SLF4J issue with WildFly
If you are getting the following error on WildFly or JBoss:
Caused by: java.lang.ClassCastException: class org.slf4j.impl.Slf4jLoggerFactory cannot be cast to class ch.qos.logback.classic.LoggerContext (org.slf4j.impl.Slf4jLoggerFactory is in unnamed module of loader 'firstname.lastname@example.org.GA' @604f2c4f; ch.qos.logback.classic.LoggerContext is in unnamed module of loader 'deployment.idp.war' @4206bf50)"
Then add a
jboss-deployment-structure.xml file to the
WEB-INF/ directory of your war archive (or the
META-INF/ in the case of an ear or ejb):
<!-- Exclude server libraries which conflict with ours -->
<module name="org.slf4j" />
<module name="org.slf4j.impl" />
This will prevent WildFly from using the its versions of the SLF4J libraries for the deployed artifact allowing it to use whatever had been packaged instead.
Note that I encountered this issue when deploying Shibboleth IdP 4.0 on WildFly.