Currently all logging in ACS is done using log4j APIs. slf4j is already
packaged as a transitive dependency in ACS. I propose that going
forward we starting using slf4j APIs as opposed to log4j APIs.
For those who don't know, slf4j is a logging abstraction API. In the
world of java logging abstractions there are basically three frameworks
java.util.logging (JUL), jakarta commons logging (JCL), and simple
logging facade for java (slf4j). Most people gravitate towards slf4j
these days [1]. JUL isn't really that usable and JCL requires you to do
"if (log.isDebug())" everywhere to avoid the overhead of string
concatenation.
Its important to note that I'm not saying we stop using log4j. At
runtime log4j will be still used as the implementation, I'm merely
talking about the API that we code against. It's a generally good
practice to use a logging abstraction API and its some what of shame
that one was never put in place to start with.
At one point we can decide if we want to switch 100% to slf4j. There is
a utility to convert your source code from log4j to slf4j. Right now I
just want to "bless" using slf4j APIs as okay.
Darren
[1] Projects depending on SLF4J at http://www.slf4j.org/
