GH-1052 Fix collection/array processing for AWS invocations with Publisher input type functions

Resolves #1052

spring-cloud-function-adapters/spring-cloud-function-adapter-aws/src/main/java/org/springframework/cloud/function/adapter/aws/AWSLambdaUtils.java

@@ -74,14 +74,7 @@ public final class AWSLambdaUtils {
 		if (FunctionTypeUtils.isMessage(inputType) || FunctionTypeUtils.isPublisher(inputType)) {
 			inputType = FunctionTypeUtils.getImmediateGenericType(inputType, 0);
 		}
-		String typeName = inputType.getTypeName();
+		return FunctionTypeUtils.getRawType(inputType).getPackage().getName().startsWith("com.amazonaws.services.lambda.runtime.events");
-		return typeName.equals("com.amazonaws.services.lambda.runtime.events.APIGatewayV2HTTPEvent")
-				|| typeName.equals("com.amazonaws.services.lambda.runtime.events.S3Event")
-				|| typeName.equals("com.amazonaws.services.lambda.runtime.events.APIGatewayProxyRequestEvent")
-				|| typeName.equals("com.amazonaws.services.lambda.runtime.events.SNSEvent")
-				|| typeName.equals("com.amazonaws.services.lambda.runtime.events.SQSEvent")
-				|| typeName.equals("com.amazonaws.services.lambda.runtime.events.APIGatewayCustomAuthorizerEvent")
-				|| typeName.equals("com.amazonaws.services.lambda.runtime.events.KinesisEvent");
 	}
 
 	@SuppressWarnings("rawtypes")
@@ -121,6 +114,9 @@ public final class AWSLambdaUtils {
 		MessageBuilder<byte[]> builder = MessageBuilder.withPayload(payload);
 		if (isApiGateway) {
 			builder.setHeader(AWSLambdaUtils.AWS_API_GATEWAY, true);
+			if (JsonMapper.isJsonStringRepresentsCollection(((Map) structMessage).get("body"))) {
+				builder.setHeader("payload", ((Map) structMessage).get("body"));
+			}
 		}
 		if (!isSupplier && AWSLambdaUtils.isSupportedAWSType(inputType)) {
 			builder.setHeader(AWSLambdaUtils.AWS_EVENT, true);
@@ -145,35 +141,50 @@ public final class AWSLambdaUtils {
 		}
 	}
 
+	private static Object convertFromJsonIfNecessary(Object value, JsonMapper objectMapper) {
+		if (JsonMapper.isJsonString(value)) {
+			return objectMapper.fromJson(value, Object.class);
+		}
+		return value;
+	}
+
 	@SuppressWarnings("unchecked")
 	public static byte[] generateOutputFromObject(Message<?> requestMessage, Object output, JsonMapper objectMapper, Type functionOutputType) {
 		Message<byte[]> responseMessage = null;
 		if (output instanceof Publisher<?>) {
 			List<Object> result = new ArrayList<>();
-			for (Object value : Flux.from((Publisher<?>) output).toIterable()) {
+			Message<?> lastMessage = null;
+			for (Object item : Flux.from((Publisher<?>) output).toIterable()) {
 				if (logger.isDebugEnabled()) {
-					logger.debug("Response value: " + value);
+					logger.debug("Response value: " + item);
+				}
+				if (item instanceof Message<?> message) {
+					result.add(convertFromJsonIfNecessary(message.getPayload(), objectMapper));
+					lastMessage = message;
+				}
+				else {
+					result.add(convertFromJsonIfNecessary(item, objectMapper));
 				}
-				result.add(value);
 			}
-			if (result.size() > 1) {
+
-				output = result;
+			byte[] resultPayload;
+			if (result.size() == 1) {
+				resultPayload = objectMapper.toJson(result.get(0));
 			}
-			else if (result.size() == 1) {
+			else if (result.size() > 1) {
-				output = result.get(0);
+				resultPayload = objectMapper.toJson(result);
 			}
 			else {
-				output = null;
+				resultPayload = null;
 			}
-			if (output instanceof Message<?> && ((Message<?>) output).getPayload() instanceof byte[]) {
+
-				responseMessage = (Message<byte[]>) output;
+			if (resultPayload != null) {
-			}
+				System.out.println(new String(resultPayload));
-			else if (output != null) {
+				MessageBuilder<byte[]> messageBuilder = MessageBuilder.withPayload(resultPayload);
-				if (logger.isDebugEnabled()) {
+				if (lastMessage != null) {
-					logger.debug("OUTPUT: " + output + " - " + output.getClass().getName());
+					messageBuilder.copyHeaders(lastMessage.getHeaders());
 				}
-				byte[] payload = objectMapper.toJson(output);
+				responseMessage = messageBuilder.build();
-				responseMessage = MessageBuilder.withPayload(payload).build();
 			}
 		}
 		else {

spring-cloud-function-adapters/spring-cloud-function-adapter-aws/src/main/java/org/springframework/cloud/function/adapter/aws/AWSTypesMessageConverter.java

