Extract common code from BeanFactoryAwareFunctionRegistry

. . . to ensure that we can have the version of FunctionRegistry that is not dependent on BeanFactory.

spring-cloud-function-web/src/main/java/org/springframework/cloud/function/web/RequestProcessor.java

@@ -39,8 +39,8 @@ import reactor.core.publisher.Mono;
 
 import org.springframework.beans.factory.ObjectProvider;
 import org.springframework.cloud.function.context.FunctionCatalog;
-import org.springframework.cloud.function.context.catalog.BeanFactoryAwareFunctionRegistry.FunctionInvocationWrapper;
 import org.springframework.cloud.function.context.catalog.FunctionInspector;
+import org.springframework.cloud.function.context.catalog.SimpleFunctionRegistry.FunctionInvocationWrapper;
 import org.springframework.cloud.function.context.config.RoutingFunction;
 import org.springframework.cloud.function.context.message.MessageUtils;
 import org.springframework.cloud.function.core.FluxConsumer;

spring-cloud-function-web/src/main/java/org/springframework/cloud/function/web/function/FunctionEndpointInitializer.java

@@ -24,6 +24,7 @@ import java.util.function.Supplier;
 
 import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
+import org.reactivestreams.Publisher;
 import reactor.core.publisher.Flux;
 import reactor.core.publisher.Mono;
 import reactor.netty.DisposableServer;
@@ -38,6 +39,7 @@ import org.springframework.boot.web.reactive.error.ErrorAttributes;
 import org.springframework.cloud.function.context.FunctionCatalog;
 import org.springframework.cloud.function.context.FunctionalSpringApplication;
 import org.springframework.cloud.function.context.catalog.FunctionInspector;
+import org.springframework.cloud.function.context.catalog.SimpleFunctionRegistry.FunctionInvocationWrapper;
 import org.springframework.cloud.function.context.config.ContextFunctionCatalogInitializer;
 import org.springframework.cloud.function.json.JsonMapper;
 import org.springframework.cloud.function.web.BasicStringConverter;
@@ -244,10 +246,15 @@ class FunctionEndpointFactory {
 		.andRoute(GET("/**"), request -> {
 			Object functionComponent = extract(request);
 			Class<T> outputType = (Class<T>) this.inspector.getOutputType(functionComponent);
-			if (functionComponent instanceof Supplier) {
+//			if (functionComponent instanceof Supplier) {
+			if (((FunctionInvocationWrapper) functionComponent).isSupplier()) {
 				Supplier<? extends Flux<?>> supplier = (Supplier<Flux<?>>) functionComponent;
 				FunctionWrapper wrapper = RequestProcessor.wrapper(null, null, supplier);
-				return ServerResponse.ok().body(wrapper.supplier().get(), outputType);
+				Object result = wrapper.supplier().get();
+				if (!(result instanceof Publisher)) {
+					result = Mono.just(result);
+				}
+				return ServerResponse.ok().body(result, outputType);
 			}
 			else {
 				Function<Flux<?>, Flux<?>> function = (Function<Flux<?>, Flux<?>>) functionComponent;

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

@@ -58,7 +58,7 @@ public class FunctionalExporterTests {
 	@Autowired
 	private SupplierExporter forwarder;
 
-	private static RestConfiguration app;
+	private static RestPojoConfiguration app;
 
 	private static ConfigurableApplicationContext context;
 
@@ -67,9 +67,9 @@ public class FunctionalExporterTests {
 		String port = "" + SocketUtils.findAvailableTcpPort();
 		System.setProperty("server.port", port);
 		System.setProperty("my.port", port);
-		context = SpringApplication.run(RestConfiguration.class,
+		context = SpringApplication.run(RestPojoConfiguration.class,
 				"--spring.main.web-application-type=reactive");
-		app = context.getBean(RestConfiguration.class);
+		app = context.getBean(RestPojoConfiguration.class);
 		// Sometimes the server doesn't start quick enough
 		Thread.sleep(500L);
 	}
@@ -97,8 +97,8 @@ public class FunctionalExporterTests {
 	protected static class ApplicationConfiguration
 			implements ApplicationContextInitializer<GenericApplicationContext> {
 
