Use AutoClosables with try-with-resources

Closes gh-33538

buildSrc/src/main/java/org/springframework/boot/build/classpath/CheckClasspathForConflicts.java

@@ -34,6 +34,7 @@ import java.util.function.Predicate;
 import java.util.jar.JarEntry;
 import java.util.jar.JarFile;
 import java.util.stream.Collectors;
+import java.util.stream.Stream;
 
 import org.gradle.api.DefaultTask;
 import org.gradle.api.GradleException;
@@ -68,8 +69,10 @@ public class CheckClasspathForConflicts extends DefaultTask {
 		for (File file : this.classpath) {
 			if (file.isDirectory()) {
 				Path root = file.toPath();
-				Files.walk(root).filter(Files::isRegularFile)
-						.forEach((entry) -> classpathContents.add(root.relativize(entry).toString(), root.toString()));
+				try (Stream<Path> pathStream = Files.walk(root)) {
+					pathStream.filter(Files::isRegularFile).forEach(
+							(entry) -> classpathContents.add(root.relativize(entry).toString(), root.toString()));
+				}
 			}
 			else {
 				try (JarFile jar = new JarFile(file)) {

spring-boot-project/spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/amqp/RabbitAutoConfigurationTests.java

@@ -178,11 +178,15 @@ class RabbitAutoConfigurationTests {
 			com.rabbitmq.client.ConnectionFactory rcf = mock(com.rabbitmq.client.ConnectionFactory.class);
 			given(rcf.newConnection(isNull(), eq(addresses), anyString())).willReturn(mock(Connection.class));
 			ReflectionTestUtils.setField(connectionFactory, "rabbitConnectionFactory", rcf);
-			connectionFactory.createConnection();
-			then(rcf).should().newConnection(isNull(), eq(addresses), eq("test#0"));
+			try (org.springframework.amqp.rabbit.connection.Connection connection = connectionFactory
+					.createConnection()) {
+				then(rcf).should().newConnection(isNull(), eq(addresses), eq("test#0"));
+			}
 			connectionFactory.resetConnection();
-			connectionFactory.createConnection();
-			then(rcf).should().newConnection(isNull(), eq(addresses), eq("test#1"));
+			try (org.springframework.amqp.rabbit.connection.Connection connection = connectionFactory
+					.createConnection()) {
+				then(rcf).should().newConnection(isNull(), eq(addresses), eq("test#1"));
+			}
 		});
 	}
 

spring-boot-project/spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/web/servlet/MultipartAutoConfigurationTests.java

@@ -205,8 +205,9 @@ class MultipartAutoConfigurationTests {
 		HttpComponentsClientHttpRequestFactory requestFactory = new HttpComponentsClientHttpRequestFactory();
 		ClientHttpRequest request = requestFactory.createRequest(
 				new URI("http://localhost:" + this.context.getWebServer().getPort() + "/"), HttpMethod.GET);
-		ClientHttpResponse response = request.execute();
-		assertThat(response.getStatusCode()).isEqualTo(HttpStatus.NOT_FOUND);
+		try (ClientHttpResponse response = request.execute()) {
+			assertThat(response.getStatusCode()).isEqualTo(HttpStatus.NOT_FOUND);
+		}
 	}
 
 	private void verifyServletWorks() {

spring-boot-project/spring-boot-devtools/src/main/java/org/springframework/boot/devtools/autoconfigure/DevToolsDataSourceAutoConfiguration.java

@@ -111,7 +111,7 @@ public class DevToolsDataSourceAutoConfiguration {
 			DERBY(null, new HashSet<>(Arrays.asList("org.apache.derby.jdbc.EmbeddedDriver")), (dataSource) -> {
 				String url = dataSource.getConnection().getMetaData().getURL();
 				try {
-					new EmbeddedDriver().connect(url + ";drop=true", new Properties());
+					new EmbeddedDriver().connect(url + ";drop=true", new Properties()).close();
 				}
 				catch (SQLException ex) {
 					if (!"08006".equals(ex.getSQLState())) {

spring-boot-project/spring-boot-devtools/src/main/java/org/springframework/boot/devtools/remote/client/ClassPathChangeUploader.java

