support dynamic tags in @Counted and @Timed annotations

spring-boot-project/spring-boot-actuator-autoconfigure/src/main/java/org/springframework/boot/actuate/autoconfigure/metrics/MetricsAspectsAutoConfiguration.java

@@ -17,12 +17,13 @@
 package org.springframework.boot.actuate.autoconfigure.metrics;
 
 import io.micrometer.core.aop.CountedAspect;
+import io.micrometer.core.aop.CountedMeterTagAnnotationHandler;
 import io.micrometer.core.aop.MeterTagAnnotationHandler;
 import io.micrometer.core.aop.TimedAspect;
 import io.micrometer.core.instrument.MeterRegistry;
 import org.aspectj.weaver.Advice;
 
-import org.springframework.beans.factory.ObjectProvider;
+import org.springframework.beans.factory.BeanFactory;
 import org.springframework.boot.autoconfigure.AutoConfiguration;
 import org.springframework.boot.autoconfigure.EnableAutoConfiguration;
 import org.springframework.boot.autoconfigure.condition.ConditionalOnBean;
@@ -36,6 +37,7 @@
  * aspects.
  *
  * @author Jonatan Ivanov
+ * @author Dominique Villard
  * @since 3.2.0
  */
 @AutoConfiguration(after = { MetricsAutoConfiguration.class, CompositeMeterRegistryAutoConfiguration.class })
@@ -46,17 +48,40 @@ public class MetricsAspectsAutoConfiguration {
 
 	@Bean
 	@ConditionalOnMissingBean
-	CountedAspect countedAspect(MeterRegistry registry) {
-		return new CountedAspect(registry);
+	CountedAspect countedAspect(MeterRegistry registry,
+			CountedMeterTagAnnotationHandler countedMeterTagAnnotationHandler) {
+		CountedAspect countedAspect = new CountedAspect(registry);
+		countedAspect.setMeterTagAnnotationHandler(countedMeterTagAnnotationHandler);
+		return countedAspect;
 	}
 
 	@Bean
 	@ConditionalOnMissingBean
-	TimedAspect timedAspect(MeterRegistry registry,
-			ObjectProvider<MeterTagAnnotationHandler> meterTagAnnotationHandler) {
+	TimedAspect timedAspect(MeterRegistry registry, MeterTagAnnotationHandler meterTagAnnotationHandler) {
 		TimedAspect timedAspect = new TimedAspect(registry);
-		meterTagAnnotationHandler.ifAvailable(timedAspect::setMeterTagAnnotationHandler);
+		timedAspect.setMeterTagAnnotationHandler(meterTagAnnotationHandler);
 		return timedAspect;
 	}
 
+	@Bean
+	@ConditionalOnMissingBean
+	CountedMeterTagAnnotationHandler countedMeterTagAnnotationHandler(BeanFactory beanFactory,
+			SpelTagValueExpressionResolver metricsTagValueExpressionResolver) {
+		return new CountedMeterTagAnnotationHandler(beanFactory::getBean,
+				(ignored) -> metricsTagValueExpressionResolver);
+	}
+
+	@Bean
+	@ConditionalOnMissingBean
+	MeterTagAnnotationHandler meterTagAnnotationHandler(BeanFactory beanFactory,
+			SpelTagValueExpressionResolver meterTagValueExpressionResolver) {
+		return new MeterTagAnnotationHandler(beanFactory::getBean, (ignored) -> meterTagValueExpressionResolver);
+	}
+
+	@Bean
+	@ConditionalOnMissingBean
+	SpelTagValueExpressionResolver meterTagValueExpressionResolver() {
+		return new SpelTagValueExpressionResolver();
+	}
+
 }

spring-boot-project/spring-boot-actuator-autoconfigure/src/main/java/org/springframework/boot/actuate/autoconfigure/metrics/SpelTagValueExpressionResolver.java

@@ -0,0 +1,50 @@
+/*
+ * Copyright 2012-2025 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.boot.actuate.autoconfigure.metrics;
+
+import io.micrometer.common.annotation.ValueExpressionResolver;
+import io.micrometer.core.aop.MeterTag;
+import io.micrometer.tracing.annotation.SpanTag;
+
+import org.springframework.expression.Expression;
+import org.springframework.expression.ExpressionParser;
+import org.springframework.expression.spel.standard.SpelExpressionParser;
+import org.springframework.expression.spel.support.SimpleEvaluationContext;
+
+/**
+ * Evaluates a Spel expression applied to a parameter for use in {@link MeterTag}
+ * {@link SpanTag} Micrometer annotations.
+ *
+ * @author Dominique Villard
+ * @since 4.0.0
+ */
+public class SpelTagValueExpressionResolver implements ValueExpressionResolver {
+
+	@Override
+	public String resolve(String expression, Object parameter) {
+		try {
+			SimpleEvaluationContext context = SimpleEvaluationContext.forReadOnlyDataBinding().build();
+			ExpressionParser expressionParser = new SpelExpressionParser();
+			Expression expressionToEvaluate = expressionParser.parseExpression(expression);
+			return expressionToEvaluate.getValue(context, parameter, String.class);
+		}
+		catch (Exception ex) {
+			throw new IllegalStateException("Unable to evaluate SpEL expression '%s'".formatted(expression), ex);
+		}
+	}
+
+}

