I want to implement a task scheduler to run in Apache Felix. The idea is the task scheduler will read a crontab file, and execute the task (the task is defined by a installed services or bundles) periodically. What is the best way to do this? I am new to OSGI, and good suggestions is appreciated.
Well, it's not really an OSGi matter (OSGi doesn't cover crontab-type event scheduling), I'd say use a 3rd party open source scheduler like Quartz:
However, it's not an OSGi bundle out of the box, so that still might require some effort to make it work.
Other suggestion: Apache Sling seems to have a built in scheduler (also based on Quartz), and as Sling is OSGi based, it should be reasonably easy to add to your app.
http://sling.apache.org/documentation/bundles/scheduler-service-commons-scheduler.html
Hope this helps, Frank