Add EnableWebReactive + WebReactiveConfigurer

This commit improves the existing web reactive configuration
infrastructure with the following changes:

* renamed `WebReactiveConfiguration` to
`WebReactiveConfigurationSupport` and is is no longer a Configuration
class
* created the `WebReactiveConfigurer` interface; Configuration classes
implementing it will augment the web reactive configuration support
* created the `DelegatingWebReactiveConfiguration` and
`WebReactiveConfigurerComposite` to effectively tie those custom-defined
configurers to the main configuration support
* created the `@EnableWebReactive` to active that support in
configuration classes

Issue: SPR-14754

spring-web-reactive/src/test/java/org/springframework/web/reactive/config/DelegatingWebReactiveConfigurationTests.java

@@ -0,0 +1,128 @@
+package org.springframework.web.reactive.config;
+
+import java.util.Collections;
+import java.util.List;
+import java.util.Optional;
+
+import org.junit.Before;
+import org.junit.Test;
+import org.mockito.ArgumentCaptor;
+import org.mockito.Captor;
+import org.mockito.Mock;
+import org.mockito.MockitoAnnotations;
+
+import org.springframework.context.support.StaticApplicationContext;
+import org.springframework.core.convert.ConversionService;
+import org.springframework.format.FormatterRegistry;
+import org.springframework.http.codec.HttpMessageReader;
+import org.springframework.http.codec.HttpMessageWriter;
+import org.springframework.validation.beanvalidation.LocalValidatorFactoryBean;
+import org.springframework.web.bind.support.ConfigurableWebBindingInitializer;
+import org.springframework.web.reactive.accept.RequestedContentTypeResolverBuilder;
+import org.springframework.web.reactive.result.method.annotation.RequestMappingHandlerAdapter;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertSame;
+import static org.junit.Assert.assertTrue;
+import static org.mockito.BDDMockito.given;
+import static org.mockito.Matchers.any;
+import static org.mockito.Mockito.doAnswer;
+import static org.mockito.Mockito.verify;
+
+/**
+ * Test fixture for {@link DelegatingWebReactiveConfiguration} tests.
+ *
+ * @author Brian Clozel
+ */
+public class DelegatingWebReactiveConfigurationTests {
+
+	private DelegatingWebReactiveConfiguration delegatingConfig;
+
+	@Mock
+	private WebReactiveConfigurer webReactiveConfigurer;
+
+	@Captor
+	private ArgumentCaptor<List<HttpMessageReader<?>>> readers;
+
+	@Captor
+	private ArgumentCaptor<List<HttpMessageWriter<?>>> writers;
+
+	@Captor
+	private ArgumentCaptor<FormatterRegistry> formatterRegistry;
+
+
+	@Before
+	public void setUp() {
+		MockitoAnnotations.initMocks(this);
+		delegatingConfig = new DelegatingWebReactiveConfiguration();
+		delegatingConfig.setApplicationContext(new StaticApplicationContext());
+		given(webReactiveConfigurer.createRequestMappingHandlerMapping()).willReturn(Optional.empty());
+		given(webReactiveConfigurer.createRequestMappingHandlerAdapter()).willReturn(Optional.empty());
+		given(webReactiveConfigurer.getValidator()).willReturn(Optional.empty());
+		given(webReactiveConfigurer.getMessageCodesResolver()).willReturn(Optional.empty());
+	}
+
+	@Test
+	public void requestMappingHandlerAdapter() throws Exception {
+		delegatingConfig.setConfigurers(Collections.singletonList(webReactiveConfigurer));
+		RequestMappingHandlerAdapter adapter = delegatingConfig.requestMappingHandlerAdapter();
+
+		ConfigurableWebBindingInitializer initializer = (ConfigurableWebBindingInitializer) adapter.getWebBindingInitializer();
+		ConversionService initializerConversionService = initializer.getConversionService();
+		assertTrue(initializer.getValidator() instanceof LocalValidatorFactoryBean);
+
+		verify(webReactiveConfigurer).createRequestMappingHandlerAdapter();
+		verify(webReactiveConfigurer).configureMessageReaders(readers.capture());
+		verify(webReactiveConfigurer).extendMessageReaders(readers.capture());
+		verify(webReactiveConfigurer).getValidator();
+		verify(webReactiveConfigurer).getMessageCodesResolver();
+		verify(webReactiveConfigurer).addFormatters(formatterRegistry.capture());
+		verify(webReactiveConfigurer).addArgumentResolvers(any());
+
+		assertSame(formatterRegistry.getValue(), initializerConversionService);
+		assertEquals(5, readers.getValue().size());
+	}
+
+	@Test
+	public void requestMappingHandlerMapping() throws Exception {
+		delegatingConfig.setConfigurers(Collections.singletonList(webReactiveConfigurer));
+		delegatingConfig.requestMappingHandlerMapping();
+
+		verify(webReactiveConfigurer).createRequestMappingHandlerMapping();
+		verify(webReactiveConfigurer).configureRequestedContentTypeResolver(any(RequestedContentTypeResolverBuilder.class));
+		verify(webReactiveConfigurer).addCorsMappings(any(CorsRegistry.class));
+		verify(webReactiveConfigurer).configurePathMatching(any(PathMatchConfigurer.class));
+	}
+
+	@Test
+	public void resourceHandlerMapping() throws Exception {
+		delegatingConfig.setConfigurers(Collections.singletonList(webReactiveConfigurer));
+		doAnswer(invocation -> {
+			ResourceHandlerRegistry registry = invocation.getArgumentAt(0, ResourceHandlerRegistry.class);
+			registry.addResourceHandler("/static/**").addResourceLocations("classpath:/static");
+			return null;
+		}).when(webReactiveConfigurer).addResourceHandlers(any(ResourceHandlerRegistry.class));
+
+		delegatingConfig.resourceHandlerMapping();
+		verify(webReactiveConfigurer).addResourceHandlers(any(ResourceHandlerRegistry.class));
+		verify(webReactiveConfigurer).configurePathMatching(any(PathMatchConfigurer.class));
+	}
+
+	@Test
+	public void responseBodyResultHandler() throws Exception {
+		delegatingConfig.setConfigurers(Collections.singletonList(webReactiveConfigurer));
+		delegatingConfig.responseBodyResultHandler();
+
+		verify(webReactiveConfigurer).configureMessageWriters(writers.capture());
+		verify(webReactiveConfigurer).extendMessageWriters(writers.capture());
+		verify(webReactiveConfigurer).configureRequestedContentTypeResolver(any(RequestedContentTypeResolverBuilder.class));
+	}
+
+	@Test
+	public void viewResolutionResultHandler() throws Exception {
+		delegatingConfig.setConfigurers(Collections.singletonList(webReactiveConfigurer));
+		delegatingConfig.viewResolutionResultHandler();
+
+		verify(webReactiveConfigurer).configureViewResolvers(any(ViewResolverRegistry.class));
+	}
+}

