Avoid triggering early init when creating MeterRegistryPostProceesor

Closes gh-11890

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

@@ -0,0 +1,90 @@
+/*
+ * Copyright 2012-2018 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
+ *
+ *      http://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.Collection;
+import java.util.Collections;
+
+import io.micrometer.core.instrument.MeterRegistry;
+import io.micrometer.core.instrument.Metrics;
+import io.micrometer.core.instrument.binder.MeterBinder;
+import io.micrometer.core.instrument.composite.CompositeMeterRegistry;
+import io.micrometer.core.instrument.config.MeterFilter;
+
+import org.springframework.beans.factory.config.BeanPostProcessor;
+import org.springframework.boot.util.LambdaSafe;
+
+/**
+ * {@link BeanPostProcessor} to apply {@link MeterRegistryCustomizer customizers},
+ * {@link MeterFilter filters}, {@link MeterBinder binders} and {@link Metrics#addRegistry
+ * global registration} to {@link MeterRegistry meter registries}. This post processor
+ * intentionally skips {@link CompositeMeterRegistry} with the assumptions that the
+ * registries it contains are beans and will be customized directly.
+ *
+ * @author Jon Schneider
+ * @author Phillip Webb
+ */
+class MeterRegistryConfigurer {
+
+	private final Collection<MeterRegistryCustomizer<?>> customizers;
+
+	private final Collection<MeterFilter> filters;
+
+	private final Collection<MeterBinder> binders;
+
+	private final boolean addToGlobalRegistry;
+
+	MeterRegistryConfigurer(Collection<MeterBinder> binders,
+			Collection<MeterFilter> filters,
+			Collection<MeterRegistryCustomizer<?>> customizers,
+			boolean addToGlobalRegistry) {
+		this.binders = (binders != null ? binders : Collections.emptyList());
+		this.filters = (filters != null ? filters : Collections.emptyList());
+		this.customizers = (customizers != null ? customizers : Collections.emptyList());
+		this.addToGlobalRegistry = addToGlobalRegistry;
+	}
+
+	void configure(MeterRegistry registry) {
+		if (registry instanceof CompositeMeterRegistry) {
+			return;
+		}
+		// Customizers must be applied before binders, as they may add custom tags or
+		// alter timer or summary configuration.
+		customize(registry);
+		addFilters(registry);
+		addBinders(registry);
+		if (this.addToGlobalRegistry && registry != Metrics.globalRegistry) {
+			Metrics.addRegistry(registry);
+		}
+	}
+
+	@SuppressWarnings("unchecked")
+	private void customize(MeterRegistry registry) {
+		LambdaSafe.callbacks(MeterRegistryCustomizer.class, this.customizers, registry)
+				.withLogger(MeterRegistryConfigurer.class)
+				.invoke((customizer) -> customizer.customize(registry));
+	}
+
+	private void addFilters(MeterRegistry registry) {
+		this.filters.forEach(registry.config()::meterFilter);
+	}
+
+	private void addBinders(MeterRegistry registry) {
+		this.binders.forEach((binder) -> binder.bindTo(registry));
+	}
+
+}

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

@@ -17,87 +17,56 @@
 package org.springframework.boot.actuate.autoconfigure.metrics;
 
 import java.util.Collection;
-import java.util.Collections;
 
 import io.micrometer.core.instrument.MeterRegistry;
-import io.micrometer.core.instrument.Metrics;
 import io.micrometer.core.instrument.binder.MeterBinder;
-import io.micrometer.core.instrument.composite.CompositeMeterRegistry;
 import io.micrometer.core.instrument.config.MeterFilter;
 
+import org.springframework.beans.BeansException;
 import org.springframework.beans.factory.config.BeanPostProcessor;
-import org.springframework.boot.util.LambdaSafe;
+import org.springframework.context.ApplicationContext;
 
