I wrote an article for the IBM Enterprise Content Management Application Center on developerWork called “Developing Event Action Handlers for the FileNet P8 Content Engine”. The article describes how to gets you started developing Java event action handlers for the FileNet P8 Content Engine. A real world example describing a unique number dispenser is used to show how to use the infrastructure around event actions, subscriptions to your full benefit. It also discusses several use cases for custom events and shows an example using a custom event. The source code is also included along with the article. The complete article can be found here.
A follow-up on this article is the post Developing Change Preprocessors for the FileNet P8 Content Engine.