spring-web-reactive/src/test/java/org/springframework/web/reactive/config/WebReactiveConfigurationSupportTests.java

@@ -80,10 +80,10 @@ import static org.springframework.http.MediaType.IMAGE_PNG;
 import static org.springframework.http.MediaType.TEXT_PLAIN;
 
 /**
- * Unit tests for {@link WebReactiveConfiguration}.
+ * Unit tests for {@link WebReactiveConfigurationSupport}.
  * @author Rossen Stoyanchev
  */
-public class WebReactiveConfigurationTests {
+public class WebReactiveConfigurationSupportTests {
 
 	private MockServerHttpRequest request;
 
@@ -100,7 +100,7 @@ public class WebReactiveConfigurationTests {
 
 	@Test
 	public void requestMappingHandlerMapping() throws Exception {
-		ApplicationContext context = loadConfig(WebReactiveConfiguration.class);
+		ApplicationContext context = loadConfig(WebReactiveConfig.class);
 
 		String name = "requestMappingHandlerMapping";
 		RequestMappingHandlerMapping mapping = context.getBean(name, RequestMappingHandlerMapping.class);
@@ -138,10 +138,10 @@ public class WebReactiveConfigurationTests {
 
 	@Test
 	public void requestMappingHandlerAdapter() throws Exception {
-		ApplicationContext context = loadConfig(WebReactiveConfiguration.class);
+		ApplicationContext context = loadConfig(WebReactiveConfig.class);
 
 		String name = "requestMappingHandlerAdapter";
-		RequestMappingHandlerAdapter adapter = context.getBean(name,  RequestMappingHandlerAdapter.class);
+		RequestMappingHandlerAdapter adapter = context.getBean(name, RequestMappingHandlerAdapter.class);
 		assertNotNull(adapter);
 
 		List<HttpMessageReader<?>> readers = adapter.getMessageReaders();
@@ -185,7 +185,7 @@ public class WebReactiveConfigurationTests {
 
