Make jar caching configurable through setUseCaches

Closes gh-34694

Author: jhoeller

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

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2024 the original author or authors.
+ * Copyright 2002-2025 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.
@@ -206,6 +206,8 @@
  */
 public class PathMatchingResourcePatternResolver implements ResourcePatternResolver {
 
+	private static final Resource[] EMPTY_RESOURCE_ARRAY = {};
+
 	private static final Log logger = LogFactory.getLog(PathMatchingResourcePatternResolver.class);
 
 	/**
@@ -248,6 +250,8 @@ public class PathMatchingResourcePatternResolver implements ResourcePatternResol
 
 	private PathMatcher pathMatcher = new AntPathMatcher();
 
+	private boolean useCaches = true;
+
 
 	/**
 	 * Create a {@code PathMatchingResourcePatternResolver} with a
@@ -315,6 +319,21 @@ public PathMatcher getPathMatcher() {
 		return this.pathMatcher;
 	}
 
+	/**
+	 * Specify whether this resolver should use jar caches. Default is {@code true}.
+	 * <p>Switch this flag to {@code false} in order to avoid jar caching at the
+	 * {@link JarURLConnection} level.
+	 * <p>Note that {@link JarURLConnection#setDefaultUseCaches} can be turned off
+	 * independently. This resolver-level setting is designed to only enforce
+	 * {@code JarURLConnection#setUseCaches(false)} if necessary but otherwise
+	 * leaves the JVM-level default in place.
+	 * @since 6.1.19
+	 * @see JarURLConnection#setUseCaches
+	 */
+	public void setUseCaches(boolean useCaches) {
+		this.useCaches = useCaches;
+	}
+
 
 	@Override
 	public Resource getResource(String location) {
@@ -338,7 +357,7 @@ public Resource[] getResources(String locationPattern) throws IOException {
 				// all class path resources with the given name
 				Collections.addAll(resources, findAllClassPathResources(locationPatternWithoutPrefix));
 			}
-			return resources.toArray(new Resource[0]);
+			return resources.toArray(EMPTY_RESOURCE_ARRAY);
 		}
 		else {
 			// Generally only look for a pattern after a prefix here,
@@ -371,7 +390,7 @@ protected Resource[] findAllClassPathResources(String location) throws IOExcepti
 		if (logger.isTraceEnabled()) {
 			logger.trace("Resolved class path location [" + path + "] to resources " + result);
 		}
-		return result.toArray(new Resource[0]);
+		return result.toArray(EMPTY_RESOURCE_ARRAY);
 	}
 
 	/**
@@ -607,7 +626,7 @@ else if (ResourceUtils.isJarURL(rootDirUrl) || isJarResource(rootDirResource)) {
 		if (logger.isTraceEnabled()) {
 			logger.trace("Resolved location pattern [" + locationPattern + "] to resources " + result);
 		}
-		return result.toArray(new Resource[0]);
+		return result.toArray(EMPTY_RESOURCE_ARRAY);
 	}
 
 	/**
@@ -695,6 +714,9 @@ protected Set<Resource> doFindPathMatchingJarResources(Resource rootDirResource,
 
 		if (con instanceof JarURLConnection jarCon) {
 			// Should usually be the case for traditional JAR files.
+			if (!this.useCaches) {
+				jarCon.setUseCaches(false);
+			}
 			jarFile = jarCon.getJarFile();
 			jarFileUrl = jarCon.getJarFileURL().toExternalForm();
 			JarEntry jarEntry = jarCon.getJarEntry();

spring-core/src/test/java/org/springframework/core/io/support/PathMatchingResourcePatternResolverTests.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2024 the original author or authors.
+ * Copyright 2002-2025 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.
@@ -108,9 +108,11 @@ void encodedHashtagInPath() throws IOException {
 			Path rootDir = Paths.get("src/test/resources/custom%23root").toAbsolutePath();
 			URL root = new URL("file:" + rootDir + "/");
 			resolver = new PathMatchingResourcePatternResolver(new DefaultResourceLoader(new URLClassLoader(new URL[] {root})));
+			resolver.setUseCaches(false);
 			assertExactFilenames("classpath*:scanned/*.txt", "resource#test1.txt", "resource#test2.txt");
 		}
 
+
 		@Nested
 		class WithHashtagsInTheirFilenames {
 
@@ -332,7 +334,7 @@ private String getPath(Resource resource) {
 		// Tests fail if we use resource.getURL().getPath(). They would also fail on macOS when
 		// using resource.getURI().getPath() if the resource paths are not Unicode normalized.
 		//
-		// On the JVM, all tests should pass when using resouce.getFile().getPath(); however,
+		// On the JVM, all tests should pass when using resource.getFile().getPath(); however,
 		// we use FileSystemResource#getPath since this test class is sometimes run within a
 		// GraalVM native image which cannot support Path#toFile.
 		//