Merge pull request #1785 from cakofony/iterator_allocation

spring-messaging/src/main/java/org/springframework/messaging/handler/invocation/AbstractMethodMessageHandler.java

@@ -84,7 +84,7 @@ public abstract class AbstractMethodMessageHandler<T>
 
 	protected final Log logger = LogFactory.getLog(getClass());
 
-	private Collection<String> destinationPrefixes = new ArrayList<>();
+	private final List<String> destinationPrefixes = new ArrayList<>();
 
 	private final List<HandlerMethodArgumentResolver> customArgumentResolvers = new ArrayList<>(4);
 
@@ -420,6 +420,7 @@ public abstract class AbstractMethodMessageHandler<T>
 	 * <p>If there are no matching prefixes, return {@code null}.
 	 * <p>If there are no destination prefixes, return the destination as is.
 	 */
+	@SuppressWarnings("ForLoopReplaceableByForEach")
 	@Nullable
 	protected String getLookupDestination(@Nullable String destination) {
 		if (destination == null) {
@@ -428,7 +429,8 @@ public abstract class AbstractMethodMessageHandler<T>
 		if (CollectionUtils.isEmpty(this.destinationPrefixes)) {
 			return destination;
 		}
-		for (String prefix : this.destinationPrefixes) {
+		for (int i = 0; i < this.destinationPrefixes.size(); i++) {
+			String prefix = this.destinationPrefixes.get(i);
 			if (destination.startsWith(prefix)) {
 				return destination.substring(prefix.length());
 			}

spring-messaging/src/main/java/org/springframework/messaging/handler/invocation/HandlerMethodArgumentResolverComposite.java

@@ -71,9 +71,7 @@ public class HandlerMethodArgumentResolverComposite implements HandlerMethodArgu
 			@Nullable List<? extends HandlerMethodArgumentResolver> argumentResolvers) {
 
 		if (argumentResolvers != null) {
-			for (HandlerMethodArgumentResolver resolver : argumentResolvers) {
-				this.argumentResolvers.add(resolver);
-			}
+			this.argumentResolvers.addAll(argumentResolvers);
 		}
 		return this;
 	}

spring-messaging/src/main/java/org/springframework/messaging/handler/invocation/HandlerMethodReturnValueHandlerComposite.java

@@ -1,5 +1,6 @@
 /*
- * Copyright 2002-2017 the original author or authors.
+/*
+ * Copyright 2002-2018 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.
@@ -71,9 +72,7 @@ public class HandlerMethodReturnValueHandlerComposite implements AsyncHandlerMet
 			@Nullable List<? extends HandlerMethodReturnValueHandler> handlers) {
 
 		if (handlers != null) {
-			for (HandlerMethodReturnValueHandler handler : handlers) {
-				this.returnValueHandlers.add(handler);
-			}
+			this.returnValueHandlers.addAll(handlers);
 		}
 		return this;
 	}
@@ -83,9 +82,11 @@ public class HandlerMethodReturnValueHandlerComposite implements AsyncHandlerMet
 		return getReturnValueHandler(returnType) != null;
 	}
 
+	@SuppressWarnings("ForLoopReplaceableByForEach")
 	@Nullable
 	private HandlerMethodReturnValueHandler getReturnValueHandler(MethodParameter returnType) {
-		for (HandlerMethodReturnValueHandler handler : this.returnValueHandlers) {
+		for (int i = 0; i < this.returnValueHandlers.size(); i++) {
+			HandlerMethodReturnValueHandler handler = this.returnValueHandlers.get(i);
 			if (handler.supportsReturnType(returnType)) {
 				return handler;
 			}