Enforce use of ClassLoader.loadClass in case of temporary ClassLoader

Issue: SPR-17452

Author: jhoeller

spring-beans/src/main/java/org/springframework/beans/factory/support/AbstractBeanFactory.java

@@ -1362,6 +1362,7 @@ public void clearMetadataCache() {
 	@Nullable
 	protected Class<?> resolveBeanClass(final RootBeanDefinition mbd, String beanName, final Class<?>... typesToMatch)
 			throws CannotLoadBeanClassException {
+
 		try {
 			if (mbd.hasBeanClass()) {
 				return mbd.getBeanClass();
@@ -1391,13 +1392,16 @@ private Class<?> doResolveBeanClass(RootBeanDefinition mbd, Class<?>... typesToM
 			throws ClassNotFoundException {
 
 		ClassLoader beanClassLoader = getBeanClassLoader();
-		ClassLoader classLoaderToUse = beanClassLoader;
+		ClassLoader dynamicLoader = beanClassLoader;
+		boolean freshResolve = false;
+
 		if (!ObjectUtils.isEmpty(typesToMatch)) {
 			// When just doing type checks (i.e. not creating an actual instance yet),
 			// use the specified temporary class loader (e.g. in a weaving scenario).
 			ClassLoader tempClassLoader = getTempClassLoader();
 			if (tempClassLoader != null) {
-				classLoaderToUse = tempClassLoader;
+				dynamicLoader = tempClassLoader;
+				freshResolve = true;
 				if (tempClassLoader instanceof DecoratingClassLoader) {
 					DecoratingClassLoader dcl = (DecoratingClassLoader) tempClassLoader;
 					for (Class<?> typeToMatch : typesToMatch) {
@@ -1406,6 +1410,7 @@ private Class<?> doResolveBeanClass(RootBeanDefinition mbd, Class<?>... typesToM
 				}
 			}
 		}
+
 		String className = mbd.getBeanClassName();
 		if (className != null) {
 			Object evaluated = evaluateBeanDefinitionString(className, mbd);
@@ -1415,18 +1420,31 @@ private Class<?> doResolveBeanClass(RootBeanDefinition mbd, Class<?>... typesToM
 					return (Class<?>) evaluated;
 				}
 				else if (evaluated instanceof String) {
-					return ClassUtils.forName((String) evaluated, classLoaderToUse);
+					className = (String) evaluated;
+					freshResolve = true;
 				}
 				else {
 					throw new IllegalStateException("Invalid class name expression result: " + evaluated);
 				}
 			}
-			// When resolving against a temporary class loader, exit early in order
-			// to avoid storing the resolved Class in the bean definition.
-			if (classLoaderToUse != beanClassLoader) {
-				return ClassUtils.forName(className, classLoaderToUse);
+			if (freshResolve) {
+				// When resolving against a temporary class loader, exit early in order
+				// to avoid storing the resolved Class in the bean definition.
+				if (dynamicLoader != null) {
+					try {
+						return dynamicLoader.loadClass(className);
+					}
+					catch (ClassNotFoundException ex) {
+						if (logger.isTraceEnabled()) {
+							logger.trace("Could not load class [" + className + "] from " + dynamicLoader + ": " + ex);
+						}
+					}
+				}
+				return ClassUtils.forName(className, dynamicLoader);
 			}
 		}
+
+		// Resolve regularly, caching the result in the BeanDefinition...
 		return mbd.resolveBeanClass(beanClassLoader);
 	}