Create MetadataReaderFactory instances with factory methods

Prior to this commit, Spring would create directly
`SimpleMetadataReaderFactory` instances or would manually create
`CachingMetadataReaderFactory` which extend
`SimpleMetadataReaderFactory`. This would prevent usage of the new
`ClassFileMetadataReaderFactory` in our internal codebase.

This commit replaces manual instantiations with calls to
`MetadataReaderFactory` factory methods and makes
`CachingMetadataReaderFactory` delegate to another factory created with
the same factory methods.

This allows internal usage of `ClassFileMetadataReaderFactory`
internally.

Closes gh-33616

Author: bclozel

spring-beans/src/main/java/org/springframework/beans/factory/annotation/AutowiredAnnotationBeanPostProcessor.java

@@ -83,7 +83,6 @@
 import org.springframework.core.type.AnnotationMetadata;
 import org.springframework.core.type.MethodMetadata;
 import org.springframework.core.type.classreading.MetadataReaderFactory;
-import org.springframework.core.type.classreading.SimpleMetadataReaderFactory;
 import org.springframework.javapoet.ClassName;
 import org.springframework.javapoet.CodeBlock;
 import org.springframework.lang.Nullable;
@@ -284,7 +283,7 @@ public void setBeanFactory(BeanFactory beanFactory) {
 					"AutowiredAnnotationBeanPostProcessor requires a ConfigurableListableBeanFactory: " + beanFactory);
 		}
 		this.beanFactory = clbf;
-		this.metadataReaderFactory = new SimpleMetadataReaderFactory(clbf.getBeanClassLoader());
+		this.metadataReaderFactory = MetadataReaderFactory.create(clbf.getBeanClassLoader());
 	}
 
 

spring-core/src/main/java/org/springframework/core/type/classreading/CachingMetadataReaderFactory.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2022 the original author or authors.
+ * Copyright 2002-2024 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.
@@ -35,11 +35,13 @@
  * @author Costin Leau
  * @since 2.5
  */
-public class CachingMetadataReaderFactory extends SimpleMetadataReaderFactory {
+public class CachingMetadataReaderFactory implements MetadataReaderFactory {
 
 	/** Default maximum number of entries for a local MetadataReader cache: 256. */
 	public static final int DEFAULT_CACHE_LIMIT = 256;
 
+	private final MetadataReaderFactory delegate;
+
 	/** MetadataReader cache: either local or shared at the ResourceLoader level. */
 	@Nullable
 	private Map<Resource, MetadataReader> metadataReaderCache;
@@ -50,7 +52,7 @@ public class CachingMetadataReaderFactory extends SimpleMetadataReaderFactory {
 	 * using a local resource cache.
 	 */
 	public CachingMetadataReaderFactory() {
-		super();
+		this.delegate = MetadataReaderFactory.create((ClassLoader) null);
 		setCacheLimit(DEFAULT_CACHE_LIMIT);
 	}
 
@@ -60,7 +62,7 @@ public CachingMetadataReaderFactory() {
 	 * @param classLoader the ClassLoader to use
 	 */
 	public CachingMetadataReaderFactory(@Nullable ClassLoader classLoader) {
-		super(classLoader);
+		this.delegate = MetadataReaderFactory.create(classLoader);
 		setCacheLimit(DEFAULT_CACHE_LIMIT);
 	}
 
@@ -72,7 +74,7 @@ public CachingMetadataReaderFactory(@Nullable ClassLoader classLoader) {
 	 * @see DefaultResourceLoader#getResourceCache
 	 */
 	public CachingMetadataReaderFactory(@Nullable ResourceLoader resourceLoader) {
-		super(resourceLoader);
+		this.delegate = MetadataReaderFactory.create(resourceLoader);
 		if (resourceLoader instanceof DefaultResourceLoader defaultResourceLoader) {
 			this.metadataReaderCache = defaultResourceLoader.getResourceCache(MetadataReader.class);
 		}
@@ -81,7 +83,6 @@ public CachingMetadataReaderFactory(@Nullable ResourceLoader resourceLoader) {
 		}
 	}
 
-
 	/**
 	 * Specify the maximum number of entries for the MetadataReader cache.
 	 * <p>Default is 256 for a local cache, whereas a shared cache is
@@ -112,14 +113,18 @@ public int getCacheLimit() {
 		}
 	}
 
+	@Override
+	public MetadataReader getMetadataReader(String className) throws IOException {
+		return this.delegate.getMetadataReader(className);
+	}
 
 	@Override
 	public MetadataReader getMetadataReader(Resource resource) throws IOException {
 		if (this.metadataReaderCache instanceof ConcurrentMap) {
 			// No synchronization necessary...
 			MetadataReader metadataReader = this.metadataReaderCache.get(resource);
 			if (metadataReader == null) {
-				metadataReader = super.getMetadataReader(resource);
+				metadataReader = this.delegate.getMetadataReader(resource);
 				this.metadataReaderCache.put(resource, metadataReader);
 			}
 			return metadataReader;
@@ -128,14 +133,14 @@ else if (this.metadataReaderCache != null) {
 			synchronized (this.metadataReaderCache) {
 				MetadataReader metadataReader = this.metadataReaderCache.get(resource);
 				if (metadataReader == null) {
-					metadataReader = super.getMetadataReader(resource);
+					metadataReader = this.delegate.getMetadataReader(resource);
 					this.metadataReaderCache.put(resource, metadataReader);
 				}
 				return metadataReader;
 			}
 		}
 		else {
-			return super.getMetadataReader(resource);
+			return this.delegate.getMetadataReader(resource);
 		}
 	}