Module io.jstach.rainbowgum.jul.logmanager

module io.jstach.rainbowgum.jul.logmanager
A LogManager replacement that routes every java.util.logging.Logger directly through Rainbow Gum, bypassing the standard JUL Handler/Level dispatch machinery entirely.

This is a separate module from io.jstach.rainbowgum.jul (which stays a Handler-based bridge, installed onto whatever the default LogManager already is) because replacing the LogManager itself is a much more invasive, whole-JVM decision: it can only be activated via the java.util.logging.manager system property, set before anything in the JVM has touched java.util.logging, and it changes the behavior of every JUL Logger in the process, not just the ones a Handler happens to see. Install by setting: 

java.util.logging.manager=io.jstach.rainbowgum.jul.logmanager.RainbowGumLogManager
as a real -D JVM argument (or JDK_JAVA_OPTIONS environment variable) - this cannot be done with System.setProperty(String, String) once the JVM has started, since java.util.logging.LogManager's own bootstrap reads the property exactly once, the first time anything touches JUL.

This is primarily useful for frameworks whose own internal logging is JUL-based and which offer no other seam to redirect it. Helidon is the motivating case (see doc/other-web-frameworks.md): Helidon's own helidon-logging-log4j module uses the exact same mechanism, setting java.util.logging.manager=org.apache.logging.log4j.jul.LogManager. This module's own RainbowGumLogManager is modeled closely on that Log4j2 implementation.

Works under GraalVM native-image with no consumer-side configuration - see RainbowGumLogManager's own javadoc for the build-time mechanism this module bundles to make that true.