Extend support for simple types to Consumer and Supplier

The function catalog now always wraps beans that deal with non-flux
generic types.

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

@@ -41,7 +41,9 @@ import org.springframework.beans.factory.support.RootBeanDefinition;
 import org.springframework.boot.autoconfigure.condition.ConditionalOnClass;
 import org.springframework.boot.autoconfigure.condition.ConditionalOnMissingBean;
 import org.springframework.cloud.function.registry.FunctionCatalog;
+import org.springframework.cloud.function.support.FluxConsumer;
 import org.springframework.cloud.function.support.FluxFunction;
+import org.springframework.cloud.function.support.FluxSupplier;
 import org.springframework.cloud.function.support.FunctionUtils;
 import org.springframework.context.annotation.Bean;
 import org.springframework.context.annotation.Configuration;
@@ -113,6 +115,11 @@ public class ContextFunctionCatalogAutoConfiguration {
 				Supplier<Flux<?>> supplier = (Supplier<Flux<?>>) target;
 				return wrapSupplier(supplier, mapper, key);
 			}
+			else if (!isFluxSupplier(key, target)) {
+				@SuppressWarnings({ "unchecked", "rawtypes" })
+				FluxSupplier value = new FluxSupplier(target);
+				return value;
+			}
 			else {
 				return target;
 			}
@@ -167,6 +174,11 @@ public class ContextFunctionCatalogAutoConfiguration {
 				Consumer<Flux<?>> consumer = (Consumer<Flux<?>>) target;
 				return wrapConsumer(consumer, mapper, key);
 			}
+			else if (!isFluxConsumer(key, target)) {
+				@SuppressWarnings({ "unchecked", "rawtypes" })
+				FluxConsumer value = new FluxConsumer(target);
+				return value;
+			}
 			else {
 				return target;
 			}
@@ -211,6 +223,48 @@ public class ContextFunctionCatalogAutoConfiguration {
 			return FunctionUtils.isFluxFunction(function);
 		}
 
+		private boolean isFluxConsumer(String name, Consumer<?> function) {
+			if (this.registry.containsBeanDefinition(name)) {
+				BeanDefinition beanDefinition = this.registry.getBeanDefinition(name);
+				Object source = beanDefinition.getSource();
+				if (source instanceof StandardMethodMetadata) {
+					StandardMethodMetadata metadata = (StandardMethodMetadata) source;
+					Type returnType = metadata.getIntrospectedMethod()
+							.getGenericReturnType();
+					if (returnType instanceof ParameterizedType) {
+						Type[] types = ((ParameterizedType) returnType)
+								.getActualTypeArguments();
+						if (types != null && types.length == 1) {
+							return (types[0].getTypeName()
+									.startsWith(Flux.class.getName()));
+						}
+					}
+				}
+			}
+			return FunctionUtils.isFluxConsumer(function);
+		}
+
+		private boolean isFluxSupplier(String name, Supplier<?> function) {
+			if (this.registry.containsBeanDefinition(name)) {
+				BeanDefinition beanDefinition = this.registry.getBeanDefinition(name);
+				Object source = beanDefinition.getSource();
+				if (source instanceof StandardMethodMetadata) {
+					StandardMethodMetadata metadata = (StandardMethodMetadata) source;
+					Type returnType = metadata.getIntrospectedMethod()
+							.getGenericReturnType();
+					if (returnType instanceof ParameterizedType) {
+						Type[] types = ((ParameterizedType) returnType)
+								.getActualTypeArguments();
+						if (types != null && types.length == 1) {
+							return (types[0].getTypeName()
+									.startsWith(Flux.class.getName()));
+						}
+					}
+				}
+			}
+			return FunctionUtils.isFluxSupplier(function);
+		}
+
 		private boolean isGenericSupplier(ConfigurableListableBeanFactory factory,
 				String name) {
 			return factory.isTypeMatch(name,

spring-cloud-function-core/src/main/java/org/springframework/cloud/function/support/ConsumerProxy.java

