What logging facility shoould in my Solr plugin?

[Teruhiko Kurosaka]

I see Solr uses the JDK java.util.logging.Logger.
I should also be using this Logger when I write
a plugin, correct?

I am asking only because I see commons-logging.jar
in apache-solr-1.1.0-incubating/example/ext
What is this for?

-kuro