-		Function<Message<String>, Message<String>> uppercase() {
-			return value -> MessageBuilder.withPayload(value.getPayload().toUpperCase())
+		Function<Message<Person>, Message<String>> uppercase() {
+			return value -> MessageBuilder.withPayload(value.getPayload().getName().toUpperCase())
 					.copyHeaders(value.getHeaders()).build();
 		}
 
@@ -106,9 +106,20 @@ public class FunctionalExporterTests {
 		public void initialize(GenericApplicationContext context) {
 			context.registerBean("uppercase", FunctionRegistration.class,
 					() -> new FunctionRegistration<>(uppercase()).type(
-							FunctionType.from(String.class).to(String.class).message()));
+							FunctionType.from(Person.class).to(String.class).message()));
 		}
-
 	}
 
 }
+
+class Person {
+	private String name;
+
+	public String getName() {
+		return name;
+	}
+
+	public void setName(String name) {
+		this.name = name;
+	}
+}

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

@@ -0,0 +1,67 @@
+/*
+ * Copyright 2018-2019 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
+ *
+ *      https://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.test;
+
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.Iterator;
+import java.util.List;
+
+import org.apache.commons.logging.Log;
+import org.apache.commons.logging.LogFactory;
+
+import org.springframework.boot.SpringApplication;
+import org.springframework.boot.SpringBootConfiguration;
+import org.springframework.boot.autoconfigure.EnableAutoConfiguration;
+import org.springframework.http.ResponseEntity;
+import org.springframework.web.bind.annotation.GetMapping;
+import org.springframework.web.bind.annotation.PostMapping;
+import org.springframework.web.bind.annotation.RequestBody;
+import org.springframework.web.bind.annotation.RestController;
+
+@SpringBootConfiguration
+@EnableAutoConfiguration
+@RestController
+public class RestPojoConfiguration {
+
+	private static Log logger = LogFactory.getLog(RestPojoConfiguration.class);
+
+	List<String> inputs = new ArrayList<>();
+
+	private Iterator<String> outputs = Arrays.asList("{\"name\":\"hello\"}").iterator();
+
+	@GetMapping("/")
+	ResponseEntity<String> home() {
+		logger.info("HOME");
+		if (this.outputs.hasNext()) {
+			return ResponseEntity.ok(this.outputs.next());
+		}
+		return ResponseEntity.notFound().build();
+	}
+
+	@PostMapping("/")
+	ResponseEntity<String> accept(@RequestBody String body) {
+		logger.info("ACCEPT");
+		this.inputs.add(body);
+		return ResponseEntity.accepted().body(body);
+	}
+
+	public static void main(String[] args) throws Exception {
+		SpringApplication.run(RestPojoConfiguration.class, args);
+	}
+
+}

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

@@ -96,9 +96,10 @@ public class FunctionEndpointInitializerTests {
 		FunctionalSpringApplication.run(ApplicationConfiguration.class);
 		TestRestTemplate testRestTemplate = new TestRestTemplate();
 		String port = System.getProperty("server.port");
-		Thread.sleep(200);
+		Thread.sleep(2000);
 		ResponseEntity<String> response = testRestTemplate
 				.getForEntity(new URI("http://localhost:" + port + "/reverse/stressed"), String.class);
+		System.out.println();
 		assertThat(response.getBody()).isEqualTo("desserts");
 	}
 
@@ -131,7 +132,9 @@ public class FunctionEndpointInitializerTests {
 		}
 
 		public Function<String, String> reverse() {
-			return s -> new StringBuilder(s).reverse().toString();
+			return s -> {
+				return new StringBuilder(s).reverse().toString();
+			};
 		}
 
 		@Override