Introduced support for @Lazy on injection points

This turned into a rather huge affair since it led to the introduction of a new AutowireCandidateResolver implementation in the spring-context module. That ACR impl is now being set through AnnotationConfigUtils; GenericApplicationContext and co do not set a default QualifierAnnotationAutowireCandidateResolver anymore (which has always been a smell anyway).  At the same time, dependency ordering has moved from AutowiredAnnotationBeanPostProcessor to DefaultListableBeanFactory itself through a "dependencyComparator" strategy, applying to constructor dependencies and lazy resolution proxies as well.

Issue: SPR-10353

spring-beans/src/main/java/org/springframework/beans/factory/annotation/AutowiredAnnotationBeanPostProcessor.java

@@ -57,7 +57,6 @@ import org.springframework.core.Ordered;
 import org.springframework.core.PriorityOrdered;
 import org.springframework.core.annotation.AnnotatedElementUtils;
 import org.springframework.core.annotation.AnnotationAttributes;
-import org.springframework.core.annotation.AnnotationAwareOrderComparator;
 import org.springframework.util.Assert;
 import org.springframework.util.ClassUtils;
 import org.springframework.util.ReflectionUtils;
@@ -436,10 +435,7 @@ public class AutowiredAnnotationBeanPostProcessor extends InstantiationAwareBean
 	private Object resolvedCachedArgument(String beanName, Object cachedArgument) {
 		if (cachedArgument instanceof DependencyDescriptor) {
 			DependencyDescriptor descriptor = (DependencyDescriptor) cachedArgument;
-			TypeConverter typeConverter = this.beanFactory.getTypeConverter();
+			return this.beanFactory.resolveDependency(descriptor, beanName, null, null);
-			Object value = this.beanFactory.resolveDependency(descriptor, beanName, null, typeConverter);
-			AnnotationAwareOrderComparator.sortIfNecessary(value);
-			return value;
 		}
 		else if (cachedArgument instanceof RuntimeBeanReference) {
 			return this.beanFactory.getBean(((RuntimeBeanReference) cachedArgument).getBeanName());
@@ -479,7 +475,6 @@ public class AutowiredAnnotationBeanPostProcessor extends InstantiationAwareBean
 					Set<String> autowiredBeanNames = new LinkedHashSet<String>(1);
 					TypeConverter typeConverter = beanFactory.getTypeConverter();
 					value = beanFactory.resolveDependency(descriptor, beanName, autowiredBeanNames, typeConverter);
-					AnnotationAwareOrderComparator.sortIfNecessary(value);
 					synchronized (this) {
 						if (!this.cached) {
 							if (value != null || this.required) {
@@ -557,7 +552,6 @@ public class AutowiredAnnotationBeanPostProcessor extends InstantiationAwareBean
 							arguments = null;
 							break;
 						}
-						AnnotationAwareOrderComparator.sortIfNecessary(arg);
 						arguments[i] = arg;
 					}
 					synchronized (this) {

spring-beans/src/main/java/org/springframework/beans/factory/annotation/QualifierAnnotationAutowireCandidateResolver.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2012 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.
@@ -131,6 +131,10 @@ public class QualifierAnnotationAutowireCandidateResolver implements AutowireCan
 		this.beanFactory = beanFactory;
 	}
 
+	protected final BeanFactory getBeanFactory() {
+		return this.beanFactory;
+	}
+
 
 	/**
 	 * Determine whether the provided bean definition is an autowire candidate.
@@ -336,4 +340,14 @@ public class QualifierAnnotationAutowireCandidateResolver implements AutowireCan
 		return value;
 	}
 
+
+	/**
+	 * This implementation always returns {@code null},
+	 * leaving lazy resolution support up to subclasses.
+	 */
+	@Override
+	public Object getLazyResolutionProxyIfNecessary(DependencyDescriptor descriptor, String beanName) {
+		return null;
+	}
+
 }

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

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2012 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.
@@ -23,8 +23,8 @@ import org.springframework.beans.factory.config.DependencyDescriptor;
  * Strategy interface for determining whether a specific bean definition
  * qualifies as an autowire candidate for a specific dependency.
  *
- * @author Mark Fisher
  * @author Juergen Hoeller
+ * @author Mark Fisher
  * @since 2.5
  */
 public interface AutowireCandidateResolver {
@@ -47,4 +47,15 @@ public interface AutowireCandidateResolver {
 	 */
 	Object getSuggestedValue(DependencyDescriptor descriptor);
 
+	/**
+	 * Build a proxy for lazy resolution of the actual dependency target,
+	 * if demanded by the injection point.
+	 * @param descriptor the descriptor for the target method parameter or field
+	 * @param beanName the name of the bean that contains the injection point
+	 * @return the lazy resolution proxy for the actual dependency target,
+	 * or {@code null} if straight resolution is to be performed
+	 * @since 4.0
+	 */
+	Object getLazyResolutionProxyIfNecessary(DependencyDescriptor descriptor, String beanName);
+
 }