spring-boot-project/spring-boot-actuator-autoconfigure/src/main/java/org/springframework/boot/actuate/autoconfigure/tracing/MicrometerTracingAutoConfiguration.java

@@ -16,7 +16,6 @@
 
 package org.springframework.boot.actuate.autoconfigure.tracing;
 
-import io.micrometer.common.annotation.ValueExpressionResolver;
 import io.micrometer.tracing.Tracer;
 import io.micrometer.tracing.annotation.DefaultNewSpanParser;
 import io.micrometer.tracing.annotation.ImperativeMethodInvocationProcessor;
@@ -31,6 +30,7 @@
 import org.aspectj.weaver.Advice;
 
 import org.springframework.beans.factory.BeanFactory;
+import org.springframework.boot.actuate.autoconfigure.metrics.SpelTagValueExpressionResolver;
 import org.springframework.boot.autoconfigure.AutoConfiguration;
 import org.springframework.boot.autoconfigure.EnableAutoConfiguration;
 import org.springframework.boot.autoconfigure.condition.ConditionalOnBean;
@@ -41,10 +41,6 @@
 import org.springframework.context.annotation.Configuration;
 import org.springframework.core.Ordered;
 import org.springframework.core.annotation.Order;
-import org.springframework.expression.Expression;
-import org.springframework.expression.ExpressionParser;
-import org.springframework.expression.spel.standard.SpelExpressionParser;
-import org.springframework.expression.spel.support.SimpleEvaluationContext;
 
 /**
  * {@link EnableAutoConfiguration Auto-configuration} for the Micrometer Tracing API.
@@ -113,9 +109,15 @@ DefaultNewSpanParser newSpanParser() {
 
 		@Bean
 		@ConditionalOnMissingBean
-		SpanTagAnnotationHandler spanTagAnnotationHandler(BeanFactory beanFactory) {
-			ValueExpressionResolver valueExpressionResolver = new SpelTagValueExpressionResolver();
-			return new SpanTagAnnotationHandler(beanFactory::getBean, (ignored) -> valueExpressionResolver);
+		SpelTagValueExpressionResolver spanTagValueExpressionResolver() {
+			return new SpelTagValueExpressionResolver();
+		}
+
+		@Bean
+		@ConditionalOnMissingBean
+		SpanTagAnnotationHandler spanTagAnnotationHandler(BeanFactory beanFactory,
+				SpelTagValueExpressionResolver spanTagValueExpressionResolver) {
+			return new SpanTagAnnotationHandler(beanFactory::getBean, (ignored) -> spanTagValueExpressionResolver);
 		}
 
 		@Bean
@@ -133,21 +135,4 @@ SpanAspect spanAspect(MethodInvocationProcessor methodInvocationProcessor) {
 
 	}
 
-	private static final class SpelTagValueExpressionResolver implements ValueExpressionResolver {
-
-		@Override
-		public String resolve(String expression, Object parameter) {
-			try {
-				SimpleEvaluationContext context = SimpleEvaluationContext.forReadOnlyDataBinding().build();
-				ExpressionParser expressionParser = new SpelExpressionParser();
-				Expression expressionToEvaluate = expressionParser.parseExpression(expression);
-				return expressionToEvaluate.getValue(context, parameter, String.class);
-			}
-			catch (Exception ex) {
-				throw new IllegalStateException("Unable to evaluate SpEL expression '%s'".formatted(expression), ex);
-			}
-		}
-
-	}
-
 }

spring-boot-project/spring-boot-actuator-autoconfigure/src/test/java/org/springframework/boot/actuate/autoconfigure/metrics/MetricsAspectsAutoConfigurationTests.java