@@ -86,7 +86,13 @@ class AWSTypesMessageConverter extends JsonMessageConverter {
 				return structMessage;
 			}
 			else {
-				Object body = structMessage.get("body");
+				Object body;
+				if (message.getHeaders().containsKey("payload")) {
+					body = message.getPayload();
+				}
+				else {
+					body = structMessage.get("body");
+				}
 				Object convertedResult = this.jsonMapper.fromJson(body, targetClass);
 				return convertedResult;
 			}

spring-cloud-function-adapters/spring-cloud-function-adapter-aws/src/main/java/org/springframework/cloud/function/adapter/aws/CustomRuntimeEventLoop.java

@@ -16,6 +16,7 @@
 
 package org.springframework.cloud.function.adapter.aws;
 
+import java.io.ByteArrayInputStream;
 import java.io.PrintWriter;
 import java.io.StringWriter;
 import java.net.SocketException;
@@ -44,11 +45,8 @@ import org.springframework.http.RequestEntity;
 import org.springframework.http.ResponseEntity;
 import org.springframework.messaging.Message;
 import org.springframework.util.Assert;
-import org.springframework.util.StringUtils;
 import org.springframework.web.client.RestTemplate;
 
-
-
 import static org.apache.http.HttpHeaders.USER_AGENT;
 
 /**
@@ -107,7 +105,6 @@ public final class CustomRuntimeEventLoop implements SmartLifecycle {
 		return this.running;
 	}
 
-	@SuppressWarnings("unchecked")
 	private void eventLoop(ConfigurableApplicationContext context) {
 		Environment environment = context.getEnvironment();
 		logger.info("Starting spring-cloud-function CustomRuntimeEventLoop");
@@ -140,33 +137,18 @@ public final class CustomRuntimeEventLoop implements SmartLifecycle {
 				try {
 					FunctionInvocationWrapper function = locateFunction(environment, functionCatalog, response.getHeaders());
 
-					Message<byte[]> eventMessage = AWSLambdaUtils
+					ByteArrayInputStream is = new ByteArrayInputStream(response.getBody().getBytes(StandardCharsets.UTF_8));
-							.generateMessage(response.getBody().getBytes(StandardCharsets.UTF_8), function.getInputType(), function.isSupplier(), mapper);
+					Message<?> requestMessage = AWSLambdaUtils.generateMessage(is, function.getInputType(), function.isSupplier(), mapper, null);
 
-					if (logger.isDebugEnabled()) {
+					Object functionResponse = function.apply(requestMessage);
-						logger.debug("Event message: " + eventMessage);
+					byte[] responseBytes = AWSLambdaUtils.generateOutputFromObject(requestMessage, functionResponse, mapper, function.getOutputType());
-					}
 
 					String invocationUrl = MessageFormat
 							.format(LAMBDA_INVOCATION_URL_TEMPLATE, runtimeApi, LAMBDA_VERSION_DATE, requestId);
 
-					String traceId = response.getHeaders().getFirst("Lambda-Runtime-Trace-Id");
-					if (StringUtils.hasText(traceId)) {
-						if (logger.isDebugEnabled()) {
-							logger.debug("Lambda-Runtime-Trace-Id: " + traceId);
-						}
-						System.setProperty("com.amazonaws.xray.traceHeader", traceId);
-					}
-					Object responseObject = function.apply(eventMessage);
-
-					if (responseObject != null && logger.isDebugEnabled()) {
-						logger.debug("Reply from function: " + responseObject);
-					}
-
-					byte[] outputBody = AWSLambdaUtils.generateOutputFromObject(eventMessage, responseObject, mapper, function.getOutputType());
 					ResponseEntity<Object> result = rest.exchange(RequestEntity.post(URI.create(invocationUrl))
 						.header(USER_AGENT, USER_AGENT_VALUE)
-						.body(outputBody), Object.class);
+						.body(responseBytes), Object.class);
 
 					if (logger.isInfoEnabled()) {
 						logger.info("Result POST status: " + result);

spring-cloud-function-adapters/spring-cloud-function-adapter-aws/src/test/java/org/springframework/cloud/function/adapter/aws/CustomRuntimeEventLoopTest.java

