Adjust defaults for ExtractCommand

It now extracts the contents of the JAR in a folder named after the JAR
without the extension. It now also checks if the folder is empty.
There's a new --force option to skip those checks.

The "runner.jar" is now named like the uber JAR from which the
extraction has been started.

See gh-38276

spring-boot-project/spring-boot-tools/spring-boot-gradle-plugin/src/test/resources/org/springframework/boot/gradle/tasks/bundling/BootJarIntegrationTests-customLayers.gradle

@@ -45,5 +45,5 @@ task listLayers(type: JavaExec) {
 task extractLayers(type: JavaExec) {
 	classpath = bootJar.outputs.files
 	systemProperties = [ "jarmode": "tools" ]
-	args "extract", "--layers", "--launcher"
+	args "extract", "--layers", "--launcher", "--destination", ".", "--force"
 }

spring-boot-project/spring-boot-tools/spring-boot-gradle-plugin/src/test/resources/org/springframework/boot/gradle/tasks/bundling/BootJarIntegrationTests-implicitLayers.gradle

@@ -28,5 +28,5 @@ task listLayers(type: JavaExec) {
 task extractLayers(type: JavaExec) {
 	classpath = bootJar.outputs.files
 	systemProperties = [ "jarmode": "tools" ]
-	args "extract", "--layers", "--launcher"
+	args "extract", "--layers", "--launcher", "--destination", ".", "--force"
 }

spring-boot-project/spring-boot-tools/spring-boot-gradle-plugin/src/test/resources/org/springframework/boot/gradle/tasks/bundling/BootJarIntegrationTests-layersWithCustomSourceSet.gradle

@@ -31,5 +31,5 @@ task listLayers(type: JavaExec) {
 task extractLayers(type: JavaExec) {
 	classpath = bootJar.outputs.files
 	systemProperties = [ "jarmode": "tools" ]
-	args "extract", "--layers", "--launcher"
+	args "extract", "--layers", "--launcher", "--destination", ".", "--force"
 }

spring-boot-project/spring-boot-tools/spring-boot-gradle-plugin/src/test/resources/org/springframework/boot/gradle/tasks/bundling/BootJarIntegrationTests-multiModuleCustomLayers.gradle

@@ -62,5 +62,5 @@ task listLayers(type: JavaExec) {
 task extractLayers(type: JavaExec) {
 	classpath = bootJar.outputs.files
 	systemProperties = [ "jarmode": "tools" ]
-	args "extract", "--layers", "--launcher"
+	args "extract", "--layers", "--launcher", "--destination", ".", "--force"
 }

spring-boot-project/spring-boot-tools/spring-boot-gradle-plugin/src/test/resources/org/springframework/boot/gradle/tasks/bundling/BootJarIntegrationTests-multiModuleImplicitLayers.gradle

@@ -40,5 +40,5 @@ task listLayers(type: JavaExec) {
 task extractLayers(type: JavaExec) {
 	classpath = bootJar.outputs.files
 	systemProperties = [ "jarmode": "tools" ]
-	args "extract", "--layers", "--launcher"
+	args "extract", "--layers", "--launcher", "--destination", ".", "--force"
 }

spring-boot-project/spring-boot-tools/spring-boot-gradle-plugin/src/test/resources/org/springframework/boot/gradle/tasks/bundling/BootWarIntegrationTests-customLayers.gradle

@@ -46,5 +46,5 @@ task listLayers(type: JavaExec) {
 task extractLayers(type: JavaExec) {
 	classpath = bootWar.outputs.files
 	systemProperties = [ "jarmode": "tools" ]
-	args "extract", "--layers", "--launcher"
+	args "extract", "--layers", "--launcher", "--destination", ".", "--force"
 }

spring-boot-project/spring-boot-tools/spring-boot-gradle-plugin/src/test/resources/org/springframework/boot/gradle/tasks/bundling/BootWarIntegrationTests-implicitLayers.gradle

@@ -29,5 +29,5 @@ task listLayers(type: JavaExec) {
 task extractLayers(type: JavaExec) {
 	classpath = bootWar.outputs.files
 	systemProperties = [ "jarmode": "tools" ]
-	args "extract", "--layers", "--launcher"
+	args "extract", "--layers", "--launcher", "--destination", ".", "--force"
 }

spring-boot-project/spring-boot-tools/spring-boot-gradle-plugin/src/test/resources/org/springframework/boot/gradle/tasks/bundling/BootWarIntegrationTests-layersWithCustomSourceSet.gradle