@@ -110,10 +110,11 @@ public class ClassPathChangeUploader implements ApplicationListener<ClassPathCha
 					headers.setContentLength(bytes.length);
 					FileCopyUtils.copy(bytes, request.getBody());
 					logUpload(event);
-					ClientHttpResponse response = request.execute();
-					HttpStatusCode statusCode = response.getStatusCode();
-					Assert.state(statusCode == HttpStatus.OK,
-							() -> "Unexpected " + statusCode + " response uploading class files");
+					try (ClientHttpResponse response = request.execute()) {
+						HttpStatusCode statusCode = response.getStatusCode();
+						Assert.state(statusCode == HttpStatus.OK,
+								() -> "Unexpected " + statusCode + " response uploading class files");
+					}
 					return;
 				}
 				catch (SocketException ex) {

spring-boot-project/spring-boot-devtools/src/main/java/org/springframework/boot/devtools/remote/client/DelayedLiveReloadTrigger.java

@@ -103,8 +103,9 @@ class DelayedLiveReloadTrigger implements Runnable {
 	private boolean isUp() {
 		try {
 			ClientHttpRequest request = createRequest();
-			ClientHttpResponse response = request.execute();
-			return response.getStatusCode() == HttpStatus.OK;
+			try (ClientHttpResponse response = request.execute()) {
+				return response.getStatusCode() == HttpStatus.OK;
+			}
 		}
 		catch (Exception ex) {
 			return false;

spring-boot-project/spring-boot-devtools/src/test/java/org/springframework/boot/devtools/tunnel/client/HttpTunnelConnectionTests.java

@@ -139,9 +139,10 @@ class HttpTunnelConnectionTests {
 	@Test
 	void connectFailureLogsWarning(CapturedOutput output) throws Exception {
 		this.requestFactory.willRespond(new ConnectException());
-		TunnelChannel tunnel = openTunnel(true);
-		assertThat(tunnel.isOpen()).isFalse();
-		assertThat(output).contains("Failed to connect to remote application at http://localhost:12345");
+		try (TunnelChannel tunnel = openTunnel(true)) {
+			assertThat(tunnel.isOpen()).isFalse();
+			assertThat(output).contains("Failed to connect to remote application at http://localhost:12345");
+		}
 	}
 
 	private void write(TunnelChannel channel, String string) throws IOException {

spring-boot-project/spring-boot-devtools/src/test/java/org/springframework/boot/devtools/tunnel/server/SocketTargetServerConnectionTests.java

@@ -53,34 +53,37 @@ class SocketTargetServerConnectionTests {
 	void readData() throws Exception {
 		this.server.willSend("hello".getBytes());
 		this.server.start();
-		ByteChannel channel = this.connection.open(DEFAULT_TIMEOUT);
-		ByteBuffer buffer = ByteBuffer.allocate(5);
-		channel.read(buffer);
-		assertThat(buffer.array()).isEqualTo("hello".getBytes());
+		try (ByteChannel channel = this.connection.open(DEFAULT_TIMEOUT)) {
+			ByteBuffer buffer = ByteBuffer.allocate(5);
+			channel.read(buffer);
+			assertThat(buffer.array()).isEqualTo("hello".getBytes());
+		}
 	}
 
 	@Test
 	void writeData() throws Exception {
 		this.server.expect("hello".getBytes());
 		this.server.start();
-		ByteChannel channel = this.connection.open(DEFAULT_TIMEOUT);
-		ByteBuffer buffer = ByteBuffer.wrap("hello".getBytes());
-		channel.write(buffer);
-		this.server.closeAndVerify();
+		try (ByteChannel channel = this.connection.open(DEFAULT_TIMEOUT)) {
+			ByteBuffer buffer = ByteBuffer.wrap("hello".getBytes());
+			channel.write(buffer);
+			this.server.closeAndVerify();
+		}
 	}
 
