121 Java Object Oriented Design

This is a refactoring aid that runs your Java code through an OOD quality check before making any changes. It enforces compilation as a safety gate, then applies SOLID principles, fixes code smells like God Class and Feature Envy, and improves patterns around object creation, method signatures, and exception handling. The workflow is deliberate: compile first, read the reference guide for good and bad patterns, apply focused refactorings, then verify with a full Maven build. It's built for systematic cleanup work rather than greenfield development, and the hard stop on compilation failures keeps you from digging deeper holes. Part of the cursor-rules-java project by Juan Antonio Breña Moral.