Quartz is a library for task scheduling for JAVA/J2EE. It is very easy to configure and use. Here are some features that I like:
- works in both J2SE and J2EE
- different jobs storing modes (memory or DB)
- jobs can be declared in XML (no need to compile the code after changes)
- different triggering modes (e.g. Cron like one)
- predefined set of triggers e.g. minutely, daily etc.
- it's for free (Apache License 2.0)
Check it out at: www.opensymphony.com/quartz/