Add support for using WebFlux's WebTestClient to document an API

Closes gh-384

samples/web-test-client/src/main/java/com/example/webtestclient/SampleWebTestClientApplication.java

@@ -0,0 +1,48 @@
+/*
+ * Copyright 2014-2017 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 com.example.webtestclient;
+
+import org.springframework.context.annotation.AnnotationConfigApplicationContext;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.http.HttpStatus;
+import org.springframework.http.server.reactive.ReactorHttpHandlerAdapter;
+import org.springframework.web.reactive.config.EnableWebFlux;
+import org.springframework.web.reactive.function.server.RequestPredicates;
+import org.springframework.web.reactive.function.server.RouterFunction;
+import org.springframework.web.reactive.function.server.RouterFunctions;
+import org.springframework.web.reactive.function.server.ServerResponse;
+
+import reactor.ipc.netty.http.server.HttpServer;
+
+@EnableWebFlux
+@Configuration
+public class SampleWebTestClientApplication {
+
+	@Bean
+	public RouterFunction<ServerResponse> routerFunction() {
+		return RouterFunctions.route(RequestPredicates.GET("/"), (request) -> ServerResponse.status(HttpStatus.OK).syncBody("Hello, World"));
+	}
+
+	public static void main(String[] args) {
+		RouterFunction<?> routerFunction = new AnnotationConfigApplicationContext(SampleWebTestClientApplication.class).getBean(RouterFunction.class);
+		ReactorHttpHandlerAdapter adapter = new ReactorHttpHandlerAdapter(RouterFunctions.toHttpHandler(routerFunction));
+		HttpServer httpServer = HttpServer.create(8080);
+		httpServer.startAndAwait(adapter);
+	}
+
+}