GH-2358: Register IntGraphController for WebFlux

Fixes https://github.com/spring-projects/spring-integration/issues/2358

The WebFlux on the server side can deal with MVC `@Controllers` as well
without any Servlet environment.

* Enable `IntegrationGraphController` when we not only in the
Servlet environment, but also in the WebFlux
* Upgrade to SF-5.0.4 and fix WebFlux tests to meet the latest requirements
  (https://jira.spring.io/browse/SPR-16337)
* Move `WEB_FLUX_PRESENT` to the `HttpContextUtils`;
deprecate it in the `WebFluxContextUtils`
* Mention WebFlux ability for the `IntegrationGraphController` in the
`graph.adoc`

build.gradle

@@ -138,7 +138,7 @@ subprojects { subproject ->
 		springSecurityVersion = '5.0.1.RELEASE'
 		springSocialTwitterVersion = '1.1.2.RELEASE'
 		springRetryVersion = '1.2.2.RELEASE'
-		springVersion = project.hasProperty('springVersion') ? project.springVersion : '5.0.3.RELEASE'
+		springVersion = project.hasProperty('springVersion') ? project.springVersion : '5.0.4.BUILD-SNAPSHOT'
 		springWsVersion = '3.0.0.RELEASE'
 		tomcatVersion = "8.5.23"
 		xmlUnitVersion = '1.6'

spring-integration-http/src/main/java/org/springframework/integration/http/config/EnableIntegrationGraphController.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2016 the original author or authors.
+ * Copyright 2016-2018 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.
@@ -28,13 +28,15 @@ import org.springframework.integration.http.management.IntegrationGraphControlle
 import org.springframework.integration.http.support.HttpContextUtils;
 
 /**
- * Enables the {@link IntegrationGraphController} if {@code DispatcherServlet} is present in the classpath.
+ * Enables the {@link IntegrationGraphController} if
+ * {@code org.springframework.web.servlet.DispatcherServlet} or
+ * {@code org.springframework.web.reactive.DispatcherHandler} is present in the classpath.
  *
  * @author Artem Bilan
  *
  * @since 4.3
  *
- * @see  IntegrationGraphController
+ * @see IntegrationGraphController
  */
 @Target(ElementType.TYPE)
 @Retention(RetentionPolicy.RUNTIME)
@@ -64,6 +66,6 @@ public @interface EnableIntegrationGraphController {
 	 * @return the URLs.
 	 * @since 4.3.5
 	 */
-	String[] allowedOrigins() default {};
+	String[] allowedOrigins() default { };
 
 }

spring-integration-http/src/main/java/org/springframework/integration/http/config/IntegrationGraphControllerRegistrarImportSelector.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2016-2017 the original author or authors.
+ * Copyright 2016-2018 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.
@@ -34,12 +34,13 @@ class IntegrationGraphControllerRegistrarImportSelector implements ImportSelecto
 
 	@Override
 	public String[] selectImports(AnnotationMetadata importingClassMetadata) {
-		if (HttpContextUtils.WEB_MVC_PRESENT) {
+		if (HttpContextUtils.WEB_MVC_PRESENT || HttpContextUtils.WEB_FLUX_PRESENT) {
 			return new String[] { IntegrationGraphControllerRegistrar.class.getName() };
 		}
 		else {
 			logger.warn("The 'IntegrationGraphController' isn't registered with the application context because" +
-					" there is no 'org.springframework.web.servlet.DispatcherServlet' in the classpath.");
+					" there is no 'org.springframework.web.servlet.DispatcherServlet' or" +
+					" 'org.springframework.web.reactive.DispatcherHandler' in the classpath.");
 			return new String[0];
 		}
 	}

spring-integration-http/src/main/java/org/springframework/integration/http/support/HttpContextUtils.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2013-2017 the original author or authors.
+ * Copyright 2013-2018 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.
@@ -39,15 +39,25 @@ public final class HttpContextUtils {
 	}
 
 	/**
-	 * The {@code boolean} flag to indicate if the
-	 * {@code org.springframework.web.servlet.DispatcherServlet}
-	 * is present in the CLASSPATH to allow to register the Integration server components,
+	 * A {@code boolean} flag to indicate if the
+	 * {@code org.springframework.web.servlet.DispatcherServlet} is present in the
+	 * CLASSPATH to allow the registration of Integration server components,
 	 * e.g. {@code IntegrationGraphController}.
 	 */
 	public static final boolean WEB_MVC_PRESENT =
 			ClassUtils.isPresent("org.springframework.web.servlet.DispatcherServlet",
 					HttpContextUtils.class.getClassLoader());
 
