2009/4/19 Filippo Diotalevi <[email protected]> > Hi, > reading this thread on the Spring DM forum [1] reminded me of the > "logging madness" (commons, log4j, slf4, slf4j bridges, ...) that > everybody starting with Felix and OSGi (and JaveEE, nowadays) will > eventually find. > > In brief the problem is the base API of slf4j is a bundle, but > implementations like lf4j-log4j12 are bundle fragments with > import/export, therefore currently not supported by Felix. > These prevents newbies to run, f.i., Spring DM out of the box, > confusion, and maybe migrating to other osgi containers. Of course > there are many simple solutions to this problem, but I think it would > be nice to provide some FAQ/precooked solution for everybody. > > So the question is: what do you use? What's the best option? > > - in my case, I have osgi-fied slf4 with the log4j binding with the > maven osgi plugin. Maybe a candidate for felix commons? > > - does such a bundle already exist anywhere, so we can point user to > that bundle? > > - I actually noticed that if I remove the Fragment-Host property in > the lf4j-log4j12.jar everything seems to work. Such property was added > to make it work with Equinox (bug 73 [2]) due to a dependency cycle > between the api and the impl. > However, removing the fragmeng-host, Felix doesn't complain >
ouch, making an implementation bundle a fragment of the API bundle just to work around a bug in the Eclipse build process sounds like madness to me! you'll notice that this isn't even a runtime issue, the only reason they added the fragment directive was to avoid a build-time bug - and this has caused no end of problems for probably many more people in the long run :( there is a valid use-case for fragments, but this definitely is not one of them! [1] http://forum.springsource.org/showthread.php?t=70639 > [2] http://bugzilla.slf4j.org/show_bug.cgi?id=73 > -- > Filippo Diotalevi > -- Cheers, Stuart