 	@Test
 	void timeout() throws Exception {
 		this.server.delay(1000);
 		this.server.start();
-		ByteChannel channel = this.connection.open(10);
-		long startTime = System.currentTimeMillis();
-		assertThatExceptionOfType(SocketTimeoutException.class).isThrownBy(() -> channel.read(ByteBuffer.allocate(5)))
-				.satisfies((ex) -> {
-					long runTime = System.currentTimeMillis() - startTime;
-					assertThat(runTime).isGreaterThanOrEqualTo(10L);
-					assertThat(runTime).isLessThan(10000L);
-				});
+		try (ByteChannel channel = this.connection.open(10)) {
+			long startTime = System.currentTimeMillis();
+			assertThatExceptionOfType(SocketTimeoutException.class)
+					.isThrownBy(() -> channel.read(ByteBuffer.allocate(5))).satisfies((ex) -> {
+						long runTime = System.currentTimeMillis() - startTime;
+						assertThat(runTime).isGreaterThanOrEqualTo(10L);
+						assertThat(runTime).isLessThan(10000L);
+					});
+		}
 	}
 
 	static class MockServer {

spring-boot-project/spring-boot-tools/spring-boot-buildpack-platform/src/test/java/org/springframework/boot/buildpack/platform/build/BuildpackCoordinatesTests.java

@@ -57,35 +57,43 @@ class BuildpackCoordinatesTests extends AbstractJsonTests {
 	}
 
 	@Test
-	void fromTomlWhenMissingIDThrowsException() {
-		InputStream coordinates = createTomlStream(null, null, true, false);
-		assertThatIllegalArgumentException().isThrownBy(() -> BuildpackCoordinates.fromToml(coordinates, this.archive))
-				.withMessageContaining("Buildpack descriptor must contain ID")
-				.withMessageContaining(this.archive.toString());
+	void fromTomlWhenMissingIDThrowsException() throws IOException {
+		try (InputStream coordinates = createTomlStream(null, null, true, false)) {
+			assertThatIllegalArgumentException()
+					.isThrownBy(() -> BuildpackCoordinates.fromToml(coordinates, this.archive))
+					.withMessageContaining("Buildpack descriptor must contain ID")
+					.withMessageContaining(this.archive.toString());
+		}
 	}
 
 	@Test
-	void fromTomlWhenMissingVersionThrowsException() {
-		InputStream coordinates = createTomlStream("example/buildpack1", null, true, false);
-		assertThatIllegalArgumentException().isThrownBy(() -> BuildpackCoordinates.fromToml(coordinates, this.archive))
-				.withMessageContaining("Buildpack descriptor must contain version")
-				.withMessageContaining(this.archive.toString());
+	void fromTomlWhenMissingVersionThrowsException() throws IOException {
+		try (InputStream coordinates = createTomlStream("example/buildpack1", null, true, false)) {
+			assertThatIllegalArgumentException()
+					.isThrownBy(() -> BuildpackCoordinates.fromToml(coordinates, this.archive))
+					.withMessageContaining("Buildpack descriptor must contain version")
+					.withMessageContaining(this.archive.toString());
+		}
 	}
 
 	@Test
-	void fromTomlWhenMissingStacksAndOrderThrowsException() {
-		InputStream coordinates = createTomlStream("example/buildpack1", "0.0.1", false, false);
-		assertThatIllegalArgumentException().isThrownBy(() -> BuildpackCoordinates.fromToml(coordinates, this.archive))
-				.withMessageContaining("Buildpack descriptor must contain either 'stacks' or 'order'")
-				.withMessageContaining(this.archive.toString());
+	void fromTomlWhenMissingStacksAndOrderThrowsException() throws IOException {
+		try (InputStream coordinates = createTomlStream("example/buildpack1", "0.0.1", false, false)) {
+			assertThatIllegalArgumentException()
+					.isThrownBy(() -> BuildpackCoordinates.fromToml(coordinates, this.archive))
+					.withMessageContaining("Buildpack descriptor must contain either 'stacks' or 'order'")
+					.withMessageContaining(this.archive.toString());
+		}
 	}
 
 	@Test
-	void fromTomlWhenContainsBothStacksAndOrderThrowsException() {
-		InputStream coordinates = createTomlStream("example/buildpack1", "0.0.1", true, true);
-		assertThatIllegalArgumentException().isThrownBy(() -> BuildpackCoordinates.fromToml(coordinates, this.archive))
-				.withMessageContaining("Buildpack descriptor must not contain both 'stacks' and 'order'")
-				.withMessageContaining(this.archive.toString());
+	void fromTomlWhenContainsBothStacksAndOrderThrowsException() throws IOException {
+		try (InputStream coordinates = createTomlStream("example/buildpack1", "0.0.1", true, true)) {
+			assertThatIllegalArgumentException()
+					.isThrownBy(() -> BuildpackCoordinates.fromToml(coordinates, this.archive))
+					.withMessageContaining("Buildpack descriptor must not contain both 'stacks' and 'order'")
+					.withMessageContaining(this.archive.toString());
+		}
 	}
 
