Package org.apache.commons.chain

package org.apache.commons.chain

The fundamental API contracts for the Chain of Responsibility Pattern as implemented in this package. See org.apache.commons.chain.impl for convenient base implementations of Chain and Context, and see org.apache.commons.chain.web for specialized Context implementations suitable for use in web applications.

Related Packages

Package	Description
org.apache.commons.chain.config	Optional package for configuring command chains in a catalog (using Digester) from an XML configuration file.
org.apache.commons.chain.generic	Concrete implementations of generic Commands that are useful in many different environments, not tied to a particular tier such as Servlets).
org.apache.commons.chain.impl	Convenient base implementations of Chain of Responsibility Pattern contracts from org.apache.commons.chain.
org.apache.commons.chain.web	Basis for specialized Context implementations suitable for use in web applications, and generic Command implementations useful across web application environments.

Class	Description
Catalog<C extends Context>	A Catalog is a collection of named Commands (or Chains) that can be used to retrieve the set of commands that should be performed based on a symbolic identifier.
CatalogFactory<C extends Context>	A CatalogFactory is a class used to store and retrieve Catalogs.
Chain<C extends Context>	A Chain represents a configured list of Commands that will be executed in order to perform processing on a specified Context.
Command<C extends Context>	A Command encapsulates a unit of processing work to be performed, whose purpose is to examine and/or modify the state of a transaction that is represented by a Context.
Context	A Context represents the state information that is accessed and manipulated by the execution of a Command or a Chain.
Filter<C extends Context>	A Filter is a specialized Command that also expects the Chain that is executing it to call the postprocess() method if it called the execute() method.