Change NestedLocation to hold a Path rather than a File

Refactor `NestedLocation` so that it holds a `Path` rather than a
`File`.

See gh-37668

Author: philwebb

spring-boot-project/spring-boot-tools/spring-boot-loader/src/main/java/org/springframework/boot/loader/net/protocol/jar/UrlJarFileFactory.java

@@ -82,7 +82,7 @@ private boolean isNestedUrl(URL url) {
 	private JarFile createJarFileForNested(URL url, Runtime.Version version, Consumer<JarFile> closeAction)
 			throws IOException {
 		NestedLocation location = NestedLocation.fromUrl(url);
-		return new UrlNestedJarFile(location.file(), location.nestedEntryName(), version, closeAction);
+		return new UrlNestedJarFile(location.path().toFile(), location.nestedEntryName(), version, closeAction);
 	}
 
 	private JarFile createJarFileForStream(URL url, Version version, Consumer<JarFile> closeAction) throws IOException {

spring-boot-project/spring-boot-tools/spring-boot-loader/src/main/java/org/springframework/boot/loader/net/protocol/nested/NestedLocation.java

@@ -16,8 +16,9 @@
 
 package org.springframework.boot.loader.net.protocol.nested;
 
-import java.io.File;
+import java.net.URI;
 import java.net.URL;
+import java.nio.file.Path;
 import java.util.Map;
 import java.util.concurrent.ConcurrentHashMap;
 
@@ -43,18 +44,18 @@
  * uncompressed entry that contains the nested jar, or a directory entry. The entry must
  * not start with a {@code '/'}.
  *
- * @param file the zip file that contains the nested entry
+ * @param path the path to the zip that contains the nested entry
  * @param nestedEntryName the nested entry name
  * @author Phillip Webb
  * @since 3.2.0
  */
-public record NestedLocation(File file, String nestedEntryName) {
+public record NestedLocation(Path path, String nestedEntryName) {
 
 	private static final Map<String, NestedLocation> cache = new ConcurrentHashMap<>();
 
 	public NestedLocation {
-		if (file == null) {
-			throw new IllegalArgumentException("'file' must not be null");
+		if (path == null) {
+			throw new IllegalArgumentException("'path' must not be null");
 		}
 		if (nestedEntryName == null || nestedEntryName.trim().isEmpty()) {
 			throw new IllegalArgumentException("'nestedEntryName' must not be empty");
@@ -86,9 +87,9 @@ static NestedLocation parse(String path) {
 	}
 
 	private static NestedLocation create(int index, String location) {
-		String file = location.substring(0, index);
+		String path = location.substring(0, index);
 		String nestedEntryName = location.substring(index + 2);
-		return new NestedLocation((!file.isEmpty()) ? new File(file) : null, nestedEntryName);
+		return new NestedLocation((!path.isEmpty()) ? Path.of(path) : null, nestedEntryName);
 	}
 
 	static void clearCache() {

spring-boot-project/spring-boot-tools/spring-boot-loader/src/main/java/org/springframework/boot/loader/net/protocol/nested/NestedUrlConnection.java

@@ -16,6 +16,7 @@
 
 package org.springframework.boot.loader.net.protocol.nested;
 
+import java.io.File;
 import java.io.FilePermission;
 import java.io.FilterInputStream;
 import java.io.IOException;
@@ -25,6 +26,7 @@
 import java.net.MalformedURLException;
 import java.net.URL;
 import java.net.URLConnection;
+import java.nio.file.Files;
 import java.security.Permission;
 
 import org.springframework.boot.loader.ref.Cleaner;
@@ -43,7 +45,7 @@ class NestedUrlConnection extends URLConnection {
 
 	private final Cleanable cleanup;
 
-	private long lastModified;
+	private long lastModified = -1;
 
 	private FilePermission permission;
 
@@ -91,16 +93,22 @@ public String getContentType() {
 
 	@Override
 	public long getLastModified() {
-		if (this.lastModified == 0) {
-			this.lastModified = this.resources.getLocation().file().lastModified();
+		if (this.lastModified == -1) {
+			try {
+				this.lastModified = Files.getLastModifiedTime(this.resources.getLocation().path()).toMillis();
+			}
+			catch (IOException ex) {
+				this.lastModified = 0;
+			}
 		}
 		return this.lastModified;
 	}
 
 	@Override
 	public Permission getPermission() throws IOException {
 		if (this.permission == null) {
-			this.permission = new FilePermission(this.resources.getLocation().file().getCanonicalPath(), "read");
+			File file = this.resources.getLocation().path().toFile();
+			this.permission = new FilePermission(file.getCanonicalPath(), "read");
 		}
 		return this.permission;
 	}

spring-boot-project/spring-boot-tools/spring-boot-loader/src/main/java/org/springframework/boot/loader/net/protocol/nested/NestedUrlConnectionResources.java

@@ -51,7 +51,7 @@ NestedLocation getLocation() {
 	void connect() throws IOException {
 		synchronized (this) {
 			if (this.zipContent == null) {
-				this.zipContent = ZipContent.open(this.location.file().toPath(), this.location.nestedEntryName());
+				this.zipContent = ZipContent.open(this.location.path(), this.location.nestedEntryName());
 				try {
 					connectData();
 				}

spring-boot-project/spring-boot-tools/spring-boot-loader/src/test/java/org/springframework/boot/loader/net/protocol/nested/NestedLocationTests.java

@@ -18,6 +18,7 @@
 
 import java.io.File;
 import java.net.URL;
+import java.nio.file.Path;
 
 import org.junit.jupiter.api.BeforeAll;
 import org.junit.jupiter.api.Test;
@@ -44,20 +45,20 @@ static void registerHandlers() {
 	}
 
 	@Test
-	void createWhenFileIsNullThrowsException() {
+	void createWhenPathIsNullThrowsException() {
 		assertThatIllegalArgumentException().isThrownBy(() -> new NestedLocation(null, "nested.jar"))
-			.withMessageContaining("'file' must not be null");
+			.withMessageContaining("'path' must not be null");
 	}
 
 	@Test
 	void createWhenNestedEntryNameIsNullThrowsException() {
-		assertThatIllegalArgumentException().isThrownBy(() -> new NestedLocation(new File("test.jar"), null))
+		assertThatIllegalArgumentException().isThrownBy(() -> new NestedLocation(Path.of("test.jar"), null))
 			.withMessageContaining("'nestedEntryName' must not be empty");
 	}
 
 	@Test
 	void createWhenNestedEntryNameIsEmptyThrowsException() {
-		assertThatIllegalArgumentException().isThrownBy(() -> new NestedLocation(new File("test.jar"), null))
+		assertThatIllegalArgumentException().isThrownBy(() -> new NestedLocation(Path.of("test.jar"), null))
 			.withMessageContaining("'nestedEntryName' must not be empty");
 	}
 
@@ -91,7 +92,7 @@ void fromUrlReturnsNestedLocation() throws Exception {
 		File file = new File(this.temp, "test.jar");
 		NestedLocation location = NestedLocation
 			.fromUrl(new URL("nested:" + file.getAbsolutePath() + "/!lib/nested.jar"));
-		assertThat(location.file()).isEqualTo(file);
+		assertThat(location.path()).isEqualTo(file.toPath());
 		assertThat(location.nestedEntryName()).isEqualTo("lib/nested.jar");
 	}