Ensure FunctionalSpringApplication works with String sources

spring-cloud-function-context/src/main/java/org/springframework/cloud/function/context/FunctionalSpringApplication.java

@@ -54,6 +54,10 @@ public class FunctionalSpringApplication
 	 */
 	public static final String SPRING_WEB_APPLICATION_TYPE = "spring.main.web-application-type";
 
+	public static void main(String[] args) throws Exception {
+		FunctionalSpringApplication.run(new Class<?>[0], args);
+	}
+
 	public static ConfigurableApplicationContext run(Class<?> primarySource,
 			String... args) {
 		return run(new Class<?>[] { primarySource }, args);
@@ -70,7 +74,8 @@ public class FunctionalSpringApplication
 		if (ClassUtils.isPresent("org.springframework.web.reactive.DispatcherHandler",
 				null)) {
 			setWebApplicationType(WebApplicationType.REACTIVE);
-		} else {
+		}
+		else {
 			setWebApplicationType(WebApplicationType.NONE);
 		}
 	}
@@ -82,40 +87,39 @@ public class FunctionalSpringApplication
 		if (context instanceof GenericApplicationContext) {
 			GenericApplicationContext generic = (GenericApplicationContext) context;
 			for (Object source : getAllSources()) {
-				if (source instanceof Class<?>) {
+				Class<?> type = null;
-					Class<?> type = (Class<?>) source;
+				Object handler = null;
-					if (ApplicationContextInitializer.class.isAssignableFrom(type)) {
+				if (source instanceof String) {
-						@SuppressWarnings("unchecked")
+					String name = (String) source;
-						ApplicationContextInitializer<GenericApplicationContext> initializer = BeanUtils
+					if (ClassUtils.isPresent(name, null)) {
-								.instantiateClass(type,
+						type = ClassUtils.resolveClassName(name, null);
-										ApplicationContextInitializer.class);
-						initializer.initialize(generic);
-						functional = true;
-					}
-					else if (Function.class.isAssignableFrom(type)
-							|| Consumer.class.isAssignableFrom(type)
-							|| Supplier.class.isAssignableFrom(type)) {
-						generic.registerBean("function", FunctionRegistration.class,
-								() -> new FunctionRegistration<>(context
-										.getAutowireCapableBeanFactory().createBean(type))
-												.type(FunctionType.of(type)));
-						functional = true;
 					}
 				}
+				else if (source instanceof Class<?>) {
+					type = (Class<?>) source;
+				}
 				else {
-					Class<?> type = source.getClass();
+					type = source.getClass();
+					handler = source;
+				}
+				if (type != null) {
 					if (ApplicationContextInitializer.class.isAssignableFrom(type)) {
+						if (handler == null) {
+							handler = BeanUtils.instantiateClass(type);
+						}
 						@SuppressWarnings("unchecked")
-						ApplicationContextInitializer<GenericApplicationContext> initializer = (ApplicationContextInitializer<GenericApplicationContext>) source;
+						ApplicationContextInitializer<GenericApplicationContext> initializer = (ApplicationContextInitializer<GenericApplicationContext>) handler;
 						initializer.initialize(generic);
 						functional = true;
 					}
 					else if (Function.class.isAssignableFrom(type)
 							|| Consumer.class.isAssignableFrom(type)
 							|| Supplier.class.isAssignableFrom(type)) {
+						Class<?> functionType = type;
+						Object function = handler;
 						generic.registerBean("function", FunctionRegistration.class,
-								() -> new FunctionRegistration<>(source)
+								() -> new FunctionRegistration<>(handler(generic, function, functionType))
-										.type(FunctionType.of(type)));
+										.type(FunctionType.of(functionType)));
 						functional = true;
 					}
 				}
@@ -126,6 +130,13 @@ public class FunctionalSpringApplication
 		}
 	}
 
+	private Object handler(GenericApplicationContext generic, Object handler, Class<?> type) {
+		if (handler == null) {
+			handler = generic.getAutowireCapableBeanFactory().createBean(type);
+		}
+		return handler;
+	}
+
 	@Override
 	protected void load(ApplicationContext context, Object[] sources) {
 		if (!context.getEnvironment().getProperty(SPRING_FUNCTIONAL_ENABLED,

spring-cloud-function-context/src/test/java/org/springframework/cloud/function/context/string/FunctionalStringSourceTests.java

@@ -0,0 +1,59 @@
+/*
+ * 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.cloud.function.context.string;
+
+import java.util.function.Function;
+
+import org.junit.Test;
+import org.junit.runner.RunWith;
+
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.cloud.function.context.FunctionCatalog;
+import org.springframework.cloud.function.context.test.FunctionalSpringBootTest;
+import org.springframework.test.context.junit4.SpringRunner;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+import reactor.core.publisher.Flux;
+
+/**
+ * Test that spring.main.sources works with the functional approach.
+ * 
+ * @author Dave Syer
+ *
+ */
+@RunWith(SpringRunner.class)
+@FunctionalSpringBootTest(classes = Object.class, properties = "spring.main.sources=org.springframework.cloud.function.context.string.FunctionalStringSourceTests.TestConfiguration")
+public class FunctionalStringSourceTests {
+
+	@Autowired
+	private FunctionCatalog catalog;
+
+	@Test
+	public void words() throws Exception {
+		Function<Flux<String>, Flux<String>> function = catalog.lookup(Function.class,
+				"function");
+		assertThat(function.apply(Flux.just("foo")).blockFirst()).isEqualTo("FOO");
+	}
+
+	protected static class TestConfiguration implements Function<String, String> {
+		@Override
+		public String apply(String value) {
+			return value.toUpperCase();
+		}
+	}
+}