Software Architecture Design Patterns in Java

36 STRATEGY

This pattern was previously described in GoF95.

DESCRIPTION

The Strategy pattern is useful when there is a set of related algorithms and a client object needs to be able to dynamically pick and choose an algorithm from this set that suits its current need.

The Strategy pattern suggests keeping the implementation of each of the algorithms in a separate class. Each such algorithm encapsulated in a separate class is referred to as a strategy. An object that uses a Strategy object is often referred to as a context object.

With different Strategy objects in place, changing the behavior of a Context object is simply a matter of changing its Strategy object to the one that implements the required algorithm.

To enable a Context object ...