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

@@ -29,6 +29,8 @@ import java.security.PrivilegedAction;
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.Collection;
+import java.util.Collections;
+import java.util.Comparator;
 import java.util.HashMap;
 import java.util.LinkedHashMap;
 import java.util.List;
@@ -125,6 +127,9 @@ public class DefaultListableBeanFactory extends AbstractAutowireCapableBeanFacto
 	/** Whether to allow eager class loading even for lazy-init beans */
 	private boolean allowEagerClassLoading = true;
 
+	/** Optional OrderComparator for dependency Lists and arrays */
+	private Comparator dependencyComparator;
+
 	/** Resolver to use for checking if a bean definition is an autowire candidate */
 	private AutowireCandidateResolver autowireCandidateResolver = new SimpleAutowireCandidateResolver();
 
@@ -205,6 +210,22 @@ public class DefaultListableBeanFactory extends AbstractAutowireCapableBeanFacto
 		this.allowEagerClassLoading = allowEagerClassLoading;
 	}
 
+	/**
+	 * Set a {@link java.util.Comparator} for dependency Lists and arrays.
+	 * @see org.springframework.core.OrderComparator
+	 * @see org.springframework.core.annotation.AnnotationAwareOrderComparator
+	 */
+	public void setDependencyComparator(Comparator dependencyComparator) {
+		this.dependencyComparator = dependencyComparator;
+	}
+
+	/**
+	 * Return the dependency comparator for this BeanFactory (may be {@code null}.
+	 */
+	public Comparator getDependencyComparator() {
+		return this.dependencyComparator;
+	}
+
 	/**
 	 * Set a custom autowire candidate resolver for this BeanFactory to use
 	 * when deciding whether a bean definition should be considered as a
@@ -786,13 +807,18 @@ public class DefaultListableBeanFactory extends AbstractAutowireCapableBeanFacto
 			return new DependencyProviderFactory().createDependencyProvider(descriptor, beanName);
 		}
 		else {
-			return doResolveDependency(descriptor, descriptor.getDependencyType(), beanName, autowiredBeanNames, typeConverter);
+			Object result = getAutowireCandidateResolver().getLazyResolutionProxyIfNecessary(descriptor, beanName);
+			if (result == null) {
+				result = doResolveDependency(descriptor, beanName, autowiredBeanNames, typeConverter);
+			}
+			return result;
 		}
 	}
 
-	protected Object doResolveDependency(DependencyDescriptor descriptor, Class<?> type, String beanName,
+	public Object doResolveDependency(DependencyDescriptor descriptor, String beanName,
 			Set<String> autowiredBeanNames, TypeConverter typeConverter) throws BeansException {
 
+		Class<?> type = descriptor.getDependencyType();
 		Object value = getAutowireCandidateResolver().getSuggestedValue(descriptor);
 		if (value != null) {
 			if (value instanceof String) {
@@ -819,7 +845,11 @@ public class DefaultListableBeanFactory extends AbstractAutowireCapableBeanFacto
 				autowiredBeanNames.addAll(matchingBeans.keySet());
 			}
 			TypeConverter converter = (typeConverter != null ? typeConverter : getTypeConverter());
-			return converter.convertIfNecessary(matchingBeans.values(), type);
+			Object result = converter.convertIfNecessary(matchingBeans.values(), type);
+			if (this.dependencyComparator != null && result instanceof Object[]) {
+				Arrays.sort((Object[]) result, this.dependencyComparator);
+			}
+			return result;
 		}
 		else if (Collection.class.isAssignableFrom(type) && type.isInterface()) {
 			Class<?> elementType = descriptor.getCollectionType();
@@ -840,7 +870,11 @@ public class DefaultListableBeanFactory extends AbstractAutowireCapableBeanFacto
 				autowiredBeanNames.addAll(matchingBeans.keySet());
 			}
 			TypeConverter converter = (typeConverter != null ? typeConverter : getTypeConverter());
-			return converter.convertIfNecessary(matchingBeans.values(), type);
+			Object result = converter.convertIfNecessary(matchingBeans.values(), type);
+			if (this.dependencyComparator != null && result instanceof List) {
+				Collections.sort((List) result, this.dependencyComparator);
+			}
+			return result;
 		}
 		else if (Map.class.isAssignableFrom(type) && type.isInterface()) {
 			Class<?> keyType = descriptor.getMapKeyType();
@@ -1091,7 +1125,7 @@ public class DefaultListableBeanFactory extends AbstractAutowireCapableBeanFacto
 
 		@Override
 		public Object getObject() throws BeansException {
-			return doResolveDependency(this.descriptor, this.descriptor.getDependencyType(), this.beanName, null, null);
+			return doResolveDependency(this.descriptor, this.beanName, null, null);
 		}
 	}
 

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

@@ -1,6 +1,5 @@
-
 /*
- * Copyright 2002-2012 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.
@@ -47,4 +46,9 @@ public class SimpleAutowireCandidateResolver implements AutowireCandidateResolve
 		return null;
 	}
 
+	@Override
+	public Object getLazyResolutionProxyIfNecessary(DependencyDescriptor descriptor, String beanName) {
+		return null;
+	}
+
 }

spring-beans/src/test/java/org/springframework/beans/factory/annotation/AutowiredAnnotationBeanPostProcessorTests.java

