SmartObjectFactory provides getObject(args) variant as well

Issue: SPR-13956

Author: jhoeller

spring-beans/src/main/java/org/springframework/beans/factory/SmartObjectFactory.java

@@ -28,17 +28,29 @@
 public interface SmartObjectFactory<T> extends ObjectFactory<T> {
 
 	/**
-	 * Return an instance (possibly shared or independent)
-	 * of the object managed by this factory.
+	 * Return an instance (possibly shared or independent) of the object
+	 * managed by this factory.
+	 * <p>Allows for specifying explicit construction arguments, along the
+	 * lines of {@link BeanFactory#getBean(String, Object...)}.
+	 * @param args arguments to use when creating a corresponding instance
+	 * @return an instance of the bean
+	 * @throws BeansException in case of creation errors
+	 * @see #getObject()
+	 */
+	T getObject(Object... args) throws BeansException;
+
+	/**
+	 * Return an instance (possibly shared or independent) of the object
+	 * managed by this factory.
 	 * @return an instance of the bean, or {@code null} if not available
 	 * @throws BeansException in case of creation errors
 	 * @see #getObject()
 	 */
 	T getIfAvailable() throws BeansException;
 
 	/**
-	 * Return an instance (possibly shared or independent)
-	 * of the object managed by this factory.
+	 * Return an instance (possibly shared or independent) of the object
+	 * managed by this factory.
 	 * @return an instance of the bean, or {@code null} if not available or
 	 * not unique (i.e. multiple candidates found with none marked as primary)
 	 * @throws BeansException in case of creation errors

spring-beans/src/main/java/org/springframework/beans/factory/config/DependencyDescriptor.java

@@ -26,6 +26,7 @@
 import java.util.Map;
 
 import org.springframework.beans.BeansException;
+import org.springframework.beans.factory.BeanFactory;
 import org.springframework.beans.factory.NoUniqueBeanDefinitionException;
 import org.springframework.core.GenericCollectionTypeResolver;
 import org.springframework.core.GenericTypeResolver;
@@ -200,6 +201,20 @@ public Object resolveNotUnique(Class<?> type, Map<String, Object> matchingBeans)
 		throw new NoUniqueBeanDefinitionException(type, matchingBeans.keySet());
 	}
 
+	/**
+	 * Resolve the specified bean name, as a candidate result of the matching
+	 * algorithm for this dependency, to a bean instance from the given factory.
+	 * <p>The default implementation calls {@link BeanFactory#getBean(String)}.
+	 * Subclasses may provide additional arguments or other customizations.
+	 * @param beanName the bean name, as a candidate result for this dependency
+	 * @param beanFactory the associated factory
+	 * @return the bean instance (never {@code null})
+	 * @see BeanFactory#getBean(String)
+	 */
+	public Object resolveCandidate(String beanName, BeanFactory beanFactory) {
+		return beanFactory.getBean(beanName);
+	}
+
 
 	/**
 	 * Increase this descriptor's nesting level.

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

@@ -1052,7 +1052,7 @@ public Object doResolveDependency(DependencyDescriptor descriptor, String beanNa
 		if (matchingBeans.size() > 1) {
 			String primaryBeanName = determineAutowireCandidate(matchingBeans, descriptor);
 			if (primaryBeanName == null) {
-				if (!indicatesMultipleBeans(type) || descriptor.isRequired()) {
+				if (descriptor.isRequired() || !indicatesMultipleBeans(type)) {
 					return descriptor.resolveNotUnique(type, matchingBeans);
 				}
 				else {
@@ -1198,22 +1198,22 @@ protected Map<String, Object> findAutowireCandidates(
 		}
 		for (String candidateName : candidateNames) {
 			if (!isSelfReference(beanName, candidateName) && isAutowireCandidate(candidateName, descriptor)) {
-				result.put(candidateName, getBean(candidateName));
+				result.put(candidateName, descriptor.resolveCandidate(candidateName, this));
 			}
 		}
 		if (result.isEmpty() && !indicatesMultipleBeans(requiredType)) {
 			// Consider fallback matches if the first pass failed to find anything...
 			DependencyDescriptor fallbackDescriptor = descriptor.forFallbackMatch();
 			for (String candidateName : candidateNames) {
 				if (!isSelfReference(beanName, candidateName) && isAutowireCandidate(candidateName, fallbackDescriptor)) {
-					result.put(candidateName, getBean(candidateName));
+					result.put(candidateName, descriptor.resolveCandidate(candidateName, this));
 				}
 			}
 			if (result.isEmpty()) {
 				// Consider self references before as a final pass
 				for (String candidateName : candidateNames) {
 					if (isSelfReference(beanName, candidateName) && isAutowireCandidate(candidateName, fallbackDescriptor)) {
-						result.put(candidateName, getBean(candidateName));
+						result.put(candidateName, descriptor.resolveCandidate(candidateName, this));
 					}
 				}
 			}
@@ -1462,12 +1462,17 @@ private Object readResolve() {
 	@UsesJava8
 	private class OptionalDependencyFactory {
 
