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-http/src/main/java/org/springframework/integration/http/converter/MultipartAwareFormHttpMessageConverter.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.
@@ -20,6 +20,7 @@ import java.io.IOException;
 import java.nio.charset.Charset;
 import java.util.List;
 import java.util.Map;
+import java.util.Map.Entry;
 
 import org.springframework.http.HttpInputMessage;
 import org.springframework.http.HttpOutputMessage;
@@ -42,6 +43,7 @@ import org.springframework.web.multipart.MultipartFile;
  * <code>multipart/form-data</code> content in an HTTP request.
  *
  * @author Mark Fisher
+ * @author Gary Russell
  * @since 2.0
  */
 public class MultipartAwareFormHttpMessageConverter implements HttpMessageConverter<MultiValueMap<String, ?>> {
@@ -112,11 +114,10 @@ public class MultipartAwareFormHttpMessageConverter implements HttpMessageConver
 	private MultiValueMap<String, ?> readMultipart(MultipartHttpInputMessage multipartRequest) throws IOException {
 		MultiValueMap<String, Object> resultMap = new LinkedMultiValueMap<String, Object>();
 		Map<?, ?> parameterMap = multipartRequest.getParameterMap();
-		for (Object key : parameterMap.keySet()) {
-			resultMap.add((String) key, parameterMap.get(key));
+		for (Entry<?, ?> entry : parameterMap.entrySet()) {
+			resultMap.add((String) entry.getKey(), entry.getValue());
 		}
-		Map<String, MultipartFile> fileMap = multipartRequest.getFileMap();
-		for (Map.Entry<String, MultipartFile> entry : fileMap.entrySet()) {
+		for (Map.Entry<String, MultipartFile> entry : multipartRequest.getFileMap().entrySet()) {
 			MultipartFile multipartFile = entry.getValue();
 			if (multipartFile.isEmpty()) {
 				continue;

spring-integration-http/src/main/java/org/springframework/integration/http/converter/SerializingHttpMessageConverter.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2012 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.
@@ -61,7 +61,7 @@ public class SerializingHttpMessageConverter extends AbstractHttpMessageConverte
 	@SuppressWarnings("rawtypes")
 	public Serializable readInternal(Class clazz, HttpInputMessage inputMessage) throws IOException {
 		try {
-			return (Serializable) new ObjectInputStream(inputMessage.getBody()).readObject();
+			return (Serializable) new ObjectInputStream(inputMessage.getBody()).readObject();//NOSONAR
 		}
 		catch (ClassNotFoundException e) {
 			throw new IllegalArgumentException(e);

spring-integration-http/src/main/java/org/springframework/integration/http/outbound/HttpRequestExecutingMessageHandler.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.
@@ -24,6 +24,7 @@ import java.util.Collection;
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
+import java.util.Map.Entry;
 
 import javax.xml.transform.Source;
 
@@ -556,11 +557,11 @@ public class HttpRequestExecutingMessageHandler extends AbstractReplyProducingMe
 
 	private MultiValueMap<Object, Object> convertToMultiValueMap(Map<?, ?> simpleMap) {
 		LinkedMultiValueMap<Object, Object> multipartValueMap = new LinkedMultiValueMap<Object, Object>();
-		for (Object key : simpleMap.keySet()) {
-			Object value = simpleMap.get(key);
+		for (Entry<?, ?> entry : simpleMap.entrySet()) {
+			Object key = entry.getKey();
+			Object value = entry.getValue();
 			if (value instanceof Object[]) {
-				Object[] valueArray = (Object[]) value;
-				value = Arrays.asList(valueArray);
+				value = Arrays.asList((Object[]) value);
 			}
 			if (value instanceof Collection) {
 				multipartValueMap.put(key, new ArrayList<Object>((Collection<?>) value));
@@ -577,8 +578,7 @@ public class HttpRequestExecutingMessageHandler extends AbstractReplyProducingMe
 	 * the Map to be multipart/form-data
 	 */
 	private boolean isMultipart(Map<String, ?> map) {
-		for (String key : map.keySet()) {
-			Object value = map.get(key);
+		for (Object value : map.values()) {
 			if (value != null) {
 				if (value.getClass().isArray()) {
 					value = CollectionUtils.arrayToList(value);

spring-integration-http/src/main/java/org/springframework/integration/http/support/DefaultHttpHeaderMapper.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.
@@ -33,6 +33,7 @@ import java.util.HashSet;
 import java.util.List;
 import java.util.Locale;
 import java.util.Map;
+import java.util.Map.Entry;
 import java.util.Set;
 import java.util.TimeZone;
 
@@ -308,7 +309,7 @@ public class DefaultHttpHeaderMapper implements HeaderMapper<HttpHeaders>, BeanF
 	public void setOutboundHeaderNames(String[] outboundHeaderNames) {
 		this.outboundHeaderNames = (outboundHeaderNames != null) ? outboundHeaderNames : new String[0];
 		this.outboundHeaderNamesLower = new String[this.outboundHeaderNames.length];
-		for (int i = 0; i < outboundHeaderNames.length; i++) {
+		for (int i = 0; i < this.outboundHeaderNames.length; i++) {
 			if (HTTP_REQUEST_HEADER_NAME_PATTERN.equals(this.outboundHeaderNames[i])
 					|| HTTP_RESPONSE_HEADER_NAME_PATTERN.equals(this.outboundHeaderNames[i])) {
 				this.outboundHeaderNamesLower[i] = this.outboundHeaderNames[i];
@@ -335,7 +336,7 @@ public class DefaultHttpHeaderMapper implements HeaderMapper<HttpHeaders>, BeanF
 	public void setInboundHeaderNames(String[] inboundHeaderNames) {
 		this.inboundHeaderNames = (inboundHeaderNames != null) ? inboundHeaderNames : new String[0];
 		this.inboundHeaderNamesLower = new String[this.inboundHeaderNames.length];
-		for (int i = 0; i < inboundHeaderNames.length; i++) {
+		for (int i = 0; i < this.inboundHeaderNames.length; i++) {
 			if (HTTP_REQUEST_HEADER_NAME_PATTERN.equals(this.inboundHeaderNames[i])
 					|| HTTP_RESPONSE_HEADER_NAME_PATTERN.equals(this.inboundHeaderNames[i])) {
 				this.inboundHeaderNamesLower[i] = this.inboundHeaderNames[i];
@@ -387,11 +388,11 @@ public class DefaultHttpHeaderMapper implements HeaderMapper<HttpHeaders>, BeanF
 			logger.debug(MessageFormat.format("outboundHeaderNames={0}",
 					CollectionUtils.arrayToList(outboundHeaderNames)));
 		}
-		Set<String> headerNames = headers.keySet();
-		for (String name : headerNames) {
+		for (Entry<String, Object> entry : headers.entrySet()) {
+			String name = entry.getKey();
 			String lowerName = name.toLowerCase();
 			if (this.shouldMapOutboundHeader(lowerName)) {
-				Object value = headers.get(name);
+				Object value = entry.getValue();
 				if (value != null) {
 					if (!HTTP_REQUEST_HEADER_NAMES_LOWER.contains(lowerName) &&
 							!HTTP_RESPONSE_HEADER_NAMES_LOWER.contains(lowerName) &&