Add actuator specific ObjectMapper

Prior to this commit, Actuator endpoints would use the application
ObjectMapper instance for serializing payloads as JSON. This was
problematic in several cases:

* application-specific configuration would change the actuator endpoint
output.
* choosing a different JSON mapper implementation in the application
would break completely some endpoints.

Spring Boot Actuator already has a hard dependency on Jackson, and this
commit uses that fact to configure a shared `ObjectMapper` instance that
will be used by the Actuator infrastructure consistently, without
polluting the application context.

This `ObjectMapper` is used in Actuator for:

* JMX endpoints
* Spring MVC endpoints with an HTTP message converter
* Spring WebFlux endpoints with an `Encoder`
* Jersey endpoints with a `ContextResolver<ObjectMapper>`

For all web endpoints, this configuration is limited to the
actuator-specific media types such as
`"application/vnd.spring-boot.actuator.v3+json"`.

Fixes gh-12951

spring-boot-project/spring-boot-actuator-autoconfigure/src/main/java/org/springframework/boot/actuate/autoconfigure/endpoint/EndpointAutoConfiguration.java

 /*
- * Copyright 2012-2019 the original author or authors.
+ * Copyright 2012-2020 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.
@@ -25,6 +25,7 @@ import org.springframework.boot.actuate.endpoint.annotation.EndpointConverter;
 import org.springframework.boot.actuate.endpoint.invoke.ParameterValueMapper;
 import org.springframework.boot.actuate.endpoint.invoke.convert.ConversionServiceParameterValueMapper;
 import org.springframework.boot.actuate.endpoint.invoker.cache.CachingOperationInvokerAdvisor;
+import org.springframework.boot.actuate.endpoint.json.ActuatorJsonMapperProvider;
 import org.springframework.boot.autoconfigure.EnableAutoConfiguration;
 import org.springframework.boot.autoconfigure.condition.ConditionalOnMissingBean;
 import org.springframework.boot.convert.ApplicationConversionService;
@@ -75,4 +76,9 @@ public class EndpointAutoConfiguration {
 		return new CachingOperationInvokerAdvisor(new EndpointIdTimeToLivePropertyFunction(environment));
 	}
 
+	@Bean
+	public ActuatorJsonMapperProvider actuatorJsonMapperProvider() {
+		return new ActuatorJsonMapperProvider();
+	}
+
 }

spring-boot-project/spring-boot-actuator-autoconfigure/src/main/java/org/springframework/boot/actuate/autoconfigure/endpoint/jmx/JmxEndpointAutoConfiguration.java

 /*
- * Copyright 2012-2019 the original author or authors.
+ * Copyright 2012-2020 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.
@@ -20,8 +20,6 @@ import java.util.stream.Collectors;
 
 import javax.management.MBeanServer;
 
-import com.fasterxml.jackson.databind.ObjectMapper;
-
 import org.springframework.beans.factory.ObjectProvider;
 import org.springframework.boot.actuate.autoconfigure.endpoint.ExposeExcludePropertyEndpointFilter;
 import org.springframework.boot.actuate.endpoint.EndpointFilter;
@@ -35,6 +33,7 @@ import org.springframework.boot.actuate.endpoint.jmx.JmxEndpointExporter;
 import org.springframework.boot.actuate.endpoint.jmx.JmxEndpointsSupplier;
 import org.springframework.boot.actuate.endpoint.jmx.JmxOperationResponseMapper;
 import org.springframework.boot.actuate.endpoint.jmx.annotation.JmxEndpointDiscoverer;
+import org.springframework.boot.actuate.endpoint.json.ActuatorJsonMapperProvider;
 import org.springframework.boot.autoconfigure.AutoConfigureAfter;
 import org.springframework.boot.autoconfigure.EnableAutoConfiguration;
 import org.springframework.boot.autoconfigure.condition.ConditionalOnMissingBean;
@@ -85,12 +84,12 @@ public class JmxEndpointAutoConfiguration {
 	@Bean
 	@ConditionalOnSingleCandidate(MBeanServer.class)
 	public JmxEndpointExporter jmxMBeanExporter(MBeanServer mBeanServer, Environment environment,
-			ObjectProvider<ObjectMapper> objectMapper, JmxEndpointsSupplier jmxEndpointsSupplier) {
+			ActuatorJsonMapperProvider actuatorJsonMapperProvider, JmxEndpointsSupplier jmxEndpointsSupplier) {
 		String contextId = ObjectUtils.getIdentityHexString(this.applicationContext);
 		EndpointObjectNameFactory objectNameFactory = new DefaultEndpointObjectNameFactory(this.properties, environment,
 				mBeanServer, contextId);
 		JmxOperationResponseMapper responseMapper = new JacksonJmxOperationResponseMapper(
-				objectMapper.getIfAvailable());
+				actuatorJsonMapperProvider.getInstance());
 		return new JmxEndpointExporter(mBeanServer, objectNameFactory, responseMapper,
 				jmxEndpointsSupplier.getEndpoints());
 

spring-boot-project/spring-boot-actuator-autoconfigure/src/main/java/org/springframework/boot/actuate/autoconfigure/endpoint/web/jersey/JerseyWebEndpointManagementContextConfiguration.java

