What problem does it solve? Java codebases often accumulate design problems like god classes, fat interfaces, and hard-coded dependencies that make code hard to test, extend, and maintain. This Skill provides a structured checklist to detect violations of the five SOLID principles and shows concrete refactored solutions for each. ## Core Features & Use Cases - Violation Detection: Identifies Single Responsibility, Open/Closed, Liskov Substitution, Interface Segregation, and Dependency Inversion violations using concrete detection patterns like type-switching, instanceof checks, and empty method implementations. - Refactored Java Examples: Each principle includes a violation example followed by a corrected implementation using patterns like Strategy, Dependency Injection, and interface segregation. - Review Checklist: Provides quick-check questions per principle for systematic code reviews, including Spring-based dependency injection examples. - Use Case: Ask it to review a UserService class, and it identifies an SRP violation where validation, persistence, email, and audit logic are mixed, then suggests extracting each concern into dedicated classes. ## Quick Start Review this UserService class for SOLID principle violations and suggest refactorings.
