Design Patterns

This is a repository with collection of design patterns written in Java.

Context

In many interviews, I've been asked about design patterns. Talking about patterns is a nice conversation, but it is even better when you can support this conversation with real examples or some coding examples.

I created this repository for that purpose. The examples may not be perfect or differ from traditional books. These differences are also a good opportunity for interviews and debate.

Index

• Creational patterns
  • Singleton
  • Factory method
  • Abstract Factory
  • Builder
  • Prototype
• Structural patterns
  • Adapter
  • Decorator
  • Composite
  • Proxy
  • Facade
  • Bridge
  • Flyweight
• Behavioural patterns
  • State
  • Strategy
  • Observer
  • Iterator
  • Chain of Responsibility
  • Mediator
  • Template Method
  • Command
  • Memento
  • Visitor

Class diagrams generation

The class diagrams are generated using PlantUML.

You can generate the class diagram images from the corresponding markdown file code using inline plantUML syntax.

plantuml -tsvg ./Adapter/readme.md

You can also use the plantuml jar file from the root folder.

java -jar plantuml-mit-1.2024.4.jar ./Adapter/class-diagram.txt -tsvg

Sources

• Head First Design Patterns: A Brain-Friendly Guide
• Design Patterns: Elements of Reusable Object-Oriented Software
• Christopher Okhravi
• refactoring.guru