@@ -32,5 +32,5 @@ task listLayers(type: JavaExec) {
 task extractLayers(type: JavaExec) {
 	classpath = bootWar.outputs.files
 	systemProperties = [ "jarmode": "tools" ]
-	args "extract", "--layers", "--launcher"
+	args "extract", "--layers", "--launcher", "--destination", ".", "--force"
 }

spring-boot-project/spring-boot-tools/spring-boot-gradle-plugin/src/test/resources/org/springframework/boot/gradle/tasks/bundling/BootWarIntegrationTests-multiModuleCustomLayers.gradle

@@ -63,5 +63,5 @@ task listLayers(type: JavaExec) {
 task extractLayers(type: JavaExec) {
 	classpath = bootWar.outputs.files
 	systemProperties = [ "jarmode": "tools" ]
-	args "extract", "--layers", "--launcher"
+	args "extract", "--layers", "--launcher", "--destination", ".", "--force"
 }

spring-boot-project/spring-boot-tools/spring-boot-gradle-plugin/src/test/resources/org/springframework/boot/gradle/tasks/bundling/BootWarIntegrationTests-multiModuleImplicitLayers.gradle

@@ -41,5 +41,5 @@ task listLayers(type: JavaExec) {
 task extractLayers(type: JavaExec) {
 	classpath = bootWar.outputs.files
 	systemProperties = [ "jarmode": "tools" ]
-	args "extract", "--layers", "--launcher"
+	args "extract", "--layers", "--launcher", "--destination", ".", "--force"
 }

spring-boot-project/spring-boot-tools/spring-boot-jarmode-tools/src/main/java/org/springframework/boot/jarmode/tools/ExtractCommand.java

@@ -27,6 +27,7 @@ import java.nio.file.Files;
 import java.nio.file.attribute.BasicFileAttributeView;
 import java.nio.file.attribute.FileTime;
 import java.util.List;
+import java.util.Locale;
 import java.util.Map;
 import java.util.Set;
 import java.util.jar.JarEntry;
@@ -52,7 +53,7 @@ class ExtractCommand extends Command {
 	/**
 	 * Option to create a launcher.
 	 */
-	static final Option LAUNCHER_OPTION = Option.of("launcher", null, "Whether to extract the Spring Boot launcher");
+	static final Option LAUNCHER_OPTION = Option.flag("launcher", "Whether to extract the Spring Boot launcher");
 
 	/**
 	 * Option to extract layers.
@@ -63,13 +64,18 @@ class ExtractCommand extends Command {
 	 * Option to specify the destination to write to.
 	 */
 	static final Option DESTINATION_OPTION = Option.of("destination", "string",
-			"Directory to extract files to. Defaults to the current working directory");
+			"Directory to extract files to. Defaults to a directory named after the uber JAR (without the file extension)");
+
+	/**
+	 * Option to ignore non-empty directory error.
+	 */
+	static final Option FORCE_OPTION = Option.flag("force", "Whether to ignore non-empty directories, extract anyway");
 
 	private static final Option LIBRARIES_DIRECTORY_OPTION = Option.of("libraries", "string",
 			"Name of the libraries directory. Only applicable when not using --launcher. Defaults to lib/");
 
-	private static final Option RUNNER_FILENAME_OPTION = Option.of("runner-filename", "string",
-			"Name of the runner JAR file. Only applicable when not using --launcher. Defaults to runner.jar");
+	private static final Option APPLICATION_FILENAME_OPTION = Option.of("application-filename", "string",
+			"Name of the application JAR file. Only applicable when not using --launcher. Defaults to the uber JAR filename");
 
 	private final Context context;
 
@@ -81,7 +87,8 @@ class ExtractCommand extends Command {
 
 	ExtractCommand(Context context, Layers layers) {
 		super("extract", "Extract the contents from the jar", Options.of(LAUNCHER_OPTION, LAYERS_OPTION,
-				DESTINATION_OPTION, LIBRARIES_DIRECTORY_OPTION, RUNNER_FILENAME_OPTION), Parameters.none());
+				DESTINATION_OPTION, LIBRARIES_DIRECTORY_OPTION, APPLICATION_FILENAME_OPTION, FORCE_OPTION),
+				Parameters.none());
 		this.context = context;
 		this.layers = layers;
 	}
@@ -90,7 +97,8 @@ class ExtractCommand extends Command {
 	void run(PrintStream out, Map<Option, String> options, List<String> parameters) {
 		try {
 			checkJarCompatibility();
-			File destination = getWorkingDirectory(options);
+			File destination = getDestination(options);
+			checkDirectoryIsEmpty(options, destination);
 			FileResolver fileResolver = getFileResolver(destination, options);
 			fileResolver.createDirectories();
 			if (options.containsKey(LAUNCHER_OPTION)) {
@@ -99,7 +107,7 @@ class ExtractCommand extends Command {
 			else {
 				JarStructure jarStructure = getJarStructure();
 				extractLibraries(fileResolver, jarStructure, options);
-				createRunner(jarStructure, fileResolver, options);
+				createApplication(jarStructure, fileResolver, options);
 			}
 		}
 		catch (IOException ex) {
@@ -108,15 +116,36 @@ class ExtractCommand extends Command {
 		catch (LayersNotEnabledException ex) {
 			printError(out, "Layers are not enabled");
 		}
+		catch (AbortException ex) {
+			printError(out, ex.getMessage());
+		}
+	}
+
+	private static void checkDirectoryIsEmpty(Map<Option, String> options, File destination) {
+		if (options.containsKey(FORCE_OPTION)) {
+			return;
+		}
+		if (!destination.exists()) {
+			return;
+		}
+		if (!destination.isDirectory()) {
+			throw new AbortException(destination.getAbsoluteFile() + " already exists and is not a directory");
+		}
+		File[] files = destination.listFiles();
+		if (files != null && files.length > 0) {
+			throw new AbortException(destination.getAbsoluteFile() + " already exists and is not empty");
+		}
 	}
 
