GH-3376: Remove gauges on application ctx close

spring-integration-core/src/main/java/org/springframework/integration/config/EnableIntegrationManagement.java

@@ -23,6 +23,7 @@
 import java.lang.annotation.Target;
 
 import org.springframework.context.annotation.Import;
+import org.springframework.integration.support.management.micrometer.MicrometerMetricsCaptorRegistrar;
 
 /**
  * Enables default configuring of management in Spring Integration components in an existing application.
@@ -31,13 +32,14 @@
  * bean is defined under the name {@code integrationManagementConfigurer}.
  *
  * @author Gary Russell
+ * @author Artem Bilan
  *
  * @since 4.2
  */
 @Target(ElementType.TYPE)
 @Retention(RetentionPolicy.RUNTIME)
 @Documented
-@Import(IntegrationManagementConfiguration.class)
+@Import({ MicrometerMetricsCaptorRegistrar.class, IntegrationManagementConfiguration.class })
 public @interface EnableIntegrationManagement {
 
 	/**

spring-integration-core/src/main/java/org/springframework/integration/config/IntegrationManagementConfiguration.java

@@ -18,6 +18,7 @@
 
 import java.util.Map;
 
+import org.springframework.beans.factory.ObjectProvider;
 import org.springframework.beans.factory.config.BeanDefinition;
 import org.springframework.context.EnvironmentAware;
 import org.springframework.context.annotation.Bean;
@@ -27,6 +28,7 @@
 import org.springframework.core.annotation.AnnotationAttributes;
 import org.springframework.core.env.Environment;
 import org.springframework.core.type.AnnotationMetadata;
+import org.springframework.integration.support.management.metrics.MetricsCaptor;
 import org.springframework.util.Assert;
 
 /**
@@ -62,11 +64,13 @@ public void setImportMetadata(AnnotationMetadata importMetadata) {
 
 	@Bean(name = IntegrationManagementConfigurer.MANAGEMENT_CONFIGURER_NAME)
 	@Role(BeanDefinition.ROLE_INFRASTRUCTURE)
-	public IntegrationManagementConfigurer managementConfigurer() {
+	public IntegrationManagementConfigurer managementConfigurer(ObjectProvider<MetricsCaptor> metricsCaptorProvider) {
+
 		IntegrationManagementConfigurer configurer = new IntegrationManagementConfigurer();
 		configurer.setDefaultLoggingEnabled(
 				Boolean.parseBoolean(this.environment.resolvePlaceholders(
 						(String) this.attributes.get("defaultLoggingEnabled"))));
+		configurer.setMetricsCaptor(metricsCaptorProvider.getIfUnique());
 		return configurer;
 	}
 

spring-integration-core/src/main/java/org/springframework/integration/config/IntegrationManagementConfigurer.java

@@ -16,24 +16,27 @@
 
 package org.springframework.integration.config;
 
+import java.util.HashSet;
 import java.util.Map;
 import java.util.Map.Entry;
+import java.util.Set;
 
 import org.springframework.beans.BeansException;
 import org.springframework.beans.factory.BeanNameAware;
+import org.springframework.beans.factory.DisposableBean;
 import org.springframework.beans.factory.SmartInitializingSingleton;
 import org.springframework.beans.factory.config.BeanPostProcessor;
 import org.springframework.context.ApplicationContext;
 import org.springframework.context.ApplicationContextAware;
 import org.springframework.integration.core.MessageSource;
 import org.springframework.integration.support.management.IntegrationManagement;
 import org.springframework.integration.support.management.IntegrationManagement.ManagementOverrides;
+import org.springframework.integration.support.management.metrics.MeterFacade;
 import org.springframework.integration.support.management.metrics.MetricsCaptor;
-import org.springframework.integration.support.management.micrometer.MicrometerMetricsCaptor;
+import org.springframework.lang.Nullable;
 import org.springframework.messaging.MessageChannel;
 import org.springframework.messaging.MessageHandler;
 import org.springframework.util.Assert;
-import org.springframework.util.ClassUtils;
 
