Polish

spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/orm/jpa/JpaBaseConfiguration.java

@@ -69,7 +69,7 @@ import org.springframework.web.servlet.config.annotation.WebMvcConfigurerAdapter
 @Import(DataSourceInitializedPublisher.Registrar.class)
 public abstract class JpaBaseConfiguration implements BeanFactoryAware {
 
-	private final Log logger = LogFactory.getLog(getClass());
+	private static final Log logger = LogFactory.getLog(JpaBaseConfiguration.class);
 
 	private final DataSource dataSource;
 
@@ -197,8 +197,8 @@ public abstract class JpaBaseConfiguration implements BeanFactoryAware {
 			return ResourceUtils.extractJarFileURL(url);
 		}
 		catch (Exception ex) {
-			logger.info("Could not determine persistence "
-					+ "unit root location from " + source + " : " + ex);
+			logger.info("Could not determine persistence " + "unit root location from "
+					+ source + " : " + ex);
 		}
 		return null;
 	}

spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/thymeleaf/AbstractTemplateResolverConfiguration.java

@@ -37,7 +37,7 @@ abstract class AbstractTemplateResolverConfiguration {
 	private static final Log logger = LogFactory
 			.getLog(AbstractTemplateResolverConfiguration.class);
 
-	protected final ThymeleafProperties properties;
+	private final ThymeleafProperties properties;
 
 	private final ApplicationContext applicationContext;
 
@@ -47,6 +47,10 @@ abstract class AbstractTemplateResolverConfiguration {
 		this.applicationContext = applicationContext;
 	}
 
+	protected final ThymeleafProperties getProperties() {
+		return this.properties;
+	}
+
 	@PostConstruct
 	public void checkTemplateLocationExists() {
 		boolean checkTemplateLocation = this.properties.isCheckTemplateLocation();

spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/thymeleaf/ThymeleafAutoConfiguration.java

@@ -137,9 +137,10 @@ public class ThymeleafAutoConfiguration {
 			@Override
 			public SpringResourceTemplateResolver defaultTemplateResolver() {
 				SpringResourceTemplateResolver resolver = super.defaultTemplateResolver();
-				Method setCheckExistence = ReflectionUtils
-						.findMethod(resolver.getClass(), "setCheckExistence", boolean.class);
-				ReflectionUtils.invokeMethod(setCheckExistence, resolver, this.properties.isCheckTemplate());
+				Method setCheckExistence = ReflectionUtils.findMethod(resolver.getClass(),
+						"setCheckExistence", boolean.class);
+				ReflectionUtils.invokeMethod(setCheckExistence, resolver,
+						getProperties().isCheckTemplate());
 				return resolver;
 			}
 

spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/thymeleaf/ThymeleafProperties.java

@@ -109,7 +109,7 @@ public class ThymeleafProperties {
 	}
 
 	public boolean isCheckTemplate() {
-		return checkTemplate;
+		return this.checkTemplate;
 	}
 
 	public void setCheckTemplate(boolean checkTemplate) {

spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/web/MultipartAutoConfiguration.java

@@ -68,7 +68,7 @@ public class MultipartAutoConfiguration {
 	@ConditionalOnMissingBean(MultipartResolver.class)
 	public StandardServletMultipartResolver multipartResolver() {
 		StandardServletMultipartResolver multipartResolver = new StandardServletMultipartResolver();
-		multipartResolver.setResolveLazily(multipartProperties.isResolveLazily());
+		multipartResolver.setResolveLazily(this.multipartProperties.isResolveLazily());
 		return multipartResolver;
 	}
 

spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/web/MultipartProperties.java

@@ -123,7 +123,7 @@ public class MultipartProperties {
 	}
 
 	public boolean isResolveLazily() {
-		return resolveLazily;
+		return this.resolveLazily;
 	}
 
 	public void setResolveLazily(boolean resolveLazily) {

spring-boot-parent/pom.xml

@@ -264,7 +264,7 @@
 						<dependency>
 							<groupId>com.puppycrawl.tools</groupId>
 							<artifactId>checkstyle</artifactId>
-							<version>6.17</version>
+							<version>7.1.1</version>
 						</dependency>
 					</dependencies>
 				</plugin>

spring-boot-parent/src/checkstyle/checkstyle.xml

@@ -62,6 +62,7 @@
 		<module name="com.puppycrawl.tools.checkstyle.checks.coding.MultipleVariableDeclarationsCheck" />
 		<module name="com.puppycrawl.tools.checkstyle.checks.coding.RequireThisCheck">
 			<property name="checkMethods" value="false" />
+			<property name="validateOnlyOverlapping" value="false" />
 		</module>
 		<module name="com.puppycrawl.tools.checkstyle.checks.coding.OneStatementPerLineCheck" />
 

spring-boot-tools/spring-boot-loader/src/main/java/org/springframework/boot/loader/data/RandomAccessDataFile.java

@@ -260,10 +260,10 @@ public class RandomAccessDataFile implements RandomAccessData {
 		public void close() throws IOException {
 			this.available.acquireUninterruptibly(this.size);
 			try {
-				RandomAccessFile file = this.files.poll();
-				while (file != null) {
-					file.close();
-					file = this.files.poll();
+				RandomAccessFile pooledFile = this.files.poll();
+				while (pooledFile != null) {
+					pooledFile.close();
+					pooledFile = this.files.poll();
 				}
 			}
 			finally {

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

@@ -158,12 +158,12 @@ public class Handler extends URLStreamHandler {
 			String path = name.substring(FILE_PROTOCOL.length());
 			File file = new File(URLDecoder.decode(path, "UTF-8"));
 			Map<File, JarFile> cache = rootFileCache.get();
-			JarFile jarFile = (cache == null ? null : cache.get(file));
-			if (jarFile == null) {
-				jarFile = new JarFile(file);
-				addToRootFileCache(file, jarFile);
+			JarFile result = (cache == null ? null : cache.get(file));
+			if (result == null) {
+				result = new JarFile(file);
+				addToRootFileCache(file, result);
 			}
-			return jarFile;
+			return result;
 		}
 		catch (Exception ex) {
 			throw new IOException("Unable to open root Jar file '" + name + "'", ex);

spring-boot/src/main/java/org/springframework/boot/context/embedded/tomcat/TomcatErrorPage.java

@@ -54,14 +54,12 @@ class TomcatErrorPage {
 	}
 
 	private Object createNativePage(ErrorPage errorPage) {
-		Object nativePage = null;
 		try {
 			if (ClassUtils.isPresent(ERROR_PAGE_CLASS, null)) {
-				nativePage = BeanUtils
-						.instantiate(ClassUtils.forName(ERROR_PAGE_CLASS, null));
+				return BeanUtils.instantiate(ClassUtils.forName(ERROR_PAGE_CLASS, null));
 			}
-			else if (ClassUtils.isPresent(LEGACY_ERROR_PAGE_CLASS, null)) {
-				nativePage = BeanUtils
+			if (ClassUtils.isPresent(LEGACY_ERROR_PAGE_CLASS, null)) {
+				return BeanUtils
 						.instantiate(ClassUtils.forName(LEGACY_ERROR_PAGE_CLASS, null));
 			}
 		}
@@ -71,7 +69,7 @@ class TomcatErrorPage {
 		catch (LinkageError ex) {
 			// Swallow and continue
 		}
-		return nativePage;
+		return null;
 	}
 
 	public void addToContext(Context context) {