Loggifier.unkrig.de / Tools / Java agent
Probably the most convenient way to loggify classes at runtime is to start the JVM with the following command line option:
$ java -javaagent:path/to/de.unkrig.loggifier.jar ...
The LOGGIFIER plugs into the "Java programming language agents" API (available since Java 5) and implements loggification at class-loading time.
The agent interprets its argument as (newline-separated) loggification rules:
$ java '-javaagent:path/to/de.unkrig.loggifier.jar=CLINIT=INFO
> ALL=FINER' ...