Apache Karaf - bundle starts but does nothing?

Question

I'm new to Karaf. I have a jar that has a class App with a method main. When I drop the jar in the The Karaf log service console says the bundle is started but nothing seems to happen. The first thing (the jar) does is a simple database write so I can see if it's running (no log file is generated although one is expected).

The jar depends on lots of other jars. Our sysadmin will not install Maven on the production servers. Where does one put helper jars (like mysql-connector-java-[version].jar)?

Does Karaf use the Manifest file to find the main class? Do I have to implement some special interface or something?

thanks for any help.

Answer 1

As Karaf is a OSGi Container, you should first read some stuff on how to write proper OSGi bundles. First of all you'll need a Activator that'll start your bundle (just like a main). A Main Class is never interpreted. Yes Karaf, as it is a OSGi container, does "read" the Manifest, but to make sure first it's a proper OSGi bundle second how the resolving should take place by reading Package-Import/-Export.

Regarding the "Packaging" - using lot's of other jar's/bunldes - , you'd either can built a custom Karaf (read the Karaf documentation on how to do this) or create a KAR for your Bundles containing your bundles and a feature.xml (again take a look at the documentation at Karaf)