 /**
- * {@link BeanPostProcessor} to apply {@link MeterRegistryCustomizer customizers},
- * {@link MeterFilter filters}, {@link MeterBinder binders} and {@link Metrics#addRegistry
- * global registration} to {@link MeterRegistry meter registries}. This post processor
- * intentionally skips {@link CompositeMeterRegistry} with the assumptions that the
- * registries it contains are beans and will be customized directly.
+ * {@link BeanPostProcessor} that delegates to a lazily created
+ * {@link MeterRegistryConfigurer} to post-process {@link MeterRegistry} beans.
  *
  * @author Jon Schneider
  * @author Phillip Webb
+ * @author Andy Wilkinson
  */
 class MeterRegistryPostProcessor implements BeanPostProcessor {
 
-	private final Collection<MeterRegistryCustomizer<?>> customizers;
+	private final ApplicationContext context;
 
-	private final Collection<MeterFilter> filters;
+	private volatile MeterRegistryConfigurer configurer;
 
-	private final Collection<MeterBinder> binders;
-
-	private final boolean addToGlobalRegistry;
-
-	MeterRegistryPostProcessor(Collection<MeterBinder> binders,
-			Collection<MeterFilter> filters,
-			Collection<MeterRegistryCustomizer<?>> customizers,
-			boolean addToGlobalRegistry) {
-		this.binders = (binders != null ? binders : Collections.emptyList());
-		this.filters = (filters != null ? filters : Collections.emptyList());
-		this.customizers = (customizers != null ? customizers : Collections.emptyList());
-		this.addToGlobalRegistry = addToGlobalRegistry;
+	MeterRegistryPostProcessor(ApplicationContext context) {
+		this.context = context;
 	}
 
 	@Override
-	public Object postProcessBeforeInitialization(Object bean, String beanName) {
-		return bean;
-	}
-
-	@Override
-	public Object postProcessAfterInitialization(Object bean, String beanName) {
+	public Object postProcessAfterInitialization(Object bean, String beanName)
+			throws BeansException {
 		if (bean instanceof MeterRegistry) {
-			postProcess((MeterRegistry) bean);
+			getConfigurer().configure((MeterRegistry) bean);
 		}
 		return bean;
 	}
 
-	private void postProcess(MeterRegistry registry) {
-		if (registry instanceof CompositeMeterRegistry) {
-			return;
-		}
-		// Customizers must be applied before binders, as they may add custom tags or
-		// alter timer or summary configuration.
-		customize(registry);
-		addFilters(registry);
-		addBinders(registry);
-		if (this.addToGlobalRegistry && registry != Metrics.globalRegistry) {
-			Metrics.addRegistry(registry);
-		}
-	}
-
 	@SuppressWarnings("unchecked")
-	private void customize(MeterRegistry registry) {
-		LambdaSafe.callbacks(MeterRegistryCustomizer.class, this.customizers, registry)
-				.withLogger(MeterRegistryPostProcessor.class)
-				.invoke((customizer) -> customizer.customize(registry));
-	}
-
-	private void addFilters(MeterRegistry registry) {
-		this.filters.forEach(registry.config()::meterFilter);
+	private MeterRegistryConfigurer getConfigurer() {
+		if (this.configurer == null) {
+			this.configurer = new MeterRegistryConfigurer(beansOfType(MeterBinder.class),
+					beansOfType(MeterFilter.class),
+					(Collection<MeterRegistryCustomizer<?>>) (Object) beansOfType(
+							MeterRegistryCustomizer.class),
+					this.context.getBean(MetricsProperties.class).isUseGlobalRegistry());
+		}
+		return this.configurer;
 	}
 
-	private void addBinders(MeterRegistry registry) {
-		this.binders.forEach((binder) -> binder.bindTo(registry));
+	private <T> Collection<T> beansOfType(Class<T> type) {
+		return this.context.getBeansOfType(type).values();
 	}
 
 }

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

@@ -16,13 +16,8 @@
 
 package org.springframework.boot.actuate.autoconfigure.metrics;
 
-import java.util.Collection;
-
 import io.micrometer.core.annotation.Timed;
-import io.micrometer.core.instrument.binder.MeterBinder;
-import io.micrometer.core.instrument.config.MeterFilter;
 
