https://devops-monk.com/tags/jep506/Recent content in Jep506 on Devops MonkHugoen-usSun, 10 May 2026 00:00:00 +0000https://devops-monk.com/tutorials/java25/scoped-values/Sun, 10 May 2026 00:00:00 +0000https://devops-monk.com/tutorials/java25/scoped-values/The ThreadLocal Problem ThreadLocal has been the standard way to pass contextual data through a call chain without polluting method signatures since Java 1.2. Every Java developer has seen it used for things like: Web request context (user ID, correlation ID, tenant ID) Database transaction binding Security principal propagation Logging MDC (Mapped Diagnostic Context) Here is the classic pattern: public class RequestContext { // ThreadLocal stores one value per thread private static final ThreadLocal<String> CURRENT_USER = new ThreadLocal<>(); public static void set(String userId) { CURRENT_USER.