📝 What You’ll Learn

• What the Abstract Factory Pattern is
• How it differs from the Factory Method
• How to implement it in Java
• Real-world examples and use cases
• Pitfalls and best practices

🔍 What Is the Abstract Factory Pattern?

The Abstract Factory Pattern provides an interface for creating families of related objects without specifying their concrete classes.

It’s like a factory of factories.

🏭 Factory vs Abstract Factory

Aspect	Factory Method	Abstract Factory
Focus	One object at a time	Multiple related objects
Structure	Single product	Product families
Example	NotificationFactory	UIComponentFactory

🧱 Java Implementation Example

Imagine you’re building UI for multiple operating systems — you want to produce consistent buttons and checkboxes for each.

🧩 Step 1: Define Product Interfaces

public interface Button {
    void render();
}

public interface Checkbox {
    void render();
}

🧩 Step 2: Concrete Implementations

public class WindowsButton implements Button {
    public void render() {
        System.out.println("Rendering Windows Button");
    }
}

public class MacButton implements Button {
    public void render() {
        System.out.println("Rendering Mac Button");
    }
}

public class WindowsCheckbox implements Checkbox {
    public void render() {
        System.out.println("Rendering Windows Checkbox");
    }
}

public class MacCheckbox implements Checkbox {
    public void render() {
        System.out.println("Rendering Mac Checkbox");
    }
}

🧩 Step 3: Create Abstract Factory

public interface GUIFactory {
    Button createButton();
    Checkbox createCheckbox();
}

🧩 Step 4: Concrete Factories

public class WindowsFactory implements GUIFactory {
    public Button createButton() {
        return new WindowsButton();
    }
    public Checkbox createCheckbox() {
        return new WindowsCheckbox();
    }
}

public class MacFactory implements GUIFactory {
    public Button createButton() {
        return new MacButton();
    }
    public Checkbox createCheckbox() {
        return new MacCheckbox();
    }
}

✅ Usage

public class Application {
    private Button button;
    private Checkbox checkbox;

    public Application(GUIFactory factory) {
        button = factory.createButton();
        checkbox = factory.createCheckbox();
    }

    public void renderUI() {
        button.render();
        checkbox.render();
    }
}

GUIFactory factory = new MacFactory();
Application app = new Application(factory);
app.renderUI();

💡 Real-World Analogy

Think of a furniture showroom. An abstract furniture factory might produce a ModernChair and ModernTable, or a VictorianChair and VictorianTable — always a matching set.

⚠️ Pitfalls to Avoid

• ❌ Overcomplicating simple object creation scenarios
• ❌ Tight coupling with factories — favor interfaces
• ❌ Making all product families identical

✅ Best Practices

• Favor interfaces for all product types
• Keep factories extensible
• Combine with Dependency Injection when possible
• Maintain clear separation between client code and creation logic

📘 Recap

• Abstract Factory lets you produce related object families
• It provides a way to isolate object creation from usage
• Great for UI frameworks, plugins, and theming systems
• Promotes scalability and consistency across products