Creational Design Patterns

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Sure! Here’s an example of the Factory Pattern in Java. The Factory Pattern is a creational design pattern that provides an interface for creating objects, but allows subclasses to alter the type of objects that will be created.

Scenario:

Let’s create a system for a logistics company where different types of vehicles (e.g., Truck, Ship) can be used for transportation. We’ll use the Factory Pattern to create these vehicle objects.

Components:

1. Product Interface: Declares the interface for objects that the factory method creates.
2. Concrete Product Classes: Implement the Product interface.
3. Creator (Factory) Interface: Declares the factory method.
4. Concrete Creator (Factory) Classes: Implement the factory method to create specific products.

Explanation:

• Product Interface: The Transport interface declares the deliver method.
• Concrete Product Classes: The Truck and Ship classes implement the Transport interface and provide specific implementations of the deliver method.
• Creator (Factory) Interface: The Logistics abstract class declares the factory method createTransport and a method planDelivery that uses the product created by the factory method.
• Concrete Creator (Factory) Classes: The RoadLogistics and SeaLogistics classes implement the factory method createTransport to create specific products (Truck and Ship respectively).
• Client Class: The Client class uses the factory classes to create and use products.

Advantages of Factory Pattern:

1. Encapsulation: The Factory Pattern encapsulates the object creation process, hiding it from the client.
2. Decoupling: It decouples the client code from the object creation code, making the system more flexible and easier to extend.
3. Single Responsibility Principle: It adheres to the Single Responsibility Principle by delegating the responsibility of object creation to specific factory classes.
4. Open/Closed Principle: The system can be extended with new product types without modifying existing code, adhering to the Open/Closed Principle.