The Jakarta Commons subproject chain codifies and combines 'Template Method' and 'Chain of Responsibility' patterns into a reusable Java framework for representing sequential process flows.
Commons chain is a popular technique for organizing the execution of complex processing flows.
The Home page for chain is http://commons.apache.org/chain/
Chain can be downloaded from http://commons.apache.org/downloads/download_chain.cgi
A Cookbook explaining usage of chain is available at http://commons.apache.org/chain/cookbook.html
A nice article on commons chain from ONJava.com can be found at http://www.onjava.com/pub/a/onjava/2005/03/02/commonchains.html
Other useful links can be
Java World
Design Pattern