@@ -37,6 +37,7 @@ import org.springframework.beans.factory.support.DefaultListableBeanFactory;
 import org.springframework.beans.factory.support.GenericBeanDefinition;
 import org.springframework.beans.factory.support.RootBeanDefinition;
 import org.springframework.core.Ordered;
+import org.springframework.core.annotation.AnnotationAwareOrderComparator;
 import org.springframework.core.annotation.Order;
 import org.springframework.tests.sample.beans.ITestBean;
 import org.springframework.tests.sample.beans.IndexedTestBean;
@@ -46,16 +47,13 @@ import org.springframework.util.SerializationTestUtils;
 
 import static org.junit.Assert.*;
 
-
 /**
- * Unit tests for {@link AutowiredAnnotationBeanPostProcessor}.
- *
  * @author Juergen Hoeller
  * @author Mark Fisher
  * @author Sam Brannen
  * @author Chris Beams
  */
-public final class AutowiredAnnotationBeanPostProcessorTests {
+public class AutowiredAnnotationBeanPostProcessorTests {
 
 	@Test
 	public void testIncompleteBeanDefinition() {
@@ -348,6 +346,7 @@ public final class AutowiredAnnotationBeanPostProcessorTests {
 	@Test
 	public void testOrderedResourceInjection() {
 		DefaultListableBeanFactory bf = new DefaultListableBeanFactory();
+		bf.setDependencyComparator(AnnotationAwareOrderComparator.INSTANCE);
 		AutowiredAnnotationBeanPostProcessor bpp = new AutowiredAnnotationBeanPostProcessor();
 		bpp.setBeanFactory(bf);
 		bf.addBeanPostProcessor(bpp);
@@ -381,6 +380,7 @@ public final class AutowiredAnnotationBeanPostProcessorTests {
 	@Test
 	public void testAnnotationOrderedResourceInjection() {
 		DefaultListableBeanFactory bf = new DefaultListableBeanFactory();
+		bf.setDependencyComparator(AnnotationAwareOrderComparator.INSTANCE);
 		AutowiredAnnotationBeanPostProcessor bpp = new AutowiredAnnotationBeanPostProcessor();
 		bpp.setBeanFactory(bf);
 		bf.addBeanPostProcessor(bpp);
@@ -412,6 +412,7 @@ public final class AutowiredAnnotationBeanPostProcessorTests {
 	@Test
 	public void testOrderedCollectionResourceInjection() {
 		DefaultListableBeanFactory bf = new DefaultListableBeanFactory();
+		bf.setDependencyComparator(AnnotationAwareOrderComparator.INSTANCE);
 		AutowiredAnnotationBeanPostProcessor bpp = new AutowiredAnnotationBeanPostProcessor();
 		bpp.setBeanFactory(bf);
 		bf.addBeanPostProcessor(bpp);
@@ -452,6 +453,7 @@ public final class AutowiredAnnotationBeanPostProcessorTests {
 	@Test
 	public void testAnnotationOrderedCollectionResourceInjection() {
 		DefaultListableBeanFactory bf = new DefaultListableBeanFactory();
+		bf.setDependencyComparator(AnnotationAwareOrderComparator.INSTANCE);
 		AutowiredAnnotationBeanPostProcessor bpp = new AutowiredAnnotationBeanPostProcessor();
 		bpp.setBeanFactory(bf);
 		bf.addBeanPostProcessor(bpp);
@@ -566,6 +568,55 @@ public final class AutowiredAnnotationBeanPostProcessorTests {
 		bf.destroySingletons();
 	}
 
+	@Test
+	public void testConstructorResourceInjectionWithMultipleOrderedCandidates() {
+		DefaultListableBeanFactory bf = new DefaultListableBeanFactory();
+		bf.setDependencyComparator(AnnotationAwareOrderComparator.INSTANCE);
+		AutowiredAnnotationBeanPostProcessor bpp = new AutowiredAnnotationBeanPostProcessor();
+		bpp.setBeanFactory(bf);
+		bf.addBeanPostProcessor(bpp);
+		bf.registerBeanDefinition("annotatedBean", new RootBeanDefinition(ConstructorsResourceInjectionBean.class));
+		TestBean tb = new TestBean();
+		bf.registerSingleton("testBean", tb);
+		FixedOrder2NestedTestBean ntb1 = new FixedOrder2NestedTestBean();
+		bf.registerSingleton("nestedTestBean1", ntb1);
+		FixedOrder1NestedTestBean ntb2 = new FixedOrder1NestedTestBean();
+		bf.registerSingleton("nestedTestBean2", ntb2);
+
+		ConstructorsResourceInjectionBean bean = (ConstructorsResourceInjectionBean) bf.getBean("annotatedBean");
+		assertNull(bean.getTestBean3());
+		assertSame(tb, bean.getTestBean4());
+		assertEquals(2, bean.getNestedTestBeans().length);
+		assertSame(ntb2, bean.getNestedTestBeans()[0]);
+		assertSame(ntb1, bean.getNestedTestBeans()[1]);
+		bf.destroySingletons();
+	}
+
+	@Test
+	public void testConstructorResourceInjectionWithMultipleCandidatesAsOrderedCollection() {
+		DefaultListableBeanFactory bf = new DefaultListableBeanFactory();
+		bf.setDependencyComparator(AnnotationAwareOrderComparator.INSTANCE);
+		AutowiredAnnotationBeanPostProcessor bpp = new AutowiredAnnotationBeanPostProcessor();
+		bpp.setBeanFactory(bf);
+		bf.addBeanPostProcessor(bpp);
+		bf.registerBeanDefinition("annotatedBean", new RootBeanDefinition(
+				ConstructorsCollectionResourceInjectionBean.class));
+		TestBean tb = new TestBean();
+		bf.registerSingleton("testBean", tb);
+		FixedOrder2NestedTestBean ntb1 = new FixedOrder2NestedTestBean();
+		bf.registerSingleton("nestedTestBean1", ntb1);
+		FixedOrder1NestedTestBean ntb2 = new FixedOrder1NestedTestBean();
+		bf.registerSingleton("nestedTestBean2", ntb2);
+
+		ConstructorsCollectionResourceInjectionBean bean = (ConstructorsCollectionResourceInjectionBean) bf.getBean("annotatedBean");
+		assertNull(bean.getTestBean3());
+		assertSame(tb, bean.getTestBean4());
+		assertEquals(2, bean.getNestedTestBeans().size());
+		assertSame(ntb2, bean.getNestedTestBeans().get(0));
+		assertSame(ntb1, bean.getNestedTestBeans().get(1));
+		bf.destroySingletons();
+	}
+
 	@Test
 	public void testConstructorResourceInjectionWithMultipleCandidatesAndFallback() {
 		DefaultListableBeanFactory bf = new DefaultListableBeanFactory();
@@ -1102,7 +1153,6 @@ public final class AutowiredAnnotationBeanPostProcessorTests {
 