+	/**
+	 * A {@code boolean} flag to indicate if the
+	 * {@code org.springframework.web.reactive.DispatcherHandler} is present in the
+	 * CLASSPATH to allow the registration of Integration server reactive components,
+	 * e.g. {@code IntegrationGraphController}.
+	 */
+	public static final boolean WEB_FLUX_PRESENT =
+			ClassUtils.isPresent("org.springframework.web.reactive.DispatcherHandler",
+					HttpContextUtils.class.getClassLoader());
+
 	/**
 	 * The name for the infrastructure
 	 * {@link org.springframework.integration.http.inbound.IntegrationRequestMappingHandlerMapping} bean.

spring-integration-webflux/src/main/java/org/springframework/integration/webflux/config/WebFluxIntegrationConfigurationInitializer.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2017 the original author or authors.
+ * Copyright 2017-2018 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.
@@ -28,6 +28,7 @@ import org.springframework.beans.factory.support.BeanDefinitionRegistry;
 import org.springframework.beans.factory.support.RootBeanDefinition;
 import org.springframework.integration.config.IntegrationConfigurationInitializer;
 import org.springframework.integration.config.xml.IntegrationNamespaceUtils;
+import org.springframework.integration.http.support.HttpContextUtils;
 import org.springframework.integration.webflux.inbound.IntegrationHandlerResultHandler;
 import org.springframework.integration.webflux.inbound.WebFluxIntegrationRequestMappingHandlerMapping;
 import org.springframework.integration.webflux.support.WebFluxContextUtils;
@@ -66,7 +67,7 @@ public class WebFluxIntegrationConfigurationInitializer implements IntegrationCo
 	 * the HTTP server components.
 	 */
 	private void registerReactiveRequestMappingHandlerMappingIfNecessary(BeanDefinitionRegistry registry) {
-		if (WebFluxContextUtils.WEB_FLUX_PRESENT &&
+		if (HttpContextUtils.WEB_FLUX_PRESENT &&
 				!registry.containsBeanDefinition(WebFluxContextUtils.HANDLER_MAPPING_BEAN_NAME)) {
 			BeanDefinitionBuilder requestMappingBuilder =
 					BeanDefinitionBuilder.genericBeanDefinition(WebFluxIntegrationRequestMappingHandlerMapping.class);

spring-integration-webflux/src/main/java/org/springframework/integration/webflux/support/WebFluxContextUtils.java

@@ -16,7 +16,7 @@
 
 package org.springframework.integration.webflux.support;
 
-import org.springframework.util.ClassUtils;
+import org.springframework.integration.http.support.HttpContextUtils;
 
 /**
  * Utility class for accessing WebFlux integration components
@@ -36,10 +36,11 @@ public final class WebFluxContextUtils {
 	 * The {@code boolean} flag to indicate if the
 	 * {@code org.springframework.web.reactive.result.method.RequestMappingInfo}
 	 * is present in the CLASSPATH to allow to register the Integration server reactive components.
+	 * @deprecated since 5.0.2 in favor of {@link HttpContextUtils#WEB_FLUX_PRESENT}.
+	 * Will be removed in the 5.1.
 	 */
-	public static final boolean WEB_FLUX_PRESENT =
-			ClassUtils.isPresent("org.springframework.web.reactive.result.method.RequestMappingInfo",
-					WebFluxContextUtils.class.getClassLoader());
+	@Deprecated
+	public static final boolean WEB_FLUX_PRESENT = HttpContextUtils.WEB_FLUX_PRESENT;
 
 	/**
 	 * The name for the infrastructure

spring-integration-webflux/src/test/java/org/springframework/integration/webflux/dsl/WebFluxDslTests.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2016-2017 the original author or authors.
+ * Copyright 2016-2018 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.
@@ -129,9 +129,7 @@ public class WebFluxDslTests {
 			response.getHeaders().setContentType(MediaType.TEXT_PLAIN);
 
 			DataBufferFactory bufferFactory = response.bufferFactory();
-			return response.writeWith(
-					Flux.just(bufferFactory.wrap("FOO".getBytes()),
-							bufferFactory.wrap("BAR".getBytes())))
+			return response.writeWith(Mono.just(bufferFactory.wrap("FOO\nBAR\n".getBytes())))
 					.then(Mono.defer(response::setComplete));
 		});
 
@@ -198,7 +196,7 @@ public class WebFluxDslTests {
 	@SuppressWarnings("unchecked")
 	public void testHttpReactivePost() {
 		this.webTestClient.post().uri("/reactivePost")
-				.body(Flux.just("foo", "bar", "baz"), String.class)
+				.body(Mono.just("foo\nbar\nbaz"), String.class)
 				.exchange()
 				.expectStatus().isAccepted();
 

spring-integration-webflux/src/test/java/org/springframework/integration/webflux/management/IntegrationGraphControllerTests.java

