Today we brought our card game to life, implementing a complete multiplayer High Card game while diving deeper into Java’s object-oriented features.

The code changes from this session can be found here.

Day 5 Summary

Overview

Built a complete multiplayer High Card game while exploring Java’s object-oriented features, modern syntax, and clean code practices.

Environment & Tools

  • Git workflow with feature branching
  • zsh git shortcuts for efficient version control
  • Proper package organization

Concepts Covered

Domain Modeling

  • Record types for immutable data (Card, GameResult)
  • Class design for mutable state (Player, Game)
  • Enum implementation with behavior
  • Clean separation of concerns

Modern Java Features

  • Records with validation
  • Enhanced enum capabilities
  • String formatting
  • Stream operations for collections
  • Optional for null safety

Design Patterns & Principles

  • Dependency Injection (IO handling)
  • Immutable value objects
  • Builder pattern for game setup
  • Interface segregation
  • Single Responsibility Principle

Console Interface

  • Interactive gameplay
  • Input/Output abstraction
  • Error handling
  • User feedback
  • Game state management

Implementation Progress

  • Created core game entities
  • Implemented deck management
  • Added player validation
  • Built interactive console interface
  • Established proper error handling

Key Takeaways

  • Java enums can contain behavior
  • Records provide clean immutable data structures
  • Dependency injection enhances testability
  • Clean separation between domain and UI
  • Proper error handling improves user experience

Next Steps

Ready to explore:

  • Score tracking system
  • Deck reshuffling mechanism
  • Different card game variants
  • Unit testing implementation
  • Player statistics

Master’s Reflection

The apprentice demonstrated excellent judgment in design choices, particularly in separating concerns and managing mutability. The evolution from a simple two-player game to a flexible multiplayer system showed growing comfort with Java’s features. The intuitive grasp of when to use records vs classes and the thoughtful approach to dependency injection suggests a strong foundation in Java principles.