 	private void checkJarCompatibility() throws IOException {
 		File file = this.context.getArchiveFile();
 		try (ZipInputStream stream = new ZipInputStream(new FileInputStream(file))) {
 			ZipEntry entry = stream.getNextEntry();
-			Assert.state(entry != null,
-					() -> "File '%s' is not compatible; ensure jar file is valid and launch script is not enabled"
-						.formatted(file));
+			if (entry == null) {
+				throw new AbortException(
+						"File '%s' is not compatible; ensure jar file is valid and launch script is not enabled"
+							.formatted(file));
+			}
 		}
 	}
 
@@ -149,20 +178,31 @@ class ExtractCommand extends Command {
 	}
 
 	private FileResolver getFileResolver(File destination, Map<Option, String> options) {
-		String runnerFilename = getRunnerFilename(options);
+		String applicationFilename = getApplicationFilename(options);
 		if (!options.containsKey(LAYERS_OPTION)) {
-			return new NoLayersFileResolver(destination, runnerFilename);
+			return new NoLayersFileResolver(destination, applicationFilename);
 		}
 		Layers layers = getLayers();
 		Set<String> layersToExtract = StringUtils.commaDelimitedListToSet(options.get(LAYERS_OPTION));
-		return new LayersFileResolver(destination, layers, layersToExtract, runnerFilename);
+		return new LayersFileResolver(destination, layers, layersToExtract, applicationFilename);
 	}
 
-	private File getWorkingDirectory(Map<Option, String> options) {
+	private File getDestination(Map<Option, String> options) {
 		if (options.containsKey(DESTINATION_OPTION)) {
-			return new File(options.get(DESTINATION_OPTION));
+			File destination = new File(options.get(DESTINATION_OPTION));
+			if (destination.isAbsolute()) {
+				return destination;
+			}
+			return new File(this.context.getWorkingDir(), destination.getPath());
 		}
-		return this.context.getWorkingDir();
+		return new File(this.context.getWorkingDir(), stripExtension(this.context.getArchiveFile().getName()));
+	}
+
+	private static String stripExtension(String name) {
+		if (name.toLowerCase(Locale.ROOT).endsWith(".jar") || name.toLowerCase(Locale.ROOT).endsWith(".war")) {
+			return name.substring(0, name.length() - 4);
+		}
+		return name;
 	}
 
 	private JarStructure getJarStructure() {
@@ -199,9 +239,9 @@ class ExtractCommand extends Command {
 		return Layers.get(this.context);
 	}
 
-	private void createRunner(JarStructure jarStructure, FileResolver fileResolver, Map<Option, String> options)
+	private void createApplication(JarStructure jarStructure, FileResolver fileResolver, Map<Option, String> options)
 			throws IOException {
-		File file = fileResolver.resolveRunner();
+		File file = fileResolver.resolveApplication();
 		if (file == null) {
 			return;
 		}
@@ -221,11 +261,11 @@ class ExtractCommand extends Command {
 		}
 	}
 
-	private String getRunnerFilename(Map<Option, String> options) {
-		if (options.containsKey(RUNNER_FILENAME_OPTION)) {
-			return options.get(RUNNER_FILENAME_OPTION);
+	private String getApplicationFilename(Map<Option, String> options) {
+		if (options.containsKey(APPLICATION_FILENAME_OPTION)) {
+			return options.get(APPLICATION_FILENAME_OPTION);
 		}
-		return "runner.jar";
+		return this.context.getArchiveFile().getName();
 	}
 
 	private static boolean isType(Entry entry, Type type) {
@@ -338,11 +378,12 @@ class ExtractCommand extends Command {
 		File resolve(String originalName, String newName) throws IOException;
 
