Logging

Logging

We are using SLF4J for logging as it promises to integrate different logging approaches well.
See http://ekkes-corner.blogspot.com/2008/10/logging-in-osgi-enterprise-applications_31.html

The pattern for logging should be as follows.

In an Activator:

private static Logger LOG = LoggerFactory.getLogger(Activator.class);
public static final String ID = "symbolic_bundle_name";
public static final Marker BUNDLE_MARKER = createBundleMarker();
private static Marker createBundleMarker() {
    Marker bundleMarker = MarkerFactory.getMarker(ID);
    bundleMarker.add(MarkerFactory.getMarker("IS_MARKER"));
    return bundleMarker;
}

In each class of the bundle we declare:

import static MyActivator.BUNDLE_MARKER;
private static final Logger LOG = LoggerFactory.getLogger(Foo.class);

To actually log with the bundle marker, we write log statements like this:

if (LOG.isInfoEnabled()) LOG.info(BUNDLE_MARKER, "Starting BundleBee carrier...");

Currently, logging is configured with trunk/src/main/equinox/plugins/logback.xml (or plugins/logback.xml in the distr. package).

Configuring logging with a fragment bundle failed due to classloading difficulties (one framework extensions does not seem to be able to see another). See notes in the top part of the class BundleBeeClassLoadingHook.

TODO: Add BundleMarkerConverter Fragment, so that we actually benefit from the marker!