☕ Java Design Patterns (GoF) — AU_CCE Term 5 (Programming II)

A clean, runnable collection of Gang of Four (GoF) design patterns implemented in Java, organized by category (Creational / Structural / Behavioural) with simple demo runners.

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✅ Patterns Covered

Behavioural

• Observer
• Iterator
• Strategy
• Chain of Responsibility
• State

Creational

• Factory
• Abstract Factory
• Builder
• Prototype
• Singleton

Structural

• Composite
• Adapter
• Proxy
• Flyweight
• Facade
• Bridge
• Decorator

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🚀 Running the Demos

You have two ways to run this project:

Option 1: Run the prebuilt version (recommended)

Use the release/ folder — it contains a ready-to-run JAR so you don’t need NetBeans or compiling.

1. Open release/
2. Open the jar/ folder (this contains Design_Patterns.jar)
3. Run it:

• Windows: double-click run.bat
• macOS: double-click run.command (may show a one-time security prompt)
• Linux: double-click Design Patterns.desktop (some desktops may ask “Allow Launching” once)

If you prefer command line, go inside release/jar/ and run:

java -jar "Design_Patterns.jar"

Requirements: Java 21.

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Option 2: Run from NetBeans (source code)

Use this if you want to inspect/edit the code.

Run the Menu App (recommended inside NetBeans)

1. Open Demo/DemoApp.java
2. Right-click → Run File
3. Use the menu to pick the category + pattern demo

Run a single pattern demo

1. Expand a category package (e.g., Behavioral/Strategy)
2. Open the *Demo class
3. Right-click → Run File

All demos extend Demo and implement Runnable (run()), so every pattern runs in a consistent way.

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✍️ Conventions used

• Demo.java provides a common structure for consistent execution
• Patterns are separated by category and kept in their own packages
• Naming is kept straightforward (e.g., Context, State, Strategy, Factory, etc.)