 		/**
-		 * Resolves the file for the runner.
-		 * @return the file for the runner or {@code null} if the runner should be skipped
+		 * Resolves the file for the application.
+		 * @return the file for the application or {@code null} if the application should
+		 * be skipped
 		 * @throws IOException if something went wrong
 		 */
-		File resolveRunner() throws IOException;
+		File resolveApplication() throws IOException;
 
 	}
 
@@ -350,11 +391,11 @@ class ExtractCommand extends Command {
 
 		private final File directory;
 
-		private final String runnerFilename;
+		private final String applicationFilename;
 
-		private NoLayersFileResolver(File directory, String runnerFilename) {
+		private NoLayersFileResolver(File directory, String applicationFilename) {
 			this.directory = directory;
-			this.runnerFilename = runnerFilename;
+			this.applicationFilename = applicationFilename;
 		}
 
 		@Override
@@ -367,8 +408,8 @@ class ExtractCommand extends Command {
 		}
 
 		@Override
-		public File resolveRunner() throws IOException {
-			return resolve(this.runnerFilename, this.runnerFilename);
+		public File resolveApplication() throws IOException {
+			return resolve(this.applicationFilename, this.applicationFilename);
 		}
 
 	}
@@ -381,13 +422,13 @@ class ExtractCommand extends Command {
 
 		private final File directory;
 
-		private final String runnerFilename;
+		private final String applicationFilename;
 
-		LayersFileResolver(File directory, Layers layers, Set<String> layersToExtract, String runnerFilename) {
+		LayersFileResolver(File directory, Layers layers, Set<String> layersToExtract, String applicationFilename) {
 			this.layers = layers;
 			this.layersToExtract = layersToExtract;
 			this.directory = directory;
-			this.runnerFilename = runnerFilename;
+			this.applicationFilename = applicationFilename;
 		}
 
 		@Override
@@ -410,12 +451,12 @@ class ExtractCommand extends Command {
 		}
 
 		@Override
-		public File resolveRunner() throws IOException {
+		public File resolveApplication() throws IOException {
 			String layer = this.layers.getApplicationLayerName();
 			if (shouldExtractLayer(layer)) {
 				File directory = getLayerDirectory(layer);
-				return assertFileIsContainedInDirectory(directory, new File(directory, this.runnerFilename),
-						this.runnerFilename);
+				return assertFileIsContainedInDirectory(directory, new File(directory, this.applicationFilename),
+						this.applicationFilename);
 			}
 			return null;
 		}
@@ -433,4 +474,12 @@ class ExtractCommand extends Command {
 
 	}
 
+	private static final class AbortException extends RuntimeException {
+
+		AbortException(String message) {
+			super(message);
+		}
+
+	}
+
 }

spring-boot-project/spring-boot-tools/spring-boot-jarmode-tools/src/main/java/org/springframework/boot/jarmode/tools/ExtractLayersCommand.java

@@ -58,11 +58,10 @@ class ExtractLayersCommand extends Command {
 	@Override
 	void run(PrintStream out, Map<Option, String> options, List<String> parameters) {
 		Map<Option, String> rewrittenOptions = new HashMap<>();
-		if (options.containsKey(DESTINATION_OPTION)) {
-			rewrittenOptions.put(ExtractCommand.DESTINATION_OPTION, options.get(DESTINATION_OPTION));
-		}
+		rewrittenOptions.put(ExtractCommand.DESTINATION_OPTION, options.getOrDefault(DESTINATION_OPTION, "."));
 		rewrittenOptions.put(ExtractCommand.LAYERS_OPTION, StringUtils.collectionToCommaDelimitedString(parameters));
 		rewrittenOptions.put(ExtractCommand.LAUNCHER_OPTION, null);
+		rewrittenOptions.put(ExtractCommand.FORCE_OPTION, null);
 		this.delegate.run(out, rewrittenOptions, Collections.emptyList());
 	}
 

spring-boot-project/spring-boot-tools/spring-boot-jarmode-tools/src/test/java/org/springframework/boot/jarmode/tools/ExtractCommandTests.java

@@ -119,46 +119,46 @@ class ExtractCommandTests extends AbstractTests {
 	class Extract {
 
 		@Test
-		void extractLibrariesAndCreatesRunner() throws IOException {
+		void extractLibrariesAndCreatesApplication() throws IOException {
 			run(ExtractCommandTests.this.archive);
 			List<String> filenames = listFilenames();
-			assertThat(filenames).contains("lib/dependency-1.jar")
-				.contains("lib/dependency-2.jar")
-				.contains("lib/dependency-3-SNAPSHOT.jar")
-				.contains("runner.jar")
-				.doesNotContain("org/springframework/boot/loader/launch/JarLauncher.class");
+			assertThat(filenames).contains("test/lib/dependency-1.jar")
+				.contains("test/lib/dependency-2.jar")
+				.contains("test/lib/dependency-3-SNAPSHOT.jar")
+				.contains("test/test.jar")
+				.doesNotContain("test/org/springframework/boot/loader/launch/JarLauncher.class");
 		}
 
