiko.seeberger at googlemail.com> wrote:
>
>> Thank you for reviewing!
>>
>> If I understand correctly we should relax the versioning policy to
>> import ranges from x.y instead of x.y.z, right? IMHO that makes sense.
>> An it's easily done: Just a little switch in the config. Let me know
>> and I will change it.
>>
>
> That would be the one thing I would change.
> Thanks Heiko!
> Hugues
>
>
>
>>
>> Heiko
>>
>> On Tuesday, November 2, 2010, Hugues Malphettes <hmalphettes at intalio.com>
>> wrote:
>> > Hi Ceki,Thanks for reminding us to review the changes introduced by BND.
>> > On Mon, Nov 1, 2010 at 2:16 PM, Ceki Gülcü <ceki at qos.ch> wrote:
>> > Hello all,
>> >
>> > I pulled in changes made by Heiko http://github.com/ceki/slf4j/pull/2.
>> Here is the version of the MANIFEST file from slf4j-api-1.6.1.jar.
>> >
>> > Manifest-Version: 1.0
>> > Archiver-Version: Plexus Archiver
>> > Created-By: Apache Maven
>> > Built-By: ceki
>> > Build-Jdk: 1.6.0_16
>> > Bundle-Description: The slf4j API
>> >
>> > Bundle-Version: 1.6.1
>> > Implementation-Version: 1.6.1
>> > Implementation-Title: slf4j-api
>> > Bundle-ManifestVersion: 2
>> > Bundle-SymbolicName: slf4j.api
>> > Bundle-Name: slf4j-api
>> > Bundle-Vendor: SLF4J.ORG
>> > Bundle-RequiredExecutionEnvironment: J2SE-1.3
>> > Export-Package: org.slf4j;version=1.6.1, org.slf4j.spi;version=1.6.1,
>> >  org.slf4j.helpers;version=1.6.1
>> > Import-Package: org.slf4j.impl;version=1.6.0
>> >
>> > Here is the version generated after Heiko's changes have been applied:
>> >
>> > Manifest-Version: 1.0
>> > Export-Package: org.slf4j.spi;uses:="org.slf4j";version="1.6.2.SNAPSHO
>> >  T",org.slf4j.helpers;uses:="org.slf4j.spi,org.slf4j";version="1.6.2.S
>> >  NAPSHOT",org.slf4j;uses:="org.slf4j.helpers,org.slf4j.spi";version="1
>> >  .6.2.SNAPSHOT"
>> > Ignore-Package: org.slf4j.impl
>> > Implementation-Title: slf4j-api
>> >
>> > Built-By: ceki
>> > Tool: Bnd-0.0.357
>> >
>> > Bundle-Name: SLF4J API Module
>> >
>> > Created-By: Apache Maven Bundle Plugin
>> >
>> > Bundle-RequiredExecutionEnvironment: J2SE-1.4
>> >
>> > Bundle-Vendor: QOS.ch
>> > Build-Jdk: 1.6.0_16
>> > Bundle-Version: 1.6.2.SNAPSHOT
>> >
>> > Bnd-LastModified: 1288644768461
>> > Bundle-ManifestVersion: 2
>> > Bundle-License: http://www.opensource.org/licenses/mit-license.php
>> > Bundle-Description: The slf4j API
>> > Bundle-DocURL: http://www.qos.ch
>> >
>> > Bundle-SymbolicName: org.slf4j.api
>> > Import-Package: org.slf4j;version="[1.6.2.SNAPSHOT,1.7)",org.slf4j.hel
>> >  pers;version="[1.6.2.SNAPSHOT,1.7)",org.slf4j.spi;version="[1.6.2.SNA
>> >  PSHOT,1.7)"
>> >
>> >
>> > Admittedly, I am a little lost. The previous MANIFEST file imported
>> org.slf4j.impl, whereas the latest MANIFEST does not. Strangely enough,
>> org.slf4j.impl is not mentioned at all.
>> > Heiko packages org.slf4j.impl as bundle fragments that are hosted by
>> org.slf4j.api.
>> >
>> > In our situation, there must not be more than one provider of
>> org.slf4j.impl: this means there must one and exactly one fragment that
>> provides org.slf4j.impl.
>> >
>> > At runtime the fragment classes are part of the classloader of
>> org.slf4j.api.This is why org.slf4j.api does not import org.slf4j.impl at
>> all.
>> > The MANIFEST.MF of org.slf4j.api does look good.
>> >
>> > It contains a few of extra lines that are read by BND alone:
>> Private-Package and Bnd-LastModified for example.
>> >
>> >
>> > The MANIFEST.MF of jcl.over.slf4j (aka jcl-over-slf4j) uses these
>> statements: Export-Package: org.apache.commons.logging;version=1.1.1,
>>  org.apache. commons.logging.impl;version=1.1.1
>> >
>> > Import-Package: org.slf4j;version=1.6.2.SNAPSHOT,
>> org.slf4j.spi;versio n=1.6.2.SNAPSHOT
>> > It will work.The versioning constrain on the import-package is I think
>> too much: strictly speaking, the produced fragment is going to work with
>> version 1.6 of slf4j.
>> >
>> > I apologize for sounding picky and in the case where we always build and
>> distribute together slf4j-api and jcl-over-slf4j it probably does not matter
>> much.If we were to adopt BND to generate the MANIFESTs of logback let's make
>> sure that we generate version=1.6 only so that we don't suddenly force
>> everyone to upgrade both slf4j and logback at once for no actual reason.
>> >
>> >
>> > Best regards,Hugues
>> >
>> >
>> >
>> >
>> > In earlier message Heiko wrote:
>> >
>> >> As all the logging backends are fragments I excluded org.slf4j.impl
>> >> package from imported packages. This means you can install the
>> >> slf4j-api bundle in an OSGi container successfully without a backend. >
>> Not sure whether this is what we want.
>> >
>> >
>> > I think it makes life easier if the slf4j-api bundle can be installed
>> without a back-end. However, this is assuming that a desired back-end bundle
>> can be installed and successfully bound with slf4j-api. (It is an obvious
>> requirement but still may be useful to mention.)
>> >
>> > This version can be pulled in either from
>> http://github.com/weiglewilczek/slf4j (master) or from
>> http://github.com/ceki/slf4j (weiglewilczek-master).
>> >
>> > Your comments are most welcome,
>> >
>> > --
>> >
>> > Ceki
>> > _______________________________________________
>> > slf4j-dev mailing list
>> > slf4j-dev at qos.ch
>> > http://qos.ch/mailman/listinfo/slf4j-dev
>> >
>> >
>> >
>>
>> --
>> Heiko Seeberger
>>
>> Company: weiglewilczek.com
>> Blog: heikoseeberger.name
>> Follow me: twitter.com/hseeberger
>> OSGi on Scala: scalamodules.org
>> Lift, the simply functional web framework: liftweb.net
>> Akka - Simpler Scalability, Fault-Tolerance, Concurrency & Remoting
>> through
>> Actors: akkasource.org
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>> http://qos.ch/mailman/listinfo/slf4j-dev
>>
>
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-- 
Heiko Seeberger

Company: weiglewilczek.com
Blog: heikoseeberger.name
Follow me: twitter.com/hseeberger
OSGi on Scala: scalamodules.org
Lift, the simply functional web framework: liftweb.net
Akka - Simpler Scalability, Fault-Tolerance, Concurrency & Remoting through
Actors: akkasource.org
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