 /*
- * Copyright 2012-2019 the original author or authors.
+ * Copyright 2012-2020 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.
@@ -22,7 +22,10 @@ import java.util.HashSet;
 import java.util.List;
 
 import javax.annotation.PostConstruct;
+import javax.ws.rs.Produces;
+import javax.ws.rs.ext.ContextResolver;
 
+import com.fasterxml.jackson.databind.ObjectMapper;
 import org.glassfish.jersey.server.ResourceConfig;
 import org.glassfish.jersey.server.model.Resource;
 
@@ -32,6 +35,8 @@ import org.springframework.boot.actuate.autoconfigure.web.ManagementContextConfi
 import org.springframework.boot.actuate.autoconfigure.web.server.ManagementPortType;
 import org.springframework.boot.actuate.endpoint.ExposableEndpoint;
 import org.springframework.boot.actuate.endpoint.annotation.Endpoint;
+import org.springframework.boot.actuate.endpoint.http.ActuatorMediaType;
+import org.springframework.boot.actuate.endpoint.json.ActuatorJsonMapperProvider;
 import org.springframework.boot.actuate.endpoint.web.EndpointLinksResolver;
 import org.springframework.boot.actuate.endpoint.web.EndpointMapping;
 import org.springframework.boot.actuate.endpoint.web.EndpointMediaTypes;
@@ -84,6 +89,12 @@ class JerseyWebEndpointManagementContextConfiguration {
 				|| ManagementPortType.get(environment).equals(ManagementPortType.DIFFERENT);
 	}
 
+	@Bean
+	ResourceConfigCustomizer actuatorResourceConfigCustomizer(ActuatorJsonMapperProvider jsonMapperProvider) {
+		return (ResourceConfig config) -> config.register(
+				new ActuatorJsonMapperContextResolver(jsonMapperProvider.getInstance()), ContextResolver.class);
+	}
+
 	/**
 	 * Register endpoints with the {@link ResourceConfig}. The
 	 * {@link ResourceConfigCustomizer} cannot be used because we don't want to apply
@@ -145,4 +156,20 @@ class JerseyWebEndpointManagementContextConfiguration {
 
 	}
 
+	@Produces({ ActuatorMediaType.V3_JSON, ActuatorMediaType.V2_JSON })
+	private static final class ActuatorJsonMapperContextResolver implements ContextResolver<ObjectMapper> {
+
+		private final ObjectMapper objectMapper;
+
+		private ActuatorJsonMapperContextResolver(ObjectMapper objectMapper) {
+			this.objectMapper = objectMapper;
+		}
+
+		@Override
+		public ObjectMapper getContext(Class<?> type) {
+			return this.objectMapper;
+		}
+
+	}
+
 }

spring-boot-project/spring-boot-actuator-autoconfigure/src/main/java/org/springframework/boot/actuate/autoconfigure/endpoint/web/reactive/WebFluxEndpointManagementContextConfiguration.java

 /*
- * Copyright 2012-2019 the original author or authors.
+ * Copyright 2012-2020 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.
@@ -26,6 +26,8 @@ import org.springframework.boot.actuate.autoconfigure.web.ManagementContextConfi
 import org.springframework.boot.actuate.autoconfigure.web.server.ManagementPortType;
 import org.springframework.boot.actuate.endpoint.ExposableEndpoint;
 import org.springframework.boot.actuate.endpoint.annotation.Endpoint;
+import org.springframework.boot.actuate.endpoint.http.ActuatorMediaType;
+import org.springframework.boot.actuate.endpoint.json.ActuatorJsonMapperProvider;
 import org.springframework.boot.actuate.endpoint.web.EndpointLinksResolver;
 import org.springframework.boot.actuate.endpoint.web.EndpointMapping;
 import org.springframework.boot.actuate.endpoint.web.EndpointMediaTypes;
@@ -40,8 +42,13 @@ import org.springframework.boot.autoconfigure.condition.ConditionalOnMissingBean
 import org.springframework.boot.autoconfigure.condition.ConditionalOnWebApplication;
 import org.springframework.boot.autoconfigure.condition.ConditionalOnWebApplication.Type;
 import org.springframework.boot.context.properties.EnableConfigurationProperties;
+import org.springframework.boot.web.codec.CodecCustomizer;
 import org.springframework.context.annotation.Bean;
+import org.springframework.core.annotation.Order;
 import org.springframework.core.env.Environment;
+import org.springframework.http.MediaType;
+import org.springframework.http.codec.CodecConfigurer;
+import org.springframework.http.codec.json.Jackson2JsonEncoder;
 import org.springframework.http.server.reactive.HttpHandler;
 import org.springframework.util.StringUtils;
 import org.springframework.web.reactive.DispatcherHandler;
@@ -52,6 +59,7 @@ import org.springframework.web.reactive.DispatcherHandler;
  *
  * @author Andy Wilkinson
  * @author Phillip Webb
+ * @author Brian Clozel
  * @since 2.0.0
  */
 @ManagementContextConfiguration(proxyBeanMethods = false)
@@ -93,4 +101,16 @@ public class WebFluxEndpointManagementContextConfiguration {
 				corsProperties.toCorsConfiguration());
 	}
 
