eclipse-rdf4jGH-5208 Enable request tracing through logs using new as…

…sociated request id

tools/server-spring/src/main/java/org/eclipse/rdf4j/http/server/ServerInterceptor.java

@@ -10,9 +10,12 @@
  *******************************************************************************/
 package org.eclipse.rdf4j.http.server;
 
+import java.util.UUID;
+
 import javax.servlet.http.HttpServletRequest;
 import javax.servlet.http.HttpServletResponse;
 
+import org.slf4j.MDC;
 import org.springframework.web.servlet.HandlerInterceptor;
 
 /**
@@ -24,13 +27,15 @@
  */
 public abstract class ServerInterceptor implements HandlerInterceptor {
 
+	private static final String REQUEST_ID = "requestId";
 	private volatile String origThreadName;
 
 	@Override
 	public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler)
 			throws Exception {
 		origThreadName = Thread.currentThread().getName();
 		Thread.currentThread().setName(getThreadName());
+		MDC.put(REQUEST_ID, UUID.randomUUID().toString());
 
 		setRequestAttributes(request);
 
@@ -43,6 +48,7 @@ public void afterCompletion(HttpServletRequest request, HttpServletResponse resp
 		try {
 			cleanUpResources();
 		} finally {
+			MDC.remove(REQUEST_ID);
 			Thread.currentThread().setName(origThreadName);
 		}
 	}