As a developer, we often need to apply object-oriented applications to essentially process-oriented systems. Business analysts and managers use flowcharts and workflow charts instead of class inheritance and sequence diagrams to describe such systems. However, when solving such problems, object-oriented is flexible for such a fusion. Object-oriented design patterns, such as template methods [GOF] and liability chains [GOF], provide a useful structure and behavior for the process of drawing sequential processing.
Jakarta's Commons sub-project Chain combines these patterns into a reusable Java framework to depict the process of sequential processing. This framework has been developed under the community protection of Jakarta Commons Project, which has been recognized and used silently in a large number of interesting applications, the most famous is the underlying mechanism for the HTTP request processing in the web framework of Struts and Shale. You can use commons chain when you need to define and perform some order operations.
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Original: http://www.onjava.com/pub/a/onjava/2005/03/02/commonchains.html
