Polished BinderFactoryConfiguration to ensure MessageHandlerMethodFactory consistency

spring-cloud-stream/src/main/java/org/springframework/cloud/stream/config/BinderFactoryConfiguration.java

@@ -17,6 +17,7 @@
 package org.springframework.cloud.stream.config;
 
 import java.io.IOException;
+import java.lang.reflect.Field;
 import java.net.URL;
 import java.util.ArrayList;
 import java.util.Collection;
@@ -62,6 +63,7 @@ import org.springframework.messaging.handler.annotation.support.HeadersMethodArg
 import org.springframework.messaging.handler.annotation.support.MessageHandlerMethodFactory;
 import org.springframework.messaging.handler.invocation.HandlerMethodArgumentResolver;
 import org.springframework.util.ClassUtils;
+import org.springframework.util.ReflectionUtils;
 import org.springframework.util.StringUtils;
 import org.springframework.validation.Validator;
 
@@ -189,6 +191,13 @@ public class BinderFactoryConfiguration {
 		resolvers.add(new HeadersMethodArgumentResolver());
 		resolvers.addAll(ahmar.getResolvers());
 		
+		// modify HandlerMethodArgumentResolversHolder
+		Field field = ReflectionUtils.findField(HandlerMethodArgumentResolversHolder.class, "resolvers");
+		field.setAccessible(true);
+		((List<?>) ReflectionUtils.getField(field, ahmar)).clear();	
+		resolvers.forEach(ahmar::addResolver);
+		// --
+		
 		messageHandlerMethodFactory.setArgumentResolvers(resolvers);
 		messageHandlerMethodFactory.setValidator(validator);
 		return messageHandlerMethodFactory;

spring-cloud-stream/src/test/java/org/springframework/cloud/stream/binder/tck/ContentTypeTckTests.java

@@ -1051,4 +1051,28 @@ public class ContentTypeTckTests {
 			return value;
 		}
 	}
+	
+	@Test
+	public void testWithTypelessInputParameterAndServiceActivator() {
+		ApplicationContext context = new SpringApplicationBuilder(TypelessPayloadConfigurationSA.class)
+				.web(WebApplicationType.NONE)
+				.run("--spring.jmx.enabled=false");
+		InputDestination source = context.getBean(InputDestination.class);
+		OutputDestination target = context.getBean(OutputDestination.class);
+		String jsonPayload = "[\"foo\",\"bar\"]";
+		source.send(MessageBuilder.withPayload(jsonPayload.getBytes()).build());
+		Message<byte[]> outputMessage = target.receive();
+		assertEquals(jsonPayload, new String(outputMessage.getPayload(), StandardCharsets.UTF_8));
+	}
+	
+	@EnableBinding(Processor.class)
+	@Import(TestChannelBinderConfiguration.class)
+	@EnableAutoConfiguration
+	public static class TypelessPayloadConfigurationSA {
+		@ServiceActivator(inputChannel=Processor.INPUT, outputChannel=Processor.OUTPUT)
+		public Object echo(Object value) throws Exception {
+			System.out.println(value);
+			return value;
+		}
+	}
 }