+	@Bean
+	@Order(-1)
+	public CodecCustomizer actuatorJsonCodec(ActuatorJsonMapperProvider actuatorJsonMapperProvider) {
+		return (configurer) -> {
+			MediaType v3MediaType = MediaType.parseMediaType(ActuatorMediaType.V3_JSON);
+			MediaType v2MediaType = MediaType.parseMediaType(ActuatorMediaType.V2_JSON);
+			CodecConfigurer.CustomCodecs customCodecs = configurer.customCodecs();
+			customCodecs.register(
+					new Jackson2JsonEncoder(actuatorJsonMapperProvider.getInstance(), v3MediaType, v2MediaType));
+		};
+	}
+
 }

spring-boot-project/spring-boot-actuator-autoconfigure/src/main/java/org/springframework/boot/actuate/autoconfigure/endpoint/web/servlet/WebMvcEndpointManagementContextConfiguration.java

 /*
- * Copyright 2012-2019 the original author or authors.
+ * Copyright 2012-2020 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.
@@ -20,12 +20,16 @@ import java.util.ArrayList;
 import java.util.Collection;
 import java.util.List;
 
+import com.fasterxml.jackson.databind.ObjectMapper;
+
 import org.springframework.boot.actuate.autoconfigure.endpoint.web.CorsEndpointProperties;
 import org.springframework.boot.actuate.autoconfigure.endpoint.web.WebEndpointProperties;
 import org.springframework.boot.actuate.autoconfigure.web.ManagementContextConfiguration;
 import org.springframework.boot.actuate.autoconfigure.web.server.ManagementPortType;
 import org.springframework.boot.actuate.endpoint.ExposableEndpoint;
 import org.springframework.boot.actuate.endpoint.annotation.Endpoint;
+import org.springframework.boot.actuate.endpoint.http.ActuatorMediaType;
+import org.springframework.boot.actuate.endpoint.json.ActuatorJsonMapperProvider;
 import org.springframework.boot.actuate.endpoint.web.EndpointLinksResolver;
 import org.springframework.boot.actuate.endpoint.web.EndpointMapping;
 import org.springframework.boot.actuate.endpoint.web.EndpointMediaTypes;
@@ -42,9 +46,15 @@ import org.springframework.boot.autoconfigure.condition.ConditionalOnWebApplicat
 import org.springframework.boot.autoconfigure.condition.ConditionalOnWebApplication.Type;
 import org.springframework.boot.context.properties.EnableConfigurationProperties;
 import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.core.Ordered;
 import org.springframework.core.env.Environment;
+import org.springframework.http.MediaType;
+import org.springframework.http.converter.HttpMessageConverter;
+import org.springframework.http.converter.json.AbstractJackson2HttpMessageConverter;
 import org.springframework.util.StringUtils;
 import org.springframework.web.servlet.DispatcherServlet;
+import org.springframework.web.servlet.config.annotation.WebMvcConfigurer;
 
 /**
  * {@link ManagementContextConfiguration @ManagementContextConfiguration} for Spring MVC
@@ -91,4 +101,35 @@ public class WebMvcEndpointManagementContextConfiguration {
 				corsProperties.toCorsConfiguration());
 	}
 
+	@Configuration(proxyBeanMethods = false)
+	public static class JsonWebMvcConfigurer implements WebMvcConfigurer, Ordered {
+
+		private final ActuatorJsonMapperProvider actuatorJsonMapperProvider;
+
+		public JsonWebMvcConfigurer(ActuatorJsonMapperProvider objectMapperFactory) {
+			this.actuatorJsonMapperProvider = objectMapperFactory;
+		}
+
+		@Override
+		public void configureMessageConverters(List<HttpMessageConverter<?>> converters) {
+			converters.add(new ActuatorJsonHttpMessageConverter(this.actuatorJsonMapperProvider.getInstance()));
+		}
+
+		// WebMvcAutoConfiguration is ordered at 0
+		@Override
+		public int getOrder() {
+			return -1;
+		}
+
+	}
+
+	static class ActuatorJsonHttpMessageConverter extends AbstractJackson2HttpMessageConverter {
+
+		ActuatorJsonHttpMessageConverter(ObjectMapper objectMapper) {
+			super(objectMapper, MediaType.parseMediaType(ActuatorMediaType.V3_JSON),
+					MediaType.parseMediaType(ActuatorMediaType.V2_JSON));
+		}
+
+	}
+
 }

spring-boot-project/spring-boot-actuator-autoconfigure/src/main/java/org/springframework/boot/actuate/autoconfigure/web/servlet/WebMvcEndpointChildContextConfiguration.java