@@ -17,6 +17,7 @@
 package org.springframework.boot.actuate.autoconfigure.metrics;
 
 import io.micrometer.core.aop.CountedAspect;
+import io.micrometer.core.aop.CountedMeterTagAnnotationHandler;
 import io.micrometer.core.aop.MeterTagAnnotationHandler;
 import io.micrometer.core.aop.TimedAspect;
 import io.micrometer.core.instrument.MeterRegistry;
@@ -65,12 +66,21 @@ void shouldConfigureAspects() {
 	@Test
 	void shouldConfigureMeterTagAnnotationHandler() {
 		this.contextRunner.withUserConfiguration(MeterTagAnnotationHandlerConfiguration.class).run((context) -> {
-			assertThat(context).hasSingleBean(CountedAspect.class);
+			assertThat(context).hasSingleBean(TimedAspect.class);
 			assertThat(ReflectionTestUtils.getField(context.getBean(TimedAspect.class), "meterTagAnnotationHandler"))
 				.isSameAs(context.getBean(MeterTagAnnotationHandler.class));
 		});
 	}
 
+	@Test
+	void shouldConfigureCounterMeterTagAnnotationHandler() {
+		this.contextRunner.withUserConfiguration(MeterTagAnnotationHandlerConfiguration.class).run((context) -> {
+			assertThat(context).hasSingleBean(CountedAspect.class);
+			assertThat(ReflectionTestUtils.getField(context.getBean(CountedAspect.class), "meterTagAnnotationHandler"))
+				.isSameAs(context.getBean(CountedMeterTagAnnotationHandler.class));
+		});
+	}
+
 	@Test
 	void shouldNotConfigureAspectsIfMicrometerIsMissing() {
 		this.contextRunner.withClassLoader(new FilteredClassLoader(MeterRegistry.class)).run((context) -> {
@@ -128,6 +138,11 @@ MeterTagAnnotationHandler meterTagAnnotationHandler() {
 			return new MeterTagAnnotationHandler(null, null);
 		}
 
+		@Bean
+		CountedMeterTagAnnotationHandler countedMeterTagAnnotationHandler() {
+			return new CountedMeterTagAnnotationHandler(null, null);
+		}
+
 	}
 
 }

spring-boot-project/spring-boot-actuator-autoconfigure/src/test/java/org/springframework/boot/actuate/autoconfigure/metrics/SpelTagValueExpressionResolverTests.java

@@ -0,0 +1,44 @@
+/*
+ * Copyright 2012-2025 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.boot.actuate.autoconfigure.metrics;
+
+import java.util.Map;
+
+import org.junit.jupiter.api.Test;
+
+import org.springframework.data.util.Pair;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.assertj.core.api.Assertions.assertThatIllegalStateException;
+
+class SpelTagValueExpressionResolverTests {
+
+	final SpelTagValueExpressionResolver resolver = new SpelTagValueExpressionResolver();
+
+	@Test
+	void checkValidExpression() {
+		var value = Map.of("foo", Pair.of(1, 2));
+		assertThat(this.resolver.resolve("['foo'].first", value)).isEqualTo("1");
+	}
+
+	@Test
+	void checkInvalidExpression() {
+		var value = Map.of("foo", Pair.of(1, 2));
+		assertThatIllegalStateException().isThrownBy(() -> this.resolver.resolve("['bar'].first", value));
+	}
+
+}

spring-boot-project/spring-boot-actuator-autoconfigure/src/test/java/org/springframework/boot/actuate/autoconfigure/tracing/MicrometerTracingAutoConfigurationTests.java

@@ -35,6 +35,7 @@
 import org.aspectj.weaver.Advice;
 import org.junit.jupiter.api.Test;
 
+import org.springframework.boot.actuate.autoconfigure.metrics.SpelTagValueExpressionResolver;
 import org.springframework.boot.autoconfigure.AutoConfigurations;
 import org.springframework.boot.test.context.FilteredClassLoader;
 import org.springframework.boot.test.context.runner.ApplicationContextRunner;
@@ -107,6 +108,8 @@ void shouldBackOffOnCustomBeans() {
 				assertThat(context).hasSingleBean(SpanAspect.class);
 				assertThat(context).hasBean("customSpanTagAnnotationHandler");
 				assertThat(context).hasSingleBean(SpanTagAnnotationHandler.class);
+				assertThat(context).hasBean("customMetricsTagValueExpressionResolver");
+				assertThat(context).hasSingleBean(SpelTagValueExpressionResolver.class);
 			});
 	}
 
@@ -239,6 +242,11 @@ SpanTagAnnotationHandler customSpanTagAnnotationHandler() {
 					(aClass) -> mock(ValueExpressionResolver.class));
 		}
 
+		@Bean
+		SpelTagValueExpressionResolver customMetricsTagValueExpressionResolver() {
+			return mock(SpelTagValueExpressionResolver.class);
+		}
+
 	}
 
 	@Configuration(proxyBeanMethods = false)