@@ -39,6 +39,90 @@ import static org.assertj.core.api.Assertions.assertThat;
  */
 public class CustomRuntimeEventLoopTest {
 
+	private String API_EVENT = "{\n"
+			+ "    \"version\": \"1.0\",\n"
+			+ "    \"resource\": \"$default\",\n"
+			+ "    \"path\": \"/question\",\n"
+			+ "    \"httpMethod\": \"POST\",\n"
+			+ "    \"headers\": {\n"
+			+ "        \"Content-Length\": \"40\",\n"
+			+ "        \"Content-Type\": \"application/json\",\n"
+			+ "        \"Host\": \"emcdxu5ijj.execute-api.us-east-2.amazonaws.com\",\n"
+			+ "        \"User-Agent\": \"curl/7.88.1\",\n"
+			+ "        \"X-Amzn-Trace-Id\": \"Root=1-64ad9787-4c89d5af7607eb9e522e01d5\",\n"
+			+ "        \"X-Forwarded-For\": \"109.210.252.44\",\n"
+			+ "        \"X-Forwarded-Port\": \"443\",\n"
+			+ "        \"X-Forwarded-Proto\": \"https\",\n"
+			+ "        \"accept\": \"*/*\"\n"
+			+ "    },\n"
+			+ "    \"multiValueHeaders\": {\n"
+			+ "        \"Content-Length\": [\n"
+			+ "            \"40\"\n"
+			+ "        ],\n"
+			+ "        \"Content-Type\": [\n"
+			+ "            \"application/json\"\n"
+			+ "        ],\n"
+			+ "        \"Host\": [\n"
+			+ "            \"emcdxu5ijj.execute-api.us-east-2.amazonaws.com\"\n"
+			+ "        ],\n"
+			+ "        \"User-Agent\": [\n"
+			+ "            \"curl/7.88.1\"\n"
+			+ "        ],\n"
+			+ "        \"X-Amzn-Trace-Id\": [\n"
+			+ "            \"Root=1-64ad9787-4c89d5af7607eb9e522e01d5\"\n"
+			+ "        ],\n"
+			+ "        \"X-Forwarded-For\": [\n"
+			+ "            \"109.210.252.44\"\n"
+			+ "        ],\n"
+			+ "        \"X-Forwarded-Port\": [\n"
+			+ "            \"443\"\n"
+			+ "        ],\n"
+			+ "        \"X-Forwarded-Proto\": [\n"
+			+ "            \"https\"\n"
+			+ "        ],\n"
+			+ "        \"accept\": [\n"
+			+ "            \"*/*\"\n"
+			+ "        ]\n"
+			+ "    },\n"
+			+ "    \"queryStringParameters\": null,\n"
+			+ "    \"multiValueQueryStringParameters\": null,\n"
+			+ "    \"requestContext\": {\n"
+			+ "        \"accountId\": \"313369169943\",\n"
+			+ "        \"apiId\": \"emcdxu5ijj\",\n"
+			+ "        \"domainName\": \"emcdxu5ijj.execute-api.us-east-2.amazonaws.com\",\n"
+			+ "        \"domainPrefix\": \"emcdxu5ijj\",\n"
+			+ "        \"extendedRequestId\": \"H6SdPgXtiYcEP1w=\",\n"
+			+ "        \"httpMethod\": \"POST\",\n"
+			+ "        \"identity\": {\n"
+			+ "            \"accessKey\": null,\n"
+			+ "            \"accountId\": null,\n"
+			+ "            \"caller\": null,\n"
+			+ "            \"cognitoAmr\": null,\n"
+			+ "            \"cognitoAuthenticationProvider\": null,\n"
+			+ "            \"cognitoAuthenticationType\": null,\n"
+			+ "            \"cognitoIdentityId\": null,\n"
+			+ "            \"cognitoIdentityPoolId\": null,\n"
+			+ "            \"principalOrgId\": null,\n"
+			+ "            \"sourceIp\": \"109.210.252.44\",\n"
+			+ "            \"user\": null,\n"
+			+ "            \"userAgent\": \"curl/7.88.1\",\n"
+			+ "            \"userArn\": null\n"
+			+ "        },\n"
+			+ "        \"path\": \"/question\",\n"
+			+ "        \"protocol\": \"HTTP/1.1\",\n"
+			+ "        \"requestId\": \"H6SdPgXtiYcEP1w=\",\n"
+			+ "        \"requestTime\": \"11/Jul/2023:17:55:19 +0000\",\n"
+			+ "        \"requestTimeEpoch\": 1689098119662,\n"
+			+ "        \"resourceId\": \"$default\",\n"
+			+ "        \"resourcePath\": \"$default\",\n"
+			+ "        \"stage\": \"$default\"\n"
+			+ "    },\n"
+			+ "    \"pathParameters\": null,\n"
+			+ "    \"stageVariables\": null,\n"
+			+ "    \"body\": \"[{\\\"latitude\\\": 41.34, \\\"longitude\\\": 2.78},{\\\"latitude\\\": 43.24, \\\"longitude\\\": 3.78}]\",\n"
+			+ "    \"isBase64Encoded\": false\n"
+			+ "}";
+
 	@Test
 	public void testDefaultFunctionLookup() throws Exception {
 		testDefaultFunctionLookup("uppercase", SingleFunctionConfiguration.class);
@@ -98,6 +182,21 @@ public class CustomRuntimeEventLoopTest {
 		}
 	}
 
