Merge pull request #11624 from igor-suhorukov:master

* pr/11624:
  Polish "Fix potential resource leaks"
  Fix potential resource leaks

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

 /*
- * Copyright 2012-2017 the original author or authors.
+ * Copyright 2012-2018 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -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

 /*
- * Copyright 2012-2017 the original author or authors.
+ * Copyright 2012-2018 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -215,16 +215,16 @@ 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()));
-		JarEntry entry;
-		while ((entry = inputStream.getNextJarEntry()) != null) {
-			if (entry.getName().endsWith(".class")) {
-				writeEntry(new JarArchiveEntry(entry),
-						new InputStreamEntryWriter(inputStream, false));
+		try (JarInputStream inputStream = new JarInputStream(
+				new BufferedInputStream(loaderJar.openStream()))) {
+			JarEntry entry;
+			while ((entry = inputStream.getNextJarEntry()) != null) {
+				if (entry.getName().endsWith(".class")) {
+					writeEntry(new JarArchiveEntry(entry),
+							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

 /*
- * Copyright 2012-2017 the original author or authors.
+ * Copyright 2012-2018 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -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

 /*
- * Copyright 2012-2017 the original author or authors.
+ * Copyright 2012-2018 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -123,12 +123,12 @@ public class RunMojo extends AbstractRunMojo {
 		return this.hasDevtools;
 	}
 
-	@SuppressWarnings("resource")
 	private boolean checkForDevtools() {
 		try {
 			URL[] urls = getClassPathUrls();
-			URLClassLoader classLoader = new URLClassLoader(urls);
-			return (classLoader.findResource(RESTARTER_CLASS_LOCATION) != null);
+			try (URLClassLoader classLoader = new URLClassLoader(urls)) {
+				return (classLoader.findResource(RESTARTER_CLASS_LOCATION) != null);
+			}
 		}
 		catch (Exception ex) {
 			return false;