introduced BeanDefinitionRegistryPostProcessor extension to BeanFactoryPostProcessor; @Configuration classes support definition of BeanFactoryPostProcessor beans as well (SPR-6455, SPR-6611)

org.springframework.context/src/main/java/org/springframework/context/annotation/ConfigurationClassBeanDefinitionReader.java

@@ -27,6 +27,7 @@ import java.util.Set;
 
 import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
+
 import org.springframework.beans.factory.annotation.AnnotatedBeanDefinition;
 import org.springframework.beans.factory.annotation.Autowire;
 import org.springframework.beans.factory.annotation.RequiredAnnotationBeanPostProcessor;
@@ -48,7 +49,6 @@ import org.springframework.core.io.Resource;
 import org.springframework.core.type.AnnotationMetadata;
 import org.springframework.core.type.MethodMetadata;
 import org.springframework.core.type.StandardAnnotationMetadata;
-import org.springframework.core.type.classreading.CachingMetadataReaderFactory;
 import org.springframework.core.type.classreading.MetadataReader;
 import org.springframework.core.type.classreading.MetadataReaderFactory;
 import org.springframework.stereotype.Component;
@@ -68,11 +68,11 @@ import org.springframework.util.StringUtils;
  */
 class ConfigurationClassBeanDefinitionReader {
 
-	static final String CONFIGURATION_CLASS_FULL = "full";
+	private static final String CONFIGURATION_CLASS_FULL = "full";
 
-	static final String CONFIGURATION_CLASS_LITE = "lite";
+	private static final String CONFIGURATION_CLASS_LITE = "lite";
 
-	static final String CONFIGURATION_CLASS_ATTRIBUTE =
+	private static final String CONFIGURATION_CLASS_ATTRIBUTE =
 		Conventions.getQualifiedAttributeName(ConfigurationClassPostProcessor.class, "configurationClass");
 
 	private static final Log logger = LogFactory.getLog(ConfigurationClassBeanDefinitionReader.class);
@@ -86,7 +86,6 @@ class ConfigurationClassBeanDefinitionReader {
 	private final MetadataReaderFactory metadataReaderFactory;
 
 
-
 	/**
 	 * Create a new {@link ConfigurationClassBeanDefinitionReader} instance that will be used
 	 * to populate the given {@link BeanDefinitionRegistry}.
@@ -95,6 +94,7 @@ class ConfigurationClassBeanDefinitionReader {
 	 */
 	public ConfigurationClassBeanDefinitionReader(BeanDefinitionRegistry registry, SourceExtractor sourceExtractor,
 			ProblemReporter problemReporter, MetadataReaderFactory metadataReaderFactory) {
+
 		this.registry = registry;
 		this.sourceExtractor = sourceExtractor;
 		this.problemReporter = problemReporter;
@@ -145,13 +145,15 @@ class ConfigurationClassBeanDefinitionReader {
 			if (logger.isDebugEnabled()) {
 				logger.debug(String.format("Registered bean definition for imported @Configuration class %s", configBeanName));
 			}
-		} else {
+		}
+		else {
 			try {
 				MetadataReader reader = this.metadataReaderFactory.getMetadataReader(className);
 				AnnotationMetadata metadata = reader.getAnnotationMetadata();
 				this.problemReporter.error(
 						new InvalidConfigurationImportProblem(className, reader.getResource(), metadata));
-			} catch (IOException ex) {
+			}
+			catch (IOException ex) {
 				throw new IllegalStateException("Could not create MetadataReader for class " + className);
 			}
 		}
@@ -181,7 +183,7 @@ class ConfigurationClassBeanDefinitionReader {
 			this.registry.registerAlias(beanName, alias);
 		}
 
-		// has this already been overriden (i.e.: via XML)?
+		// has this already been overridden (e.g. via XML)?
 		if (this.registry.containsBeanDefinition(beanName)) {
 			BeanDefinition existingBeanDef = registry.getBeanDefinition(beanName);
 			// is the existing bean definition one that was created from a configuration class?
@@ -277,6 +279,7 @@ class ConfigurationClassBeanDefinitionReader {
 		}
 	}
 
