CachedIntrospectionResults uses full WeakReference for any non-safe ClassLoader arrangement

Previously, CachedIntrospectionResults had three modes of caching, with the intermediate mode relying on WeakReferences in the JDK PropertyDescriptor implementation. Since the JDK is actually using SoftReferences there these days, losing information in case of a GC run with tough memory constraints, we want to allow for hard references in PropertyDescriptor objects and therefore use a full WeakReference for the CachedIntrospectionResults object itself.

Issue: SPR-10028

Author: jhoeller

spring-beans/src/main/java/org/springframework/beans/CachedIntrospectionResults.java

@@ -146,20 +146,16 @@ static CachedIntrospectionResults forClass(Class beanClass) throws BeansExceptio
 			results = (CachedIntrospectionResults) value;
 		}
 		if (results == null) {
-			// On JDK 1.5 and higher, it is almost always safe to cache the bean class...
-			// The sole exception is a custom BeanInfo class being provided in a non-safe ClassLoader.
-			boolean fullyCacheable =
-					ClassUtils.isCacheSafe(beanClass, CachedIntrospectionResults.class.getClassLoader()) ||
-					isClassLoaderAccepted(beanClass.getClassLoader());
-			if (fullyCacheable || !ClassUtils.isPresent(beanClass.getName() + "BeanInfo", beanClass.getClassLoader())) {
-				results = new CachedIntrospectionResults(beanClass, fullyCacheable);
+			if (ClassUtils.isCacheSafe(beanClass, CachedIntrospectionResults.class.getClassLoader()) ||
+					isClassLoaderAccepted(beanClass.getClassLoader())) {
+				results = new CachedIntrospectionResults(beanClass);
 				classCache.put(beanClass, results);
 			}
 			else {
 				if (logger.isDebugEnabled()) {
 					logger.debug("Not strongly caching class [" + beanClass.getName() + "] because it is not cache-safe");
 				}
-				results = new CachedIntrospectionResults(beanClass, true);
+				results = new CachedIntrospectionResults(beanClass);
 				classCache.put(beanClass, new WeakReference<CachedIntrospectionResults>(results));
 			}
 		}
@@ -222,7 +218,7 @@ private static boolean isUnderneathClassLoader(ClassLoader candidate, ClassLoade
 	 * @param beanClass the bean class to analyze
 	 * @throws BeansException in case of introspection failure
 	 */
-	private CachedIntrospectionResults(Class beanClass, boolean cacheFullMetadata) throws BeansException {
+	private CachedIntrospectionResults(Class beanClass) throws BeansException {
 		try {
 			if (logger.isTraceEnabled()) {
 				logger.trace("Getting BeanInfo for class [" + beanClass.getName() + "]");
@@ -270,9 +266,7 @@ private CachedIntrospectionResults(Class beanClass, boolean cacheFullMetadata) t
 							(pd.getPropertyEditorClass() != null ?
 									"; editor [" + pd.getPropertyEditorClass().getName() + "]" : ""));
 				}
-				if (cacheFullMetadata) {
-					pd = buildGenericTypeAwarePropertyDescriptor(beanClass, pd);
-				}
+				pd = buildGenericTypeAwarePropertyDescriptor(beanClass, pd);
 				this.propertyDescriptorCache.put(pd.getName(), pd);
 			}
 		}