Upgrade to Reactor 2025.0.0-M5 and Micrometer 1.16.0-M1

Includes Netty 4.2.3

Closes gh-35169
Closes gh-35170

Author: jhoeller

framework-platform/framework-platform.gradle

@@ -8,9 +8,9 @@ javaPlatform {
 
 dependencies {
 	api(platform("com.fasterxml.jackson:jackson-bom:2.18.4"))
-	api(platform("io.micrometer:micrometer-bom:1.15.1"))
-	api(platform("io.netty:netty-bom:4.2.2.Final"))
-	api(platform("io.projectreactor:reactor-bom:2025.0.0-M4"))
+	api(platform("io.micrometer:micrometer-bom:1.16.0-M1"))
+	api(platform("io.netty:netty-bom:4.2.3.Final"))
+	api(platform("io.projectreactor:reactor-bom:2025.0.0-M5"))
 	api(platform("io.rsocket:rsocket-bom:1.1.5"))
 	api(platform("org.apache.groovy:groovy-bom:4.0.27"))
 	api(platform("org.apache.logging.log4j:log4j-bom:3.0.0-beta3"))

spring-web/src/main/java/org/springframework/http/server/observation/DefaultServerRequestObservationConvention.java

@@ -23,6 +23,7 @@
 
 import io.micrometer.common.KeyValue;
 import io.micrometer.common.KeyValues;
+import org.jspecify.annotations.Nullable;
 
 import org.springframework.http.HttpMethod;
 import org.springframework.http.HttpStatus;
@@ -89,12 +90,15 @@ public String getName() {
 	}
 
 	@Override
-	public String getContextualName(ServerRequestObservationContext context) {
-		String httpMethod = context.getCarrier().getMethod().toLowerCase(Locale.ROOT);
-		if (context.getPathPattern() != null) {
-			return "http " + httpMethod + " " + context.getPathPattern();
+	public @Nullable String getContextualName(ServerRequestObservationContext context) {
+		if (context.getCarrier() != null) {
+			String httpMethod = context.getCarrier().getMethod().toLowerCase(Locale.ROOT);
+			if (context.getPathPattern() != null) {
+				return "http " + httpMethod + " " + context.getPathPattern();
+			}
+			return "http " + httpMethod;
 		}
-		return "http " + httpMethod;
+		return null;
 	}
 
 	@Override

spring-web/src/main/java/org/springframework/http/server/reactive/observation/DefaultServerRequestObservationConvention.java

@@ -21,6 +21,7 @@
 
 import io.micrometer.common.KeyValue;
 import io.micrometer.common.KeyValues;
+import org.jspecify.annotations.Nullable;
 
 import org.springframework.http.HttpMethod;
 import org.springframework.http.HttpStatus;
@@ -87,12 +88,15 @@ public String getName() {
 	}
 
 	@Override
-	public String getContextualName(ServerRequestObservationContext context) {
-		String httpMethod = context.getCarrier().getMethod().name().toLowerCase(Locale.ROOT);
-		if (context.getPathPattern() != null) {
-			return "http " + httpMethod + " " + context.getPathPattern();
+	public @Nullable String getContextualName(ServerRequestObservationContext context) {
+		if (context.getCarrier() != null) {
+			String httpMethod = context.getCarrier().getMethod().name().toLowerCase(Locale.ROOT);
+			if (context.getPathPattern() != null) {
+				return "http " + httpMethod + " " + context.getPathPattern();
+			}
+			return "http " + httpMethod;
 		}
-		return "http " + httpMethod;
+		return null;
 	}
 
 	@Override

spring-web/src/main/java/org/springframework/web/filter/ServerHttpObservationFilter.java

@@ -55,19 +55,23 @@
 public class ServerHttpObservationFilter extends OncePerRequestFilter {
 
 	/**
-	 * Name of the request attribute holding the {@link ServerRequestObservationContext context} for the current observation.
+	 * Name of the request attribute holding the {@link ServerRequestObservationContext} for the current observation.
 	 */
-	public static final String CURRENT_OBSERVATION_CONTEXT_ATTRIBUTE = ServerHttpObservationFilter.class.getName() + ".context";
+	public static final String CURRENT_OBSERVATION_CONTEXT_ATTRIBUTE =
+			ServerHttpObservationFilter.class.getName() + ".context";
 