+	@Test
+	public void test_HANDLERWithApiGatewayRequestAndFlux() throws Exception {
+		try (ConfigurableApplicationContext userContext =
+				new SpringApplicationBuilder(MultipleFunctionConfiguration.class, AWSCustomRuntime.class)
+					.web(WebApplicationType.SERVLET)
+					.properties("_HANDLER=echoFlux", "server.port=0")
+					.run()) {
+
+			AWSCustomRuntime aws = userContext.getBean(AWSCustomRuntime.class);
+			String response = aws.exchange(API_EVENT).getPayload();
+			assertThat(response).contains("{\\\"latitude\\\":2.78,\\\"longitude\\\":41.34}");
+			assertThat(response).contains("{\\\"latitude\\\":3.78,\\\"longitude\\\":43.24}");
+		}
+	}
+
 	@Test
 	@DirtiesContext
 	public void test_definitionLookupAndComposition() throws Exception {
@@ -149,6 +248,13 @@ public class CustomRuntimeEventLoopTest {
 		public Function<Person, Person> uppercasePerson() {
 			return p -> new Person(p.getName().toUpperCase());
 		}
+
+		@Bean
+		public Function<Flux<GeoLocation>, Flux<GeoLocation>> echoFlux() {
+			return flux -> flux.map(g -> {
+				return new GeoLocation(g.longitude(), g.latitude());
+			});
+		}
 	}
 
 	@EnableAutoConfiguration
@@ -185,4 +291,7 @@ public class CustomRuntimeEventLoopTest {
 		}
 	}
 
+
+	public record GeoLocation(Float latitude, Float longitude) {
+	}
 }

spring-cloud-function-adapters/spring-cloud-function-adapter-aws/src/test/java/org/springframework/cloud/function/adapter/aws/FunctionInvokerTests.java

@@ -74,6 +74,8 @@ public class FunctionInvokerTests {
 
 	String jsonCollection = "[\"Ricky\",\"Julien\",\"Bubbles\"]";
 
+	String jsonPojoCollection = "[{\"name\":\"Ricky\"},{\"name\":\"Julien\"},{\"name\":\"Julien\"}]";
+
 	String dynamoDbEvent = "{\n"
 			+ "  \"Records\": [\n"
 			+ "    {\n"
@@ -610,6 +612,84 @@ public class FunctionInvokerTests {
 			"    \"isBase64Encoded\": false\n" +
 			"}";
 
