Design Patterns Lab — Lecture 8: Command Pattern

In this lecture, we explore the Command Pattern, one of the core Behavioral Design Patterns used to decouple requests from execution and transform actions into reusable objects. Step by step, we learn how the pattern separates: - the object requesting the action from - the object performing the action Using Smart Home and Smart Office examples, we implement the complete pattern in Java and understand the roles of: - Command Interface - Concrete Commands - Receivers - Invokers We also implement undo functionality and discuss real-world use cases such as automation systems, GUI actions, task schedulers, and undo/redo systems. This lecture focuses on both: - practical implementation - design thinking behind the pattern 📚 Topics Covered • Command Pattern fundamentals • Encapsulating requests as objects • Loose coupling and delegation • Invoker, Receiver, and Command roles • Runtime command switching • Undo functionality • Smart Office automation example • Command vs Strategy comparison 📂 Repository (Code + Activity) 🔹 Command Pattern: https://github.com/Maryam-Skaik/design-patterns-lab-command.git 🧪 Practice Activity Build a Smart Office Automation System using the Command Pattern with runtime flexibility and optional undo/macro commands.