 	@Test

spring-boot-project/spring-boot-tools/spring-boot-gradle-plugin/src/test/java/org/springframework/boot/gradle/tasks/bundling/AbstractBootArchiveIntegrationTests.java

@@ -585,8 +585,12 @@ abstract class AbstractBootArchiveIntegrationTests {
 		for (String layerName : layerNames) {
 			File layer = new File(root, layerName);
 			assertThat(layer).isDirectory();
-			extractedLayers.put(layerName, Files.walk(layer.toPath()).filter((path) -> path.toFile().isFile())
-					.map(layer.toPath()::relativize).map(Path::toString).map(StringUtils::cleanPath).toList());
+			List<String> files;
+			try (Stream<Path> pathStream = Files.walk(layer.toPath())) {
+				files = pathStream.filter((path) -> path.toFile().isFile()).map(layer.toPath()::relativize)
+						.map(Path::toString).map(StringUtils::cleanPath).toList();
+			}
+			extractedLayers.put(layerName, files);
 		}
 		return extractedLayers;
 	}

spring-boot-project/spring-boot-tools/spring-boot-loader/src/test/java/org/springframework/boot/loader/jar/JarFileTests.java

@@ -294,9 +294,10 @@ class JarFileTests {
 	void getEntryUrlStream() throws Exception {
 		URL url = new URL(this.jarFile.getUrl(), "1.dat");
 		url.openConnection();
-		InputStream stream = url.openStream();
-		assertThat(stream.read()).isEqualTo(1);
-		assertThat(stream.read()).isEqualTo(-1);
+		try (InputStream stream = url.openStream()) {
+			assertThat(stream.read()).isEqualTo(1);
+			assertThat(stream.read()).isEqualTo(-1);
+		}
 	}
 
 	@Test

spring-boot-project/spring-boot-tools/spring-boot-maven-plugin/src/intTest/java/org/springframework/boot/maven/AotTests.java

@@ -20,6 +20,7 @@ import java.io.File;
 import java.io.IOException;
 import java.nio.file.Files;
 import java.nio.file.Path;
+import java.util.List;
 import java.util.stream.Stream;
 
 import org.junit.jupiter.api.TestTemplate;
@@ -173,10 +174,10 @@ public class AotTests {
 		});
 	}
 
-	Stream<Path> collectRelativePaths(Path sourceDirectory) {
-		try {
-			return Files.walk(sourceDirectory).filter(Files::isRegularFile)
-					.map((path) -> path.subpath(sourceDirectory.getNameCount(), path.getNameCount()));
+	List<Path> collectRelativePaths(Path sourceDirectory) {
+		try (Stream<Path> pathStream = Files.walk(sourceDirectory)) {
+			return pathStream.filter(Files::isRegularFile)
+					.map((path) -> path.subpath(sourceDirectory.getNameCount(), path.getNameCount())).toList();
 		}
 		catch (IOException ex) {
 			throw new IllegalStateException(ex);

spring-boot-project/spring-boot-tools/spring-boot-maven-plugin/src/intTest/java/org/springframework/boot/maven/MavenBuildExtension.java

@@ -47,6 +47,8 @@ class MavenBuildExtension implements TestTemplateInvocationContextProvider {
 	@Override
 	public Stream<TestTemplateInvocationContext> provideTestTemplateInvocationContexts(ExtensionContext context) {
 		try {
+			// Returning a stream which must be closed here is fine, as JUnit will take
+			// care of closing it
 			return Files.list(Paths.get("build/maven-binaries")).map(MavenVersionTestTemplateInvocationContext::new);
 		}
 		catch (IOException ex) {

spring-boot-project/spring-boot-tools/spring-boot-maven-plugin/src/main/java/org/springframework/boot/maven/AbstractAotMojo.java