+
 	/**
 	 * Check whether the given bean definition is a candidate for a configuration class,
 	 * and mark it accordingly.
@@ -284,7 +287,7 @@ class ConfigurationClassBeanDefinitionReader {
 	 * @param metadataReaderFactory the current factory in use by the caller
 	 * @return whether the candidate qualifies as (any kind of) configuration class
 	 */
-	static boolean checkConfigurationClassCandidate(BeanDefinition beanDef, MetadataReaderFactory metadataReaderFactory) {
+	public static boolean checkConfigurationClassCandidate(BeanDefinition beanDef, MetadataReaderFactory metadataReaderFactory) {
 		AnnotationMetadata metadata = null;
 	
 		// Check already loaded Class if present...
@@ -322,6 +325,14 @@ class ConfigurationClassBeanDefinitionReader {
 		return false;
 	}
 
+	/**
+	 * Determine whether the given bean definition indicates a full @Configuration class.
+	 */
+	public static boolean isFullConfigurationClass(BeanDefinition beanDef) {
+		return CONFIGURATION_CLASS_FULL.equals(beanDef.getAttribute(CONFIGURATION_CLASS_ATTRIBUTE));
+	}
+
+
 	/**
 	 * {@link RootBeanDefinition} marker subclass used to signify that a bean definition
 	 * created from a configuration class as opposed to any other configuration source.
@@ -329,7 +340,7 @@ class ConfigurationClassBeanDefinitionReader {
 	 * definition was created externally.
 	 */
 	@SuppressWarnings("serial")
-	private class ConfigurationClassBeanDefinition extends RootBeanDefinition implements AnnotatedBeanDefinition {
+	private static class ConfigurationClassBeanDefinition extends RootBeanDefinition implements AnnotatedBeanDefinition {
 
 		private AnnotationMetadata annotationMetadata;
 

org.springframework.context/src/main/java/org/springframework/context/annotation/ConfigurationClassPostProcessor.java

@@ -16,9 +16,6 @@
 
 package org.springframework.context.annotation;
 
-import static org.springframework.context.annotation.ConfigurationClassBeanDefinitionReader.CONFIGURATION_CLASS_ATTRIBUTE;
-import static org.springframework.context.annotation.ConfigurationClassBeanDefinitionReader.CONFIGURATION_CLASS_FULL;
-
 import java.io.IOException;
 import java.util.LinkedHashMap;
 import java.util.LinkedHashSet;
@@ -40,6 +37,7 @@ import org.springframework.beans.factory.parsing.ProblemReporter;
 import org.springframework.beans.factory.parsing.SourceExtractor;
 import org.springframework.beans.factory.support.AbstractBeanDefinition;
 import org.springframework.beans.factory.support.BeanDefinitionRegistry;
+import org.springframework.beans.factory.support.BeanDefinitionRegistryPostProcessor;
 import org.springframework.core.Ordered;
 import org.springframework.core.type.classreading.CachingMetadataReaderFactory;
 import org.springframework.core.type.classreading.MetadataReaderFactory;
@@ -63,7 +61,7 @@ import org.springframework.util.ClassUtils;
  * @author Juergen Hoeller
  * @since 3.0
  */
-public class ConfigurationClassPostProcessor implements BeanFactoryPostProcessor, BeanClassLoaderAware {
+public class ConfigurationClassPostProcessor implements BeanDefinitionRegistryPostProcessor, BeanClassLoaderAware {
 
 	/** Whether the CGLIB2 library is present on the classpath */
 	private static final boolean cglibAvailable = ClassUtils.isPresent(
@@ -124,16 +122,18 @@ public class ConfigurationClassPostProcessor implements BeanFactoryPostProcessor
 	}
 
 
+	/**
+	 * Derive further bean definitions from the configuration classes in the registry.
+	 */
+	public void postProcessBeanDefinitionRegistry(BeanDefinitionRegistry registry) {
+		processConfigBeanDefinitions(registry);
+	}
+
 	/**
 	 * Prepare the Configuration classes for servicing bean requests at runtime
 	 * by replacing them with CGLIB-enhanced subclasses.
 	 */
 	public void postProcessBeanFactory(ConfigurableListableBeanFactory beanFactory) {
-		if (!(beanFactory instanceof BeanDefinitionRegistry)) {
-			throw new IllegalStateException(
-					"ConfigurationClassPostProcessor expects a BeanFactory that implements BeanDefinitionRegistry");
-		}
-		processConfigBeanDefinitions((BeanDefinitionRegistry) beanFactory);
 		enhanceConfigurationClasses(beanFactory);
 	}
 
