Thanks a lot Rob,
I've added slf4j-log4j12-1.7.12 as dependency, and upgraded slf4j-api to 1.7.12 as well.
Nothing has changed yet, but this is what I can see in the Console when the webapp starts:
SLF4J: Class path contains multiple SLF4J bindings.
SLF4J: Found binding in [jar:file:/apache-tomcat-7.0.34/wtpwebapps/webapp-test/WEB-INF/lib/logback-classic-1.0.0.jar!/org/slf4j/impl/StaticLoggerBinder.class]
SLF4J: Found binding in [jar:file://apache-tomcat-7.0.34/wtpwebapps/webapp-test/WEB-INF/lib/slf4j-log4j12-1.7.12.jar!/org/slf4j/impl/StaticLoggerBinder.class]
SLF4J: See
http://www.slf4j.org/codes.html#multiple_bindings for an explanation.
Of course, I've already performed a search on google about it, but after many attempts, I wasn't able to solve.
Removing logback-classic from my pom.xml causes no logging at all both in systemout and the log file configured.