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From Niclas Hedhman <nic...@hedhman.org>
Subject Re: Support for OSGi
Date Mon, 31 Dec 2007 09:00:58 GMT
On Monday 31 December 2007 14:57, Alan D. Cabrera wrote:
> I'm sorry but I'm not completely following.  What problems does this  
> create?  How is it counter-productive.

Commons-logging is not designed for
 a) OSGi environment with classes loaded and unloaded in runtime.
 b) Unifying Commons-logging, Log4J, SLF4J, Avalon Logging API, KF Log API, 
    JDK Logging API and OSGi's own Log service API, to be routed to the 
    same logging backend.

When we did the Pax Logging system, we addressed the above very seriously and 
have a solution that works, BUT it required us to high-jack the 
commons-logging API namespace and interfaces (that goes for Log4J as well), 
and it is possible to crash Pax Logging by installing commons-logging 
packages in parallel (unless the user remembers to do 
a "provider=paxlogging;mandatory:=provider" in the ImportPackage).

I have not checked the implementation details on commons-logging recently, but 
older versions have been one of the largest single cause of "wasted time" in 
Java history, with its class caching and runtime "detection" of logging 
system to use. I suspect that some of that has been corrected, but I likewise 
suspect that it there are still many problems for the OSGi environment, which 
will be hard to track/find for the average user. A quick look at LogFactory, 
and I am pretty convinced that I my suspicion is accurate.

Personally, I think the "Logging scene" is absurd...

Niclas Hedhman, Software Developer

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