INT-3632: Sonar Improvements

JIRA: https://jira.spring.io/browse/INT-3632

- Use Map.entrySet()
- Double check locking only works when the field(s) are volatile
- Remove unnecessary instanceof tests

spring-integration-core/src/main/java/org/springframework/integration/aggregator/AbstractAggregatingMessageGroupProcessor.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2014 the original author or authors.
+ * Copyright 2002-2015 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
@@ -16,6 +16,7 @@ package org.springframework.integration.aggregator;
 import java.util.HashMap;
 import java.util.HashSet;
 import java.util.Map;
+import java.util.Map.Entry;
 import java.util.Set;
 
 import org.apache.commons.logging.Log;
@@ -41,6 +42,7 @@ import org.springframework.util.Assert;
  * @author Alexander Peters
  * @author Mark Fisher
  * @author Dave Syer
+ * @author Gary Russell
  * @since 2.0
  */
 public abstract class AbstractAggregatingMessageGroupProcessor implements MessageGroupProcessor,
@@ -84,13 +86,13 @@ public abstract class AbstractAggregatingMessageGroupProcessor implements Messag
 		Map<String, Object> aggregatedHeaders = new HashMap<String, Object>();
 		Set<String> conflictKeys = new HashSet<String>();
 		for (Message<?> message : group.getMessages()) {
-			MessageHeaders currentHeaders = message.getHeaders();
-			for (String key : currentHeaders.keySet()) {
+			for (Entry<String, Object> entry : message.getHeaders().entrySet()) {
+				String key = entry.getKey();
 				if (MessageHeaders.ID.equals(key) || MessageHeaders.TIMESTAMP.equals(key)
 						|| IntegrationMessageHeaderAccessor.SEQUENCE_SIZE.equals(key) || IntegrationMessageHeaderAccessor.SEQUENCE_NUMBER.equals(key)) {
 					continue;
 				}
-				Object value = currentHeaders.get(key);
+				Object value = entry.getValue();
 				if (!aggregatedHeaders.containsKey(key)) {
 					aggregatedHeaders.put(key, value);
 				}

spring-integration-core/src/main/java/org/springframework/integration/aggregator/MethodInvokingCorrelationStrategy.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2014 the original author or authors.
+ * Copyright 2002-2015 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.
@@ -21,7 +21,6 @@ import java.lang.reflect.Method;
 import org.springframework.beans.BeansException;
 import org.springframework.beans.factory.BeanFactory;
 import org.springframework.beans.factory.BeanFactoryAware;
-import org.springframework.integration.handler.MessageProcessor;
 import org.springframework.integration.handler.MethodInvokingMessageProcessor;
 import org.springframework.messaging.Message;
 import org.springframework.util.Assert;
@@ -32,10 +31,11 @@ import org.springframework.util.Assert;
  * @author Marius Bogoevici
  * @author Dave Syer
  * @author Artem Bilan
+ * @author Gary Russell
  */
 public class MethodInvokingCorrelationStrategy implements CorrelationStrategy, BeanFactoryAware {
 
-	private final MessageProcessor<?> processor;
+	private final MethodInvokingMessageProcessor<?> processor;
 
 	public MethodInvokingCorrelationStrategy(Object object, String methodName) {
 		this.processor = new MethodInvokingMessageProcessor<Object>(object, methodName, true);
@@ -50,8 +50,8 @@ public class MethodInvokingCorrelationStrategy implements CorrelationStrategy, B
 
 	@Override
 	public void setBeanFactory(BeanFactory beanFactory) throws BeansException {
-		if (beanFactory != null && this.processor instanceof BeanFactoryAware) {
-			((BeanFactoryAware) this.processor).setBeanFactory(beanFactory);
+		if (beanFactory != null) {
+			this.processor.setBeanFactory(beanFactory);
 		}
 	}
 