@@ -0,0 +1,33 @@
+/*
+ * Copyright 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 org.springframework.cloud.function.support;
+
+import java.util.function.Consumer;
+
+/**
+ * @author Mark Fisher
+ *
+ * @param <T> output type of target Consumer
+ */
+public interface ConsumerProxy<T> extends Consumer<T> {
+
+	default boolean isFluxConsumer() {
+		return FunctionUtils.isFluxConsumer(getTarget());
+	}
+
+	Consumer<T> getTarget();
+}

spring-cloud-function-core/src/main/java/org/springframework/cloud/function/support/FluxConsumer.java

@@ -0,0 +1,43 @@
+/*
+ * Copyright 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 org.springframework.cloud.function.support;
+
+import java.util.function.Consumer;
+
+import reactor.core.publisher.Flux;
+
+/**
+ * {@link Consumer} implementation that wraps a target Consumer so that the target's
+ * simple input type will be wrapped as a {@link Flux} instance.
+ *
+ * @author Dave Syer
+ *
+ * @param <T> input type of target consumer
+ */
+public class FluxConsumer<T> implements Consumer<Flux<T>> {
+
+	private final Consumer<T> function;
+
+	public FluxConsumer(Consumer<T> function) {
+		this.function = function;
+	}
+
+	@Override
+	public void accept(Flux<T> input) {
+		input.subscribe(t -> function.accept(t));
+	}
+}

spring-cloud-function-core/src/main/java/org/springframework/cloud/function/support/FluxFunction.java

@@ -39,6 +39,6 @@ public class FluxFunction<T, R> implements Function<Flux<T>, Flux<R>> {
 
 	@Override
 	public Flux<R> apply(Flux<T> input) {
-		return input.map(i->this.function.apply(i));
+		return input.map(i -> this.function.apply(i));
 	}
 }

spring-cloud-function-core/src/main/java/org/springframework/cloud/function/support/FunctionUtils.java

@@ -22,6 +22,7 @@ import java.lang.reflect.ParameterizedType;
 import java.lang.reflect.Type;
 import java.util.ArrayList;
 import java.util.List;
+import java.util.function.Consumer;
 import java.util.function.Function;
 import java.util.function.Supplier;
 
@@ -37,7 +38,20 @@ public abstract class FunctionUtils {
 
 	private static final String FLUX_CLASS_NAME = Flux.class.getName();
 
-	private FunctionUtils() {}
+	private FunctionUtils() {
+	}
+
+	@SuppressWarnings("rawtypes")
+	public static boolean isFluxConsumer(Consumer<?> consumer) {
+		if (consumer instanceof ConsumerProxy) {
+			return ((ConsumerProxy) consumer).isFluxConsumer();
+		}
+		String[] types = getParameterizedTypeNames(consumer, Consumer.class);
+		if (ObjectUtils.isEmpty(types)) {
+			return false;
+		}
+		return (types[0].startsWith(FLUX_CLASS_NAME));
+	}
 
 	@SuppressWarnings("rawtypes")
 	public static boolean isFluxSupplier(Supplier<?> supplier) {
@@ -60,14 +74,17 @@ public abstract class FunctionUtils {
 		if (ObjectUtils.isEmpty(types) || types.length != 2) {
 			return false;
 		}
-		return (types[0].startsWith(FLUX_CLASS_NAME) && types[1].startsWith(FLUX_CLASS_NAME));
+		return (types[0].startsWith(FLUX_CLASS_NAME)
+				&& types[1].startsWith(FLUX_CLASS_NAME));
 	}
 