 	@Test
 	public void responseEntityResultHandler() throws Exception {
-		ApplicationContext context = loadConfig(WebReactiveConfiguration.class);
+		ApplicationContext context = loadConfig(WebReactiveConfig.class);
 
 		String name = "responseEntityResultHandler";
 		ResponseEntityResultHandler handler = context.getBean(name, ResponseEntityResultHandler.class);
@@ -210,7 +210,7 @@ public class WebReactiveConfigurationTests {
 
 	@Test
 	public void responseBodyResultHandler() throws Exception {
-		ApplicationContext context = loadConfig(WebReactiveConfiguration.class);
+		ApplicationContext context = loadConfig(WebReactiveConfig.class);
 
 		String name = "responseBodyResultHandler";
 		ResponseBodyResultHandler handler = context.getBean(name, ResponseBodyResultHandler.class);
@@ -262,7 +262,7 @@ public class WebReactiveConfigurationTests {
 		AbstractHandlerMapping handlerMapping = context.getBean(name, AbstractHandlerMapping.class);
 		assertNotNull(handlerMapping);
 
-		assertEquals(Ordered.LOWEST_PRECEDENCE -1, handlerMapping.getOrder());
+		assertEquals(Ordered.LOWEST_PRECEDENCE - 1, handlerMapping.getOrder());
 
 		assertNotNull(handlerMapping.getPathHelper());
 		assertNotNull(handlerMapping.getPathMatcher());
@@ -296,9 +296,12 @@ public class WebReactiveConfigurationTests {
 		return context;
 	}
 
+	@EnableWebReactive
+	static class WebReactiveConfig {
+	}
 
 	@Configuration
-	static class CustomPatchMatchConfig extends WebReactiveConfiguration {
+	static class CustomPatchMatchConfig extends WebReactiveConfigurationSupport {
 
 		@Override
 		public void configurePathMatching(PathMatchConfigurer configurer) {
@@ -308,7 +311,7 @@ public class WebReactiveConfigurationTests {
 	}
 
 	@Configuration
-	static class CustomMessageConverterConfig extends WebReactiveConfiguration {
+	static class CustomMessageConverterConfig extends WebReactiveConfigurationSupport {
 
 		@Override
 		protected void configureMessageReaders(List<HttpMessageReader<?>> messageReaders) {
@@ -331,8 +334,9 @@ public class WebReactiveConfigurationTests {
 		}
 	}
 
-	@Configuration @SuppressWarnings("unused")
-	static class CustomViewResolverConfig extends WebReactiveConfiguration {
+	@Configuration
+	@SuppressWarnings("unused")
+	static class CustomViewResolverConfig extends WebReactiveConfigurationSupport {
 
 		@Override
 		protected void configureViewResolvers(ViewResolverRegistry registry) {
@@ -348,7 +352,7 @@ public class WebReactiveConfigurationTests {
 	}
 
 	@Configuration
-	static class CustomResourceHandlingConfig extends WebReactiveConfiguration {
+	static class CustomResourceHandlingConfig extends WebReactiveConfigurationSupport {
 
 		@Override
 		protected void addResourceHandlers(ResourceHandlerRegistry registry) {

spring-web-reactive/src/test/java/org/springframework/web/reactive/function/DispatcherHandlerIntegrationTests.java

@@ -43,7 +43,7 @@ import org.springframework.web.client.RestTemplate;
 import org.springframework.web.reactive.DispatcherHandler;
 import org.springframework.web.reactive.HandlerAdapter;
 import org.springframework.web.reactive.HandlerMapping;
-import org.springframework.web.reactive.config.WebReactiveConfiguration;
+import org.springframework.web.reactive.config.WebReactiveConfigurationSupport;
 import org.springframework.web.reactive.function.support.HandlerFunctionAdapter;
 import org.springframework.web.reactive.function.support.ResponseResultHandler;
 import org.springframework.web.reactive.result.view.ViewResolver;
@@ -104,7 +104,7 @@ public class DispatcherHandlerIntegrationTests extends AbstractHttpHandlerIntegr
 	
 
 	@Configuration
-	static class TestConfiguration extends WebReactiveConfiguration {
+	static class TestConfiguration extends WebReactiveConfigurationSupport {
 
 		@Bean
 		public PersonHandler personHandler() {

spring-web-reactive/src/test/java/org/springframework/web/reactive/result/method/annotation/CrossOriginAnnotationIntegrationTests.java

