Fix potential resource leaks

See gh-11624

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

@@ -16,6 +16,8 @@
 
 package org.springframework.boot.devtools.autoconfigure;
 
+import java.sql.Connection;
+import java.sql.Statement;
 import java.util.Arrays;
 import java.util.HashSet;
 import java.util.Set;
@@ -97,7 +99,11 @@ public class DevToolsDataSourceAutoConfiguration {
 		@Override
 		public void destroy() throws Exception {
 			if (dataSourceRequiresShutdown()) {
-				this.dataSource.getConnection().createStatement().execute("SHUTDOWN");
+				try (Connection connection = this.dataSource.getConnection()) {
+					try (Statement statement = connection.createStatement()) {
+						statement.execute("SHUTDOWN");
+					}
+				}
 			}
 		}
 

spring-boot-project/spring-boot-tools/spring-boot-loader-tools/src/main/java/org/springframework/boot/loader/tools/JarWriter.java

@@ -215,8 +215,8 @@ public class JarWriter implements LoaderClassesWriter, AutoCloseable {
 	@Override
 	public void writeLoaderClasses(String loaderJarResourceName) throws IOException {
 		URL loaderJar = getClass().getClassLoader().getResource(loaderJarResourceName);
-		JarInputStream inputStream = new JarInputStream(
-				new BufferedInputStream(loaderJar.openStream()));
+		try (JarInputStream inputStream = new JarInputStream(
+				new BufferedInputStream(loaderJar.openStream()))) {
 			JarEntry entry;
 			while ((entry = inputStream.getNextJarEntry()) != null) {
 				if (entry.getName().endsWith(".class")) {
@@ -224,7 +224,7 @@ public class JarWriter implements LoaderClassesWriter, AutoCloseable {
 							new InputStreamEntryWriter(inputStream, false));
 				}
 			}
-		inputStream.close();
+		}
 	}
 
 	/**

spring-boot-project/spring-boot-tools/spring-boot-loader/src/main/java/org/springframework/boot/loader/jar/JarFile.java

@@ -157,7 +157,9 @@ public class JarFile extends java.util.jar.JarFile {
 		Manifest manifest = (this.manifest == null ? null : this.manifest.get());
 		if (manifest == null) {
 			if (this.type == JarFileType.NESTED_DIRECTORY) {
-				manifest = new JarFile(this.getRootJarFile()).getManifest();
+				try (JarFile rootJarFile = new JarFile(this.getRootJarFile())) {
+					manifest = rootJarFile.getManifest();
+				}
 			}
 			else {
 				try (InputStream inputStream = getInputStream(MANIFEST_NAME,

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

@@ -127,9 +127,10 @@ public class RunMojo extends AbstractRunMojo {
 	private boolean checkForDevtools() {
 		try {
 			URL[] urls = getClassPathUrls();
-			URLClassLoader classLoader = new URLClassLoader(urls);
+			try (URLClassLoader classLoader = new URLClassLoader(urls)) {
 				return (classLoader.findResource(RESTARTER_CLASS_LOCATION) != null);
 			}
+		}
 		catch (Exception ex) {
 			return false;
 		}