@@ -59,4 +59,5 @@ public class MethodInvokingCorrelationStrategy implements CorrelationStrategy, B
 	public Object getCorrelationKey(Message<?> message) {
 		return processor.processMessage(message);
 	}
+
 }

spring-integration-core/src/main/java/org/springframework/integration/channel/FixedSubscriberChannel.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2014 the original author or authors.
+ * Copyright 2014-2015 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.
@@ -21,7 +21,6 @@ import org.apache.commons.logging.LogFactory;
 import org.springframework.beans.factory.BeanNameAware;
 import org.springframework.integration.support.context.NamedComponent;
 import org.springframework.messaging.Message;
-import org.springframework.messaging.MessageDeliveryException;
 import org.springframework.messaging.MessageHandler;
 import org.springframework.messaging.MessagingException;
 import org.springframework.messaging.SubscribableChannel;
@@ -70,16 +69,14 @@ public final class FixedSubscriberChannel implements SubscribableChannel, BeanNa
 			this.handler.handleMessage(message);
 			return true;
 		}
-		catch (Exception e) {
-			RuntimeException runtimeException = (e instanceof RuntimeException)
-					? (RuntimeException) e
-					: new MessageDeliveryException(message,
-							this.getComponentName() + " failed to deliver Message.", e);
+		catch (RuntimeException e) {
 			if (e instanceof MessagingException &&
 					((MessagingException) e).getFailedMessage() == null) {
-				runtimeException = new MessagingException(message, e);
+				throw new MessagingException(message, e);
+			}
+			else {
+				throw e;
 			}
-			throw runtimeException;
 		}
 	}
 

spring-integration-core/src/main/java/org/springframework/integration/config/GlobalChannelInterceptorProcessor.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2014 the original author or authors.
+ * Copyright 2002-2015 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.
@@ -70,7 +70,7 @@ final class GlobalChannelInterceptorProcessor implements BeanFactoryAware, Smart
 	@Override
 	public void setBeanFactory(BeanFactory beanFactory) throws BeansException {
 		Assert.isInstanceOf(ListableBeanFactory.class, beanFactory);
-		this.beanFactory = (ListableBeanFactory) beanFactory;
+		this.beanFactory = (ListableBeanFactory) beanFactory;//NOSONAR (inconsistent sync)
 	}
 
 	@Override

spring-integration-core/src/main/java/org/springframework/integration/config/IdempotentReceiverAutoProxyCreator.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2014 the original author or authors.
+ * Copyright 2014-2015 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.
@@ -37,18 +37,19 @@ import org.springframework.util.PatternMatchUtils;
  * to {@link MessageHandler}s mapped by their {@code endpoint beanName}.
  *
  * @author Artem Bilan
+ * @author Gary Russell
  * @since 4.1
  */
 @SuppressWarnings("serial")
 class IdempotentReceiverAutoProxyCreator extends AbstractAutoProxyCreator {
 
-	private List<Map<String, String>> idempotentEndpointsMapping;
+	private volatile List<Map<String, String>> idempotentEndpointsMapping;
 
-	private Map<String, List<String>> idempotentEndpoints;
+	private volatile Map<String, List<String>> idempotentEndpoints; // double check locking requires volatile
 
 	public void setIdempotentEndpointsMapping(List<Map<String, String>> idempotentEndpointsMapping) {
 		Assert.notEmpty(idempotentEndpointsMapping);
-		this.idempotentEndpointsMapping = idempotentEndpointsMapping;
+		this.idempotentEndpointsMapping = idempotentEndpointsMapping;//NOSONAR (inconsistent sync)
 	}
 
 	@Override
@@ -82,7 +83,7 @@ class IdempotentReceiverAutoProxyCreator extends AbstractAutoProxyCreator {
 	}
 
 	private void initIdempotentEndpointsIfNecessary() {
-		if (this.idempotentEndpoints == null) {
+		if (this.idempotentEndpoints == null) {//NOSONAR (inconsistent sync)
 			synchronized (this) {
 				if (this.idempotentEndpoints == null) {
 					this.idempotentEndpoints = new LinkedHashMap<String, List<String>>();