+	String apiGatewayEventWithArray = "{\n" +
+			"    \"resource\": \"/uppercase2\",\n" +
+			"    \"path\": \"/uppercase2\",\n" +
+			"    \"httpMethod\": \"POST\",\n" +
+			"    \"headers\": {\n" +
+			"        \"accept\": \"*/*\",\n" +
+			"        \"content-type\": \"application/json\",\n" +
+			"        \"Host\": \"fhul32ccy2.execute-api.eu-west-3.amazonaws.com\",\n" +
+			"        \"User-Agent\": \"curl/7.54.0\",\n" +
+			"        \"X-Amzn-Trace-Id\": \"Root=1-5ece339e-e0595766066d703ec70f1522\",\n" +
+			"        \"X-Forwarded-For\": \"90.37.8.133\",\n" +
+			"        \"X-Forwarded-Port\": \"443\",\n" +
+			"        \"X-Forwarded-Proto\": \"https\"\n" +
+			"    },\n" +
+			"    \"multiValueHeaders\": {\n" +
+			"        \"accept\": [\n" +
+			"            \"*/*\"\n" +
+			"        ],\n" +
+			"        \"content-type\": [\n" +
+			"            \"application/json\"\n" +
+			"        ],\n" +
+			"        \"Host\": [\n" +
+			"            \"fhul32ccy2.execute-api.eu-west-3.amazonaws.com\"\n" +
+			"        ],\n" +
+			"        \"User-Agent\": [\n" +
+			"            \"curl/7.54.0\"\n" +
+			"        ],\n" +
+			"        \"X-Amzn-Trace-Id\": [\n" +
+			"            \"Root=1-5ece339e-e0595766066d703ec70f1522\"\n" +
+			"        ],\n" +
+			"        \"X-Forwarded-For\": [\n" +
+			"            \"90.37.8.133\"\n" +
+			"        ],\n" +
+			"        \"X-Forwarded-Port\": [\n" +
+			"            \"443\"\n" +
+			"        ],\n" +
+			"        \"X-Forwarded-Proto\": [\n" +
+			"            \"https\"\n" +
+			"        ]\n" +
+			"    },\n" +
+			"    \"queryStringParameters\": null,\n" +
+			"    \"multiValueQueryStringParameters\": null,\n" +
+			"    \"pathParameters\": null,\n" +
+			"    \"stageVariables\": null,\n" +
+			"    \"requestContext\": {\n" +
+			"        \"resourceId\": \"qf0io6\",\n" +
+			"        \"resourcePath\": \"/uppercase2\",\n" +
+			"        \"httpMethod\": \"POST\",\n" +
+			"        \"extendedRequestId\": \"NL0A1EokCGYFZOA=\",\n" +
+			"        \"requestTime\": \"27/May/2020:09:32:14 +0000\",\n" +
+			"        \"path\": \"/test/uppercase2\",\n" +
+			"        \"accountId\": \"123456789098\",\n" +
+			"        \"protocol\": \"HTTP/1.1\",\n" +
+			"        \"stage\": \"test\",\n" +
+			"        \"domainPrefix\": \"fhul32ccy2\",\n" +
+			"        \"requestTimeEpoch\": 1590571934872,\n" +
+			"        \"requestId\": \"b96500aa-f92a-43c3-9360-868ba4053a00\",\n" +
+			"        \"identity\": {\n" +
+			"            \"cognitoIdentityPoolId\": null,\n" +
+			"            \"accountId\": null,\n" +
+			"            \"cognitoIdentityId\": null,\n" +
+			"            \"caller\": null,\n" +
+			"            \"sourceIp\": \"90.37.8.133\",\n" +
+			"            \"principalOrgId\": null,\n" +
+			"            \"accessKey\": null,\n" +
+			"            \"cognitoAuthenticationType\": null,\n" +
+			"            \"cognitoAuthenticationProvider\": null,\n" +
+			"            \"userArn\": null,\n" +
+			"            \"userAgent\": \"curl/7.54.0\",\n" +
+			"            \"user\": null\n" +
+			"        },\n" +
+			"        \"domainName\": \"fhul32ccy2.execute-api.eu-west-3.amazonaws.com\",\n" +
+			"        \"apiId\": \"fhul32ccy2\"\n" +
+			"    },\n" +
+			"    \"body\":[{\"name\":\"Jim Lahey\"},{\"name\":\"Ricky\"}],\n" +
+			"    \"isBase64Encoded\": false\n" +
+			"}";
+
 	String gwAuthorizerEvent = "{\n"
 			+ "    \"type\":\"TOKEN\",\n"
 			+ "    \"authorizationToken\":\"allow\",\n"
@@ -650,6 +730,19 @@ public class FunctionInvokerTests {
 		assertThat(result).isEqualTo(this.jsonCollection);
 	}
 
