Small Code improvements for Object Mapper auto configuration (#985)

spring-cloud-aws-autoconfigure/src/main/java/io/awspring/cloud/autoconfigure/sqs/SqsAutoConfiguration.java

@@ -99,14 +99,17 @@ public SqsMessageListenerContainerFactory<Object> defaultSqsListenerContainerFac
 		errorHandler.ifAvailable(factory::setErrorHandler);
 		interceptors.forEach(factory::addMessageInterceptor);
 		asyncInterceptors.forEach(factory::addMessageInterceptor);
-		objectMapperProvider.ifAvailable(objectMapper -> {
-			var messageConverter = new SqsMessagingMessageConverter();
-			messageConverter.setObjectMapper(objectMapper);
-			factory.configure(options -> options.messageConverter(messageConverter));
-		});
+		objectMapperProvider.ifAvailable(objectMapper -> setObjectMapper(factory, objectMapper));
 		return factory;
 	}
 
+	private void setObjectMapper(SqsMessageListenerContainerFactory<Object> factory, ObjectMapper objectMapper) {
+		// Object Mapper for early deserialization in MessageSource
+		var messageConverter = new SqsMessagingMessageConverter();
+		messageConverter.setObjectMapper(objectMapper);
+		factory.configure(options -> options.messageConverter(messageConverter));
+	}
+
 	private void configureContainerOptions(ContainerOptionsBuilder<?, ?> options) {
 		PropertyMapper mapper = PropertyMapper.get().alwaysApplyingWhenNonNull();
 		mapper.from(this.sqsProperties.getListener().getMaxConcurrentMessages()).to(options::maxConcurrentMessages);
@@ -118,6 +121,7 @@ private void configureContainerOptions(ContainerOptionsBuilder<?, ?> options) {
 	public SqsListenerConfigurer objectMapperCustomizer(ObjectProvider<ObjectMapper> objectMapperProvider) {
 		ObjectMapper objectMapper = objectMapperProvider.getIfUnique();
 		return registrar -> {
+			// Object Mapper for SqsListener annotations handler method
 			if (registrar.getObjectMapper() == null && objectMapper != null) {
 				registrar.setObjectMapper(objectMapper);
 			}

spring-cloud-aws-sqs/src/main/java/io/awspring/cloud/sqs/config/EndpointRegistrar.java

@@ -28,6 +28,7 @@
 import org.springframework.beans.factory.BeanFactory;
 import org.springframework.beans.factory.BeanFactoryAware;
 import org.springframework.beans.factory.SmartInitializingSingleton;
+import org.springframework.lang.Nullable;
 import org.springframework.messaging.MessageHandler;
 import org.springframework.messaging.converter.MessageConverter;
 import org.springframework.messaging.handler.annotation.support.DefaultMessageHandlerMethodFactory;
@@ -58,6 +59,7 @@ public class EndpointRegistrar implements BeanFactoryAware, SmartInitializingSin
 
 	private MessageListenerContainerRegistry listenerContainerRegistry;
 
+	@Nullable
 	private String messageListenerContainerRegistryBeanName;
 
 	private String defaultListenerContainerFactoryBeanName = DEFAULT_LISTENER_CONTAINER_FACTORY_BEAN_NAME;
@@ -70,7 +72,10 @@ public class EndpointRegistrar implements BeanFactoryAware, SmartInitializingSin
 	private Consumer<List<HandlerMethodArgumentResolver>> methodArgumentResolversConsumer = resolvers -> {
 	};
 
+	@Nullable
 	private ObjectMapper objectMapper;
+
+	@Nullable
 	private Validator validator;
 
 	/**
@@ -167,6 +172,7 @@ public Consumer<List<HandlerMethodArgumentResolver>> getMethodArgumentResolversC
 	 * Get the object mapper used to deserialize payloads.
 	 * @return the object mapper instance.
 	 */
+	@Nullable
 	public ObjectMapper getObjectMapper() {
 		return this.objectMapper;
 	}
@@ -185,6 +191,7 @@ public MessageHandlerMethodFactory getMessageHandlerMethodFactory() {
 	 * instances.
 	 * @return the payload validator.
 	 */
+	@Nullable
 	public Validator getValidator() {
 		return this.validator;
 	}