Page History

...

As of Wicket 1.3.0, Wicket uses the SLF4J project for logging. SLF4J is similar to commons-logging, in that it allows libraries/frameworks like Wicket to avoid forcing a choice of logging framework on their users.

To make this work in your application, you must choose You cannot use Wicket without adding an SLF4J logging implementation to your classpath. Most people use log4j. If you do, just include slf4j-log4j12.jar on your classpath to get Wicket to use log4j too. If you want to use commons-logging or JDK14 logging or something else, please see the SLF4J site for more information.

...