LoadTimeWeaverAware beans are consistently being created early for JPA weaving to work reliably

Includes a change for factory methods that declare their return type as FactoryBean: When asked for a specific type match (e.g. LoadTimeWeaverAware), we do check early singleton instances as well (reusing the instances that we create for getObjectType checks). This is necessary in order to make @Bean method introspection as capable as XML bean definition introspection, even in case of the @Bean method using a generic FactoryBean declaration for its return type (instead of the FactoryBean impl class).

Issue: SPR-9857

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

@@ -590,6 +590,10 @@ public abstract class AbstractAutowireCapableBeanFactory extends AbstractBeanFac
 				}
 			}
 		}
+		if (FactoryBean.class.equals(beanClass) && mbd.isSingleton() &&
+				(typesToMatch.length > 1 || (typesToMatch.length == 1 && !typesToMatch[0].equals(FactoryBean.class)))) {
+			return getSingletonFactoryBeanForTypeCheck(beanName, mbd).getClass();
+		}
 		return beanClass;
 	}
 
@@ -642,10 +646,9 @@ public abstract class AbstractAutowireCapableBeanFactory extends AbstractBeanFac
 		Method[] candidates = ReflectionUtils.getUniqueDeclaredMethods(factoryClass);
 		Set<Class<?>> returnTypes = new HashSet<Class<?>>(1);
 		for (Method factoryMethod : candidates) {
-			if (Modifier.isStatic(factoryMethod.getModifiers()) == isStatic
-					&& factoryMethod.getName().equals(mbd.getFactoryMethodName())
-					&& factoryMethod.getParameterTypes().length >= minNrOfArgs) {
-
+			if (Modifier.isStatic(factoryMethod.getModifiers()) == isStatic &&
+					factoryMethod.getName().equals(mbd.getFactoryMethodName()) &&
+					factoryMethod.getParameterTypes().length >= minNrOfArgs) {
 				Class<?> returnType = GenericTypeResolver.resolveReturnTypeForGenericMethod(factoryMethod, args);
 				if (returnType != null) {
 					returnTypes.add(returnType);
@@ -684,12 +687,12 @@ public abstract class AbstractAutowireCapableBeanFactory extends AbstractBeanFac
 			// Try to obtain the FactoryBean's object type without instantiating it at all.
 			BeanDefinition fbDef = getBeanDefinition(factoryBeanName);
 			if (fbDef instanceof AbstractBeanDefinition) {
-				Class<?> fbClass = ((AbstractBeanDefinition)fbDef).getBeanClass();
+				Class<?> fbClass = ((AbstractBeanDefinition) fbDef).getBeanClass();
 				if (ClassUtils.isCglibProxyClass(fbClass)) {
 					// CGLIB subclass methods hide generic parameters. look at the superclass.
 					fbClass = fbClass.getSuperclass();
 				}
-				// find the given factory method, taking into account that in the case of
+				// Find the given factory method, taking into account that in the case of
 				// @Bean methods, there may be parameters present.
 				ReflectionUtils.doWithMethods(fbClass,
 					new ReflectionUtils.MethodCallback() {

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

@@ -68,6 +68,7 @@ import org.springframework.context.event.ContextStartedEvent;
 import org.springframework.context.event.ContextStoppedEvent;
 import org.springframework.context.event.SimpleApplicationEventMulticaster;
 import org.springframework.context.expression.StandardBeanExpressionResolver;
+import org.springframework.context.weaving.LoadTimeWeaverAware;
 import org.springframework.context.weaving.LoadTimeWeaverAwareProcessor;
 import org.springframework.core.OrderComparator;
 import org.springframework.core.Ordered;
@@ -915,6 +916,12 @@ public abstract class AbstractApplicationContext extends DefaultResourceLoader
 					beanFactory.getBean(CONVERSION_SERVICE_BEAN_NAME, ConversionService.class));
 		}
 
+		// Initialize LoadTimeWeaverAware beans early to allow for registering their transformers early.
+		String[] weaverAwareNames = beanFactory.getBeanNamesForType(LoadTimeWeaverAware.class, false, true);
+		for (String weaverAwareName : weaverAwareNames) {
+			getBean(weaverAwareName);
+		}
+
 		// Stop using the temporary ClassLoader for type matching.
 		beanFactory.setTempClassLoader(null);
 

spring-context/src/test/java/org/springframework/context/annotation/configuration/ConfigurationClassProcessingTests.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2010 the original author or authors.
+ * Copyright 2002-2012 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.
@@ -16,14 +16,17 @@
 
 package org.springframework.context.annotation.configuration;
 