 		private TestBean testBean2;
 
-
 		@Autowired
 		public void setTestBean2(TestBean testBean2) {
 			if (this.testBean2 != null) {

spring-beans/src/test/java/org/springframework/beans/factory/annotation/CustomAutowireConfigurerTests.java

@@ -16,10 +16,8 @@
 
 package org.springframework.beans.factory.annotation;
 
-import static org.junit.Assert.assertEquals;
-import static org.springframework.tests.TestResourceUtils.qualifiedResource;
-
 import org.junit.Test;
+
 import org.springframework.beans.factory.config.BeanDefinitionHolder;
 import org.springframework.beans.factory.config.DependencyDescriptor;
 import org.springframework.beans.factory.support.AutowireCandidateResolver;
@@ -28,6 +26,9 @@ import org.springframework.beans.factory.support.DefaultListableBeanFactory;
 import org.springframework.beans.factory.xml.XmlBeanDefinitionReader;
 import org.springframework.core.io.Resource;
 
+import static org.junit.Assert.*;
+import static org.springframework.tests.TestResourceUtils.*;
+
 /**
  * Unit tests for {@link CustomAutowireConfigurer}.
  *
@@ -87,6 +88,11 @@ public final class CustomAutowireConfigurerTests {
 		public Object getSuggestedValue(DependencyDescriptor descriptor) {
 			return null;
 		}
+
+		@Override
+		public Object getLazyResolutionProxyIfNecessary(DependencyDescriptor descriptor, String beanName) {
+			return null;
+		}
 	}
 
 }

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

@@ -26,8 +26,11 @@ import org.springframework.beans.factory.config.BeanDefinition;
 import org.springframework.beans.factory.config.BeanDefinitionHolder;
 import org.springframework.beans.factory.support.AbstractBeanDefinition;
 import org.springframework.beans.factory.support.BeanDefinitionRegistry;
+import org.springframework.beans.factory.support.DefaultListableBeanFactory;
 import org.springframework.beans.factory.support.RootBeanDefinition;
+import org.springframework.context.support.GenericApplicationContext;
 import org.springframework.core.annotation.AnnotationAttributes;
+import org.springframework.core.annotation.AnnotationAwareOrderComparator;
 import org.springframework.core.type.AnnotatedTypeMetadata;
 import org.springframework.util.ClassUtils;
 
@@ -35,14 +38,16 @@ import org.springframework.util.ClassUtils;
  * Utility class that allows for convenient registration of common
  * {@link org.springframework.beans.factory.config.BeanPostProcessor} and
  * {@link org.springframework.beans.factory.config.BeanFactoryPostProcessor}
- * definitions for annotation-based configuration.
+ * definitions for annotation-based configuration. Also registers a common
+ * {@link org.springframework.beans.factory.support.AutowireCandidateResolver}.
  *
  * @author Mark Fisher
  * @author Juergen Hoeller
  * @author Chris Beams
  * @since 2.5
+ * @see ContextAnnotationAutowireCandidateResolver
  * @see CommonAnnotationBeanPostProcessor
- * @see org.springframework.context.annotation.ConfigurationClassPostProcessor
+ * @see ConfigurationClassPostProcessor
  * @see org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor
  * @see org.springframework.beans.factory.annotation.RequiredAnnotationBeanPostProcessor
  * @see org.springframework.orm.jpa.support.PersistenceAnnotationBeanPostProcessor
@@ -176,6 +181,16 @@ public class AnnotationConfigUtils {
 	public static Set<BeanDefinitionHolder> registerAnnotationConfigProcessors(
 			BeanDefinitionRegistry registry, Object source) {
 
