PathMatchingResourcePatternResolver consistently logs retrieval results

Issue: SPR-13923
(cherry picked from commit 449f704)

Author: jhoeller

spring-core/src/main/java/org/springframework/core/io/support/PathMatchingResourcePatternResolver.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2015 the original author or authors.
+ * Copyright 2002-2016 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.
@@ -156,9 +156,9 @@
  *     classpath:com/mycompany/**/service-context.xml
  * </pre>
  * is used to try to resolve it, the resolver will work off the (first) URL
- * returned by {@code getResource("com/mycompany");}. If this base package
- * node exists in multiple classloader locations, the actual end resource may
- * not be underneath. Therefore, preferably, use "{@code classpath*:}" with the same
+ * returned by {@code getResource("com/mycompany");}. If this base package node
+ * exists in multiple classloader locations, the actual end resource may not be
+ * underneath. Therefore, preferably, use "{@code classpath*:}" with the same
  * Ant-style pattern in such a case, which will search <i>all</i> class path
  * locations that contain the root package.
  *
@@ -308,6 +308,9 @@ protected Resource[] findAllClassPathResources(String location) throws IOExcepti
 			path = path.substring(1);
 		}
 		Set<Resource> result = doFindAllClassPathResources(path);
+		if (logger.isDebugEnabled()) {
+			logger.debug("Resolved classpath location [" + location + "] to resources " + result);
+		}
 		return result.toArray(new Resource[result.size()]);
 	}
 
@@ -316,6 +319,7 @@ protected Resource[] findAllClassPathResources(String location) throws IOExcepti
 	 * Called by {@link #findAllClassPathResources(String)}.
 	 * @param path the absolute path within the classpath (never a leading slash)
 	 * @return a mutable Set of matching Resource instances
+	 * @since 4.1.1
 	 */
 	protected Set<Resource> doFindAllClassPathResources(String path) throws IOException {
 		Set<Resource> result = new LinkedHashSet<Resource>(16);
@@ -350,6 +354,7 @@ protected Resource convertClassLoaderURL(URL url) {
 	 * given set of resources in the form of pointers to the root of the jar file content.
 	 * @param classLoader the ClassLoader to search (including its ancestors)
 	 * @param result the set of resources to add jar roots to
+	 * @since 4.1.1
 	 */
 	protected void addAllClassLoaderJarRoots(ClassLoader classLoader, Set<Resource> result) {
 		if (classLoader instanceof URLClassLoader) {
@@ -381,6 +386,7 @@ protected void addAllClassLoaderJarRoots(ClassLoader classLoader, Set<Resource>
 		}
 		if (classLoader != null) {
 			try {
+				// Hierarchy traversal...
 				addAllClassLoaderJarRoots(classLoader.getParent(), result);
 			}
 			catch (Exception ex) {