Java Design Patterns: A Hands-On Experience with Real-World Examples

© Vaskaran Sarcar 2019

Vaskaran SarcarJava Design Patternshttps://doi.org/10.1007/978-1-4842-4078-6_15

15. Strategy (Policy) Pattern

Vaskaran Sarcar¹ 

(1)

Bangalore, Karnataka, India

 

This chapter covers the strategy pattern.

GoF Definition

Define a family of algorithms, encapsulate each one, and make them interchangeable. Strategy lets the algorithm vary independently from the clients that use it.

Concept

Suppose there is an application where you have multiple algorithms and each of these algorithms can perform a specific task. A client can dynamically pick any of these algorithms to serve its current need.

The strategy pattern suggests that you implement these algorithms in separate classes. When you encapsulate an algorithm in a separate class, you call ...