Consider only current context in WebFlux setup

This commit introduces a subclass of `DispatcherHandler` that only
considers the current context when looking for WebFlux infrastructure
beans.

This avoids issues where a child context (e.g. with Actuator) picks up
infrastructure beans from the parent context and exposes all endpoints
instead of getting only the ones from the current context.

Closes gh-14012

spring-boot-project/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/web/reactive/SingleContextDispatcherHandler.java

+/*
+ * 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.autoconfigure.web.reactive;
+
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.Map;
+
+import org.springframework.context.ApplicationContext;
+import org.springframework.core.annotation.AnnotationAwareOrderComparator;
+import org.springframework.web.reactive.DispatcherHandler;
+import org.springframework.web.reactive.HandlerAdapter;
+import org.springframework.web.reactive.HandlerMapping;
+import org.springframework.web.reactive.HandlerResultHandler;
+
+/**
+ * {@link DispatcherHandler} implementation that only checks for infrastructure beans in
+ * the current application context (i.e. does not consider the parent context).
+ *
+ * @author Brian Clozel
+ * @since 2.1.0
+ */
+public class SingleContextDispatcherHandler extends DispatcherHandler {
+
+	@Override
+	protected void initStrategies(ApplicationContext context) {
+		Map<String, HandlerMapping> mappingBeans = context
+				.getBeansOfType(HandlerMapping.class, true, false);
+		ArrayList<HandlerMapping> mappings = new ArrayList<>(mappingBeans.values());
+		AnnotationAwareOrderComparator.sort(mappings);
+		this.handlerMappings = Collections.unmodifiableList(mappings);
+		Map<String, HandlerAdapter> adapterBeans = context
+				.getBeansOfType(HandlerAdapter.class, true, false);
+		this.handlerAdapters = new ArrayList(adapterBeans.values());
+		AnnotationAwareOrderComparator.sort(this.handlerAdapters);
+		Map<String, HandlerResultHandler> beans = context
+				.getBeansOfType(HandlerResultHandler.class, true, false);
+		this.resultHandlers = new ArrayList<>(beans.values());
+		AnnotationAwareOrderComparator.sort(this.resultHandlers);
+	}
+
+}

spring-boot-project/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/web/reactive/WebFluxAutoConfiguration.java

@@ -57,6 +57,7 @@ import org.springframework.http.codec.ServerCodecConfigurer;
 import org.springframework.util.ClassUtils;
 import org.springframework.validation.Validator;
 import org.springframework.web.filter.reactive.HiddenHttpMethodFilter;
+import org.springframework.web.reactive.DispatcherHandler;
 import org.springframework.web.reactive.config.DelegatingWebFluxConfiguration;
 import org.springframework.web.reactive.config.EnableWebFlux;
 import org.springframework.web.reactive.config.ResourceChainRegistration;
@@ -245,6 +246,11 @@ public class WebFluxAutoConfiguration {
 			return conversionService;
 		}
 
+		@Override
+		public DispatcherHandler webHandler() {
+			return new SingleContextDispatcherHandler();
+		}
+
 		@Bean
 		@Override
 		public Validator webFluxValidator() {

spring-boot-project/spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/web/reactive/WebFluxAutoConfigurationTests.java

@@ -28,6 +28,8 @@ import org.springframework.beans.DirectFieldAccessor;
 import org.springframework.boot.autoconfigure.AutoConfigurations;
 import org.springframework.boot.autoconfigure.validation.ValidationAutoConfiguration;
 import org.springframework.boot.autoconfigure.validation.ValidatorAdapter;
+import org.springframework.boot.test.context.assertj.ApplicationContextAssert;
+import org.springframework.boot.test.context.runner.ApplicationContextRunner;
 import org.springframework.boot.test.context.runner.ReactiveWebApplicationContextRunner;
 import org.springframework.boot.web.codec.CodecCustomizer;
 import org.springframework.boot.web.reactive.filter.OrderedHiddenHttpMethodFilter;
@@ -44,6 +46,7 @@ import org.springframework.test.util.ReflectionTestUtils;
 import org.springframework.validation.Validator;
 import org.springframework.validation.beanvalidation.LocalValidatorFactoryBean;
 import org.springframework.web.filter.reactive.HiddenHttpMethodFilter;
+import org.springframework.web.reactive.DispatcherHandler;
 import org.springframework.web.reactive.HandlerMapping;
 import org.springframework.web.reactive.accept.RequestedContentTypeResolver;
 import org.springframework.web.reactive.config.WebFluxConfigurationSupport;
@@ -398,6 +401,26 @@ public class WebFluxAutoConfigurationTests {
 				});
 	}
 
+	@Test
+	public void shouldNotGetHandlerMappingsFromParentContext() {
+		ApplicationContextRunner parentRunner = new ApplicationContextRunner()
+				.withUserConfiguration(CustomHandlerMapping.class);
+		parentRunner.run((parent) -> {
+			this.contextRunner.withParent(parent).run((context) -> {
+				assertThat(parent).hasSingleBean(HandlerMapping.class);
+				assertThat(context).getBeans(HandlerMapping.class).hasSize(4);
+				assertThat(context)
+						.getBeans(HandlerMapping.class,
+								ApplicationContextAssert.Scope.NO_ANCESTORS)
+						.doesNotContainKey("customHandlerMapping");
+				assertThat(context).hasSingleBean(DispatcherHandler.class);
+				DispatcherHandler dispatcherHandler = context
+						.getBean(DispatcherHandler.class);
+				assertThat(dispatcherHandler.getHandlerMappings()).hasSize(3);
+			});
+		});
+	}
+
 	@Configuration
 	protected static class CustomArgumentResolvers {
 
@@ -564,4 +587,14 @@ public class WebFluxAutoConfigurationTests {
 
 	}
 
+	@Configuration
+	static class CustomHandlerMapping {
+
+		@Bean
+		public HandlerMapping customHandlerMapping() {
+			return mock(HandlerMapping.class);
+		}
+
+	}
+
 }