I eventually came up with something that works that's basically consistent with what I think you're saying, though I'm not sure about transitively getting the slf4j-api class since I encountered a fatal error until I explicitly provided that myself.
As for the binding, my initial thought was to use whatever the main idp app was using (logback), but even there I'm confused by the the combination of situations I encountered: if I don't provide a binding, it warns and defaults to NOP; if I provide a logback binding, it complains of conflict and barfs; and if I provide an non-logback alternate binding, it notes the multiple bindings and choose the main app's logback binding (where it previously did not pick it up in the NOP case). So this is where I question my approach to resolving this. I mean, it seems to work, but it doesn't seem like this is the right way to go about it. Ideally it seems like it should pick up or re-use the binding provided in the idp war, but I don't know how you do that. -baron On Fri, Feb 06, 2015 at 01:16:07PM -0500, Scott Battaglia wrote: >SLF4J is very similar to Commons Logging in that there is an API jar and >then one or more implementations/bindings. > >You should have transitively gotten the slf4j-api class (since we would >have to compile against it) and you would have to provide the binding that >maps to your logger of choice (Logback is one common one): >http://www.slf4j.org/manual.html > >On Thu, Feb 5, 2015 at 10:16 PM, Baron Fujimoto <[email protected]> wrote: > >> We're using the Java cas-client (3.3.3) to provide RemoteUser >> authentication for our Shibboleth IdP service. >> >> This version seems of the cas-client seems to require slf4j where our >> previously used version (3.2.1) didn't(?). I encountered the the following >> error until I put a copy of slf4j-api-1.7.10.jar in out {tomcat_base}/lib >> directory: >> >> ===== >> ~/tomcat/lib/ >> 106079 Sep 9 17:46 cas-client-core-3.3.3.jar >> SEVERE: Exception loading sessions from persistent storage >> java.lang.NoClassDefFoundError: Lorg/slf4j/Logger; >> [...] >> ===== >> >> Then I discovered that unless I also provided a binding for a logging >> framework, it generates the warning: >> >> ===== >> ~/tomcat/lib/ >> Sep 9 17:46 cas-client-core-3.3.3.jar >> Jan 6 10:15 slf4j-api-1.7.10.jar >> >> SLF4J: Failed to load class "org.slf4j.impl.StaticLoggerBinder". >> SLF4J: Defaulting to no-operation (NOP) logger implementation >> SLF4J: See http://www.slf4j.org/codes.html#StaticLoggerBinder for further >> details. >> ===== >> >> The IdP war includes the logback-core binding, but apparently that doesn't >> get picked up: >> >> ~/idp/war/idp.war!/WEB-INF/lib/logback-core-1.0.11.jar >> >> If I include the logback-core binding from the slf4j-1.7.10 distribution >> it generates the fatal error: >> >> ===== >> ~/tomcat/lib/ >> 106079 Sep 9 17:46 cas-client-core-3.3.3.jar >> 270747 Apr 2 2014 logback-classic-1.1.2.jar >> 32119 Jan 6 10:15 slf4j-api-1.7.10.jar >> >> SLF4J: Class path contains multiple SLF4J bindings. >> SLF4J: Found binding in >> [jar:file:/home/shib/tomcat/lib/logback-classic-1.1.2.jar!/org/slf4j/impl/StaticLoggerBinder.class] >> SLF4J: Found binding in >> [jar:war:file:/home/shib/idp/war/idp.war^/WEB-INF/lib/logback-classic-1.0.11.jar!/org/slf4j/impl/StaticLoggerBinder.class] >> SLF4J: See http://www.slf4j.org/codes.html#multiple_bindings for an >> explanation. >> SLF4J: Actual binding is of type >> [ch.qos.logback.classic.util.ContextSelectorStaticBinder] >> Failed to instantiate SLF4J LoggerFactory >> Reported exception: >> java.lang.NoClassDefFoundError: >> ch/qos/logback/core/joran/spi/JoranException >> at org.slf4j.LoggerFactory.bind(LoggerFactory.java:142) >> [...] >> ===== >> >> Finally, I settled on using the simple binding, since that only generates >> a warning and seems to fall back on logback (From the idp.war? Now it >> picks it up?) >> >> ===== >> ~/tomcat/lib/ >> 106079 Sep 9 17:46 cas-client-core-3.3.3.jar >> 32119 Jan 6 10:15 slf4j-api-1.7.10.jar >> 10705 Jan 6 10:15 slf4j-simple-1.7.10.jar >> >> SLF4J: Class path contains multiple SLF4J bindings. >> SLF4J: Found binding in >> [jar:file:/home/shib/tomcat/lib/slf4j-simple-1.7.10.jar!/org/slf4j/impl/StaticLoggerBinder.class] >> SLF4J: Found binding in >> [jar:war:file:/home/shib/idp/war/idp.war^/WEB-INF/lib/logback-classic-1.0.11.jar!/org/slf4j/impl/StaticLoggerBinder.class] >> SLF4J: See http://www.slf4j.org/codes.html#multiple_bindings for an >> explanation. >> SLF4J: Actual binding is of type >> [ch.qos.logback.classic.util.ContextSelectorStaticBinder]====== >> >> I only arrived at this through a series of empirical experiments. I'd >> appreciate any advice on the recommended way to properly deal with this >> though. >> >> Aloha, >> -baron >> -- >> Baron Fujimoto <[email protected]> :: UH Information Technology Services >> minutas cantorum, minutas balorum, minutas carboratum desendus pantorum >> >> -- >> You are currently subscribed to [email protected] as: >> [email protected] >> To unsubscribe, change settings or access archives, see >> http://www.ja-sig.org/wiki/display/JSG/cas-user >> > >-- >You are currently subscribed to [email protected] as: [email protected] >To unsubscribe, change settings or access archives, see >http://www.ja-sig.org/wiki/display/JSG/cas-user -- Baron Fujimoto <[email protected]> :: UH Information Technology Services minutas cantorum, minutas balorum, minutas carboratum desendus pantorum -- You are currently subscribed to [email protected] as: [email protected] To unsubscribe, change settings or access archives, see http://www.ja-sig.org/wiki/display/JSG/cas-user
