Refactor Java code by identifying smells, applying patterns deliberately, using tool support, and validating changes against real behavior.
Refactoring improves design without changing observable behavior. In Java, the risk is using pattern names as a justification for large rewrites instead of making small, reversible changes tied to specific smells.
This section focuses on recognizing refactoring opportunities, choosing patterns only when they clarify the code, and using tools and case studies to keep design changes safe.