 /*
- * Copyright 2012-2019 the original author or authors.
+ * Copyright 2012-2020 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.
@@ -16,9 +16,13 @@
 
 package org.springframework.boot.actuate.autoconfigure.web.servlet;
 
+import java.util.List;
+
 import org.springframework.beans.factory.ListableBeanFactory;
+import org.springframework.beans.factory.ObjectProvider;
 import org.springframework.boot.actuate.autoconfigure.web.ManagementContextConfiguration;
 import org.springframework.boot.actuate.autoconfigure.web.ManagementContextType;
+import org.springframework.boot.actuate.endpoint.json.ActuatorJsonMapperProvider;
 import org.springframework.boot.autoconfigure.condition.ConditionalOnBean;
 import org.springframework.boot.autoconfigure.condition.ConditionalOnClass;
 import org.springframework.boot.autoconfigure.condition.ConditionalOnMissingBean;
@@ -33,11 +37,15 @@ import org.springframework.boot.web.servlet.error.ErrorAttributes;
 import org.springframework.boot.web.servlet.filter.OrderedRequestContextFilter;
 import org.springframework.boot.web.servlet.server.ConfigurableServletWebServerFactory;
 import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
 import org.springframework.core.Ordered;
+import org.springframework.http.converter.HttpMessageConverter;
+import org.springframework.http.converter.json.MappingJackson2HttpMessageConverter;
 import org.springframework.web.context.request.RequestContextListener;
 import org.springframework.web.filter.RequestContextFilter;
 import org.springframework.web.servlet.DispatcherServlet;
 import org.springframework.web.servlet.config.annotation.EnableWebMvc;
+import org.springframework.web.servlet.config.annotation.WebMvcConfigurer;
 
 /**
  * {@link ManagementContextConfiguration @ManagementContextConfiguration} for Spring MVC
@@ -108,6 +116,29 @@ class WebMvcEndpointChildContextConfiguration {
 		return new OrderedRequestContextFilter();
 	}
 
+	/**
+	 * Since {@code WebMvcEndpointManagementContextConfiguration} is adding an
+	 * actuator-specific JSON message converter, {@code @EnableWebMvc} will not register
+	 * default converters. We need to register a JSON converter for plain
+	 * {@code "application/json"} still.
+	 * WebMvcEndpointChildContextConfigurationIntegrationTests
+	 */
+	@Configuration(proxyBeanMethods = false)
+	public static class FallbackJsonConverterConfigurer implements WebMvcConfigurer {
+
+		private final ActuatorJsonMapperProvider actuatorJsonMapperProvider;
+
+		FallbackJsonConverterConfigurer(ObjectProvider<ActuatorJsonMapperProvider> objectMapperSupplier) {
+			this.actuatorJsonMapperProvider = objectMapperSupplier.getIfAvailable(ActuatorJsonMapperProvider::new);
+		}
+
+		@Override
+		public void extendMessageConverters(List<HttpMessageConverter<?>> converters) {
+			converters.add(new MappingJackson2HttpMessageConverter(this.actuatorJsonMapperProvider.getInstance()));
+		}
+
+	}
+
 	/**
 	 * {@link WebServerFactoryCustomizer} to add an {@link ErrorPage} so that the
 	 * {@link ManagementErrorEndpoint} can be used.

spring-boot-project/spring-boot-actuator-autoconfigure/src/test/java/org/springframework/boot/actuate/autoconfigure/endpoint/web/documentation/ScheduledTasksEndpointDocumentationTests.java

 /*
- * Copyright 2012-2019 the original author or authors.
+ * Copyright 2012-2020 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.
@@ -52,7 +52,7 @@ class ScheduledTasksEndpointDocumentationTests extends MockMvcEndpointDocumentat
 
 	@Test
 	void scheduledTasks() throws Exception {
-		this.mockMvc.perform(get("/actuator/scheduledtasks")).andExpect(status().isOk())
+		this.mockMvc.perform(get("/actuator/scheduledtasks").accept("application/json")).andExpect(status().isOk())
 				.andDo(document("scheduled-tasks",
 						preprocessResponse(replacePattern(
 								Pattern.compile("org.*\\.ScheduledTasksEndpointDocumentationTests\\$TestConfiguration"),

spring-boot-project/spring-boot-actuator-autoconfigure/src/test/java/org/springframework/boot/actuate/autoconfigure/endpoint/web/jersey/JerseyWebEndpointManagementContextConfigurationTests.java

 /*
- * Copyright 2012-2019 the original author or authors.
+ * Copyright 2012-2020 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.
@@ -21,6 +21,7 @@ import java.util.Collections;
 import org.glassfish.jersey.server.ResourceConfig;
 import org.junit.jupiter.api.Test;
 
