Polishing

spring-context/src/main/java/org/springframework/context/annotation/ClassPathScanningCandidateComponentProvider.java

@@ -340,13 +340,13 @@ private boolean indexSupportsIncludeFilters() {
 	 * @see #extractStereotype(TypeFilter)
 	 */
 	private boolean indexSupportsIncludeFilter(TypeFilter filter) {
-		if (filter instanceof AnnotationTypeFilter) {
-			Class<? extends Annotation> annotation = ((AnnotationTypeFilter) filter).getAnnotationType();
-			return (AnnotationUtils.isAnnotationDeclaredLocally(Indexed.class, annotation) ||
-					annotation.getName().startsWith("javax."));
+		if (filter instanceof AnnotationTypeFilter annotationTypeFilter) {
+			Class<? extends Annotation> annotationType = annotationTypeFilter.getAnnotationType();
+			return (AnnotationUtils.isAnnotationDeclaredLocally(Indexed.class, annotationType) ||
+					annotationType.getName().startsWith("javax."));
 		}
-		if (filter instanceof AssignableTypeFilter) {
-			Class<?> target = ((AssignableTypeFilter) filter).getTargetType();
+		if (filter instanceof AssignableTypeFilter assignableTypeFilter) {
+			Class<?> target = assignableTypeFilter.getTargetType();
 			return AnnotationUtils.isAnnotationDeclaredLocally(Indexed.class, target);
 		}
 		return false;
@@ -361,11 +361,11 @@ private boolean indexSupportsIncludeFilter(TypeFilter filter) {
 	 */
 	@Nullable
 	private String extractStereotype(TypeFilter filter) {
-		if (filter instanceof AnnotationTypeFilter) {
-			return ((AnnotationTypeFilter) filter).getAnnotationType().getName();
+		if (filter instanceof AnnotationTypeFilter annotationTypeFilter) {
+			return annotationTypeFilter.getAnnotationType().getName();
 		}
-		if (filter instanceof AssignableTypeFilter) {
-			return ((AssignableTypeFilter) filter).getTargetType().getName();
+		if (filter instanceof AssignableTypeFilter assignableTypeFilter) {
+			return assignableTypeFilter.getTargetType().getName();
 		}
 		return null;
 	}
@@ -536,10 +536,10 @@ protected boolean isCandidateComponent(AnnotatedBeanDefinition beanDefinition) {
 	 * Clear the local metadata cache, if any, removing all cached class metadata.
 	 */
 	public void clearCache() {
-		if (this.metadataReaderFactory instanceof CachingMetadataReaderFactory) {
+		if (this.metadataReaderFactory instanceof CachingMetadataReaderFactory cmrf) {
 			// Clear cache in externally provided MetadataReaderFactory; this is a no-op
 			// for a shared cache since it'll be cleared by the ApplicationContext.
-			((CachingMetadataReaderFactory) this.metadataReaderFactory).clearCache();
+			cmrf.clearCache();
 		}
 	}
 

spring-context/src/test/java/example/scannable/DefaultNamedComponent.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2008 the original author or authors.
+ * Copyright 2002-2022 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.
@@ -16,7 +16,6 @@
 
 package example.scannable;
 
-
 /**
  * @author Juergen Hoeller
  */

spring-context/src/testFixtures/java/org/springframework/context/testfixture/index/CandidateComponentsTestClassLoader.java

@@ -24,6 +24,7 @@
 
 import org.springframework.context.index.CandidateComponentsIndexLoader;
 import org.springframework.core.io.Resource;
+import org.springframework.lang.Nullable;
 
 /**
  * A test {@link ClassLoader} that can be used in a testing context to control the
@@ -35,7 +36,7 @@
 public class CandidateComponentsTestClassLoader extends ClassLoader {
 
 	/**
-	 * Create a test {@link ClassLoader} that disable the use of the index, even
+	 * Create a test {@link ClassLoader} that disables the use of the index, even
 	 * if resources are present at the standard location.
 	 * @param classLoader the classloader to use for all other operations
 	 * @return a test {@link ClassLoader} that has no index
@@ -48,8 +49,9 @@ public static ClassLoader disableIndex(ClassLoader classLoader) {
 
 	/**
 	 * Create a test {@link ClassLoader} that creates an index with the
-	 * specified {@link Resource} instances
+	 * specified {@link Resource} instances.
 	 * @param classLoader the classloader to use for all other operations
+	 * @param resources the resources for index files
 	 * @return a test {@link ClassLoader} with an index built based on the
 	 * specified resources.
 	 */
@@ -66,8 +68,10 @@ public static ClassLoader index(ClassLoader classLoader, Resource... resources)
 	}
 
 
+	@Nullable
 	private final Enumeration<URL> resourceUrls;
 
+	@Nullable
 	private final IOException cause;
 
 	public CandidateComponentsTestClassLoader(ClassLoader classLoader, Enumeration<URL> resourceUrls) {