@@ -39,7 +39,7 @@ import org.springframework.web.bind.annotation.RequestMapping;
 import org.springframework.web.bind.annotation.RequestMethod;
 import org.springframework.web.bind.annotation.RestController;
 import org.springframework.web.client.RestTemplate;
-import org.springframework.web.reactive.config.WebReactiveConfiguration;
+import org.springframework.web.reactive.config.EnableWebReactive;
 
 import static org.junit.Assert.assertArrayEquals;
 import static org.junit.Assert.assertEquals;
@@ -222,9 +222,10 @@ public class CrossOriginAnnotationIntegrationTests extends AbstractRequestMappin
 
 
 	@Configuration
+	@EnableWebReactive
 	@ComponentScan(resourcePattern = "**/CrossOriginAnnotationIntegrationTests*")
 	@SuppressWarnings({"unused", "WeakerAccess"})
-	static class WebConfig extends WebReactiveConfiguration {
+	static class WebConfig {
 	}
 
 	@RestController @SuppressWarnings("unused")

spring-web-reactive/src/test/java/org/springframework/web/reactive/result/method/annotation/GlobalCorsConfigIntegrationTests.java

@@ -32,7 +32,7 @@ import org.springframework.web.bind.annotation.RestController;
 import org.springframework.web.client.HttpClientErrorException;
 import org.springframework.web.client.RestTemplate;
 import org.springframework.web.reactive.config.CorsRegistry;
-import org.springframework.web.reactive.config.WebReactiveConfiguration;
+import org.springframework.web.reactive.config.WebReactiveConfigurationSupport;
 
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertNull;
@@ -137,7 +137,7 @@ public class GlobalCorsConfigIntegrationTests extends AbstractRequestMappingInte
 	@Configuration
 	@ComponentScan(resourcePattern = "**/GlobalCorsConfigIntegrationTests*.class")
 	@SuppressWarnings({"unused", "WeakerAccess"})
-	static class WebConfig extends WebReactiveConfiguration {
+	static class WebConfig extends WebReactiveConfigurationSupport {
 
 		@Override
 		protected void addCorsMappings(CorsRegistry registry) {

spring-web-reactive/src/test/java/org/springframework/web/reactive/result/method/annotation/JacksonHintsIntegrationTests.java

@@ -34,7 +34,7 @@ import org.springframework.web.bind.annotation.GetMapping;
 import org.springframework.web.bind.annotation.PostMapping;
 import org.springframework.web.bind.annotation.RequestBody;
 import org.springframework.web.bind.annotation.RestController;
-import org.springframework.web.reactive.config.WebReactiveConfiguration;
+import org.springframework.web.reactive.config.EnableWebReactive;
 
 /**
  * @author Sebastien Deleuze
@@ -93,8 +93,9 @@ public class JacksonHintsIntegrationTests extends AbstractRequestMappingIntegrat
 
 	@Configuration
 	@ComponentScan(resourcePattern = "**/JacksonHintsIntegrationTests*.class")
+	@EnableWebReactive
 	@SuppressWarnings({"unused", "WeakerAccess"})
-	static class WebConfig extends WebReactiveConfiguration {
+	static class WebConfig {
 	}
 
 	@RestController

spring-web-reactive/src/test/java/org/springframework/web/reactive/result/method/annotation/RequestMappingExceptionHandlingIntegrationTests.java

@@ -28,7 +28,7 @@ import org.springframework.http.HttpHeaders;
 import org.springframework.web.bind.annotation.ExceptionHandler;
 import org.springframework.web.bind.annotation.GetMapping;
 import org.springframework.web.bind.annotation.RestController;
-import org.springframework.web.reactive.config.WebReactiveConfiguration;
+import org.springframework.web.reactive.config.EnableWebReactive;
 
 import static org.junit.Assert.assertEquals;
 
@@ -64,9 +64,10 @@ public class RequestMappingExceptionHandlingIntegrationTests extends AbstractReq
 
 
 	@Configuration
+	@EnableWebReactive
 	@ComponentScan(resourcePattern = "**/RequestMappingExceptionHandlingIntegrationTests$*.class")
 	@SuppressWarnings({"unused", "WeakerAccess"})
-	static class WebConfig extends WebReactiveConfiguration {
+	static class WebConfig {
 
 	}
 

spring-web-reactive/src/test/java/org/springframework/web/reactive/result/method/annotation/RequestMappingIntegrationTests.java