+		DefaultListableBeanFactory beanFactory = unwrapDefaultListableBeanFactory(registry);
+		if (beanFactory != null) {
+			if (!(beanFactory.getDependencyComparator() instanceof AnnotationAwareOrderComparator)) {
+				beanFactory.setDependencyComparator(AnnotationAwareOrderComparator.INSTANCE);
+			}
+			if (!(beanFactory.getAutowireCandidateResolver() instanceof ContextAnnotationAutowireCandidateResolver)) {
+				beanFactory.setAutowireCandidateResolver(new ContextAnnotationAutowireCandidateResolver());
+			}
+		}
+
 		Set<BeanDefinitionHolder> beanDefs = new LinkedHashSet<BeanDefinitionHolder>(4);
 
 		if (!registry.containsBeanDefinition(CONFIGURATION_ANNOTATION_PROCESSOR_BEAN_NAME)) {
@@ -229,6 +244,18 @@ public class AnnotationConfigUtils {
 		return new BeanDefinitionHolder(definition, beanName);
 	}
 
+	private static DefaultListableBeanFactory unwrapDefaultListableBeanFactory(BeanDefinitionRegistry registry) {
+		if (registry instanceof DefaultListableBeanFactory) {
+			return (DefaultListableBeanFactory) registry;
+		}
+		else if (registry instanceof GenericApplicationContext) {
+			return ((GenericApplicationContext) registry).getDefaultListableBeanFactory();
+		}
+		else {
+			return null;
+		}
+	}
+
 	static void processCommonDefinitionAnnotations(AnnotatedBeanDefinition abd) {
 		processCommonDefinitionAnnotations(abd, abd.getMetadata());
 	}

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

@@ -0,0 +1,96 @@
+/*
+ * 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.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.context.annotation;
+
+import java.lang.annotation.Annotation;
+import java.lang.reflect.Method;
+
+import org.springframework.aop.TargetSource;
+import org.springframework.aop.framework.ProxyFactory;
+import org.springframework.beans.factory.annotation.QualifierAnnotationAutowireCandidateResolver;
+import org.springframework.beans.factory.config.DependencyDescriptor;
+import org.springframework.beans.factory.support.DefaultListableBeanFactory;
+import org.springframework.core.MethodParameter;
+import org.springframework.core.annotation.AnnotationUtils;
+import org.springframework.util.Assert;
+
+/**
+ * Complete implementation of the {@link org.springframework.beans.factory.support.AutowireCandidateResolver}
+ * strategy interface, providing support for qualifier annotations as well as for lazy resolution driven
+ * by the {@link Lazy} annotation in the {@code context.annotation} package.
+ *
+ * @author Juergen Hoeller
+ * @since 4.0
+ */
+public class ContextAnnotationAutowireCandidateResolver extends QualifierAnnotationAutowireCandidateResolver {
+
+	@Override
+	public Object getLazyResolutionProxyIfNecessary(DependencyDescriptor descriptor, String beanName) {
+		return (isLazy(descriptor) ? buildLazyResolutionProxy(descriptor, beanName) : null);
+	}
+
+	protected boolean isLazy(DependencyDescriptor descriptor) {
+		for (Annotation ann : descriptor.getAnnotations()) {
+			Lazy lazy = AnnotationUtils.getAnnotation(ann, Lazy.class);
+			if (lazy != null && lazy.value()) {
+				return true;
+			}
+		}
+		MethodParameter methodParam = descriptor.getMethodParameter();
+		if (methodParam != null) {
+			Method method = methodParam.getMethod();
+			if (method == null || void.class.equals(method.getReturnType())) {
+				Lazy lazy = AnnotationUtils.getAnnotation(methodParam.getAnnotatedElement(), Lazy.class);
+				if (lazy != null && lazy.value()) {
+					return true;
+				}
+			}
+		}
+		return false;
+	}
+
+	protected Object buildLazyResolutionProxy(final DependencyDescriptor descriptor, final String beanName) {
+		Assert.state(getBeanFactory() instanceof DefaultListableBeanFactory,
+				"BeanFactory needs to be a DefaultListableBeanFactory");
+		final DefaultListableBeanFactory beanFactory = (DefaultListableBeanFactory) getBeanFactory();
+		TargetSource ts = new TargetSource() {
+			@Override
+			public Class<?> getTargetClass() {
+				return descriptor.getDependencyType();
+			}
+			@Override
+			public boolean isStatic() {
+				return false;
+			}
+			@Override
+			public Object getTarget() {
+				return beanFactory.doResolveDependency(descriptor, beanName, null, null);
+			}
+			@Override
+			public void releaseTarget(Object target) {
+			}
+		};
+		ProxyFactory pf = new ProxyFactory();
+		pf.setTargetSource(ts);
+		Class<?> dependencyType = descriptor.getDependencyType();
+		if (dependencyType.isInterface()) {
+			pf.addInterface(dependencyType);
+		}
+		return pf.getProxy(beanFactory.getBeanClassLoader());
+	}
+
+}

