droolsjbpm/drools — comment on commit b7276feb7bbe6dd131a4a04295428d1aeaf4c5e8
File: drools-compiler/pom.xml line 127
By ge0ffrey:

Optional tip:
log4j is hasn't seen any active development since 2006 IIRC, it's dead. Prefer using Logback (AKA Log4j 2.0 because Log4j, SLF4J and Logback have been written by the same guy, Ceki). Logback implements the SLF4J interfaces directly (in fact, they are pretty much the same project).
I am using Logback in drools-planner's test and examples, copy paste from there. It's basically just replacing the dependency and upgrading log4j.xml to logback(-test).xml