@@ -29,7 +29,7 @@ import org.springframework.http.MediaType;
 import org.springframework.web.bind.annotation.GetMapping;
 import org.springframework.web.bind.annotation.RequestParam;
 import org.springframework.web.bind.annotation.RestController;
-import org.springframework.web.reactive.config.WebReactiveConfiguration;
+import org.springframework.web.reactive.config.EnableWebReactive;
 
 import static org.junit.Assert.assertArrayEquals;
 import static org.junit.Assert.assertEquals;
@@ -74,9 +74,10 @@ public class RequestMappingIntegrationTests extends AbstractRequestMappingIntegr
 
 
 	@Configuration
+	@EnableWebReactive
 	@ComponentScan(resourcePattern = "**/RequestMappingIntegrationTests$*.class")
 	@SuppressWarnings({"unused", "WeakerAccess"})
-	static class WebConfig extends WebReactiveConfiguration {
+	static class WebConfig {
 	}
 
 	@RestController

spring-web-reactive/src/test/java/org/springframework/web/reactive/result/method/annotation/RequestMappingMessageConversionIntegrationTests.java

@@ -56,11 +56,12 @@ import org.springframework.web.bind.annotation.PostMapping;
 import org.springframework.web.bind.annotation.RequestBody;
 import org.springframework.web.bind.annotation.RequestMapping;
 import org.springframework.web.bind.annotation.RestController;
-import org.springframework.web.reactive.config.WebReactiveConfiguration;
+import org.springframework.web.reactive.config.EnableWebReactive;
 
-import static java.util.Arrays.*;
-import static org.junit.Assert.*;
-import static org.springframework.http.MediaType.*;
+import static java.util.Arrays.asList;
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertTrue;
+import static org.springframework.http.MediaType.APPLICATION_XML;
 
 /**
  * {@code @RequestMapping} integration tests focusing on serialization and
@@ -371,9 +372,10 @@ public class RequestMappingMessageConversionIntegrationTests extends AbstractReq
 
 
 	@Configuration
+	@EnableWebReactive
 	@ComponentScan(resourcePattern = "**/RequestMappingMessageConversionIntegrationTests$*.class")
 	@SuppressWarnings({"unused", "WeakerAccess"})
-	static class WebConfig extends WebReactiveConfiguration {
+	static class WebConfig {
 	}
 
 

spring-web-reactive/src/test/java/org/springframework/web/reactive/result/method/annotation/RequestMappingViewResolutionIntegrationTests.java

@@ -35,7 +35,7 @@ import org.springframework.ui.Model;
 import org.springframework.web.bind.annotation.GetMapping;
 import org.springframework.web.bind.annotation.RequestParam;
 import org.springframework.web.reactive.config.ViewResolverRegistry;
-import org.springframework.web.reactive.config.WebReactiveConfiguration;
+import org.springframework.web.reactive.config.WebReactiveConfigurationSupport;
 import org.springframework.web.reactive.result.view.freemarker.FreeMarkerConfigurer;
 import org.springframework.web.server.ServerWebExchange;
 
@@ -81,7 +81,7 @@ public class RequestMappingViewResolutionIntegrationTests extends AbstractReques
 	@Configuration
 	@ComponentScan(resourcePattern = "**/RequestMappingViewResolutionIntegrationTests$*.class")
 	@SuppressWarnings({"unused", "WeakerAccess"})
-	static class WebConfig extends WebReactiveConfiguration {
+	static class WebConfig extends WebReactiveConfigurationSupport {
 
 		@Override
 		protected void configureViewResolvers(ViewResolverRegistry registry) {

spring-web-reactive/src/test/java/org/springframework/web/reactive/result/method/annotation/SseIntegrationTests.java

@@ -36,7 +36,7 @@ import org.springframework.web.bind.annotation.RequestMapping;
 import org.springframework.web.bind.annotation.RestController;
 import org.springframework.web.client.reactive.WebClient;
 import org.springframework.web.reactive.DispatcherHandler;
-import org.springframework.web.reactive.config.WebReactiveConfiguration;
+import org.springframework.web.reactive.config.EnableWebReactive;
 import org.springframework.web.server.adapter.WebHttpHandlerBuilder;
 
 import static org.springframework.web.client.reactive.ClientWebRequestBuilders.get;
@@ -163,8 +163,9 @@ public class SseIntegrationTests extends AbstractHttpHandlerIntegrationTests {
 	}
 
 	@Configuration
+	@EnableWebReactive
 	@SuppressWarnings("unused")
-	static class TestConfiguration extends WebReactiveConfiguration {
+	static class TestConfiguration {
 
 		@Bean
 		public SseController sseController() {