+import org.springframework.boot.actuate.autoconfigure.endpoint.EndpointAutoConfiguration;
 import org.springframework.boot.actuate.autoconfigure.endpoint.web.WebEndpointAutoConfiguration;
 import org.springframework.boot.actuate.autoconfigure.endpoint.web.jersey.JerseyWebEndpointManagementContextConfiguration.JerseyWebEndpointsResourcesRegistrar;
 import org.springframework.boot.actuate.autoconfigure.web.jersey.JerseySameManagementContextConfiguration;
@@ -41,8 +42,8 @@ import static org.assertj.core.api.Assertions.assertThat;
 class JerseyWebEndpointManagementContextConfigurationTests {
 
 	private final WebApplicationContextRunner runner = new WebApplicationContextRunner()
-			.withConfiguration(AutoConfigurations.of(WebEndpointAutoConfiguration.class,
-					JerseyWebEndpointManagementContextConfiguration.class))
+			.withConfiguration(AutoConfigurations.of(EndpointAutoConfiguration.class,
+					WebEndpointAutoConfiguration.class, JerseyWebEndpointManagementContextConfiguration.class))
 			.withBean(WebEndpointsSupplier.class, () -> Collections::emptyList);
 
 	@Test

spring-boot-project/spring-boot-actuator-autoconfigure/src/test/java/org/springframework/boot/actuate/autoconfigure/integrationtest/WebMvcEndpointIntegrationTests.java

 /*
- * Copyright 2012-2019 the original author or authors.
+ * Copyright 2012-2020 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.
@@ -20,7 +20,6 @@ import java.util.function.Supplier;
 
 import javax.servlet.http.HttpServlet;
 
-import org.junit.jupiter.api.AfterEach;
 import org.junit.jupiter.api.Test;
 
 import org.springframework.boot.actuate.autoconfigure.audit.AuditAutoConfiguration;
@@ -33,32 +32,23 @@ import org.springframework.boot.actuate.endpoint.web.EndpointServlet;
 import org.springframework.boot.actuate.endpoint.web.annotation.ControllerEndpoint;
 import org.springframework.boot.actuate.endpoint.web.annotation.RestControllerEndpoint;
 import org.springframework.boot.actuate.endpoint.web.annotation.ServletEndpoint;
-import org.springframework.boot.autoconfigure.ImportAutoConfiguration;
+import org.springframework.boot.autoconfigure.AutoConfigurations;
 import org.springframework.boot.autoconfigure.context.PropertyPlaceholderAutoConfiguration;
-import org.springframework.boot.autoconfigure.data.rest.RepositoryRestMvcAutoConfiguration;
-import org.springframework.boot.autoconfigure.hateoas.HypermediaAutoConfiguration;
+import org.springframework.boot.autoconfigure.gson.GsonAutoConfiguration;
 import org.springframework.boot.autoconfigure.http.HttpMessageConvertersAutoConfiguration;
 import org.springframework.boot.autoconfigure.jackson.JacksonAutoConfiguration;
-import org.springframework.boot.autoconfigure.security.servlet.SecurityAutoConfiguration;
 import org.springframework.boot.autoconfigure.web.servlet.DispatcherServletAutoConfiguration;
 import org.springframework.boot.autoconfigure.web.servlet.WebMvcAutoConfiguration;
-import org.springframework.boot.test.util.TestPropertyValues;
-import org.springframework.boot.web.servlet.context.AnnotationConfigServletWebApplicationContext;
+import org.springframework.boot.test.context.runner.WebApplicationContextRunner;
 import org.springframework.context.annotation.Bean;
 import org.springframework.context.annotation.Configuration;
-import org.springframework.context.annotation.Import;
-import org.springframework.http.MediaType;
-import org.springframework.mock.web.MockServletContext;
-import org.springframework.security.authentication.TestingAuthenticationToken;
-import org.springframework.security.test.context.TestSecurityContextHolder;
 import org.springframework.test.web.servlet.MockMvc;
-import org.springframework.test.web.servlet.setup.DefaultMockMvcBuilder;
+import org.springframework.test.web.servlet.result.MockMvcResultMatchers;
 import org.springframework.test.web.servlet.setup.MockMvcBuilders;
-import org.springframework.test.web.servlet.setup.MockMvcConfigurer;
 
 import static org.hamcrest.Matchers.both;
 import static org.hamcrest.Matchers.hasKey;
-import static org.springframework.security.test.web.servlet.setup.SecurityMockMvcConfigurers.springSecurity;
+import static org.hamcrest.Matchers.startsWith;
 import static org.springframework.test.web.servlet.request.MockMvcRequestBuilders.get;
 import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.jsonPath;
 import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.status;
@@ -67,98 +57,39 @@ import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.
  * Integration tests for the Actuator's MVC endpoints.
  *
  * @author Andy Wilkinson
+ * @author Brian Clozel
  */
-class WebMvcEndpointIntegrationTests {
+public class WebMvcEndpointIntegrationTests {
 
