Tomcat Logging in WTP

I’ve just been trying to enable debug logging for tomcat (don’t ask). Normally you do this by editing $CATALINA_HOME/conf/logging.properties and restarting.

Except I tried that in Eclipse (using WTP) and it didn’t work.

I tried copying it to the $CATALINA_BASE/conf directory instead¹.

Still no joy.

I’ve just found the answer, after looking in the tomcat source. It turns out that tomcat’s alternative logging implementation (JULI) is enabled via a system property. This happens inside catalina.sh:

# Set juli LogManager if it is present
if [ -r "$CATALINA_BASE"/conf/logging.properties ]; then
  JAVA_OPTS="$JAVA_OPTS -Djava.util.logging.manager=org.apache.juli.ClassLoaderLogManager"
  LOGGING_CONFIG="-Djava.util.logging.config.file=$CATALINA_BASE/conf/logging.properties"
fi

But Eclipse runs the Java code directly, without using catalina.sh. So the properties never gets set. You have to set them by hand in the “Run Configurations” dialog. Like this:

Of note there is that I’ve imported the logging.properties file into the Servers project of my workspace. It seemed liked a useful place to put it.

Of course, after realising that, I soon find the same information in the WTP FAQ: How do I enable the JULI logging in a Tomcat 5.5 Server instance?.

Anyway, now I might be able to debug that ClassLoader issue…

¹ Inside Eclipse with WTP, that will be something like $WORKSPACE/.metadata/.plugins/org.eclipse.wst.server.core/tmp0.