Factory Design Pattern – Creating Objects the Smart Way

📘 Why This Blog?

When I first came across the Factory Design Pattern, it felt like magic. But with a bit of practical exploration, I realized it’s just a smart way to decouple object creation from usage.
This devblog is my attempt to help you understand the Factory Pattern the way I wish someone explained it to me.

📖 What is the Factory Pattern?

The Factory Pattern provides a way to delegate the instantiation logic to a separate method or class. Instead of using new in multiple places, we delegate it to a Factory that knows how to create different objects based on some input.

In simple terms: You say what you want, not how to create it.

🔍 Spotting a Factory Pattern

You might be looking at a Factory Pattern if you see:

• Code like: IEnemy enemy = EnemyFactory.getEnemy("orc");
• One interface or abstract class, but many concrete implementations.
• A centralized class responsible for returning the appropriate implementation.

🧪 Code Example – Enemy Factory

Step 1: Create an interface

public interface IEnemy {
    void attack();
}

Step 2: Implement the interface in multiple classes

public class Orc implements IEnemy {
    public void attack() {
        System.out.println("Orc attacks with axe!");
    }
}

public class Goblin implements IEnemy {
    public void attack() {
        System.out.println("Goblin throws dagger!");
    }
}

Step 3: Create the Factory Class

public class EnemyFactory {
    public static IEnemy getEnemy(String enemyType) {
        if (enemyType.equalsIgnoreCase("orc")) {
            return new Orc();
        } else if (enemyType.equalsIgnoreCase("goblin")) {
            return new Goblin();
        }
        throw new IllegalArgumentException("Unknown enemy type");
    }
}

Step 4: Use it in your code

public class Game {
    public static void main(String[] args) {
        IEnemy enemy1 = EnemyFactory.getEnemy("orc");
        enemy1.attack();

        IEnemy enemy2 = EnemyFactory.getEnemy("goblin");
        enemy2.attack();
    }
}

🧠 Personal Notes to Apply Factory Pattern

Start with usage:

IEnemy enemy = EnemyFactory.getEnemy("orc");

Then build everything around it:

• Create IEnemy interface
• Create Orc, Goblin, etc. classes that implement IEnemy
• Create EnemyFactory to return IEnemy objects

Keep the logic of what to return in one place – the factory.

✅ Benefits

• Centralized object creation logic
• Clean, readable code
• Easy to add new object types
• Loose coupling between client and concrete classes

🔗 More Examples

Check out more hands-on examples of the Factory Pattern here:

👉 Factory Design Pattern on GitHub

🧵 TL;DR

Factory Pattern is a smart way to delegate object creation.

You don’t worry about new – just ask the factory for what you need.

Made with ❤️ by syedyshiraz