Builder Pattern – Custom Computer Example

Overview

This example demonstrates the Builder Pattern in a scenario where we need to assemble a custom computer with various components (CPU, GPU, RAM, storage, OS). Instead of calling a massive constructor with multiple parameters, we use a builder that allows step-by-step configuration of a Computer object, culminating in a final build() method that returns the fully constructed product.

Why Builder?

• Complex Object Setup: Constructing a Computer requires many fields (CPU, GPU, RAM size, storage type, OS, etc.). A single constructor with all parameters could become cumbersome.
• Readability: A builder clarifies each configuration step (setCpu(), setGpu(), setRamSize(), etc.) rather than forcing you to memorize parameter ordering.
• Flexibility: You can easily introduce optional steps or new fields without breaking existing constructor calls.

How to Run

1. Compile the Java Files

   • Ensure your directory structure places Computer, ComputerBuilder, GamingComputerBuilder, and BuilderDemo together (or in a suitable package).
   • Use javac to compile:

   javac *.java

   java BuilderDemo