spring-integration-core/src/main/java/org/springframework/integration/config/xml/IntegrationNamespaceUtils.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2014 the original author or authors.
+ * Copyright 2002-2015 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
@@ -300,8 +300,7 @@ public abstract class IntegrationNamespaceUtils {
 		String ref = element.getAttribute(REF_ATTRIBUTE);
 		if (StringUtils.hasText(ref) && innerComponentDefinition != null) {
 			parserContext.getReaderContext().error(
-				"Ambiguous definition. Inner bean " + (innerComponentDefinition == null ? innerComponentDefinition
-						: innerComponentDefinition.getBeanDefinition().getBeanClassName())
+				"Ambiguous definition. Inner bean " + (innerComponentDefinition.getBeanDefinition().getBeanClassName())
 						+ " declaration and \"ref\" " + ref + " are not allowed together on element " +
 					IntegrationNamespaceUtils.createElementDescription(element) + ".", parserContext.extractSource(element));
 		}

spring-integration-core/src/main/java/org/springframework/integration/dispatcher/UnicastingDispatcher.java

@@ -147,7 +147,7 @@ public class UnicastingDispatcher extends AbstractDispatcher {
 			if (allExceptions != null && allExceptions.size() == 1) {
 				throw allExceptions.get(0);
 			}
-			throw new AggregateMessageDeliveryException(message,
+			throw new AggregateMessageDeliveryException(message,//NOSONAR - false positive
 					"All attempts to deliver Message to MessageHandlers failed.", allExceptions);
 		}
 	}

spring-integration-core/src/main/java/org/springframework/integration/endpoint/AbstractPollingEndpoint.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2014 the original author or authors.
+ * Copyright 2002-2015 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.
@@ -116,10 +116,6 @@ public abstract class AbstractPollingEndpoint extends AbstractEndpoint implement
 				return;
 			}
 			Assert.notNull(this.trigger, "Trigger is required");
-			Executor providedExecutor = this.taskExecutor;
-			if (providedExecutor != null) {
-				this.taskExecutor = providedExecutor;
-			}
 			if (this.taskExecutor != null) {
 				if (!(this.taskExecutor instanceof ErrorHandlingTaskExecutor)) {
 					if (this.errorHandler == null) {

spring-integration-core/src/main/java/org/springframework/integration/endpoint/MessageProducerSupport.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2014 the original author or authors.
+ * Copyright 2002-2015 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.
@@ -22,7 +22,6 @@ import org.springframework.integration.history.MessageHistory;
 import org.springframework.integration.history.TrackableComponent;
 import org.springframework.messaging.Message;
 import org.springframework.messaging.MessageChannel;
-import org.springframework.messaging.MessageDeliveryException;
 import org.springframework.messaging.MessagingException;
 import org.springframework.messaging.support.ErrorMessage;
 import org.springframework.util.Assert;
@@ -33,6 +32,7 @@ import org.springframework.util.Assert;
  *
  * @author Mark Fisher
  * @author Artem Bilan
+ * @author Gary Russell
  */
 public abstract class MessageProducerSupport extends AbstractEndpoint implements MessageProducer, TrackableComponent {
 
@@ -100,15 +100,12 @@ public abstract class MessageProducerSupport extends AbstractEndpoint implements
 		try {
 			this.messagingTemplate.send(this.outputChannel, message);
 		}
-		catch (Exception e) {
+		catch (RuntimeException e) {
 			if (this.errorChannel != null) {
 				this.messagingTemplate.send(this.errorChannel, new ErrorMessage(e));
 			}
-			else if (e instanceof RuntimeException) {
-				throw (RuntimeException) e;
-			}
-			else {
-				throw new MessageDeliveryException(message, "failed to send message", e);
+			else  {
+				throw e;
 			}
 		}
 	}

spring-integration-core/src/main/java/org/springframework/integration/gateway/GatewayMethodInboundMessageMapper.java

