Update WebFlux samples to use Spring Boot

Fixes: gh-5411

samples/boot/hellowebfluxfn/src/main/java/sample/HelloWebfluxFnSecurityConfig.java

@@ -0,0 +1,41 @@
+/*
+ * Copyright 2002-2017 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 sample;
+
+import org.springframework.context.annotation.Bean;
+import org.springframework.security.config.annotation.web.reactive.EnableWebFluxSecurity;
+import org.springframework.security.core.userdetails.MapReactiveUserDetailsService;
+import org.springframework.security.core.userdetails.User;
+import org.springframework.security.core.userdetails.UserDetails;
+
+/**
+ * @author Rob Winch
+ * @since 5.0
+ */
+@EnableWebFluxSecurity
+public class HelloWebfluxFnSecurityConfig {
+
+	@Bean
+	public MapReactiveUserDetailsService userDetailsService() {
+		UserDetails user = User.withDefaultPasswordEncoder()
+			.username("user")
+			.password("user")
+			.roles("USER")
+			.build();
+		return new MapReactiveUserDetailsService(user);
+	}
+}