@@ -28,6 +28,7 @@ import java.util.Collections;
 import java.util.List;
 import java.util.Locale;
 import java.util.Map;
+import java.util.stream.Stream;
 
 import javax.tools.Diagnostic;
 import javax.tools.DiagnosticListener;
@@ -124,7 +125,10 @@ public abstract class AbstractAotMojo extends AbstractDependencyFilterMojo {
 
 	protected final void compileSourceFiles(URL[] classPath, File sourcesDirectory, File outputDirectory)
 			throws Exception {
-		List<Path> sourceFiles = Files.walk(sourcesDirectory.toPath()).filter(Files::isRegularFile).toList();
+		List<Path> sourceFiles;
+		try (Stream<Path> pathStream = Files.walk(sourcesDirectory.toPath())) {
+			sourceFiles = pathStream.filter(Files::isRegularFile).toList();
+		}
 		if (sourceFiles.isEmpty()) {
 			return;
 		}
@@ -167,8 +171,13 @@ public abstract class AbstractAotMojo extends AbstractDependencyFilterMojo {
 	}
 
 	protected final void copyAll(Path from, Path to) throws IOException {
-		List<Path> files = (Files.exists(from)) ? Files.walk(from).filter(Files::isRegularFile).toList()
-				: Collections.emptyList();
+		if (!Files.exists(from)) {
+			return;
+		}
+		List<Path> files;
+		try (Stream<Path> pathStream = Files.walk(from)) {
+			files = pathStream.filter(Files::isRegularFile).toList();
+		}
 		for (Path file : files) {
 			String relativeFileName = file.subpath(from.getNameCount(), file.getNameCount()).toString();
 			getLog().debug("Copying '" + relativeFileName + "' to " + to);

spring-boot-project/spring-boot/src/main/java/org/springframework/boot/env/ConfigTreePropertySource.java

@@ -30,6 +30,7 @@ import java.util.Iterator;
 import java.util.Map;
 import java.util.Set;
 import java.util.TreeMap;
+import java.util.stream.Stream;
 
 import org.springframework.boot.convert.ApplicationConversionService;
 import org.springframework.boot.origin.Origin;
@@ -204,16 +205,18 @@ public class ConfigTreePropertySource extends EnumerablePropertySource<Path> imp
 		static Map<String, PropertyFile> findAll(Path sourceDirectory, Set<Option> options) {
 			try {
 				Map<String, PropertyFile> propertyFiles = new TreeMap<>();
-				Files.find(sourceDirectory, MAX_DEPTH, PropertyFile::isPropertyFile, FileVisitOption.FOLLOW_LINKS)
-						.forEach((path) -> {
-							String name = getName(sourceDirectory.relativize(path));
-							if (StringUtils.hasText(name)) {
-								if (options.contains(Option.USE_LOWERCASE_NAMES)) {
-									name = name.toLowerCase();
-								}
-								propertyFiles.put(name, new PropertyFile(path, options));
+				try (Stream<Path> pathStream = Files.find(sourceDirectory, MAX_DEPTH, PropertyFile::isPropertyFile,
+						FileVisitOption.FOLLOW_LINKS)) {
+					pathStream.forEach((path) -> {
+						String name = getName(sourceDirectory.relativize(path));
+						if (StringUtils.hasText(name)) {
+							if (options.contains(Option.USE_LOWERCASE_NAMES)) {
+								name = name.toLowerCase();
 							}
-						});
+							propertyFiles.put(name, new PropertyFile(path, options));
+						}
+					});
+				}
 				return Collections.unmodifiableMap(propertyFiles);
 			}
 			catch (IOException ex) {

spring-boot-project/spring-boot/src/test/java/org/springframework/boot/origin/OriginTrackedResourceTests.java

@@ -17,6 +17,7 @@
 package org.springframework.boot.origin;
 
 import java.io.IOException;
+import java.nio.channels.ReadableByteChannel;
 
 import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.Test;
@@ -100,8 +101,9 @@ class OriginTrackedResourceTests {
 
 	@Test
 	void readableChannelDelegatesToResource() throws IOException {
-		this.tracked.readableChannel();
-		then(this.resource).should().readableChannel();
+		try (ReadableByteChannel ignore = this.tracked.readableChannel()) {
+			then(this.resource).should().readableChannel();
+		}
 	}
 
 	@Test