 		@Test
-		void extractLibrariesAndCreatesRunnerInDestination() throws IOException {
+		void extractLibrariesAndCreatesApplicationInDestination() throws IOException {
 			run(ExtractCommandTests.this.archive, "--destination", file("out").getAbsolutePath());
 			List<String> filenames = listFilenames();
 			assertThat(filenames).contains("out/lib/dependency-1.jar")
 				.contains("out/lib/dependency-2.jar")
 				.contains("out/lib/dependency-3-SNAPSHOT.jar")
-				.contains("out/runner.jar");
+				.contains("out/test.jar");
 		}
 
 		@Test
-		void runnerNameAndLibrariesDirectoriesCanBeCustomized() throws IOException {
-			run(ExtractCommandTests.this.archive, "--runner-filename", "runner-customized.jar", "--libraries",
+		void applicationNameAndLibrariesDirectoriesCanBeCustomized() throws IOException {
+			run(ExtractCommandTests.this.archive, "--application-filename", "application-customized.jar", "--libraries",
 					"dependencies");
 			List<String> filenames = listFilenames();
-			assertThat(filenames).contains("dependencies/dependency-1.jar")
-				.contains("dependencies/dependency-2.jar")
-				.contains("dependencies/dependency-3-SNAPSHOT.jar");
-			File runner = file("runner-customized.jar");
-			assertThat(runner).exists();
-			Map<String, String> attributes = getJarManifestAttributes(runner);
+			assertThat(filenames).contains("test/dependencies/dependency-1.jar")
+				.contains("test/dependencies/dependency-2.jar")
+				.contains("test/dependencies/dependency-3-SNAPSHOT.jar");
+			File application = file("test/application-customized.jar");
+			assertThat(application).exists();
+			Map<String, String> attributes = getJarManifestAttributes(application);
 			assertThat(attributes).containsEntry("Class-Path",
 					"dependencies/dependency-1.jar dependencies/dependency-2.jar dependencies/dependency-3-SNAPSHOT.jar");
 		}
 
 		@Test
-		void runnerContainsManifestEntries() throws IOException {
+		void applicationContainsManifestEntries() throws IOException {
 			run(ExtractCommandTests.this.archive);
-			File runner = file("runner.jar");
-			Map<String, String> attributes = getJarManifestAttributes(runner);
+			File application = file("test/test.jar");
+			Map<String, String> attributes = getJarManifestAttributes(application);
 			assertThat(attributes).containsEntry("Main-Class", "org.example.Main")
 				.containsEntry("Class-Path", "lib/dependency-1.jar lib/dependency-2.jar lib/dependency-3-SNAPSHOT.jar")
 				.containsEntry("Some-Attribute", "Some-Value")
@@ -167,27 +167,27 @@ class ExtractCommandTests extends AbstractTests {
 		}
 
 		@Test
-		void runnerContainsApplicationClassesAndResources() throws IOException {
+		void applicationContainsApplicationClassesAndResources() throws IOException {
 			run(ExtractCommandTests.this.archive);
-			File runner = file("runner.jar");
-			List<String> entryNames = getJarEntryNames(runner);
+			File application = file("test/test.jar");
+			List<String> entryNames = getJarEntryNames(application);
 			assertThat(entryNames).contains("application.properties");
 		}
 
 		@Test
 		void appliesFileTimes() {
 			run(ExtractCommandTests.this.archive);
-			assertThat(file("lib/dependency-1.jar")).exists().satisfies(ExtractCommandTests.this::timeAttributes);
-			assertThat(file("lib/dependency-2.jar")).exists().satisfies(ExtractCommandTests.this::timeAttributes);
-			assertThat(file("lib/dependency-3-SNAPSHOT.jar")).exists()
+			assertThat(file("test/lib/dependency-1.jar")).exists().satisfies(ExtractCommandTests.this::timeAttributes);
+			assertThat(file("test/lib/dependency-2.jar")).exists().satisfies(ExtractCommandTests.this::timeAttributes);
+			assertThat(file("test/lib/dependency-3-SNAPSHOT.jar")).exists()
 				.satisfies(ExtractCommandTests.this::timeAttributes);
 		}
 
 		@Test
-		void runnerDoesntContainLibraries() throws IOException {
+		void applicationDoesntContainLibraries() throws IOException {
 			run(ExtractCommandTests.this.archive);
-			File runner = file("runner.jar");
-			List<String> entryNames = getJarEntryNames(runner);
+			File application = file("test/test.jar");
+			List<String> entryNames = getJarEntryNames(application);
 			assertThat(entryNames).doesNotContain("BOOT-INF/lib/dependency-1.jar", "BOOT-INF/lib/dependency-2.jar");
 		}
 
