[re-send.. I don't see this picked up... hmmm]
Once, a long long time ago... someone wrote: > The problem: it won't work if commons-logging.jar is installed in the > parent class loader, and log4j.jar ( or another logger ) is installed > in a child loader ( like WEB-INF/lib ). > > What happens: > - the factory uses the thread class loader to check if the log4j > ( or any other impl. ) exists ( and it does ). > > - it creates an instance of the Logger adapter. This will be created > using parent loader ( the one that loads commons-logging ). > > - the Logger instance makes references to Category or other classes > that are used in it's implementation. End of story, since the class > loader can't find the reference. > > This works fine for JAXP because the adapter for a parser is part of > the parser jar. It doesn't work for c-l because the adapter is in the > root loader ( with the API), not with the logging impl. > > That doesn't affect people who just use a single logger or can put > the logger impl. in the same place with common-logging. It only affect > containers like tomcat, when you want to let each webapp use it's own > logger impl. of choice. > > I tried all kind of introspection games, it won't work. The only > solution I see is to make sure the adapters are in the same place > with the logger. > > Solution: > Split commons-logging.jar in commons-logging-api.jar ( only the API > and the LogFactoryImpl, no adapteer ) and commons-logging-impl.jar. > > Alternatively, leave commons-logging.jar as it is and create a second > commons-logging-api.jar. > > The -api will be included in the common loader. Each webapp will have > to include commons-logging.jar ( or -impl ), and it's own logger. > > Or course, the best would be to have the adapter included in the > logger impl. > > What do you think ? Craig, Remy can we make another c-l dot release > with this change ? ( I'll do some more testing to see how it works ) And now I ask... is it *ever* appropriate to use to the Thread Context Class Loader for our "auto detect" of impls? The correct class loader to use is *always* the classloader used to load the wrapper. No? ******************************************* Richard A. Sitze IBM WebSphere WebServices Development