@@ -22,6 +22,7 @@ import java.util.HashMap;
 import java.util.LinkedList;
 import java.util.List;
 import java.util.Map;
+import java.util.Map.Entry;
 
 import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
@@ -203,7 +204,8 @@ class GatewayMethodInboundMessageMapper implements InboundMessageMapper<Object[]
 
 
 	private void copyHeaders(Map<?, ?> argumentValue, Map<String, Object> headers) {
-		for (Object key : argumentValue.keySet()) {
+		for (Entry<?, ?> entry : argumentValue.entrySet()) {
+			Object key = entry.getKey();
 			if (!(key instanceof String)) {
 				if (this.logger.isWarnEnabled()){
 					this.logger.warn("Invalid header name [" + key +
@@ -211,8 +213,7 @@ class GatewayMethodInboundMessageMapper implements InboundMessageMapper<Object[]
 				}
 			}
 			else {
-				Object value = argumentValue.get(key);
-				headers.put((String) key, value);
+				headers.put((String) key, entry.getValue());
 			}
 		}
 	}

spring-integration-core/src/main/java/org/springframework/integration/handler/AbstractMessageProducingHandler.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2014 the original author or authors.
+ * Copyright 2014-2015 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.
@@ -41,6 +41,7 @@ import org.springframework.util.StringUtils;
  *
  * @author David Liu
  * @author Artem Bilan
+ * @author Gary Russell
  * since 4.1
  */
 public abstract class AbstractMessageProducingHandler extends AbstractMessageHandler
@@ -48,9 +49,9 @@ public abstract class AbstractMessageProducingHandler extends AbstractMessageHan
 
 	protected final MessagingTemplate messagingTemplate = new MessagingTemplate();
 
-	private MessageChannel outputChannel;
+	private volatile MessageChannel outputChannel;
 
-	private String outputChannelName;
+	private volatile String outputChannelName;
 
 	/**
 	 * Set the timeout for sending reply Messages.
@@ -67,7 +68,7 @@ public abstract class AbstractMessageProducingHandler extends AbstractMessageHan
 
 	public void setOutputChannelName(String outputChannelName) {
 		Assert.hasText(outputChannelName, "'outputChannelName' must not be empty");
-		this.outputChannelName = outputChannelName;
+		this.outputChannelName = outputChannelName;//NOSONAR (inconsistent sync)
 	}
 
 	/**
@@ -82,7 +83,7 @@ public abstract class AbstractMessageProducingHandler extends AbstractMessageHan
 	@Override
 	protected void onInit() throws Exception {
 		super.onInit();
-		Assert.state(!(this.outputChannelName != null && this.outputChannel != null),
+		Assert.state(!(this.outputChannelName != null && this.outputChannel != null),//NOSONAR (inconsistent sync)
 				"'outputChannelName' and 'outputChannel' are mutually exclusive.");
 		if (getBeanFactory() != null) {
 			this.messagingTemplate.setBeanFactory(getBeanFactory());

spring-integration-core/src/main/java/org/springframework/integration/handler/ServiceActivatingHandler.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2014 the original author or authors.
+ * Copyright 2002-2015 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.
@@ -22,7 +22,6 @@ import org.springframework.beans.factory.BeanFactoryAware;
 import org.springframework.context.Lifecycle;
 import org.springframework.integration.annotation.ServiceActivator;
 import org.springframework.messaging.Message;
-import org.springframework.messaging.MessageHandlingException;
 
 /**
  * @author Mark Fisher
@@ -87,15 +86,7 @@ public class ServiceActivatingHandler extends AbstractReplyProducingMessageHandl
 
 	@Override
 	protected Object handleRequestMessage(Message<?> message) {
-		try {
-			return this.processor.processMessage(message);
-		}
-		catch (Exception e) {
-			if (e instanceof RuntimeException) {
-				throw (RuntimeException) e;
-			}
-			throw new MessageHandlingException(message, "failure occurred in '" + this + "'", e);
-		}
+		return this.processor.processMessage(message);
 	}
 
