PersistenceAnnotationBeanPostProcessor obtains default EntityManagerFactory via getBean(Class) algorithm

Issue: SPR-7549

Author: jhoeller

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

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2015 the original author or authors.
+ * Copyright 2002-2016 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.
@@ -153,12 +153,12 @@ public interface BeanFactory {
 
 	/**
 	 * Return the bean instance that uniquely matches the given object type, if any.
-	 * @param requiredType type the bean must match; can be an interface or superclass.
-	 * {@code null} is disallowed.
 	 * <p>This method goes into {@link ListableBeanFactory} by-type lookup territory
 	 * but may also be translated into a conventional by-name lookup based on the name
 	 * of the given type. For more extensive retrieval operations across sets of beans,
 	 * use {@link ListableBeanFactory} and/or {@link BeanFactoryUtils}.
+	 * @param requiredType type the bean must match; can be an interface or superclass.
+	 * {@code null} is disallowed.
 	 * @return an instance of the single bean matching the required type
 	 * @throws NoSuchBeanDefinitionException if no bean of the given type was found
 	 * @throws NoUniqueBeanDefinitionException if more than one bean of the given type was found

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

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2006 the original author or authors.
+ * Copyright 2002-2016 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.
@@ -17,10 +17,10 @@
 package org.springframework.beans.factory;
 
 /**
- * Counterpart of BeanNameAware. Returns the bean name of an object.
+ * Counterpart of {@link BeanNameAware}. Returns the bean name of an object.
  *
- * <p>This interface can be introduced to avoid a brittle dependence
- * on bean name in objects used with Spring IoC and Spring AOP.
+ * <p>This interface can be introduced to avoid a brittle dependence on
+ * bean name in objects used with Spring IoC and Spring AOP.
  *
  * @author Rod Johnson
  * @since 2.0
@@ -29,7 +29,7 @@
 public interface NamedBean {
 
 	/**
-	 * Return the name of this bean in a Spring bean factory.
+	 * Return the name of this bean in a Spring bean factory, if known.
 	 */
 	String getBeanName();
 

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

@@ -21,6 +21,8 @@
 import org.springframework.beans.BeansException;
 import org.springframework.beans.TypeConverter;
 import org.springframework.beans.factory.BeanFactory;
+import org.springframework.beans.factory.NoSuchBeanDefinitionException;
+import org.springframework.beans.factory.NoUniqueBeanDefinitionException;
 
 /**
  * Extension of the {@link org.springframework.beans.factory.BeanFactory}
@@ -154,15 +156,6 @@ public interface AutowireCapableBeanFactory extends BeanFactory {
 	 */
 	Object configureBean(Object existingBean, String beanName) throws BeansException;
 
-	/**
-	 * Resolve the specified dependency against the beans defined in this factory.
-	 * @param descriptor the descriptor for the dependency
-	 * @param beanName the name of the bean which declares the present dependency
-	 * @return the resolved object, or {@code null} if none found
-	 * @throws BeansException if dependency resolution failed
-	 */
-	Object resolveDependency(DependencyDescriptor descriptor, String beanName) throws BeansException;
-
 
 	//-------------------------------------------------------------------------
 	// Specialized methods for fine-grained control over the bean lifecycle
@@ -312,18 +305,55 @@ Object applyBeanPostProcessorsAfterInitialization(Object existingBean, String be
 	 */
 	void destroyBean(Object existingBean);
 