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

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2012 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.
@@ -42,14 +42,21 @@ import java.lang.annotation.Target;
  * method within a {@code @Lazy}-annotated {@code @Configuration} class, this indicates
  * overriding the 'default lazy' behavior and that the bean should be eagerly initialized.
  *
+ * <p>In addition to its role for component initialization, this annotation may also be placed
+ * on injection points marked with {@link org.springframework.beans.factory.annotation.Autowired}
+ * or {@link javax.inject.Inject}: In that context, it leads to the creation of a
+ * lazy-resolution proxy for all affected dependencies, as an alternative to using
+ * {@link org.springframework.beans.factory.ObjectFactory} or {@link javax.inject.Provider}.
+ *
  * @author Chris Beams
+ * @author Juergen Hoeller
  * @since 3.0
  * @see Primary
  * @see Bean
  * @see Configuration
  * @see org.springframework.stereotype.Component
  */
-@Target({ElementType.TYPE, ElementType.METHOD})
+@Target({ElementType.TYPE, ElementType.METHOD, ElementType.CONSTRUCTOR, ElementType.PARAMETER, ElementType.FIELD})
 @Retention(RetentionPolicy.RUNTIME)
 @Documented
 public @interface Lazy {

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

@@ -19,7 +19,6 @@ package org.springframework.context.support;
 import java.io.IOException;
 
 import org.springframework.beans.BeansException;
-import org.springframework.beans.factory.annotation.QualifierAnnotationAutowireCandidateResolver;
 import org.springframework.beans.factory.config.ConfigurableListableBeanFactory;
 import org.springframework.beans.factory.support.DefaultListableBeanFactory;
 import org.springframework.context.ApplicationContext;
@@ -222,7 +221,6 @@ public abstract class AbstractRefreshableApplicationContext extends AbstractAppl
 		if (this.allowCircularReferences != null) {
 			beanFactory.setAllowCircularReferences(this.allowCircularReferences);
 		}
-		beanFactory.setAutowireCandidateResolver(new QualifierAnnotationAutowireCandidateResolver());
 	}
 
 	/**

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

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2012 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.
@@ -21,7 +21,6 @@ import java.io.IOException;
 import org.springframework.beans.BeansException;
 import org.springframework.beans.factory.BeanDefinitionStoreException;
 import org.springframework.beans.factory.NoSuchBeanDefinitionException;
-import org.springframework.beans.factory.annotation.QualifierAnnotationAutowireCandidateResolver;
 import org.springframework.beans.factory.config.BeanDefinition;
 import org.springframework.beans.factory.config.ConfigurableListableBeanFactory;
 import org.springframework.beans.factory.support.BeanDefinitionRegistry;
@@ -100,7 +99,6 @@ public class GenericApplicationContext extends AbstractApplicationContext implem
 	 */
 	public GenericApplicationContext() {
 		this.beanFactory = new DefaultListableBeanFactory();
-		this.beanFactory.setAutowireCandidateResolver(new QualifierAnnotationAutowireCandidateResolver());
 	}
 
 	/**

spring-context/src/test/java/org/springframework/context/annotation/LazyAutowiredAnnotationBeanPostProcessorTests.java