-		public Object createOptionalDependency(DependencyDescriptor descriptor, String beanName) {
+		public Object createOptionalDependency(DependencyDescriptor descriptor, String beanName, final Object... args) {
 			DependencyDescriptor descriptorToUse = new DependencyDescriptor(descriptor) {
 				@Override
 				public boolean isRequired() {
 					return false;
 				}
+				@Override
+				public Object resolveCandidate(String beanName, BeanFactory beanFactory) {
+					return (!ObjectUtils.isEmpty(args) ? beanFactory.getBean(beanName, args) :
+							super.resolveCandidate(beanName, beanFactory));
+				}
 			};
 			descriptorToUse.increaseNestingLevel();
 			return Optional.ofNullable(doResolveDependency(descriptorToUse, beanName, null, null));
@@ -1503,6 +1508,22 @@ public Object getObject() throws BeansException {
 			}
 		}
 
+		@Override
+		public Object getObject(final Object... args) throws BeansException {
+			if (this.optional) {
+				return new OptionalDependencyFactory().createOptionalDependency(this.descriptor, this.beanName, args);
+			}
+			else {
+				DependencyDescriptor descriptorToUse = new DependencyDescriptor(descriptor) {
+					@Override
+					public Object resolveCandidate(String beanName, BeanFactory beanFactory) {
+						return beanFactory.getBean(beanName, args);
+					}
+				};
+				return doResolveDependency(descriptorToUse, this.beanName, null, null);
+			}
+		}
+
 		@Override
 		public Object getIfAvailable() throws BeansException {
 			if (this.optional) {

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

@@ -1047,7 +1047,26 @@ public void testObjectFactorySerialization() throws Exception {
 	}
 
 	@Test
-	public void testSmartObjectFactoryInjection() {
+	public void testSmartObjectFactoryInjectionWithPrototype() {
+		DefaultListableBeanFactory bf = new DefaultListableBeanFactory();
+		AutowiredAnnotationBeanPostProcessor bpp = new AutowiredAnnotationBeanPostProcessor();
+		bpp.setBeanFactory(bf);
+		bf.addBeanPostProcessor(bpp);
+		bf.registerBeanDefinition("annotatedBean", new RootBeanDefinition(SmartObjectFactoryInjectionBean.class));
+		RootBeanDefinition tbd = new RootBeanDefinition(TestBean.class);
+		tbd.setScope(RootBeanDefinition.SCOPE_PROTOTYPE);
+		bf.registerBeanDefinition("testBean", tbd);
+
+		SmartObjectFactoryInjectionBean bean = (SmartObjectFactoryInjectionBean) bf.getBean("annotatedBean");
+		assertEquals(bf.getBean("testBean"), bean.getTestBean());
+		assertEquals(bf.getBean("testBean", "myName"), bean.getTestBean("myName"));
+		assertEquals(bf.getBean("testBean"), bean.getOptionalTestBean());
+		assertEquals(bf.getBean("testBean"), bean.getUniqueTestBean());
+		bf.destroySingletons();
+	}
+
+	@Test
+	public void testSmartObjectFactoryInjectionWithSingletonTarget() {
 		DefaultListableBeanFactory bf = new DefaultListableBeanFactory();
 		AutowiredAnnotationBeanPostProcessor bpp = new AutowiredAnnotationBeanPostProcessor();
 		bpp.setBeanFactory(bf);
@@ -2557,6 +2576,10 @@ public TestBean getTestBean() {
 			return this.testBeanFactory.getObject();
 		}
 
+		public TestBean getTestBean(String name) {
+			return this.testBeanFactory.getObject(name);
+		}
+
 		public TestBean getOptionalTestBean() {
 			return this.testBeanFactory.getIfAvailable();
 		}