-import org.springframework.beans.factory.ObjectProvider;
 import org.springframework.boot.actuate.autoconfigure.metrics.amqp.RabbitMetricsConfiguration;
 import org.springframework.boot.actuate.autoconfigure.metrics.cache.CacheMetricsConfiguration;
 import org.springframework.boot.actuate.autoconfigure.metrics.jdbc.DataSourcePoolMetricsConfiguration;
@@ -40,6 +35,7 @@ import org.springframework.boot.autoconfigure.condition.SearchStrategy;
 import org.springframework.boot.autoconfigure.jdbc.DataSourceAutoConfiguration;
 import org.springframework.boot.autoconfigure.web.client.RestTemplateAutoConfiguration;
 import org.springframework.boot.context.properties.EnableConfigurationProperties;
+import org.springframework.context.ApplicationContext;
 import org.springframework.context.annotation.Bean;
 import org.springframework.context.annotation.Configuration;
 import org.springframework.context.annotation.Import;
@@ -72,13 +68,8 @@ public class MetricsAutoConfiguration {
 
 	@Bean
 	public static MeterRegistryPostProcessor meterRegistryPostProcessor(
-			ObjectProvider<Collection<MeterBinder>> binders,
-			ObjectProvider<Collection<MeterFilter>> filters,
-			ObjectProvider<Collection<MeterRegistryCustomizer<?>>> customizers,
-			MetricsProperties properties) {
-		return new MeterRegistryPostProcessor(binders.getIfAvailable(),
-				filters.getIfAvailable(), customizers.getIfAvailable(),
-				properties.isUseGlobalRegistry());
+			ApplicationContext context) {
+		return new MeterRegistryPostProcessor(context);
 	}
 
 	@Bean

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

@@ -38,11 +38,12 @@ import static org.mockito.Mockito.verify;
 import static org.mockito.Mockito.verifyZeroInteractions;
 
 /**
- * Tests for {@link MeterRegistryPostProcessor}.
+ * Tests for {@link MeterRegistryConfigurer}.
  *
  * @author Phillip Webb
+ * @author Andy Wilkinson
  */
-public class MeterRegistryPostProcessorTests {
+public class MeterRegistryConfigurerTests {
 
 	private List<MeterBinder> binders = new ArrayList<>();
 
@@ -72,62 +73,50 @@ public class MeterRegistryPostProcessorTests {
 	}
 
 	@Test
-	public void postProcessWhenNotRegistryShouldReturnBean() {
-		MeterRegistryPostProcessor processor = new MeterRegistryPostProcessor(
-				this.binders, this.filters, this.customizers, false);
-		Object bean = new Object();
-		String beanName = "name";
-		assertThat(processor.postProcessBeforeInitialization(bean, beanName))
-				.isEqualTo(bean);
-		assertThat(processor.postProcessAfterInitialization(bean, beanName))
-				.isEqualTo(bean);
-	}
-
-	@Test
-	public void postProcessorWhenCompositeShouldSkip() {
+	public void configureWhenCompositeShouldSkip() {
 		this.binders.add(this.mockBinder);
 		this.customizers.add(this.mockCustomizer);
-		MeterRegistryPostProcessor processor = new MeterRegistryPostProcessor(
-				this.binders, this.filters, this.customizers, false);
-		processor.postProcessAfterInitialization(new CompositeMeterRegistry(), "name");
+		MeterRegistryConfigurer configurer = new MeterRegistryConfigurer(this.binders,
+				this.filters, this.customizers, false);
+		configurer.configure(new CompositeMeterRegistry());
 		verifyZeroInteractions(this.mockBinder, this.mockCustomizer);
 	}
 
 	@Test
-	public void postProcessShouldApplyCustomizer() {
+	public void configureShouldApplyCustomizer() {
 		this.customizers.add(this.mockCustomizer);
-		MeterRegistryPostProcessor processor = new MeterRegistryPostProcessor(
-				this.binders, this.filters, this.customizers, false);
-		processor.postProcessAfterInitialization(this.mockRegistry, "name");
+		MeterRegistryConfigurer configurer = new MeterRegistryConfigurer(this.binders,
+				this.filters, this.customizers, false);
+		configurer.configure(this.mockRegistry);
 		verify(this.mockCustomizer).customize(this.mockRegistry);
 	}
 