@@ -0,0 +1,254 @@
+/*
+ * 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.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.context.annotation;
+
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+
+import org.junit.Test;
+
+import org.springframework.beans.factory.NoSuchBeanDefinitionException;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor;
+import org.springframework.beans.factory.support.DefaultListableBeanFactory;
+import org.springframework.beans.factory.support.RootBeanDefinition;
+import org.springframework.tests.sample.beans.TestBean;
+
+import static org.junit.Assert.*;
+
+/**
+ * @author Juergen Hoeller
+ * @since 4.0
+ */
+public class LazyAutowiredAnnotationBeanPostProcessorTests {
+
+	private void doTestLazyResourceInjection(Class<? extends TestBeanHolder> annotatedBeanClass) {
+		AnnotationConfigApplicationContext ac = new AnnotationConfigApplicationContext();
+		RootBeanDefinition abd = new RootBeanDefinition(annotatedBeanClass);
+		abd.setScope(RootBeanDefinition.SCOPE_PROTOTYPE);
+		ac.registerBeanDefinition("annotatedBean", abd);
+		RootBeanDefinition tbd = new RootBeanDefinition(TestBean.class);
+		tbd.setLazyInit(true);
+		ac.registerBeanDefinition("testBean", tbd);
+		ac.refresh();
+
+		TestBeanHolder bean = ac.getBean("annotatedBean", TestBeanHolder.class);
+		assertFalse(ac.getBeanFactory().containsSingleton("testBean"));
+		assertNotNull(bean.getTestBean());
+		assertNull(bean.getTestBean().getName());
+		assertTrue(ac.getBeanFactory().containsSingleton("testBean"));
+		TestBean tb = (TestBean) ac.getBean("testBean");
+		tb.setName("tb");
+		assertSame("tb", bean.getTestBean().getName());
+	}
+
+	@Test
+	public void testLazyResourceInjectionWithField() {
+		doTestLazyResourceInjection(FieldResourceInjectionBean.class);
+	}
+
+	@Test
+	public void testLazyResourceInjectionWithFieldAndCustomAnnotation() {
+		doTestLazyResourceInjection(FieldResourceInjectionBeanWithCompositeAnnotation.class);
+	}
+
+	@Test
+	public void testLazyResourceInjectionWithMethod() {
+		doTestLazyResourceInjection(MethodResourceInjectionBean.class);
+	}
+
+	@Test
+	public void testLazyResourceInjectionWithMethodLevelLazy() {
+		doTestLazyResourceInjection(MethodResourceInjectionBeanWithMethodLevelLazy.class);
+	}
+
+	@Test
+	public void testLazyResourceInjectionWithMethodAndCustomAnnotation() {
+		doTestLazyResourceInjection(MethodResourceInjectionBeanWithCompositeAnnotation.class);
+	}
+
+	@Test
+	public void testLazyResourceInjectionWithConstructor() {
+		doTestLazyResourceInjection(ConstructorResourceInjectionBean.class);
+	}
+
+	@Test
+	public void testLazyResourceInjectionWithConstructorLevelLazy() {
+		doTestLazyResourceInjection(ConstructorResourceInjectionBeanWithConstructorLevelLazy.class);
+	}
+
+	@Test
+	public void testLazyResourceInjectionWithConstructorAndCustomAnnotation() {
+		doTestLazyResourceInjection(ConstructorResourceInjectionBeanWithCompositeAnnotation.class);
+	}
+
+	@Test
+	public void testLazyResourceInjectionWithNonExistingTarget() {
+		DefaultListableBeanFactory bf = new DefaultListableBeanFactory();
+		bf.setAutowireCandidateResolver(new ContextAnnotationAutowireCandidateResolver());
+		AutowiredAnnotationBeanPostProcessor bpp = new AutowiredAnnotationBeanPostProcessor();
+		bpp.setBeanFactory(bf);
+		bf.addBeanPostProcessor(bpp);
+		RootBeanDefinition bd = new RootBeanDefinition(FieldResourceInjectionBean.class);
+		bd.setScope(RootBeanDefinition.SCOPE_PROTOTYPE);
+		bf.registerBeanDefinition("annotatedBean", bd);
+
+		FieldResourceInjectionBean bean = (FieldResourceInjectionBean) bf.getBean("annotatedBean");
+		assertNotNull(bean.getTestBean());
+		try {
+			bean.getTestBean().getName();
+			fail("Should have thrown NoSuchBeanDefinitionException");
+		}
+		catch (NoSuchBeanDefinitionException ex) {
+			// expected;
+		}
+	}
+
+
+	public interface TestBeanHolder {
+
+		TestBean getTestBean();
+	}
+
+
+	public static class FieldResourceInjectionBean implements TestBeanHolder {
+
+		@Autowired @Lazy
+		private TestBean testBean;
+
+		public TestBean getTestBean() {
+			return this.testBean;
+		}
+	}
+
+
+	public static class FieldResourceInjectionBeanWithCompositeAnnotation implements TestBeanHolder {
+
+		@LazyInject
+		private TestBean testBean;
+
+		public TestBean getTestBean() {
+			return this.testBean;
+		}
+	}
+
+
+	public static class MethodResourceInjectionBean implements TestBeanHolder {
+
+		private TestBean testBean;
+
+		@Autowired
+		public void setTestBean(@Lazy TestBean testBean) {
+			if (this.testBean != null) {
+				throw new IllegalStateException("Already called");
+			}
+			this.testBean = testBean;
+		}
+
+		public TestBean getTestBean() {
+			return this.testBean;
+		}
+	}
+
+
+	public static class MethodResourceInjectionBeanWithMethodLevelLazy implements TestBeanHolder {
+
+		private TestBean testBean;
+
+		@Autowired @Lazy
+		public void setTestBean(TestBean testBean) {
+			if (this.testBean != null) {
+				throw new IllegalStateException("Already called");
+			}
+			this.testBean = testBean;
+		}
+
+		public TestBean getTestBean() {
+			return this.testBean;
+		}
+	}
+
+
+	public static class MethodResourceInjectionBeanWithCompositeAnnotation implements TestBeanHolder {
+
+		private TestBean testBean;
+
+		@LazyInject
+		public void setTestBean(TestBean testBean) {
+			if (this.testBean != null) {
+				throw new IllegalStateException("Already called");
+			}
+			this.testBean = testBean;
+		}
+
+		public TestBean getTestBean() {
+			return this.testBean;
+		}
+	}
+
+
+	public static class ConstructorResourceInjectionBean implements TestBeanHolder {
+
+		private final TestBean testBean;
+
+		@Autowired
+		public ConstructorResourceInjectionBean(@Lazy TestBean testBean) {
+			this.testBean = testBean;
+		}
+
+		public TestBean getTestBean() {
+			return this.testBean;
+		}
+	}
+
+
+	public static class ConstructorResourceInjectionBeanWithConstructorLevelLazy implements TestBeanHolder {
+
+		private final TestBean testBean;
+
+		@Autowired @Lazy
+		public ConstructorResourceInjectionBeanWithConstructorLevelLazy(TestBean testBean) {
+			this.testBean = testBean;
+		}
+
+		public TestBean getTestBean() {
+			return this.testBean;
+		}
+	}
+
+
+	public static class ConstructorResourceInjectionBeanWithCompositeAnnotation implements TestBeanHolder {
+
+		private final TestBean testBean;
+
+		@LazyInject
+		public ConstructorResourceInjectionBeanWithCompositeAnnotation(TestBean testBean) {
+			this.testBean = testBean;
+		}
+
+		public TestBean getTestBean() {
+			return this.testBean;
+		}
+	}
+
+
+	@Autowired @Lazy
+	@Retention(RetentionPolicy.RUNTIME)
+	public @interface LazyInject {
+	}
+
+}

