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_11

11. Composite Pattern

Vaskaran Sarcar¹ 

(1)

Bangalore, Karnataka, India

 

This chapter covers the composite pattern.

GoF Definition

Compose objects into tree structures to represent part-whole hierarchies. Composite lets clients treat individual objects and compositions of objects uniformly.

Concept

To help you understand this concept, I will start with an example. Consider a shop that sells different kinds of dry fruits and nuts; let’s say cashews, dates, and walnuts. Each of these items is associated with a certain price. Let’s assume that you can purchase any of these individual items or you can purchase “gift packs” (or boxed items) that contain different ...