 
 /**
@@ -49,13 +52,16 @@
  *
  */
 public class IntegrationManagementConfigurer
-		implements SmartInitializingSingleton, ApplicationContextAware, BeanNameAware, BeanPostProcessor {
+		implements SmartInitializingSingleton, ApplicationContextAware, BeanNameAware, BeanPostProcessor,
+		DisposableBean {
 
 	/**
 	 * Bean name of the configurer.
 	 */
 	public static final String MANAGEMENT_CONFIGURER_NAME = "integrationManagementConfigurer";
 
+	private final Set<MeterFacade> gauges = new HashSet<>();
+
 	private ApplicationContext applicationContext;
 
 	private String beanName;
@@ -99,15 +105,15 @@ public void setDefaultLoggingEnabled(boolean defaultLoggingEnabled) {
 		this.defaultLoggingEnabled = defaultLoggingEnabled;
 	}
 
+	public void setMetricsCaptor(@Nullable MetricsCaptor metricsCaptor) {
+		this.metricsCaptor = metricsCaptor;
+	}
+
 	@Override
 	public void afterSingletonsInstantiated() {
 		Assert.state(this.applicationContext != null, "'applicationContext' must not be null");
 		Assert.state(MANAGEMENT_CONFIGURER_NAME.equals(this.beanName), getClass().getSimpleName()
 				+ " bean name must be " + MANAGEMENT_CONFIGURER_NAME);
-		if (ClassUtils.isPresent("io.micrometer.core.instrument.MeterRegistry",
-				this.applicationContext.getClassLoader())) {
-			this.metricsCaptor = MicrometerMetricsCaptor.loadCaptor(this.applicationContext);
-		}
 		if (this.metricsCaptor != null) {
 			injectCaptor();
 			registerComponentGauges();
@@ -144,20 +150,29 @@ public Object postProcessAfterInitialization(Object bean, String name) throws Be
 	}
 
 	private void registerComponentGauges() {
-		this.metricsCaptor.gaugeBuilder("spring.integration.channels", this,
-				(c) -> this.applicationContext.getBeansOfType(MessageChannel.class).size())
-				.description("The number of message channels")
-				.build();
-
-		this.metricsCaptor.gaugeBuilder("spring.integration.handlers", this,
-				(c) -> this.applicationContext.getBeansOfType(MessageHandler.class).size())
-				.description("The number of message handlers")
-				.build();
-
-		this.metricsCaptor.gaugeBuilder("spring.integration.sources", this,
-				(c) -> this.applicationContext.getBeansOfType(MessageSource.class).size())
-				.description("The number of message sources")
-				.build();
+		this.gauges.add(
+				this.metricsCaptor.gaugeBuilder("spring.integration.channels", this,
+						(c) -> this.applicationContext.getBeansOfType(MessageChannel.class).size())
+						.description("The number of message channels")
+						.build());
+
+		this.gauges.add(
+				this.metricsCaptor.gaugeBuilder("spring.integration.handlers", this,
+						(c) -> this.applicationContext.getBeansOfType(MessageHandler.class).size())
+						.description("The number of message handlers")
+						.build());
+
+		this.gauges.add(
+				this.metricsCaptor.gaugeBuilder("spring.integration.sources", this,
+						(c) -> this.applicationContext.getBeansOfType(MessageSource.class).size())
+						.description("The number of message sources")
+						.build());
+	}
+
+	@Override
+	public void destroy() {
+		this.gauges.forEach(MeterFacade::remove);
+		this.gauges.clear();
 	}
 
