Use LinkedHashmap to preserve insert order

In several places in the spring-webmvc module, URL patterns / objects
relationships are kept in `HashMap`s. When matching with actual URLs,
the algorithm uses a pattern comparator to sort the matching patterns
and select the most specific. But the underlying collection
implementation does not keep the original order which can lead to
inconsistencies.

This commit changes the underlying collection implementation to
`LinkedHashmap`s, in order to keep the insert order if the comparator
does not reorder entries.

Issue: SPR-13798

Author: bclozel

spring-webmvc/src/main/java/org/springframework/web/servlet/handler/SimpleUrlHandlerMapping.java

@@ -16,7 +16,7 @@
 
 package org.springframework.web.servlet.handler;
 
-import java.util.HashMap;
+import java.util.LinkedHashMap;
 import java.util.Map;
 import java.util.Properties;
 
@@ -55,7 +55,7 @@
  */
 public class SimpleUrlHandlerMapping extends AbstractUrlHandlerMapping {
 
-	private final Map<String, Object> urlMap = new HashMap<String, Object>();
+	private final Map<String, Object> urlMap = new LinkedHashMap<String, Object>();
 
 
 	/**

spring-webmvc/src/main/java/org/springframework/web/servlet/resource/ResourceUrlProvider.java

@@ -19,7 +19,7 @@
 import java.util.ArrayList;
 import java.util.Collections;
 import java.util.Comparator;
-import java.util.HashMap;
+import java.util.LinkedHashMap;
 import java.util.List;
 import java.util.Map;
 import javax.servlet.http.HttpServletRequest;
@@ -55,7 +55,7 @@ public class ResourceUrlProvider implements ApplicationListener<ContextRefreshed
 
 	private PathMatcher pathMatcher = new AntPathMatcher();
 
-	private final Map<String, ResourceHttpRequestHandler> handlerMap = new HashMap<String, ResourceHttpRequestHandler>();
+	private final Map<String, ResourceHttpRequestHandler> handlerMap = new LinkedHashMap<String, ResourceHttpRequestHandler>();
 
 	private boolean autodetect = true;
 

spring-webmvc/src/main/java/org/springframework/web/servlet/resource/VersionResourceResolver.java

@@ -19,9 +19,10 @@
 import java.util.ArrayList;
 import java.util.Collections;
 import java.util.Comparator;
-import java.util.HashMap;
+import java.util.LinkedHashMap;
 import java.util.List;
 import java.util.Map;
+
 import javax.servlet.http.HttpServletRequest;
 
 import org.springframework.core.io.Resource;
@@ -60,7 +61,7 @@ public class VersionResourceResolver extends AbstractResourceResolver {
 	private AntPathMatcher pathMatcher = new AntPathMatcher();
 
 	/** Map from path pattern -> VersionStrategy */
-	private final Map<String, VersionStrategy> versionStrategyMap = new HashMap<String, VersionStrategy>();
+	private final Map<String, VersionStrategy> versionStrategyMap = new LinkedHashMap<String, VersionStrategy>();
 
 
 	/**
@@ -209,17 +210,17 @@ protected String resolveUrlPathInternal(String resourceUrlPath, List<? extends R
 	 */
 	protected VersionStrategy getStrategyForPath(String requestPath) {
 		String path = "/".concat(requestPath);
-        List<String> matchingPatterns = new ArrayList<String>();
+		List<String> matchingPatterns = new ArrayList<String>();
 		for (String pattern : this.versionStrategyMap.keySet()) {
 			if (this.pathMatcher.match(pattern, path)) {
-                matchingPatterns.add(pattern);
+				matchingPatterns.add(pattern);
 			}
 		}
-        if (!matchingPatterns.isEmpty()) {
-            Comparator<String> comparator = this.pathMatcher.getPatternComparator(path);
-            Collections.sort(matchingPatterns, comparator);
-            return this.versionStrategyMap.get(matchingPatterns.get(0));
-        }
+		if (!matchingPatterns.isEmpty()) {
+			Comparator<String> comparator = this.pathMatcher.getPatternComparator(path);
+			Collections.sort(matchingPatterns, comparator);
+			return this.versionStrategyMap.get(matchingPatterns.get(0));
+		}
 		return null;
 	}