@@ -197,7 +197,42 @@ class ExtractCommandTests extends AbstractTests {
 			try (FileWriter writer = new FileWriter(file)) {
 				writer.write("text");
 			}
-			assertThatIllegalStateException().isThrownBy(() -> run(file)).withMessageContaining("not compatible");
+			TestPrintStream out = run(file);
+			assertThat(out).contains("is not compatible; ensure jar file is valid and launch script is not enabled");
+		}
+
+		@Test
+		void shouldFailIfDirectoryIsNotEmpty() throws IOException {
+			File destination = file("out");
+			Files.createDirectories(destination.toPath());
+			Files.createFile(new File(destination, "file.txt").toPath());
+			TestPrintStream out = run(ExtractCommandTests.this.archive, "--destination", destination.getAbsolutePath());
+			assertThat(out).contains("already exists and is not empty");
+		}
+
+		@Test
+		void shouldNotFailIfDirectoryExistsButIsEmpty() throws IOException {
+			File destination = file("out");
+			Files.createDirectories(destination.toPath());
+			run(ExtractCommandTests.this.archive, "--destination", destination.getAbsolutePath());
+			List<String> filenames = listFilenames();
+			assertThat(filenames).contains("out/lib/dependency-1.jar")
+				.contains("out/lib/dependency-2.jar")
+				.contains("out/lib/dependency-3-SNAPSHOT.jar")
+				.contains("out/test.jar");
+		}
+
+		@Test
+		void shouldNotFailIfDirectoryIsNotEmptyButForceIsPassed() throws IOException {
+			File destination = file("out");
+			Files.createDirectories(destination.toPath());
+			Files.createFile(new File(destination, "file.txt").toPath());
+			run(ExtractCommandTests.this.archive, "--destination", destination.getAbsolutePath(), "--force");
+			List<String> filenames = listFilenames();
+			assertThat(filenames).contains("out/lib/dependency-1.jar")
+				.contains("out/lib/dependency-2.jar")
+				.contains("out/lib/dependency-3-SNAPSHOT.jar")
+				.contains("out/test.jar");
 		}
 
 	}
@@ -206,23 +241,23 @@ class ExtractCommandTests extends AbstractTests {
 	class ExtractWithLayers {
 
 		@Test
-		void extractLibrariesAndCreatesRunner() throws IOException {
+		void extractLibrariesAndCreatesApplication() throws IOException {
 			run(ExtractCommandTests.this.archive, "--layers");
 			List<String> filenames = listFilenames();
-			assertThat(filenames).contains("dependencies/lib/dependency-1.jar")
-				.contains("dependencies/lib/dependency-2.jar")
-				.contains("snapshot-dependencies/lib/dependency-3-SNAPSHOT.jar")
-				.contains("application/runner.jar");
+			assertThat(filenames).contains("test/dependencies/lib/dependency-1.jar")
+				.contains("test/dependencies/lib/dependency-2.jar")
+				.contains("test/snapshot-dependencies/lib/dependency-3-SNAPSHOT.jar")
+				.contains("test/application/test.jar");
 		}
 
 		@Test
 		void extractsOnlySelectedLayers() throws IOException {
 			run(ExtractCommandTests.this.archive, "--layers", "dependencies");
 			List<String> filenames = listFilenames();
-			assertThat(filenames).contains("dependencies/lib/dependency-1.jar")
-				.contains("dependencies/lib/dependency-2.jar")
-				.doesNotContain("snapshot-dependencies/lib/dependency-3-SNAPSHOT.jar")
-				.doesNotContain("application/runner.jar");
+			assertThat(filenames).contains("test/dependencies/lib/dependency-1.jar")
+				.contains("test/dependencies/lib/dependency-2.jar")
+				.doesNotContain("test/snapshot-dependencies/lib/dependency-3-SNAPSHOT.jar")
+				.doesNotContain("test/application/test.jar");
 		}
 
 		@Test
@@ -241,14 +276,14 @@ class ExtractCommandTests extends AbstractTests {
 		void extract() throws IOException {
 			run(ExtractCommandTests.this.archive, "--launcher");
 			List<String> filenames = listFilenames();
-			assertThat(filenames).contains("META-INF/MANIFEST.MF")
-				.contains("BOOT-INF/classpath.idx")
-				.contains("BOOT-INF/layers.idx")
-				.contains("BOOT-INF/lib/dependency-1.jar")
-				.contains("BOOT-INF/lib/dependency-2.jar")
-				.contains("BOOT-INF/lib/dependency-3-SNAPSHOT.jar")
-				.contains("BOOT-INF/classes/application.properties")
-				.contains("org/springframework/boot/loader/launch/JarLauncher.class");
+			assertThat(filenames).contains("test/META-INF/MANIFEST.MF")
+				.contains("test/BOOT-INF/classpath.idx")
+				.contains("test/BOOT-INF/layers.idx")
+				.contains("test/BOOT-INF/lib/dependency-1.jar")
+				.contains("test/BOOT-INF/lib/dependency-2.jar")
+				.contains("test/BOOT-INF/lib/dependency-3-SNAPSHOT.jar")
+				.contains("test/BOOT-INF/classes/application.properties")
+				.contains("test/org/springframework/boot/loader/launch/JarLauncher.class");
 		}
 