-	private AnnotationConfigServletWebApplicationContext context;
-
-	@AfterEach
-	void close() {
-		TestSecurityContextHolder.clearContext();
-		this.context.close();
-	}
-
-	@Test
-	void endpointsAreSecureByDefault() throws Exception {
-		this.context = new AnnotationConfigServletWebApplicationContext();
-		this.context.register(SecureConfiguration.class);
-		MockMvc mockMvc = createSecureMockMvc();
-		mockMvc.perform(get("/actuator/beans").accept(MediaType.APPLICATION_JSON)).andExpect(status().isUnauthorized());
-	}
-
-	@Test
-	void endpointsAreSecureByDefaultWithCustomBasePath() throws Exception {
-		this.context = new AnnotationConfigServletWebApplicationContext();
-		this.context.register(SecureConfiguration.class);
-		TestPropertyValues.of("management.endpoints.web.base-path:/management").applyTo(this.context);
-		MockMvc mockMvc = createSecureMockMvc();
-		mockMvc.perform(get("/management/beans").accept(MediaType.APPLICATION_JSON))
-				.andExpect(status().isUnauthorized());
-	}
-
-	@Test
-	void endpointsAreSecureWithActuatorRoleWithCustomBasePath() throws Exception {
-		TestSecurityContextHolder.getContext()
-				.setAuthentication(new TestingAuthenticationToken("user", "N/A", "ROLE_ACTUATOR"));
-		this.context = new AnnotationConfigServletWebApplicationContext();
-		this.context.register(SecureConfiguration.class);
-		TestPropertyValues
-				.of("management.endpoints.web.base-path:/management", "management.endpoints.web.exposure.include=*")
-				.applyTo(this.context);
-		MockMvc mockMvc = createSecureMockMvc();
-		mockMvc.perform(get("/management/beans")).andExpect(status().isOk());
-	}
+	private WebApplicationContextRunner contextRunner = new WebApplicationContextRunner()
+			.withConfiguration(AutoConfigurations.of(JacksonAutoConfiguration.class, GsonAutoConfiguration.class,
+					HttpMessageConvertersAutoConfiguration.class, EndpointAutoConfiguration.class,
+					WebEndpointAutoConfiguration.class, ServletManagementContextAutoConfiguration.class,
+					AuditAutoConfiguration.class, PropertyPlaceholderAutoConfiguration.class,
+					WebMvcAutoConfiguration.class, ManagementContextAutoConfiguration.class,
+					AuditAutoConfiguration.class, DispatcherServletAutoConfiguration.class,
+					BeansEndpointAutoConfiguration.class));
 
 	@Test
 	void linksAreProvidedToAllEndpointTypes() throws Exception {
-		this.context = new AnnotationConfigServletWebApplicationContext();
-		this.context.register(DefaultConfiguration.class, EndpointsConfiguration.class);
-		TestPropertyValues.of("management.endpoints.web.exposure.include=*").applyTo(this.context);
-		MockMvc mockMvc = doCreateMockMvc();
-		mockMvc.perform(get("/actuator").accept("*/*")).andExpect(status().isOk()).andExpect(jsonPath("_links",
-				both(hasKey("beans")).and(hasKey("servlet")).and(hasKey("restcontroller")).and(hasKey("controller"))));
+		this.contextRunner.withUserConfiguration(EndpointsConfiguration.class)
+				.withPropertyValues("management.endpoints.web.exposure.include=*").run((context) -> {
+					MockMvc mockMvc = MockMvcBuilders.webAppContextSetup(context).build();
+					mockMvc.perform(get("/actuator").accept("*/*")).andExpect(status().isOk())
+							.andExpect(jsonPath("_links", both(hasKey("beans")).and(hasKey("servlet"))
+									.and(hasKey("restcontroller")).and(hasKey("controller"))));
+				});
 	}
 
-	private MockMvc createSecureMockMvc() {
-		return doCreateMockMvc(springSecurity());
-	}
-
-	private MockMvc doCreateMockMvc(MockMvcConfigurer... configurers) {
-		this.context.setServletContext(new MockServletContext());
-		this.context.refresh();
-		DefaultMockMvcBuilder builder = MockMvcBuilders.webAppContextSetup(this.context);
-		for (MockMvcConfigurer configurer : configurers) {
-			builder.apply(configurer);
-		}
-		return builder.build();
-	}
-
-	@ImportAutoConfiguration({ JacksonAutoConfiguration.class, HttpMessageConvertersAutoConfiguration.class,
-			EndpointAutoConfiguration.class, WebEndpointAutoConfiguration.class,
-			ServletManagementContextAutoConfiguration.class, AuditAutoConfiguration.class,
-			PropertyPlaceholderAutoConfiguration.class, WebMvcAutoConfiguration.class,
-			ManagementContextAutoConfiguration.class, AuditAutoConfiguration.class,
-			DispatcherServletAutoConfiguration.class, BeansEndpointAutoConfiguration.class })
-	static class DefaultConfiguration {
-
-	}
-
-	@Import(SecureConfiguration.class)
-	@ImportAutoConfiguration({ HypermediaAutoConfiguration.class })
-	static class SpringHateoasConfiguration {
-
-	}
-
-	@Import(SecureConfiguration.class)
-	@ImportAutoConfiguration({ HypermediaAutoConfiguration.class, RepositoryRestMvcAutoConfiguration.class })
-	static class SpringDataRestConfiguration {
-
-	}
-
-	@Import(DefaultConfiguration.class)
-	@ImportAutoConfiguration({ SecurityAutoConfiguration.class })
-	static class SecureConfiguration {
-
+	@Test
+	void dedicatedJsonMapperIsUsed() throws Exception {
+		this.contextRunner.withPropertyValues("spring.mvc.converters.preferred-json-mapper:gson",
+				"management.endpoints.web.exposure.include=*").run((context) -> {
+					MockMvc mockMvc = MockMvcBuilders.webAppContextSetup(context).build();
+					mockMvc.perform(get("/actuator/beans").accept("*/*")).andExpect(status().isOk())
+							.andExpect(MockMvcResultMatchers.header().string("Content-Type",
+									startsWith("application/vnd.spring-boot.actuator")));
+				});
 	}
 