@@ -0,0 +1,74 @@
+/*
+ * Copyright 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.integration.webflux.management;
+
+import org.junit.Test;
+import org.junit.runner.RunWith;
+
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.http.MediaType;
+import org.springframework.integration.config.EnableIntegration;
+import org.springframework.integration.http.config.EnableIntegrationGraphController;
+import org.springframework.test.annotation.DirtiesContext;
+import org.springframework.test.context.TestPropertySource;
+import org.springframework.test.context.junit4.SpringRunner;
+import org.springframework.test.context.web.WebAppConfiguration;
+import org.springframework.test.web.reactive.server.WebTestClient;
+import org.springframework.web.context.WebApplicationContext;
+import org.springframework.web.reactive.config.EnableWebFlux;
+
+/**
+ * @author Artem Bilan
+ *
+ * @since 5.0.2
+ */
+@RunWith(SpringRunner.class)
+@WebAppConfiguration
+@TestPropertySource(properties = "spring.application.name:testApplication")
+@DirtiesContext
+public class IntegrationGraphControllerTests {
+
+	@Autowired
+	private WebApplicationContext wac;
+
+	@Test
+	public void testIntegrationGraphGet() {
+		WebTestClient webTestClient =
+				WebTestClient.bindToApplicationContext(this.wac)
+						.build();
+
+		webTestClient.get().uri("/testIntegration")
+				.accept(MediaType.APPLICATION_JSON_UTF8)
+				.exchange()
+				.expectStatus().isOk()
+				.expectHeader().contentType(MediaType.APPLICATION_JSON_UTF8)
+				.expectBody()
+				.jsonPath("$.nodes..name").isArray()
+				.jsonPath("$.contentDescriptor.name").isEqualTo("testApplication")
+				.jsonPath("$.links").exists();
+	}
+
+	@Configuration
+	@EnableWebFlux
+	@EnableIntegration
+	@EnableIntegrationGraphController(path = "/testIntegration")
+	public static class ContextConfiguration {
+
+	}
+
+}

spring-integration-webflux/src/test/java/org/springframework/integration/webflux/outbound/WebFluxRequestExecutingMessageHandlerTests.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2017 the original author or authors.
+ * Copyright 2017-2018 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.
@@ -198,10 +198,7 @@ public class WebFluxRequestExecutingMessageHandlerTests {
 
 			DataBufferFactory bufferFactory = response.bufferFactory();
 
-			Flux<DataBuffer> data =
-					Flux.just(bufferFactory.wrap("foo".getBytes()),
-							bufferFactory.wrap("bar".getBytes()),
-							bufferFactory.wrap("baz".getBytes()));
+			Mono<DataBuffer> data = Mono.just(bufferFactory.wrap("foo\nbar\nbaz".getBytes()));
 
 			return response.writeWith(data)
 					.then(Mono.defer(response::setComplete));

src/reference/asciidoc/graph.adoc

@@ -202,7 +202,7 @@ See also <<programming-tips>> for more information.
 
 === Integration Graph Controller
 
-If your application is WEB-based (or built on top of Spring Boot using an embedded web container) and the Spring Integration HTTP module (see <<http>>) is present on the classpath, you can use a `IntegrationGraphController` to expose the `IntegrationGraphServer` functionality as a REST service.
+If your application is WEB-based (or built on top of Spring Boot using an embedded web container) and the Spring Integration HTTP or WebFlux module (see <<http>> and <<webflux>>) is present on the classpath, you can use a `IntegrationGraphController` to expose the `IntegrationGraphServer` functionality as a REST service.
 For this purpose, the `@EnableIntegrationGraphController` `@Configuration` class annotation and the `<int-http:graph-controller/>` XML element, are available in the HTTP module.
 Together with the `@EnableWebMvc` annotation (or `<mvc:annotation-driven/>` for xml definitions), this configuration registers an `IntegrationGraphController` `@RestController` where its `@RequestMapping.path` can be configured on the `@EnableIntegrationGraphController` annotation or `<int-http:graph-controller/>` element.
 The default path is `/integration`.
@@ -242,8 +242,8 @@ For more sophistication, you can configure the CORS mappings using standard Spri
 [source,java]
 ----
 @Configuration
-@EnableWebMvc
-@EnableWebSecurity
+@EnableWebMvc // or @EnableWebFlux
+@EnableWebSecurity // or @EnableWebFluxSecurity
 @EnableIntegration
 @EnableIntegrationGraphController(path = "/testIntegration", allowedOrigins="http://localhost:9090")
 public class IntegrationConfiguration extends WebSecurityConfigurerAdapter {