 	private static ManagementOverrides getOverrides(IntegrationManagement bean) {

spring-integration-core/src/main/java/org/springframework/integration/support/management/micrometer/MicrometerMetricsCaptor.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2018-2019 the original author or authors.
+ * Copyright 2018-2020 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.
@@ -86,7 +86,10 @@ public MeterFacade removeMeter(MeterFacade facade) {
 	 * there's already a {@link MetricsCaptor} bean, return that.
 	 * @param applicationContext the application context.
 	 * @return the instance.
+	 * @deprecated since 5.2.9 in favor of {@code @Import(MicrometerMetricsCaptorRegistrar.class)};
+	 * will be removed in 6.0.
 	 */
+	@Deprecated
 	public static MetricsCaptor loadCaptor(ApplicationContext applicationContext) {
 		try {
 			MeterRegistry registry = applicationContext.getBean(MeterRegistry.class);

spring-integration-core/src/main/java/org/springframework/integration/support/management/micrometer/MicrometerMetricsCaptorRegistrar.java

@@ -0,0 +1,70 @@
+/*
+ * Copyright 2020 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.integration.support.management.micrometer;
+
+import org.springframework.beans.factory.ListableBeanFactory;
+import org.springframework.beans.factory.config.BeanDefinition;
+import org.springframework.beans.factory.support.BeanDefinitionBuilder;
+import org.springframework.beans.factory.support.BeanDefinitionRegistry;
+import org.springframework.context.annotation.ImportBeanDefinitionRegistrar;
+import org.springframework.core.type.AnnotationMetadata;
+import org.springframework.util.ClassUtils;
+
+/**
+ * An {@link ImportBeanDefinitionRegistrar} to conditionally add a {@link MicrometerMetricsCaptor}
+ * bean when {@code io.micrometer.core.instrument.MeterRegistry} is present in classpath and
+ * no {@link MicrometerMetricsCaptor#MICROMETER_CAPTOR_NAME} bean present yet.
+ *
+ * @author Artem Bilan
+ *
+ * @since 5.2.9
+ */
+public class MicrometerMetricsCaptorRegistrar implements ImportBeanDefinitionRegistrar {
+
+	private static final Class<?> METER_REGISTRY_CLASS;
+
+	static {
+		Class<?> aClass = null;
+		try {
+			aClass = ClassUtils.forName("io.micrometer.core.instrument.MeterRegistry",
+					ClassUtils.getDefaultClassLoader());
+		}
+		catch (ClassNotFoundException e) {
+			// Ignore - no Micrometer in classpath
+		}
+		METER_REGISTRY_CLASS = aClass;
+	}
+
+	@Override
+	public void registerBeanDefinitions(AnnotationMetadata importingClassMetadata, BeanDefinitionRegistry registry) {
+		if (METER_REGISTRY_CLASS != null
+				&& !registry.containsBeanDefinition(MicrometerMetricsCaptor.MICROMETER_CAPTOR_NAME)) {
+			String[] beanNamesForType =
+					((ListableBeanFactory) registry).getBeanNamesForType(METER_REGISTRY_CLASS, false, false);
+			for (String beanName : beanNamesForType) {
+				registry.registerBeanDefinition(MicrometerMetricsCaptor.MICROMETER_CAPTOR_NAME,
+						BeanDefinitionBuilder.genericBeanDefinition(MicrometerMetricsCaptor.class)
+								.addConstructorArgReference(beanName)
+								.setRole(BeanDefinition.ROLE_INFRASTRUCTURE)
+								.getBeanDefinition());
+				return;
+			}
+
+		}
+	}
+
+}

spring-integration-core/src/test/java/org/springframework/integration/endpoint/BeanNameTests.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2018-2019 the original author or authors.
+ * Copyright 2018-2020 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.
@@ -112,7 +112,7 @@ public void contextLoads() {
 	public static class Config {
 
 		@Bean
-		public MeterRegistry meterRegistry() {
+		public static MeterRegistry meterRegistry() {
 			return new SimpleMeterRegistry();
 		}
 

spring-integration-core/src/test/java/org/springframework/integration/graph/IntegrationGraphServerTests.java