 	@Override

spring-integration-core/src/main/java/org/springframework/integration/mapping/AbstractHeaderMapper.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2014 the original author or authors.
+ * Copyright 2002-2015 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.
@@ -23,6 +23,7 @@ import java.util.Collection;
 import java.util.Collections;
 import java.util.HashMap;
 import java.util.Map;
+import java.util.Map.Entry;
 
 import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
@@ -40,6 +41,7 @@ import org.springframework.util.StringUtils;
  * @author Mark Fisher
  * @author Oleg Zhurakousky
  * @author Stephane Nicoll
+ * @author Gary Russell
  * @since 2.1
  */
 public abstract class AbstractHeaderMapper<T> implements RequestReplyHeaderMapper<T> {
@@ -195,8 +197,9 @@ public abstract class AbstractHeaderMapper<T> implements RequestReplyHeaderMappe
 	}
 
 	private void populateUserDefinedHeaders(Map<String, Object> headers, T target) {
-		for (String headerName : headers.keySet()) {
-			Object value = headers.get(headerName);
+		for (Entry<String, Object> entry : headers.entrySet()) {
+			String headerName = entry.getKey();
+			Object value = entry.getValue();
 			if (value != null && !isMessageChannel(headerName, value)) {
 				try {
 					if (!headerName.startsWith(this.standardHeaderPrefix)) {

spring-integration-core/src/main/java/org/springframework/integration/router/PayloadTypeRouter.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2011 the original author or authors.
+ * Copyright 2002-2015 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.
@@ -27,9 +27,10 @@ import org.springframework.util.CollectionUtils;
 /**
  * A Message Router that resolves the {@link MessageChannel} based on the
  * {@link Message Message's} payload type.
- * 
+ *
  * @author Mark Fisher
  * @author Oleg Zhurakousky
+ * @author Gary Russell
  */
 public class PayloadTypeRouter extends AbstractMappingMessageRouter {
 
@@ -102,7 +103,7 @@ public class PayloadTypeRouter extends AbstractMappingMessageRouter {
 		}
 		for (Class<?> iface : type.getInterfaces()) {
 			if (iface.getName().equals(candidate)) {
-				return (level % 2 == 1) ? level + 2 : level + 1; 
+				return (level % 2 != 0) ? level + 2 : level + 1;
 			}
 			// no match at this level, continue up the hierarchy
 			for (Class<?> superInterface : iface.getInterfaces()) {

spring-integration-core/src/main/java/org/springframework/integration/transformer/HeaderEnricher.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2014 the original author or authors.
+ * Copyright 2002-2015 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.
@@ -18,6 +18,7 @@ package org.springframework.integration.transformer;
 
 import java.util.HashMap;
 import java.util.Map;
+import java.util.Map.Entry;
 
 import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
@@ -40,6 +41,7 @@ import org.springframework.messaging.MessagingException;
  * @author Mark Fisher
  * @author David Turanski
  * @author Artem Bilan
+ * @author Gary Russell
  */
 public class HeaderEnricher extends IntegrationObjectSupport implements Transformer, BeanNameAware, InitializingBean {
 
@@ -127,16 +129,16 @@ public class HeaderEnricher extends IntegrationObjectSupport implements Transfor
 		}
 	}
 
-	@SuppressWarnings("rawtypes")
 	private void addHeadersFromMessageProcessor(Message<?> message, Map<String, Object> headerMap) {
 		if (this.messageProcessor != null) {
 			Object result = this.messageProcessor.processMessage(message);
 			if (result instanceof Map) {
-				Map resultMap = (Map) result;
-				for (Object key : resultMap.keySet()) {
+				Map<?, ?> resultMap = (Map<?, ?>) result;
+				for (Entry<?, ?> entry : resultMap.entrySet()) {
+					Object key = entry.getKey();
 					if (key instanceof String) {
 						if (this.defaultOverwrite || headerMap.get(key) == null) {
-							headerMap.put((String) key, resultMap.get(key));
+							headerMap.put((String) key, entry.getValue());
 						}
 					}
 					else if (logger.isDebugEnabled()) {

spring-integration-core/src/main/java/org/springframework/integration/transformer/ObjectToMapTransformer.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2014 the original author or authors.
+ * Copyright 2002-2015 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.
@@ -19,9 +19,10 @@ package org.springframework.integration.transformer;
 import java.util.Collection;
 import java.util.HashMap;
 import java.util.Map;
+import java.util.Map.Entry;
 