+
+	//-------------------------------------------------------------------------
+	// Delegate methods for resolving injection points
+	//-------------------------------------------------------------------------
+
+	/**
+	 * Resolve the bean instance that uniquely matches the given object type, if any,
+	 * including its bean name.
+	 * <p>This is effectively a variant of {@link #getBean(Class)} which preserves the
+	 * bean name of the matching instance.
+	 * @param requiredType type the bean must match; can be an interface or superclass.
+	 * {@code null} is disallowed.
+	 * @return the bean name plus bean instance
+	 * @throws NoSuchBeanDefinitionException if no bean of the given type was found
+	 * @throws NoUniqueBeanDefinitionException if more than one bean of the given type was found
+	 * @throws BeansException if the bean could not be created
+	 * @since 4.3.3
+	 * @see #getBean(Class)
+	 */
+	<T> NamedBeanHolder<T> resolveNamedBean(Class<T> requiredType) throws BeansException;
+
+	/**
+	 * Resolve the specified dependency against the beans defined in this factory.
+	 * @param descriptor the descriptor for the dependency
+	 * @param requestingBeanName the name of the bean which declares the present dependency
+	 * @return the resolved object, or {@code null} if none found
+	 * @throws NoSuchBeanDefinitionException if no matching bean was found
+	 * @throws NoUniqueBeanDefinitionException if more than one matching bean was found
+	 * @throws BeansException if dependency resolution failed for any other reason
+	 * @see #resolveDependency(DependencyDescriptor, String, Set, TypeConverter)
+	 * @since 2.5
+	 */
+	Object resolveDependency(DependencyDescriptor descriptor, String requestingBeanName) throws BeansException;
+
 	/**
 	 * Resolve the specified dependency against the beans defined in this factory.
 	 * @param descriptor the descriptor for the dependency
-	 * @param beanName the name of the bean which declares the present dependency
-	 * @param autowiredBeanNames a Set that all names of autowired beans (used for
-	 * resolving the present dependency) are supposed to be added to
-	 * @param typeConverter the TypeConverter to use for populating arrays and
-	 * collections
+	 * @param requestingBeanName the name of the bean which declares the present dependency
+	 * @param autowiredBeanNames a Set that all names of autowired beans (used for resolving
+	 * the present dependency) are supposed to be added to
+	 * @param typeConverter the TypeConverter to use for populating arrays and collections
 	 * @return the resolved object, or {@code null} if none found
-	 * @throws BeansException if dependency resolution failed
+	 * @throws NoSuchBeanDefinitionException if no matching bean was found
+	 * @throws NoUniqueBeanDefinitionException if more than one matching bean was found
+	 * @throws BeansException if dependency resolution failed for any other reason
+	 * @see DependencyDescriptor
+	 * @since 2.5
 	 */
-	Object resolveDependency(DependencyDescriptor descriptor, String beanName,
+	Object resolveDependency(DependencyDescriptor descriptor, String requestingBeanName,
 			Set<String> autowiredBeanNames, TypeConverter typeConverter) throws BeansException;
 
 }

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

@@ -0,0 +1,56 @@
+/*
+ * Copyright 2002-2016 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.beans.factory.config;
+
+import org.springframework.beans.factory.NamedBean;
+
+/**
+ * A simple holder for a given bean name plus bean instance.
+ *
+ * @author Juergen Hoeller
+ * @since 4.3.3
+ * @see AutowireCapableBeanFactory#resolveNamedBean(Class)
+ */
+public class NamedBeanHolder<T> implements NamedBean {
+
+	private final String beanName;
+
+	private final T beanInstance;
+
+
+	/**
+	 * Create a new holder for the given bean name plus instance.
+	 */
+	public NamedBeanHolder(String beanName, T beanInstance) {
+		this.beanName = beanName;
+		this.beanInstance = beanInstance;
+	}
+
+
+	@Override
+	public String getBeanName() {
+		return this.beanName;
+	}
+
+	/**
+	 * Return the corresponding bean instance.
+	 */
+	public T getBeanInstance() {
+		return this.beanInstance;
+	}
+
+}

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

@@ -32,7 +32,6 @@
 import java.util.Collection;
 import java.util.Collections;
 import java.util.Comparator;
-import java.util.HashMap;
 import java.util.IdentityHashMap;
 import java.util.Iterator;
 import java.util.LinkedHashMap;
@@ -62,11 +61,13 @@
 import org.springframework.beans.factory.ObjectProvider;
 import org.springframework.beans.factory.SmartFactoryBean;
 import org.springframework.beans.factory.SmartInitializingSingleton;
+import org.springframework.beans.factory.config.AutowireCapableBeanFactory;
 import org.springframework.beans.factory.config.BeanDefinition;
 import org.springframework.beans.factory.config.BeanDefinitionHolder;
 import org.springframework.beans.factory.config.ConfigurableBeanFactory;
 import org.springframework.beans.factory.config.ConfigurableListableBeanFactory;
 import org.springframework.beans.factory.config.DependencyDescriptor;
+import org.springframework.beans.factory.config.NamedBeanHolder;
 import org.springframework.core.OrderComparator;
 import org.springframework.core.ResolvableType;
 import org.springframework.core.annotation.AnnotationUtils;
@@ -326,43 +327,15 @@ public <T> T getBean(Class<T> requiredType) throws BeansException {
 
