Tomcat Logging With Slf4j and Log4j

问题:

I've got a web-app deployed to a Tomcat 7 server. My application uses log4j and a file appender. However, not all logging messages are getting written to the file.

On my classpath, I have:

log4j-1.2.14.jar
slf4j-api-1.6.1.jar
slf4j-log4j12-1.6.1.jar

My log4j.properties file is working fine on my local machine and is deploy properly.

I see application generated error messages being written to catalina.out that are not getting written to my log4j log. The log messages in catalina.out look to be coming from some other logging framework because the output pattern is in a different format than my log4j pattern. The logging that I'm seeing in the catalina.log is like:

Nov 4, 2011 11:05:31 AM org.apache.myfaces.shared_impl.util.StateUtils reconstruct
SEVERE

And my log4j pattern is like:

2011-11-03 16:42:09,336 ["http-bio-8080"-exec-13] ERROR

Some logging appears in my log4j file log, but not all of it. From what I've read, slf4j just needs those jars for it to funnel log output. Any ideas?

回答1:

try including the jcl-over-slf4j as a dependency. myfaces is probably using commons-logging.

check the slf4j docs: http://www.slf4j.org/legacy.html#jcl-over-slf4j

回答2:

It looks like the StateUtils class is using java.util.logging (jul). It stands to reason that other myfaces classes also use jul. Thus, you would probably want to funnel jul logs through SLF4J. Have a look at bridging legacy APIs, in particular the jul-to-slf4j bridge.

Please see SLF4JBridgeHandler javadocs for usage instructions when installing jul-to-slf4j.

回答3:

Configure your tomcat server according to the steps described at http://adfinmunich.blogspot.de/2012/03/how-to-configure-tomcat-to-use-slf4j.html. This blog entry describes how to replace java.util.logging by slf4j (using log4j behind the facade).