 	@ServletEndpoint(id = "servlet")

spring-boot-project/spring-boot-actuator-autoconfigure/src/test/java/org/springframework/boot/actuate/autoconfigure/integrationtest/WebMvcEndpointSecurityIntegrationTests.java

+/*
+ * Copyright 2012-2020 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.boot.actuate.autoconfigure.integrationtest;
+
+import org.junit.jupiter.api.AfterEach;
+import org.junit.jupiter.api.Test;
+
+import org.springframework.boot.actuate.autoconfigure.audit.AuditAutoConfiguration;
+import org.springframework.boot.actuate.autoconfigure.beans.BeansEndpointAutoConfiguration;
+import org.springframework.boot.actuate.autoconfigure.endpoint.EndpointAutoConfiguration;
+import org.springframework.boot.actuate.autoconfigure.endpoint.web.WebEndpointAutoConfiguration;
+import org.springframework.boot.actuate.autoconfigure.web.server.ManagementContextAutoConfiguration;
+import org.springframework.boot.actuate.autoconfigure.web.servlet.ServletManagementContextAutoConfiguration;
+import org.springframework.boot.autoconfigure.ImportAutoConfiguration;
+import org.springframework.boot.autoconfigure.context.PropertyPlaceholderAutoConfiguration;
+import org.springframework.boot.autoconfigure.http.HttpMessageConvertersAutoConfiguration;
+import org.springframework.boot.autoconfigure.jackson.JacksonAutoConfiguration;
+import org.springframework.boot.autoconfigure.security.servlet.SecurityAutoConfiguration;
+import org.springframework.boot.autoconfigure.web.servlet.DispatcherServletAutoConfiguration;
+import org.springframework.boot.autoconfigure.web.servlet.WebMvcAutoConfiguration;
+import org.springframework.boot.test.util.TestPropertyValues;
+import org.springframework.boot.web.servlet.context.AnnotationConfigServletWebApplicationContext;
+import org.springframework.context.annotation.Import;
+import org.springframework.http.MediaType;
+import org.springframework.mock.web.MockServletContext;
+import org.springframework.security.authentication.TestingAuthenticationToken;
+import org.springframework.security.test.context.TestSecurityContextHolder;
+import org.springframework.test.web.servlet.MockMvc;
+import org.springframework.test.web.servlet.setup.DefaultMockMvcBuilder;
+import org.springframework.test.web.servlet.setup.MockMvcBuilders;
+import org.springframework.test.web.servlet.setup.MockMvcConfigurer;
+
+import static org.springframework.security.test.web.servlet.setup.SecurityMockMvcConfigurers.springSecurity;
+import static org.springframework.test.web.servlet.request.MockMvcRequestBuilders.get;
+import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.status;
+
+/**
+ * Integration tests for the Actuator's MVC endpoints security features.
+ *
+ * @author Andy Wilkinson
+ */
+class WebMvcEndpointSecurityIntegrationTests {
+
+	private AnnotationConfigServletWebApplicationContext context;
+
+	@AfterEach
+	void close() {
+		TestSecurityContextHolder.clearContext();
+		this.context.close();
+	}
+
+	@Test
+	void endpointsAreSecureByDefault() throws Exception {
+		this.context = new AnnotationConfigServletWebApplicationContext();
+		this.context.register(SecureConfiguration.class);
+		MockMvc mockMvc = createSecureMockMvc();
+		mockMvc.perform(get("/actuator/beans").accept(MediaType.APPLICATION_JSON)).andExpect(status().isUnauthorized());
+	}
+
+	@Test
+	void endpointsAreSecureByDefaultWithCustomBasePath() throws Exception {
+		this.context = new AnnotationConfigServletWebApplicationContext();
+		this.context.register(SecureConfiguration.class);
+		TestPropertyValues.of("management.endpoints.web.base-path:/management").applyTo(this.context);
+		MockMvc mockMvc = createSecureMockMvc();
+		mockMvc.perform(get("/management/beans").accept(MediaType.APPLICATION_JSON))
+				.andExpect(status().isUnauthorized());
+	}
+
+	@Test
+	void endpointsAreSecureWithActuatorRoleWithCustomBasePath() throws Exception {
+		TestSecurityContextHolder.getContext()
+				.setAuthentication(new TestingAuthenticationToken("user", "N/A", "ROLE_ACTUATOR"));
+		this.context = new AnnotationConfigServletWebApplicationContext();
+		this.context.register(SecureConfiguration.class);
+		TestPropertyValues
+				.of("management.endpoints.web.base-path:/management", "management.endpoints.web.exposure.include=*")
+				.applyTo(this.context);
+		MockMvc mockMvc = createSecureMockMvc();
+		mockMvc.perform(get("/management/beans")).andExpect(status().isOk());
+	}
+
+	private MockMvc createSecureMockMvc() {
+		return doCreateMockMvc(springSecurity());
+	}
+
+	private MockMvc doCreateMockMvc(MockMvcConfigurer... configurers) {
+		this.context.setServletContext(new MockServletContext());
+		this.context.refresh();
+		DefaultMockMvcBuilder builder = MockMvcBuilders.webAppContextSetup(this.context);
+		for (MockMvcConfigurer configurer : configurers) {
+			builder.apply(configurer);
+		}
+		return builder.build();
+	}
+
+	@ImportAutoConfiguration({ JacksonAutoConfiguration.class, HttpMessageConvertersAutoConfiguration.class,
+			EndpointAutoConfiguration.class, WebEndpointAutoConfiguration.class,
+			ServletManagementContextAutoConfiguration.class, AuditAutoConfiguration.class,
+			PropertyPlaceholderAutoConfiguration.class, WebMvcAutoConfiguration.class,
+			ManagementContextAutoConfiguration.class, AuditAutoConfiguration.class,
+			DispatcherServletAutoConfiguration.class, BeansEndpointAutoConfiguration.class })
+	static class DefaultConfiguration {
+
+	}
+
+	@Import(DefaultConfiguration.class)
+	@ImportAutoConfiguration({ SecurityAutoConfiguration.class })
+	static class SecureConfiguration {
+
+	}
+
+}

