A demonstration of Composite Design Pattern

Course Title : Object Oriented Design and Design Patterns Lab(CSE 4122)

Author

Akif Islam
Department of CSE, University of Rajshahi
iamakifislam@gmail.com

Experiment 04

Write a Java program to demonstrate the implementation of a composite design pattern by using an example with a building composed of generic housing structures.

Story of the Program

This design pattern follows the basic component-composite-leaf model of Composite Design Pattern.

Class Diagram

How to Run?

  $javac CompositePatternDemo.java
  $java CompositePatternDemo

Composite Pattern Demo Program

// Creating Leaf Node : Bathroom, Kitchen and Bedroom
Bathroom bathroom = new Bathroom();
Kitchen kitchen = new Kitchen();
Bedroom bedroom = new Bedroom();

// Sending Bathroom, Kitchen, Bedroom to its Composite Class ---> Living Room
LivingRoom livingRoom = new LivingRoom();
livingRoom.addRoom(bathroom);
livingRoom.addRoom(kitchen);
livingRoom.addRoom(bedroom);
livingRoom.getSubordinates();

// Creating Leaf Node : Elevator, Staircase and Swimming Pool
Elevator elevator = new Elevator();
Staircase staircase = new Staircase();
SwimmingPool swimmingPool = new SwimmingPool();

// Sending Elevator, Staircase, Swimming Pool to its Composite Class ---> Common Area
CommonArea commonArea = new CommonArea();
commonArea.addRoom(elevator);
commonArea.addRoom(staircase);
commonArea.addRoom(swimmingPool);
commonArea.getSubordinates();

Appartment appartment = new Appartment();
appartment.addRoom(commonArea);
appartment.addRoom(livingRoom);
appartment.roomInfo();

Output