A Look at Commons Chain, Part 1
Subject:   chaining allows for pre/post aspects
Date:   2005-03-03 07:33:23
From:   t.cowan
One feature I like about this pattern is that you can apply before/after events across a set of commands, similar to how AOP is used in most of the examples. for example, you could handle closing sql connections in one place, and have each "command" ignore that and leave it to the command processor.

When you see a repeating case of setup and teardown code, chaining can help put this in one place. Are servlet filters I type of chaining?