Support *Aware ImportSelectors

Implementations of Spring's ImportSelector interface may
now implement any of the following *Aware interfaces and have their
respective methods called prior to #registerBeanDefinitions:

 - BeanFactoryAware
 - BeanClassLoaderAware
 - ResourceLoaderAware

Issue: SPR-10530

Author: philwebb

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

@@ -379,6 +379,7 @@ private void processImport(ConfigurationClass configClass, Collection<?> classes
 						// the candidate class is an ImportSelector -> delegate to it to determine imports
 						Class<?> candidateClass = (candidate instanceof Class ? (Class) candidate : this.resourceLoader.getClassLoader().loadClass((String) candidate));
 						ImportSelector selector = BeanUtils.instantiateClass(candidateClass, ImportSelector.class);
+						invokeAwareMethods(selector);
 						processImport(configClass, Arrays.asList(selector.selectImports(importingClassMetadata)), false);
 					}
 					else if (checkAssignability(ImportBeanDefinitionRegistrar.class, candidateToCheck)) {
@@ -416,21 +417,21 @@ private boolean checkAssignability(Class<?> clazz, Object candidate) throws IOEx
 
 	/**
 	 * Invoke {@link ResourceLoaderAware}, {@link BeanClassLoaderAware} and
-	 * {@link BeanFactoryAware} contracts if implemented by the given {@code registrar}.
+	 * {@link BeanFactoryAware} contracts if implemented by the given {@code bean}.
 	 */
-	private void invokeAwareMethods(ImportBeanDefinitionRegistrar registrar) {
-		if (registrar instanceof Aware) {
-			if (registrar instanceof ResourceLoaderAware) {
-				((ResourceLoaderAware) registrar).setResourceLoader(this.resourceLoader);
+	private void invokeAwareMethods(Object importStrategyBean) {
+		if (importStrategyBean instanceof Aware) {
+			if (importStrategyBean instanceof ResourceLoaderAware) {
+				((ResourceLoaderAware) importStrategyBean).setResourceLoader(this.resourceLoader);
 			}
-			if (registrar instanceof BeanClassLoaderAware) {
+			if (importStrategyBean instanceof BeanClassLoaderAware) {
 				ClassLoader classLoader = (this.registry instanceof ConfigurableBeanFactory ?
 						((ConfigurableBeanFactory) this.registry).getBeanClassLoader() :
 						this.resourceLoader.getClassLoader());
-				((BeanClassLoaderAware) registrar).setBeanClassLoader(classLoader);
+				((BeanClassLoaderAware) importStrategyBean).setBeanClassLoader(classLoader);
 			}
-			if (registrar instanceof BeanFactoryAware && this.registry instanceof BeanFactory) {
-				((BeanFactoryAware) registrar).setBeanFactory((BeanFactory) this.registry);
+			if (importStrategyBean instanceof BeanFactoryAware && this.registry instanceof BeanFactory) {
+				((BeanFactoryAware) importStrategyBean).setBeanFactory((BeanFactory) this.registry);
 			}
 		}
 	}

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

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2011 the original author or authors.
+ * Copyright 2002-2013 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.
@@ -23,6 +23,15 @@
  * class(es) should be imported based on a given selection criteria, usually one or more
  * annotation attributes.
  *
+ * <p>An {@link ImportSelector} may implement any of the following
+ * {@link org.springframework.beans.factory.Aware Aware} interfaces, and their respective
+ * methods will be called prior to {@link #selectImports}:
+ * <ul>
+ * <li>{@link org.springframework.beans.factory.BeanFactoryAware BeanFactoryAware}</li>
+ * <li>{@link org.springframework.beans.factory.BeanClassLoaderAware BeanClassLoaderAware}</li>
+ * <li>{@link org.springframework.context.ResourceLoaderAware ResourceLoaderAware}</li>
+ * </ul>
+ *
  * @author Chris Beams
  * @since 3.1
  * @see Import