log4j with third-party-initialized JVM, multiple JAR files and Jython

Question

I have a mess I would like to attach log4j logging to. Let me try to explain the process.

1. Third-party application launches a JVM and loads Main.jar. Main.jar includes a properties file for log4j logging and code to read it in with a PropertyConfigurator. Logging in Main.jar works.
2. Later, third-party application loads JythonApp.jar.
3. JythonApp.jar starts up a Jython interpreter and runs a script which uses classes from Main.jar, included by appending the Main.jar to sys.path. This is where the logging fails. The classes used by the Jython script have logging calls, but they do not log.

Any ideas how to make this all work? If you need more information, I will certainly understand and happily provide it.

Answer 1

I'm guessing that in the Jython case the classes are be loaded by a different classloader, and hence in effect that the log4j logging there is reinitialised, presumably not by the same PropertyConfigurator. Is that possible?

In which case you need to figure out how that log4j is being initialsied. Possibly you can provide a log4j.properties file of your own, perhaps specifying its location with the system property (-D as a launch argument)

log4j.configuration