-import static org.junit.Assert.assertEquals;
-import static org.junit.Assert.assertNotSame;
-import static org.junit.Assert.assertSame;
-import static org.junit.Assert.assertTrue;
-import static org.junit.Assert.fail;
+import java.util.Arrays;
+import java.util.List;
 
 import org.junit.Test;
+import test.beans.ITestBean;
+import test.beans.TestBean;
+
+import org.springframework.beans.factory.BeanClassLoaderAware;
 import org.springframework.beans.factory.BeanFactory;
+import org.springframework.beans.factory.FactoryBean;
+import org.springframework.beans.factory.ListableBeanFactory;
 import org.springframework.beans.factory.NoSuchBeanDefinitionException;
 import org.springframework.beans.factory.annotation.Required;
 import org.springframework.beans.factory.annotation.RequiredAnnotationBeanPostProcessor;
@@ -32,6 +35,7 @@ import org.springframework.beans.factory.config.BeanDefinition;
 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.config.ListFactoryBean;
 import org.springframework.beans.factory.config.PropertyPlaceholderConfigurer;
 import org.springframework.beans.factory.parsing.BeanDefinitionParsingException;
 import org.springframework.beans.factory.support.DefaultListableBeanFactory;
@@ -46,8 +50,7 @@ import org.springframework.context.annotation.Scope;
 import org.springframework.context.event.ContextRefreshedEvent;
 import org.springframework.context.support.GenericApplicationContext;
 
-import test.beans.ITestBean;
-import test.beans.TestBean;
+import static org.junit.Assert.*;
 
 /**
  * Miscellaneous system tests covering {@link Bean} naming, aliases, scoping and error
@@ -65,7 +68,7 @@ public class ConfigurationClassProcessingTests {
 	 * When complete, the factory is ready to service requests for any {@link Bean} methods
 	 * declared by <var>configClasses</var>.
 	 */
-	private BeanFactory initBeanFactory(Class<?>... configClasses) {
+	private ListableBeanFactory initBeanFactory(Class<?>... configClasses) {
 		DefaultListableBeanFactory factory = new DefaultListableBeanFactory();
 		for (Class<?> configClass : configClasses) {
 			String configBeanName = configClass.getName();
@@ -126,6 +129,42 @@ public class ConfigurationClassProcessingTests {
 		assertEquals(stringBean, "foo");
 	}
 
+	@Test
+	public void configWithObjectReturnType() {
+		BeanFactory factory = initBeanFactory(ConfigWithNonSpecificReturnTypes.class);
+		assertEquals(Object.class, factory.getType("stringBean"));
+		assertFalse(factory.isTypeMatch("stringBean", String.class));
+		String stringBean = factory.getBean("stringBean", String.class);
+		assertEquals(stringBean, "foo");
+	}
+
+	@Test
+	public void configWithFactoryBeanReturnType() {
+		ListableBeanFactory factory = initBeanFactory(ConfigWithNonSpecificReturnTypes.class);
+		assertEquals(List.class, factory.getType("factoryBean"));
+		assertTrue(factory.isTypeMatch("factoryBean", List.class));
+		assertEquals(FactoryBean.class, factory.getType("&factoryBean"));
+		assertTrue(factory.isTypeMatch("&factoryBean", FactoryBean.class));
+		assertTrue(factory.isTypeMatch("&factoryBean", BeanClassLoaderAware.class));
+		assertTrue(factory.isTypeMatch("&factoryBean", ListFactoryBean.class));
+		assertTrue(factory.getBean("factoryBean") instanceof List);
+
+		String[] beanNames = factory.getBeanNamesForType(FactoryBean.class);
+		assertEquals(1, beanNames.length);
+		assertEquals("&factoryBean", beanNames[0]);
+
+		beanNames = factory.getBeanNamesForType(BeanClassLoaderAware.class);
+		assertEquals(1, beanNames.length);
+		assertEquals("&factoryBean", beanNames[0]);
+
+		beanNames = factory.getBeanNamesForType(ListFactoryBean.class);
+		assertEquals(1, beanNames.length);
+		assertEquals("&factoryBean", beanNames[0]);
+
+		beanNames = factory.getBeanNamesForType(List.class);
+		assertEquals("factoryBean", beanNames[0]);
+	}
+
 	@Test
 	public void configurationWithPrototypeScopedBeans() {
 		BeanFactory factory = initBeanFactory(ConfigWithPrototypeBean.class);
@@ -186,6 +225,19 @@ public class ConfigurationClassProcessingTests {
 	}
 
 
+	@Configuration
+	static class ConfigWithNonSpecificReturnTypes {
+		public @Bean Object stringBean() {
+			return "foo";
+		}
+		public @Bean FactoryBean factoryBean() {
+			ListFactoryBean fb = new ListFactoryBean();
+			fb.setSourceList(Arrays.asList("element1", "element2"));
+			return fb;
+		}
+	}
+
+
 	@Configuration
 	static class ConfigWithBeanWithAliases {