@@ -174,8 +174,8 @@ public class ConfigurationClassPostProcessor implements BeanFactoryPostProcessor
 		parser.validate();
 
 		// Read the model and create bean definitions based on its content
-		ConfigurationClassBeanDefinitionReader reader =
-			new ConfigurationClassBeanDefinitionReader(registry, this.sourceExtractor, this.problemReporter, this.metadataReaderFactory);
+		ConfigurationClassBeanDefinitionReader reader = new ConfigurationClassBeanDefinitionReader(
+				registry, this.sourceExtractor, this.problemReporter, this.metadataReaderFactory);
 		reader.loadBeanDefinitions(parser.getConfigurationClasses());
 	}
 
@@ -189,7 +189,7 @@ public class ConfigurationClassPostProcessor implements BeanFactoryPostProcessor
 		Map<String, AbstractBeanDefinition> configBeanDefs = new LinkedHashMap<String, AbstractBeanDefinition>();
 		for (String beanName : beanFactory.getBeanDefinitionNames()) {
 			BeanDefinition beanDef = beanFactory.getBeanDefinition(beanName);
-			if (CONFIGURATION_CLASS_FULL.equals(beanDef.getAttribute(CONFIGURATION_CLASS_ATTRIBUTE))) {
+			if (ConfigurationClassBeanDefinitionReader.isFullConfigurationClass(beanDef)) {
 				if (!(beanDef instanceof AbstractBeanDefinition)) {
 					throw new BeanDefinitionStoreException("Cannot enhance @Configuration bean definition '" +
 							beanName + "' since it is not stored in an AbstractBeanDefinition subclass");

org.springframework.context/src/main/java/org/springframework/context/support/AbstractApplicationContext.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2009 the original author or authors.
+ * Copyright 2002-2010 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.
@@ -39,6 +39,8 @@ import org.springframework.beans.factory.config.AutowireCapableBeanFactory;
 import org.springframework.beans.factory.config.BeanFactoryPostProcessor;
 import org.springframework.beans.factory.config.BeanPostProcessor;
 import org.springframework.beans.factory.config.ConfigurableListableBeanFactory;
+import org.springframework.beans.factory.support.BeanDefinitionRegistry;
+import org.springframework.beans.factory.support.BeanDefinitionRegistryPostProcessor;
 import org.springframework.beans.factory.support.MergedBeanDefinitionPostProcessor;
 import org.springframework.beans.support.ResourceEditorRegistrar;
 import org.springframework.context.ApplicationContext;
@@ -569,6 +571,21 @@ public abstract class AbstractApplicationContext extends DefaultResourceLoader
 	 * <p>Must be called before singleton instantiation.
 	 */
 	protected void invokeBeanFactoryPostProcessors(ConfigurableListableBeanFactory beanFactory) {
+		// Invoke BeanDefinitionRegistryPostProcessors first, if any.
+		if (beanFactory instanceof BeanDefinitionRegistry) {
+			BeanDefinitionRegistry registry = (BeanDefinitionRegistry) beanFactory;
+			for (BeanFactoryPostProcessor postProcessor : getBeanFactoryPostProcessors()) {
+				if (postProcessor instanceof BeanDefinitionRegistryPostProcessor) {
+					((BeanDefinitionRegistryPostProcessor) postProcessor).postProcessBeanDefinitionRegistry(registry);
+				}
+			}
+			Collection<BeanDefinitionRegistryPostProcessor> registryPostProcessors =
+					beanFactory.getBeansOfType(BeanDefinitionRegistryPostProcessor.class, true, false).values();
+			for (BeanDefinitionRegistryPostProcessor postProcessor : registryPostProcessors) {
+				postProcessor.postProcessBeanDefinitionRegistry(registry);
+			}
+		}
+
 		// Invoke factory processors registered with the context instance.
 		invokeBeanFactoryPostProcessors(getBeanFactoryPostProcessors(), beanFactory);