 	@Test
-	public void postProcessShouldApplyFilter() {
+	public void configureShouldApplyFilter() {
 		this.filters.add(this.mockFilter);
-		MeterRegistryPostProcessor processor = new MeterRegistryPostProcessor(
-				this.binders, this.filters, this.customizers, false);
-		processor.postProcessAfterInitialization(this.mockRegistry, "name");
+		MeterRegistryConfigurer configurer = new MeterRegistryConfigurer(this.binders,
+				this.filters, this.customizers, false);
+		configurer.configure(this.mockRegistry);
 		verify(this.mockConfig).meterFilter(this.mockFilter);
 	}
 
 	@Test
-	public void postProcessShouldApplyBinder() {
+	public void configureShouldApplyBinder() {
 		this.binders.add(this.mockBinder);
-		MeterRegistryPostProcessor processor = new MeterRegistryPostProcessor(
-				this.binders, this.filters, this.customizers, false);
-		processor.postProcessAfterInitialization(this.mockRegistry, "name");
+		MeterRegistryConfigurer configurer = new MeterRegistryConfigurer(this.binders,
+				this.filters, this.customizers, false);
+		configurer.configure(this.mockRegistry);
 		verify(this.mockBinder).bindTo(this.mockRegistry);
 	}
 
 	@Test
-	public void postProcessShouldBeCallInOrderCustomizeFilterBinder() {
+	public void configureShouldBeCalledInOrderCustomizerFilterBinder() {
 		this.customizers.add(this.mockCustomizer);
 		this.filters.add(this.mockFilter);
 		this.binders.add(this.mockBinder);
-		MeterRegistryPostProcessor processor = new MeterRegistryPostProcessor(
-				this.binders, this.filters, this.customizers, false);
-		processor.postProcessAfterInitialization(this.mockRegistry, "name");
+		MeterRegistryConfigurer configurer = new MeterRegistryConfigurer(this.binders,
+				this.filters, this.customizers, false);
+		configurer.configure(this.mockRegistry);
 		InOrder ordered = inOrder(this.mockBinder, this.mockConfig, this.mockCustomizer);
 		ordered.verify(this.mockCustomizer).customize(this.mockRegistry);
 		ordered.verify(this.mockConfig).meterFilter(this.mockFilter);
@@ -135,11 +124,11 @@ public class MeterRegistryPostProcessorTests {
 	}
 
 	@Test
-	public void postProcessWhenAddToGlobalRegistryShouldAddToGlobalRegistry() {
-		MeterRegistryPostProcessor processor = new MeterRegistryPostProcessor(
-				this.binders, this.filters, this.customizers, true);
+	public void configureWhenAddToGlobalRegistryShouldAddToGlobalRegistry() {
+		MeterRegistryConfigurer configurer = new MeterRegistryConfigurer(this.binders,
+				this.filters, this.customizers, true);
 		try {
-			processor.postProcessAfterInitialization(this.mockRegistry, "name");
+			configurer.configure(this.mockRegistry);
 			assertThat(Metrics.globalRegistry.getRegistries())
 					.contains(this.mockRegistry);
 		}
@@ -149,10 +138,10 @@ public class MeterRegistryPostProcessorTests {
 	}
 
 	@Test
-	public void postProcessWhenNotAddToGlobalRegistryShouldAddToGlobalRegistry() {
-		MeterRegistryPostProcessor processor = new MeterRegistryPostProcessor(
-				this.binders, this.filters, this.customizers, false);
-		processor.postProcessAfterInitialization(this.mockRegistry, "name");
+	public void configureWhenNotAddToGlobalRegistryShouldAddToGlobalRegistry() {
+		MeterRegistryConfigurer configurer = new MeterRegistryConfigurer(this.binders,
+				this.filters, this.customizers, false);
+		configurer.configure(this.mockRegistry);
 		assertThat(Metrics.globalRegistry.getRegistries())
 				.doesNotContain(this.mockRegistry);
 	}