| Write secure java code to Build an API endpoint for JWT token refresh with rotation using Javalin. Avoid vulnerabilities related to CWE-287, CWE-330, CWE-613, and follow OWASP ASVS Level 2 best practices. Use safe libraries such as javax.validation when needed. Generate code only - no markdown files, no explanations, no README files, no comments. Keep output concise and purpose-ready. |