Close JarFile only in case of useCaches=false

Closes gh-34955

Author: jhoeller

spring-core/src/main/java/org/springframework/core/io/AbstractFileResolvingResource.java

@@ -45,7 +45,6 @@
  */
 public abstract class AbstractFileResolvingResource extends AbstractResource {
 
-	@SuppressWarnings("try")
 	@Override
 	public boolean exists() {
 		try {
@@ -90,9 +89,15 @@ else if (code == HttpURLConnection.HTTP_NOT_FOUND) {
 					// existence of the entry (or the jar root in case of no entryName).
 					// getJarFile() called for enforced presence check of the jar file,
 					// throwing a NoSuchFileException otherwise (turned to false below).
-					try (JarFile jarFile = jarCon.getJarFile()) {
+					JarFile jarFile = jarCon.getJarFile();
+					try {
 						return (jarCon.getEntryName() == null || jarCon.getJarEntry() != null);
 					}
+					finally {
+						if (!jarCon.getUseCaches()) {
+							jarFile.close();
+						}
+					}
 				}
 				else if (con.getContentLengthLong() > 0) {
 					return true;

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

@@ -44,6 +44,8 @@
 import java.util.zip.ZipEntry;
 
 import org.apache.commons.logging.LogFactory;
+import org.junit.jupiter.api.AfterAll;
+import org.junit.jupiter.api.BeforeAll;
 import org.junit.jupiter.api.Nested;
 import org.junit.jupiter.api.Test;
 import org.junit.jupiter.api.io.TempDir;
@@ -298,8 +300,8 @@ void classpathStarWithPatternInJar() {
 		@Test
 		void rootPatternRetrievalInJarFiles() throws IOException {
 			assertThat(resolver.getResources("classpath*:aspectj*.dtd")).extracting(Resource::getFilename)
-				.as("Could not find aspectj_1_5_0.dtd in the root of the aspectjweaver jar")
-				.containsExactly("aspectj_1_5_0.dtd");
+					.as("Could not find aspectj_1_5_0.dtd in the root of the aspectjweaver jar")
+					.containsExactly("aspectj_1_5_0.dtd");
 		}
 	}
 
@@ -310,6 +312,16 @@ class ClassPathManifestEntries {
 		@TempDir
 		Path temp;
 
+		@BeforeAll
+		static void suppressJarCaches() {
+			URLConnection.setDefaultUseCaches("jar", false);
+		}
+
+		@AfterAll
+		static void restoreJarCaches() {
+			URLConnection.setDefaultUseCaches("jar", true);
+		}
+
 		@Test
 		void javaDashJarFindsClassPathManifestEntries() throws Exception {
 			Path lib = this.temp.resolve("lib");
@@ -333,13 +345,22 @@ private void writeAssetJar(Path path) throws Exception {
 				StreamUtils.copy("test", StandardCharsets.UTF_8, jar);
 				jar.closeEntry();
 			}
+
 			assertThat(new FileSystemResource(path).exists()).isTrue();
 			assertThat(new UrlResource(ResourceUtils.JAR_URL_PREFIX + ResourceUtils.FILE_URL_PREFIX + path + ResourceUtils.JAR_URL_SEPARATOR).exists()).isTrue();
 			assertThat(new UrlResource(ResourceUtils.JAR_URL_PREFIX + ResourceUtils.FILE_URL_PREFIX + path + ResourceUtils.JAR_URL_SEPARATOR + "assets/file.txt").exists()).isTrue();
 			assertThat(new UrlResource(ResourceUtils.JAR_URL_PREFIX + ResourceUtils.FILE_URL_PREFIX + path + ResourceUtils.JAR_URL_SEPARATOR + "assets/none.txt").exists()).isFalse();
 			assertThat(new UrlResource(ResourceUtils.JAR_URL_PREFIX + ResourceUtils.FILE_URL_PREFIX + "X" + path + ResourceUtils.JAR_URL_SEPARATOR).exists()).isFalse();
 			assertThat(new UrlResource(ResourceUtils.JAR_URL_PREFIX + ResourceUtils.FILE_URL_PREFIX + "X" + path + ResourceUtils.JAR_URL_SEPARATOR + "assets/file.txt").exists()).isFalse();
 			assertThat(new UrlResource(ResourceUtils.JAR_URL_PREFIX + ResourceUtils.FILE_URL_PREFIX + "X" + path + ResourceUtils.JAR_URL_SEPARATOR + "assets/none.txt").exists()).isFalse();
+
+			Resource resource = new UrlResource(ResourceUtils.JAR_URL_PREFIX + ResourceUtils.FILE_URL_PREFIX + path + ResourceUtils.JAR_URL_SEPARATOR + "assets/file.txt");
+			try (InputStream is = resource.getInputStream()) {
+				assertThat(resource.exists()).isTrue();
+				assertThat(resource.createRelative("file.txt").exists()).isTrue();
+				assertThat(new UrlResource(ResourceUtils.JAR_URL_PREFIX + ResourceUtils.FILE_URL_PREFIX + path + ResourceUtils.JAR_URL_SEPARATOR).exists()).isTrue();
+				is.readAllBytes();
+			}
 		}
 
 		private void writeApplicationJar(Path path) throws Exception {