-import org.springframework.integration.support.json.JsonObjectMapperProvider;
 import org.springframework.integration.support.json.JsonObjectMapper;
+import org.springframework.integration.support.json.JsonObjectMapperProvider;
 import org.springframework.util.CollectionUtils;
 import org.springframework.util.StringUtils;
 
@@ -50,6 +51,7 @@ import org.springframework.util.StringUtils;
  *
  * @author Oleg Zhurakousky
  * @author Artem Bilan
+ * @author Gary Russell
  * @since 2.0
  */
 public class ObjectToMapTransformer extends AbstractPayloadTransformer<Object, Map<?,?>> {
@@ -104,9 +106,8 @@ public class ObjectToMapTransformer extends AbstractPayloadTransformer<Object, M
 		if (StringUtils.hasText(propertyPrefix)) {
 			propertyPrefix = propertyPrefix + ".";
 		}
-		for (String key : inputMap.keySet()) {
-			Object value = inputMap.get(key);
-			this.doProcessElement(propertyPrefix + key, value, resultMap);
+		for (Entry<String, Object> entry : inputMap.entrySet()) {
+			this.doProcessElement(propertyPrefix + entry.getKey(), entry.getValue(), resultMap);
 		}
 	}
 

spring-integration-core/src/main/java/org/springframework/integration/transformer/support/RoutingSlipHeaderValueMessageProcessor.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2014 the original author or authors.
+ * Copyright 2014-2015 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.
@@ -42,6 +42,7 @@ import org.springframework.util.Assert;
  * with the {@code path} as {@code key} and {@code 0} as initial {@code routingSlipIndex}.
  *
  * @author Artem Bilan
+ * @author Gary Russell
  * @since 4.1
  */
 public class RoutingSlipHeaderValueMessageProcessor
@@ -74,17 +75,21 @@ public class RoutingSlipHeaderValueMessageProcessor
 	@Override
 	public void setBeanFactory(BeanFactory beanFactory) throws BeansException {
 		Assert.notNull(beanFactory, "BeanFactory must not be null");
-		this.beanFactory = beanFactory;
-		this.evaluationContext = IntegrationContextUtils.getEvaluationContext(beanFactory);
+		this.beanFactory = beanFactory;//NOSONAR (inconsistent sync)
+		this.evaluationContext = IntegrationContextUtils.getEvaluationContext(beanFactory);//NOSONAR (inconsistent sync)
 	}
 
 	@Override
 	public Map<List<Object>, Integer> processMessage(Message<?> message) {
-		if (this.routingSlip == null) {
+		// use a local variable to avoid the second access to volatile field on the happy path
+		Map<List<Object>, Integer> routingSlip = this.routingSlip;
+		if (routingSlip == null) {
 			synchronized (this) {
-				if (this.routingSlip == null) {
-					List<Object> routingSlipValues = new ArrayList<Object>(this.routingSlipPath.size());
-					for (Object path : this.routingSlipPath) {
+				routingSlip = this.routingSlip;
+				if (routingSlip == null) {
+					List<Object> routingSlipPath = this.routingSlipPath;
+					List<Object> routingSlipValues = new ArrayList<Object>(routingSlipPath.size());
+					for (Object path : routingSlipPath) {
 						if (path instanceof String) {
 							String entry = (String) path;
 							if (this.beanFactory.containsBean(entry)) {
@@ -108,10 +113,11 @@ public class RoutingSlipHeaderValueMessageProcessor
 						}
 
 					}
-					this.routingSlip = Collections.singletonMap(Collections.unmodifiableList(routingSlipValues), 0);
+					routingSlip = Collections.singletonMap(Collections.unmodifiableList(routingSlipValues), 0);
+					this.routingSlip = routingSlip;
 				}
 			}
 		}
-		return this.routingSlip;
+		return routingSlip;
 	}
 }