spring-core/src/main/java/org/springframework/core/MethodParameter.java

@@ -164,7 +164,7 @@ public class MethodParameter {
 	 * Returns the wrapped member.
 	 * @return the Method or Constructor as Member
 	 */
-	private Member getMember() {
+	public Member getMember() {
 		// NOTE: no ternary expression to retain JDK <8 compatibility even when using
 		// the JDK 8 compiler (potentially selecting java.lang.reflect.Executable
 		// as common type, with that new base class not available on older JDKs)
@@ -180,7 +180,7 @@ public class MethodParameter {
 	 * Returns the wrapped annotated element.
 	 * @return the Method or Constructor as AnnotatedElement
 	 */
-	private AnnotatedElement getAnnotatedElement() {
+	public AnnotatedElement getAnnotatedElement() {
 		// NOTE: no ternary expression to retain JDK <8 compatibility even when using
 		// the JDK 8 compiler (potentially selecting java.lang.reflect.Executable
 		// as common type, with that new base class not available on older JDKs)

spring-core/src/main/java/org/springframework/core/annotation/AnnotationUtils.java

@@ -55,6 +55,22 @@ public abstract class AnnotationUtils {
 	private static final Map<Class<?>, Boolean> annotatedInterfaceCache = new WeakHashMap<Class<?>, Boolean>();
 
 
+	/**
+	 * Get a single {@link Annotation} of {@code annotationType} from the supplied
+	 * annotation: either the given annotation itself or a meta-annotation thereof.
+	 * @param ann the Annotation to check
+	 * @param annotationType the annotation class to look for, both locally and as a meta-annotation
+	 * @return the matching annotation or {@code null} if not found
+	 * @since 4.0
+	 */
+	@SuppressWarnings("unchecked")
+	public static <T extends Annotation> T getAnnotation(Annotation ann, Class<T> annotationType) {
+		if (annotationType.isInstance(ann)) {
+			return (T) ann;
+		}
+		return ann.annotationType().getAnnotation(annotationType);
+	}
+
 	/**
 	 * Get a single {@link Annotation} of {@code annotationType} from the supplied
 	 * Method, Constructor or Field. Meta-annotations will be searched if the annotation
@@ -98,16 +114,7 @@ public abstract class AnnotationUtils {
 	 */
 	public static <A extends Annotation> A getAnnotation(Method method, Class<A> annotationType) {
 		Method resolvedMethod = BridgeMethodResolver.findBridgedMethod(method);
-		A ann = resolvedMethod.getAnnotation(annotationType);
+		return getAnnotation((AnnotatedElement) resolvedMethod, annotationType);
-		if (ann == null) {
-			for (Annotation metaAnn : resolvedMethod.getAnnotations()) {
-				ann = metaAnn.annotationType().getAnnotation(annotationType);
-				if (ann != null) {
-					break;
-				}
-			}
-		}
-		return ann;
 	}
 
 	/**

spring-web/src/test/java/org/springframework/web/context/support/SpringBeanAutowiringSupportTests.java

@@ -18,12 +18,13 @@ package org.springframework.web.context.support;
 
 import org.junit.Test;
 
-import org.springframework.tests.sample.beans.ITestBean;
 import org.springframework.beans.MutablePropertyValues;
-import org.springframework.tests.sample.beans.TestBean;
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.beans.factory.annotation.Value;
+import org.springframework.context.annotation.AnnotationConfigUtils;
 import org.springframework.mock.web.test.MockServletContext;
+import org.springframework.tests.sample.beans.ITestBean;
+import org.springframework.tests.sample.beans.TestBean;
 import org.springframework.web.context.WebApplicationContext;
 
 import static org.junit.Assert.*;
@@ -35,14 +36,18 @@ public class SpringBeanAutowiringSupportTests {
 
 	@Test
 	public void testProcessInjectionBasedOnServletContext() {
-		MockServletContext sc = new MockServletContext();
 		StaticWebApplicationContext wac = new StaticWebApplicationContext();
+		AnnotationConfigUtils.registerAnnotationConfigProcessors(wac);
+
 		MutablePropertyValues pvs = new MutablePropertyValues();
 		pvs.add("name", "tb");
 		wac.registerSingleton("testBean", TestBean.class, pvs);
+
+		MockServletContext sc = new MockServletContext();
 		wac.setServletContext(sc);
 		wac.refresh();
 		sc.setAttribute(WebApplicationContext.ROOT_WEB_APPLICATION_CONTEXT_ATTRIBUTE, wac);
+
 		InjectionTarget target = new InjectionTarget();
 		SpringBeanAutowiringSupport.processInjectionBasedOnServletContext(target, sc);
 		assertTrue(target.testBean instanceof TestBean);