A minimal incarnation of Apache Commons Logging's
providing just the common
lookup methods. This is inspired
by the JCL-over-SLF4J bridge and should be source as well as binary
compatible with all common use of the Commons Logging API (in particular:
This implementation does not support Commons Logging's original provider
detection. It rather only checks for the presence of the Log4j 2.x API
and the SLF4J 1.7 API in the Spring Framework classpath, falling back to
java.util.logging if none of the two is available. In that sense,
it works as a replacement for the Log4j 2 Commons Logging bridge as well as
the JCL-over-SLF4J bridge, both of which become irrelevant for Spring-based
setups as a consequence (with no need for manual excludes of the standard
Commons Logging API jar anymore either). Furthermore, for simple setups
without an external logging provider, Spring does not require any extra jar
on the classpath anymore since this embedded log factory automatically
java.util.logging in such a scenario.
Note that this Commons Logging variant is only meant to be used for
infrastructure logging purposes in the core framework and in extensions.
It also serves as a common bridge for third-party libraries using the
Commons Logging API, e.g. Apache HttpClient, Castor and HtmlUnit, bringing
them into the same consistent arrangement without any extra bridge jars.
For logging need in application code, prefer direct use of Log4j 2.x
or SLF4J or
java.util.logging. Simply put Log4j 2.x or Logback
(or another SLF4J provider) onto your classpath, without any extra bridges,
and let the framework auto-adapt to your choice.