How to enable DEBUG level logging with Jetty embedded?

I'm trying to set the logging level to DEBUG in an embedded Jetty instance.

The documentation at http://docs.codehaus.org/display/JETTY/Debugging says to -

call SystemProperty.set("DEBUG", "true") before calling new org.mortbay.jetty.Server().

I'm not sure what the SystemProperty class is, it doesn't seem to be documented anywhere. I tried System.setProperty(), but that didn't do the trick.

Solution

My question was answered on the Jetty mailing list by Joakim Erdfelt:

You are looking at the old Jetty 6.x docs at docs.codehaus.org.

DEBUG logging is just a logging level determined by the logging implementation you choose to use.

If you use slf4j, then use slf4j's docs for configuring logging level. http://slf4j.org/manual.html

If you use java.util.logging, use the JVM docs. http://docs.oracle.com/javase/6/docs/technotes/guides/logging/overview.html

If you use the built-in StdErrLog, then there is a pattern to follow.

-D{classref}.LEVEL={level}

Where {classref} is the class reference you want to set the level on, and all sub-class refs. and {level} is one of the values ALL, DEBUG, INFO, WARN

Example: -Dorg.eclipse.jetty.LEVEL=INFO - this will enable INFO level logging for all jetty packages / classes. -Dorg.eclipse.jetty.io.LEVEL=DEBUG - this will enable DEBUG level logging for IO classes only -Dorg.eclipse.jetty.servlet.LEVEL=ALL - this will enable ALL logging (trace events, internally ignored exceptions, etc..) for servlet packages. -Dorg.eclipse.jetty.util.thread.QueuedThreadPool.LEVEL=ALL - this will enable level ALL+ on the specific class only.