-	private static final ServerRequestObservationConvention DEFAULT_OBSERVATION_CONVENTION = new DefaultServerRequestObservationConvention();
+	private static final String CURRENT_OBSERVATION_ATTRIBUTE =
+			ServerHttpObservationFilter.class.getName() + ".observation";
 
-	private static final String CURRENT_OBSERVATION_ATTRIBUTE = ServerHttpObservationFilter.class.getName() + ".observation";
+	private static final ServerRequestObservationConvention DEFAULT_OBSERVATION_CONVENTION =
+			new DefaultServerRequestObservationConvention();
 
 
 	private final ObservationRegistry observationRegistry;
 
 	private final ServerRequestObservationConvention observationConvention;
 
+
 	/**
 	 * Create an {@code HttpRequestsObservationFilter} that records observations
 	 * against the given {@link ObservationRegistry}. The default
@@ -89,14 +93,6 @@ public ServerHttpObservationFilter(ObservationRegistry observationRegistry, Serv
 		this.observationConvention = observationConvention;
 	}
 
-	/**
-	 * Get the current {@link ServerRequestObservationContext observation context} from the given request, if available.
-	 * @param request the current request
-	 * @return the current observation context
-	 */
-	public static Optional<ServerRequestObservationContext> findObservationContext(HttpServletRequest request) {
-		return Optional.ofNullable((ServerRequestObservationContext) request.getAttribute(CURRENT_OBSERVATION_CONTEXT_ATTRIBUTE));
-	}
 
 	@Override
 	protected boolean shouldNotFilterAsyncDispatch() {
@@ -150,8 +146,9 @@ private Observation createOrFetchObservation(HttpServletRequest request, HttpSer
 		Observation observation = (Observation) request.getAttribute(CURRENT_OBSERVATION_ATTRIBUTE);
 		if (observation == null) {
 			ServerRequestObservationContext context = new ServerRequestObservationContext(request, response);
-			observation = ServerHttpObservationDocumentation.HTTP_SERVLET_SERVER_REQUESTS.observation(this.observationConvention,
-					DEFAULT_OBSERVATION_CONVENTION, () -> context, this.observationRegistry).start();
+			observation = ServerHttpObservationDocumentation.HTTP_SERVLET_SERVER_REQUESTS.observation(
+					this.observationConvention, DEFAULT_OBSERVATION_CONVENTION, () -> context, this.observationRegistry)
+					.start();
 			request.setAttribute(CURRENT_OBSERVATION_ATTRIBUTE, observation);
 			if (!observation.isNoop()) {
 				request.setAttribute(CURRENT_OBSERVATION_CONTEXT_ATTRIBUTE, observation.getContext());
@@ -160,14 +157,32 @@ private Observation createOrFetchObservation(HttpServletRequest request, HttpSer
 		return observation;
 	}
 
-	static @Nullable Throwable unwrapServletException(Throwable ex) {
-		return (ex instanceof ServletException) ? ex.getCause() : ex;
+
+	/**
+	 * Get the current {@link ServerRequestObservationContext observation context} from the given request, if available.
+	 * @param request the current request
+	 * @return the current observation context
+	 */
+	public static Optional<ServerRequestObservationContext> findObservationContext(HttpServletRequest request) {
+		return Optional.ofNullable(
+				(ServerRequestObservationContext) request.getAttribute(CURRENT_OBSERVATION_CONTEXT_ATTRIBUTE));
 	}
 
 	static @Nullable Throwable fetchException(ServletRequest request) {
 		return (Throwable) request.getAttribute(RequestDispatcher.ERROR_EXCEPTION);
 	}
 
+	static Throwable unwrapServletException(Throwable ex) {
+		if (ex instanceof ServletException) {
+			Throwable cause = ex.getCause();
+			if (cause != null) {
+				return cause;
+			}
+		}
+		return ex;
+	}
+
+
 	private static class ObservationAsyncListener implements AsyncListener {
 
 		private final Observation currentObservation;
@@ -195,7 +210,6 @@ public void onComplete(AsyncEvent event) {
 		public void onError(AsyncEvent event) {
 			this.currentObservation.error(unwrapServletException(event.getThrowable()));
 		}
-
 	}
 
 }