 		@Test
@@ -267,14 +302,14 @@ class ExtractCommandTests extends AbstractTests {
 		void extract() throws IOException {
 			run(ExtractCommandTests.this.archive, "--launcher", "--layers");
 			List<String> filenames = listFilenames();
-			assertThat(filenames).contains("application/META-INF/MANIFEST.MF")
-				.contains("application/BOOT-INF/classpath.idx")
-				.contains("application/BOOT-INF/layers.idx")
-				.contains("dependencies/BOOT-INF/lib/dependency-1.jar")
-				.contains("dependencies/BOOT-INF/lib/dependency-2.jar")
-				.contains("snapshot-dependencies/BOOT-INF/lib/dependency-3-SNAPSHOT.jar")
-				.contains("application/BOOT-INF/classes/application.properties")
-				.contains("spring-boot-loader/org/springframework/boot/loader/launch/JarLauncher.class");
+			assertThat(filenames).contains("test/application/META-INF/MANIFEST.MF")
+				.contains("test/application/BOOT-INF/classpath.idx")
+				.contains("test/application/BOOT-INF/layers.idx")
+				.contains("test/dependencies/BOOT-INF/lib/dependency-1.jar")
+				.contains("test/dependencies/BOOT-INF/lib/dependency-2.jar")
+				.contains("test/snapshot-dependencies/BOOT-INF/lib/dependency-3-SNAPSHOT.jar")
+				.contains("test/application/BOOT-INF/classes/application.properties")
+				.contains("test/spring-boot-loader/org/springframework/boot/loader/launch/JarLauncher.class");
 		}
 
 		@Test
@@ -288,14 +323,14 @@ class ExtractCommandTests extends AbstractTests {
 		void extractsOnlySelectedLayers() throws IOException {
 			run(ExtractCommandTests.this.archive, "--launcher", "--layers", "dependencies");
 			List<String> filenames = listFilenames();
-			assertThat(filenames).doesNotContain("application/META-INF/MANIFEST.MF")
-				.doesNotContain("application/BOOT-INF/classpath.idx")
-				.doesNotContain("application/BOOT-INF/layers.idx")
-				.contains("dependencies/BOOT-INF/lib/dependency-1.jar")
-				.contains("dependencies/BOOT-INF/lib/dependency-2.jar")
-				.doesNotContain("snapshot-dependencies/BOOT-INF/lib/dependency-3-SNAPSHOT.jar")
-				.doesNotContain("application/BOOT-INF/classes/application.properties")
-				.doesNotContain("spring-boot-loader/org/springframework/boot/loader/launch/JarLauncher.class");
+			assertThat(filenames).doesNotContain("test/application/META-INF/MANIFEST.MF")
+				.doesNotContain("test/application/BOOT-INF/classpath.idx")
+				.doesNotContain("test/application/BOOT-INF/layers.idx")
+				.contains("test/dependencies/BOOT-INF/lib/dependency-1.jar")
+				.contains("test/dependencies/BOOT-INF/lib/dependency-2.jar")
+				.doesNotContain("test/snapshot-dependencies/BOOT-INF/lib/dependency-3-SNAPSHOT.jar")
+				.doesNotContain("test/application/BOOT-INF/classes/application.properties")
+				.doesNotContain("test/spring-boot-loader/org/springframework/boot/loader/launch/JarLauncher.class");
 		}
 
 	}

spring-boot-project/spring-boot-tools/spring-boot-jarmode-tools/src/test/java/org/springframework/boot/jarmode/tools/ExtractLayersCommandTests.java

@@ -172,9 +172,10 @@ class ExtractLayersCommandTests {
 			writer.write("text");
 		}
 		given(this.context.getArchiveFile()).willReturn(file);
-		assertThatIllegalStateException()
-			.isThrownBy(() -> this.command.run(System.out, Collections.emptyMap(), Collections.emptyList()))
-			.withMessageContaining("not compatible");
+		try (TestPrintStream out = new TestPrintStream(this)) {
+			this.command.run(out, Collections.emptyMap(), Collections.emptyList());
+			assertThat(out).contains("is not compatible");
+		}
 	}
 