-	private static String[] getParameterizedTypeNames(Object source, Class<?> interfaceClass) {
+	private static String[] getParameterizedTypeNames(Object source,
+			Class<?> interfaceClass) {
 		Type[] genericInterfaces = source.getClass().getGenericInterfaces();
 		for (Type genericInterface : genericInterfaces) {
-			if ((genericInterface instanceof ParameterizedType)
-					&& interfaceClass.getTypeName().equals(((ParameterizedType) genericInterface).getRawType().getTypeName())) {
+			if ((genericInterface instanceof ParameterizedType) && interfaceClass
+					.getTypeName().equals(((ParameterizedType) genericInterface)
+							.getRawType().getTypeName())) {
 				ParameterizedType type = (ParameterizedType) genericInterface;
 				Type[] args = type.getActualTypeArguments();
 				if (args != null) {
@@ -88,8 +105,10 @@ public abstract class FunctionUtils {
 			return null;
 		}
 		ReflectionUtils.makeAccessible(method);
-		SerializedLambda serializedLambda = (SerializedLambda) ReflectionUtils.invokeMethod(method, source);
-		String signature = serializedLambda.getImplMethodSignature().replaceAll("[()]", "");
+		SerializedLambda serializedLambda = (SerializedLambda) ReflectionUtils
+				.invokeMethod(method, source);
+		String signature = serializedLambda.getImplMethodSignature().replaceAll("[()]",
+				"");
 		List<String> typeNames = new ArrayList<>();
 		for (String types : signature.split(";")) {
 			typeNames.add(types.substring(1).replace('/', '.'));

spring-cloud-function-web/src/test/java/org/springframework/cloud/function/web/RestApplicationTests.java

@@ -115,6 +115,14 @@ public class RestApplicationTests {
 		assertThat(result.getBody()).isEqualTo("foobar");
 	}
 
+	@Test
+	public void bareWords() throws Exception {
+		ResponseEntity<String> result = rest
+				.exchange(RequestEntity.get(new URI("/bareWords")).build(), String.class);
+		assertThat(result.getStatusCode()).isEqualTo(HttpStatus.OK);
+		assertThat(result.getBody()).isEqualTo("foobar");
+	}
+
 	@Test
 	public void updates() throws Exception {
 		ResponseEntity<String> result = rest.exchange(
@@ -124,6 +132,16 @@ public class RestApplicationTests {
 		assertThat(result.getBody()).isEqualTo("onetwo");
 	}
 
+	@Test
+	public void bareUpdates() throws Exception {
+		ResponseEntity<String> result = rest.exchange(
+				RequestEntity.post(new URI("/bareUpdates")).body("one\ntwo"),
+				String.class);
+		assertThat(result.getStatusCode()).isEqualTo(HttpStatus.ACCEPTED);
+		assertThat(test.list).hasSize(2);
+		assertThat(result.getBody()).isEqualTo("onetwo");
+	}
+
 	@Test
 	public void timeoutJson() throws Exception {
 		assertThat(rest
@@ -184,6 +202,12 @@ public class RestApplicationTests {
 				.isEqualTo("[FOO][BAR]");
 	}
 
+	@Test
+	public void bareUppercase() {
+		assertThat(rest.postForObject("/bareUppercase", "foo\nbar", String.class))
+				.isEqualTo("[FOO][BAR]");
+	}
+
 	@Test
 	public void transform() {
 		assertThat(rest.postForObject("/transform", "foo\nbar", String.class))
@@ -270,6 +294,11 @@ public class RestApplicationTests {
 					.map(value -> "[" + value.trim().toUpperCase() + "]");
 		}
 
+		@Bean
+		public Function<String, String> bareUppercase() {
+			return value -> "[" + value.trim().toUpperCase() + "]";
+		}
+
 		@Bean
 		public Function<Flux<Integer>, Flux<String>> wrap() {
 			return flux -> flux.log().map(value -> ".." + value + "..");
@@ -294,11 +323,21 @@ public class RestApplicationTests {
 			return () -> Flux.fromArray(new String[] { "foo", "bar" });
 		}
 
+		@Bean
+		public Supplier<List<String>> bareWords() {
+			return () -> Arrays.asList("foo", "bar");
+		}
+
 		@Bean
 		public Consumer<Flux<String>> updates() {
 			return flux -> flux.subscribe(value -> list.add(value));
 		}
 
+		@Bean
+		public Consumer<String> bareUpdates() {
+			return value -> list.add(value);
+		}
+
 		@Bean
 		public Supplier<Flux<String>> bang() {
 			return () -> Flux.fromArray(new String[] { "foo", "bar" }).map(value -> {