+	@Test
+	public void testCollectionPojo() throws Exception {
+		System.setProperty("MAIN_CLASS", SampleConfiguration.class.getName());
+		System.setProperty("spring.cloud.function.definition", "echoPojoReactive");
+		FunctionInvoker invoker = new FunctionInvoker();
+
+		InputStream targetStream = new ByteArrayInputStream(this.jsonPojoCollection.getBytes());
+		ByteArrayOutputStream output = new ByteArrayOutputStream();
+		invoker.handleRequest(targetStream, output, null);
+		String result = new String(output.toByteArray(), StandardCharsets.UTF_8);
+		assertThat(result).isEqualTo(this.jsonPojoCollection);
+	}
+
 	@Test
 	public void testKinesisStringEvent() throws Exception {
 		System.setProperty("MAIN_CLASS", KinesisConfiguration.class.getName());
@@ -1019,6 +1112,23 @@ public class FunctionInvokerTests {
 		assertThat(person.getName()).isEqualTo("JIM LAHEY");
 	}
 
+	@SuppressWarnings("rawtypes")
+	@Test
+	public void testApiGatewayPojoReturninPojoReactive() throws Exception {
+		System.setProperty("MAIN_CLASS", ApiGatewayConfiguration.class.getName());
+		System.setProperty("spring.cloud.function.definition", "uppercasePojoReturnPojoReactive");
+		FunctionInvoker invoker = new FunctionInvoker();
+
+		InputStream targetStream = new ByteArrayInputStream(this.apiGatewayEventWithArray.getBytes());
+		ByteArrayOutputStream output = new ByteArrayOutputStream();
+		invoker.handleRequest(targetStream, output, null);
+
+		Map response = mapper.readValue(output.toByteArray(), Map.class);
+		System.out.println(response);
+//		Person person = mapper.readValue((String) response.get("body"), Person.class);
+//		assertThat(person.getName()).isEqualTo("JIM LAHEY");
+	}
+
 	@SuppressWarnings("rawtypes")
 	@Test
 	public void testApiGatewayPojoEventBody() throws Exception {
@@ -1339,6 +1449,11 @@ public class FunctionInvokerTests {
 		public Function<Flux<String>, Flux<String>> echoStringReactive() {
 			return v -> v;
 		}
+
+		@Bean
+		public Function<Flux<Person>, Flux<Person>> echoPojoReactive() {
+			return v -> v;
+		}
 	}
 
 	@EnableAutoConfiguration
@@ -1602,6 +1717,15 @@ public class FunctionInvokerTests {
 			};
 		}
 
+		@Bean
+		public Function<Flux<Person>, Flux<Person>> uppercasePojoReturnPojoReactive() {
+			return flux -> flux.map(v -> {
+				Person p = new Person();
+				p.setName(v.getName().toUpperCase());
+				return p;
+			});
+		}
+
 		@Bean
 		public Function<APIGatewayProxyRequestEvent, String> inputApiEvent() {
 			return v -> {

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

@@ -820,7 +820,12 @@ public class SimpleFunctionRegistry implements FunctionRegistry {
 			if (!this.isRoutingFunction() && !(input instanceof Publisher)) {
 				Object payload = input;
 				if (input instanceof Message) {
-					payload = ((Message) input).getPayload();
+					if (((Message) input).getHeaders().containsKey("payload")) {
+						payload = ((Message) input).getHeaders().get("payload");
+					}
+					else {
+						payload = ((Message) input).getPayload();
+					}
 				}
 				if (JsonMapper.isJsonStringRepresentsCollection(payload)
 						&& !FunctionTypeUtils.isTypeCollection(this.inputType) && !FunctionTypeUtils.isTypeArray(this.inputType)) {

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

@@ -39,6 +39,9 @@ public abstract class JsonMapper {
 	@SuppressWarnings("unchecked")
 	public <T> T fromJson(Object json, Type type) {
 		if (json instanceof Collection<?>) {
+			if (FunctionTypeUtils.isTypeCollection(type)) {
+				return (T) json;
+			}
 			Collection<?> inputs = (Collection<?>) json;
 			Type itemType = FunctionTypeUtils.getImmediateGenericType(type, 0);
 			Collection<?> results = FunctionTypeUtils.getRawType(type).isAssignableFrom(List.class)
@@ -112,6 +115,9 @@ public abstract class JsonMapper {
 
 	public static boolean isJsonStringRepresentsCollection(Object value) {
 		boolean isJson = false;
+		if (value instanceof Iterable && !value.getClass().getPackage().getName().startsWith("reactor.util.function")) {
+			return true;
+		}
 		if (value instanceof byte[]) {
 			value = new String((byte[]) value, StandardCharsets.UTF_8);
 		}