Today we ventured into the realm of data structures, implementing our own generic stack while restructuring our project organization. It’s one thing to use Java’s built-in collections, but building them from scratch? That’s where the real learning happens!

The code changes from this session can be found here.

Day 8 Summary

Overview

Restructured project organization and implemented a generic stack data structure with modern Java features while focusing on clean code principles and API design.

Environment & Tools

  • Reorganized packages to reflect domain ownership (blog.javamastery.*)
  • Proper package structure for data structures and common utilities
  • IntelliJ IDEA refactoring tools

Concepts Covered

Project Organization

  • Domain-based package naming
  • Separation of concerns in package structure
  • Common utilities isolation
  • Test code organization

Data Structure Implementation

  • Generic type handling
  • Array growth and shrinkage strategies
  • Memory management considerations
  • Clean API design

Modern Java Features

  • Generic types with arrays
  • Iterator implementation
  • Stream API integration
  • Custom interface design

Clean Code Practices

  • Consistent exception handling
  • Single responsibility methods
  • Clear naming conventions
  • Comprehensive testing approach

Implementation Progress

  • Created SimpleStack implementation
  • Added dynamic array resizing
  • Implemented iteration support
  • Created Streamable interface
  • Built comprehensive test cases

Key Takeaways

  • Importance of proper package organization
  • Array-based implementation considerations
  • Generic type handling in Java
  • Iterator and Stream API integration
  • Memory management strategies

Next Steps

Ready to explore:

  • Queue implementation
  • Concurrent operations
  • Lock-free data structures
  • Collection interface integration

Master’s Reflection

The apprentice demonstrated excellent judgment in API design and implementation details. The evolution from basic array management to a full-featured stack with iteration and streaming capabilities shows growing mastery of Java’s ecosystem. The attention to memory management and clean code principles suggests a strong foundation for tackling more complex data structures.