@@ -257,6 +257,11 @@ void testIncludesDynamic() {
 	@ImportResource("org/springframework/integration/graph/integration-graph-context.xml")
 	public static class Config {
 
+		@Bean
+		public static MeterRegistry meterRegistry() {
+			return new SimpleMeterRegistry();
+		}
+
 		@Bean
 		public IntegrationGraphServer server() {
 			IntegrationGraphServer server = new IntegrationGraphServer();
@@ -274,11 +279,6 @@ public IntegrationGraphServer server() {
 			return server;
 		}
 
-		@Bean
-		public MeterRegistry meterRegistry() {
-			return new SimpleMeterRegistry();
-		}
-
 		@Bean
 		public MessageProducer producer() {
 			MessageProducerSupport producer = new MessageProducerSupport() {

spring-integration-core/src/test/java/org/springframework/integration/support/management/micrometer/MicrometerCustomMetricsTests.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2018-2019 the original author or authors.
+ * Copyright 2018-2020 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.
@@ -17,10 +17,9 @@
 package org.springframework.integration.support.management.micrometer;
 
 import static org.assertj.core.api.Assertions.assertThat;
-import static org.assertj.core.api.Assertions.fail;
+import static org.assertj.core.api.Assertions.assertThatExceptionOfType;
 
-import org.junit.Test;
-import org.junit.runner.RunWith;
+import org.junit.jupiter.api.Test;
 
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.context.ConfigurableApplicationContext;
@@ -32,7 +31,7 @@
 import org.springframework.integration.support.management.metrics.MetricsCaptor;
 import org.springframework.messaging.support.GenericMessage;
 import org.springframework.test.context.TestExecutionListeners;
-import org.springframework.test.context.junit4.SpringRunner;
+import org.springframework.test.context.junit.jupiter.SpringJUnitConfig;
 import org.springframework.test.context.support.DependencyInjectionTestExecutionListener;
 
 import io.micrometer.core.instrument.MeterRegistry;
@@ -46,7 +45,7 @@
  * @since 5.1
  *
  */
-@RunWith(SpringRunner.class)
+@SpringJUnitConfig
 @TestExecutionListeners(DependencyInjectionTestExecutionListener.class)
 public class MicrometerCustomMetricsTests {
 
@@ -81,20 +80,18 @@ public void testSend() {
 
 		// Test meter removal
 		this.context.close();
-		try {
-			registry.get("myTimer").timers();
-			fail("Expected MeterNotFoundException");
-		}
-		catch (MeterNotFoundException e) {
-			assertThat(e).hasMessageContaining("No meter with name 'myTimer' was found");
-		}
-		try {
-			registry.get("myCounter").counters();
-			fail("Expected MeterNotFoundException");
-		}
-		catch (MeterNotFoundException e) {
-			assertThat(e).hasMessageContaining("No meter with name 'myCounter' was found");
-		}
+
+		assertThatExceptionOfType(MeterNotFoundException.class)
+				.isThrownBy(() -> registry.get("myTimer").timers())
+				.withMessageContaining("No meter with name 'myTimer' was found");
+
+		assertThatExceptionOfType(MeterNotFoundException.class)
+				.isThrownBy(() -> registry.get("myCounter").counters())
+				.withMessageContaining("No meter with name 'myCounter' was found");
+
+		assertThatExceptionOfType(MeterNotFoundException.class)
+				.isThrownBy(() -> registry.get("spring.integration.channels").gauge())
+				.withMessageContaining("No meter with name 'spring.integration.channels' was found");
 	}
 
 	@Configuration

spring-integration-core/src/test/java/org/springframework/integration/support/management/micrometer/MicrometerMetricsTests.java

@@ -255,7 +255,7 @@ public void testMicrometerMetrics() {
 	public static class Config {
 
 		@Bean
-		public MeterRegistry meterRegistry() {
+		public static MeterRegistry meterRegistry() {
 			return new SimpleMeterRegistry();
 		}