spring-boot-project/spring-boot-actuator-autoconfigure/src/test/java/org/springframework/boot/actuate/autoconfigure/web/servlet/WebMvcEndpointChildContextConfigurationIntegrationTests.java

 /*
- * Copyright 2012-2019 the original author or authors.
+ * Copyright 2012-2020 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.
@@ -59,6 +59,7 @@ class WebMvcEndpointChildContextConfigurationIntegrationTests {
 					WebClient client = WebClient.create("http://localhost:" + port);
 					ClientResponse response = client.get().uri("actuator/fail").accept(MediaType.APPLICATION_JSON)
 							.exchange().block();
+					assertThat(response.headers().contentType().get()).isEqualTo(MediaType.APPLICATION_JSON);
 					assertThat(response.bodyToMono(String.class).block()).contains("message\":\"Epic Fail");
 				});
 	}

spring-boot-project/spring-boot-actuator/src/main/java/org/springframework/boot/actuate/endpoint/json/ActuatorJsonMapperProvider.java

+/*
+ * Copyright 2012-2020 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.boot.actuate.endpoint.json;
+
+import com.fasterxml.jackson.databind.ObjectMapper;
+import com.fasterxml.jackson.databind.SerializationFeature;
+
+import org.springframework.http.converter.json.Jackson2ObjectMapperBuilder;
+
+/**
+ * Factory for an {@code ObjectMapper} instance to be shared within Actuator
+ * infrastructure.
+ *
+ * <p>
+ * The goal is to have a Jackson configuration separate from the rest of the application
+ * to keep a consistent serialization behavior between applications.
+ *
+ * @author Brian Clozel
+ * @since 2.3.0
+ */
+public class ActuatorJsonMapperProvider {
+
+	private ObjectMapper objectMapper;
+
+	public ObjectMapper getInstance() {
+		if (this.objectMapper == null) {
+			Jackson2ObjectMapperBuilder builder = new Jackson2ObjectMapperBuilder();
+			builder.featuresToDisable(SerializationFeature.WRITE_DATES_AS_TIMESTAMPS);
+			builder.featuresToDisable(SerializationFeature.WRITE_DURATIONS_AS_TIMESTAMPS);
+			this.objectMapper = builder.build();
+		}
+		return this.objectMapper;
+	}
+
+}

spring-boot-project/spring-boot-actuator/src/main/java/org/springframework/boot/actuate/endpoint/json/package-info.java

+/*
+ * Copyright 2012-2020 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.
+ */
+
+/**
+ * JSON support for actuator endpoints.
+ */
+package org.springframework.boot.actuate.endpoint.json;

src/checkstyle/import-control.xml

@@ -46,6 +46,9 @@
 				<disallow pkg="org.springframework.web.servlet" />
 			</subpackage>
 		</subpackage>
+		<subpackage name="json">
+			<allow pkg="org.springframework.http.converter" />
+		</subpackage>
 	</subpackage>
 
 	<!-- Logging -->