 	@Test

spring-boot-project/spring-boot-tools/spring-boot-jarmode-tools/src/test/java/org/springframework/boot/jarmode/tools/TestPrintStream.java

@@ -62,15 +62,25 @@ class TestPrintStream extends PrintStream implements AssertProvider<PrintStreamA
 
 		void hasSameContentAsResource(String resource) {
 			try {
-				InputStream stream = this.actual.testClass.getResourceAsStream(resource);
-				String content = FileCopyUtils.copyToString(new InputStreamReader(stream, StandardCharsets.UTF_8));
-				Assertions.assertThat(this.actual).hasToString(content);
+				try (InputStream stream = this.actual.testClass.getResourceAsStream(resource)) {
+					Assertions.assertThat(stream).as("Resource '%s'", resource).isNotNull();
+					String content = FileCopyUtils.copyToString(new InputStreamReader(stream, StandardCharsets.UTF_8));
+					hasSameContent(content);
+				}
 			}
 			catch (IOException ex) {
 				throw new IllegalStateException(ex);
 			}
 		}
 
+		void hasSameContent(String content) {
+			Assertions.assertThat(this.actual).hasToString(content);
+		}
+
+		void contains(String text) {
+			Assertions.assertThat(this.actual.toString()).contains(text);
+		}
+
 	}
 
 }

spring-boot-project/spring-boot-tools/spring-boot-jarmode-tools/src/test/resources/org/springframework/boot/jarmode/tools/tools-error-option-missing-value-output.txt

@@ -6,8 +6,9 @@ Usage:
   java -Djarmode=tools -jar test.jar extract [options]
 
 Options:
-  --launcher                Whether to extract the Spring Boot launcher
-  --layers string list      Layers to extract
-  --destination string      Directory to extract files to. Defaults to the current working directory
-  --libraries string        Name of the libraries directory. Only applicable when not using --launcher. Defaults to lib/
-  --runner-filename string  Name of the runner JAR file. Only applicable when not using --launcher. Defaults to runner.jar
+  --launcher                     Whether to extract the Spring Boot launcher
+  --layers string list           Layers to extract
+  --destination string           Directory to extract files to. Defaults to a directory named after the uber JAR (without the file extension)
+  --libraries string             Name of the libraries directory. Only applicable when not using --launcher. Defaults to lib/
+  --application-filename string  Name of the application JAR file. Only applicable when not using --launcher. Defaults to the uber JAR filename
+  --force                        Whether to ignore non-empty directories, extract anyway

spring-boot-project/spring-boot-tools/spring-boot-jarmode-tools/src/test/resources/org/springframework/boot/jarmode/tools/tools-error-option-unknown-output.txt

@@ -6,8 +6,9 @@ Usage:
   java -Djarmode=tools -jar test.jar extract [options]
 
 Options:
-  --launcher                Whether to extract the Spring Boot launcher
-  --layers string list      Layers to extract
-  --destination string      Directory to extract files to. Defaults to the current working directory
-  --libraries string        Name of the libraries directory. Only applicable when not using --launcher. Defaults to lib/
-  --runner-filename string  Name of the runner JAR file. Only applicable when not using --launcher. Defaults to runner.jar
+  --launcher                     Whether to extract the Spring Boot launcher
+  --layers string list           Layers to extract
+  --destination string           Directory to extract files to. Defaults to a directory named after the uber JAR (without the file extension)
+  --libraries string             Name of the libraries directory. Only applicable when not using --launcher. Defaults to lib/
+  --application-filename string  Name of the application JAR file. Only applicable when not using --launcher. Defaults to the uber JAR filename
+  --force                        Whether to ignore non-empty directories, extract anyway

spring-boot-project/spring-boot-tools/spring-boot-jarmode-tools/src/test/resources/org/springframework/boot/jarmode/tools/tools-help-extract-output.txt

@@ -4,8 +4,9 @@ Usage:
   java -Djarmode=tools -jar test.jar extract [options]
 
 Options:
-  --launcher                Whether to extract the Spring Boot launcher
-  --layers string list      Layers to extract
-  --destination string      Directory to extract files to. Defaults to the current working directory
-  --libraries string        Name of the libraries directory. Only applicable when not using --launcher. Defaults to lib/
-  --runner-filename string  Name of the runner JAR file. Only applicable when not using --launcher. Defaults to runner.jar
+  --launcher                     Whether to extract the Spring Boot launcher
+  --layers string list           Layers to extract
+  --destination string           Directory to extract files to. Defaults to a directory named after the uber JAR (without the file extension)
+  --libraries string             Name of the libraries directory. Only applicable when not using --launcher. Defaults to lib/
+  --application-filename string  Name of the application JAR file. Only applicable when not using --launcher. Defaults to the uber JAR filename
+  --force                        Whether to ignore non-empty directories, extract anyway