 	@Override
 	public <T> T getBean(Class<T> requiredType, Object... args) throws BeansException {
-		Assert.notNull(requiredType, "Required type must not be null");
-		String[] beanNames = getBeanNamesForType(requiredType);
-		if (beanNames.length > 1) {
-			ArrayList<String> autowireCandidates = new ArrayList<>();
-			for (String beanName : beanNames) {
-				if (!containsBeanDefinition(beanName) || getBeanDefinition(beanName).isAutowireCandidate()) {
-					autowireCandidates.add(beanName);
-				}
-			}
-			if (autowireCandidates.size() > 0) {
-				beanNames = autowireCandidates.toArray(new String[autowireCandidates.size()]);
-			}
-		}
-		if (beanNames.length == 1) {
-			return getBean(beanNames[0], requiredType, args);
-		}
-		else if (beanNames.length > 1) {
-			Map<String, Object> candidates = new HashMap<>();
-			for (String beanName : beanNames) {
-				candidates.put(beanName, getBean(beanName, requiredType, args));
-			}
-			String primaryCandidate = determinePrimaryCandidate(candidates, requiredType);
-			if (primaryCandidate != null) {
-				return getBean(primaryCandidate, requiredType, args);
-			}
-			String priorityCandidate = determineHighestPriorityCandidate(candidates, requiredType);
-			if (priorityCandidate != null) {
-				return getBean(priorityCandidate, requiredType, args);
-			}
-			throw new NoUniqueBeanDefinitionException(requiredType, candidates.keySet());
-		}
-		else if (getParentBeanFactory() != null) {
-			return getParentBeanFactory().getBean(requiredType, args);
+		NamedBeanHolder<T> namedBean = resolveNamedBean(requiredType, args);
+		if (namedBean != null) {
+			return namedBean.getBeanInstance();
 		}
-		else {
-			throw new NoSuchBeanDefinitionException(requiredType);
+		BeanFactory parent = getParentBeanFactory();
+		if (parent != null) {
+			return parent.getBean(requiredType, args);
 		}
+		throw new NoSuchBeanDefinitionException(requiredType);
 	}
 
 
@@ -642,13 +615,15 @@ protected boolean isAutowireCandidate(String beanName, DependencyDescriptor desc
 		else if (containsSingleton(beanName)) {
 			return isAutowireCandidate(beanName, new RootBeanDefinition(getType(beanName)), descriptor, resolver);
 		}
-		else if (getParentBeanFactory() instanceof DefaultListableBeanFactory) {
+
+		BeanFactory parent = getParentBeanFactory();
+		if (parent instanceof DefaultListableBeanFactory) {
 			// No bean definition found in this factory -> delegate to parent.
-			return ((DefaultListableBeanFactory) getParentBeanFactory()).isAutowireCandidate(beanName, descriptor, resolver);
+			return ((DefaultListableBeanFactory) parent).isAutowireCandidate(beanName, descriptor, resolver);
 		}
-		else if (getParentBeanFactory() instanceof ConfigurableListableBeanFactory) {
+		else if (parent instanceof ConfigurableListableBeanFactory) {
 			// If no DefaultListableBeanFactory, can't pass the resolver along.
-			return ((ConfigurableListableBeanFactory) getParentBeanFactory()).isAutowireCandidate(beanName, descriptor);
+			return ((ConfigurableListableBeanFactory) parent).isAutowireCandidate(beanName, descriptor);
 		}
 		else {
 			return true;
@@ -989,24 +964,74 @@ private void clearByTypeCache() {
 	//---------------------------------------------------------------------
 
 	@Override
-	public Object resolveDependency(DependencyDescriptor descriptor, String beanName,
+	public <T> NamedBeanHolder<T> resolveNamedBean(Class<T> requiredType) throws BeansException {
+		NamedBeanHolder<T> namedBean = resolveNamedBean(requiredType, (Object[]) null);
+		if (namedBean != null) {
+			return namedBean;
+		}
+		BeanFactory parent = getParentBeanFactory();
+		if (parent instanceof AutowireCapableBeanFactory) {
+			return ((AutowireCapableBeanFactory) parent).resolveNamedBean(requiredType);
+		}
+		return null;
+	}
+
+	private <T> NamedBeanHolder<T> resolveNamedBean(Class<T> requiredType, Object... args) throws BeansException {
+		Assert.notNull(requiredType, "Required type must not be null");
+		String[] beanNames = getBeanNamesForType(requiredType);
+		if (beanNames.length > 1) {
+			ArrayList<String> autowireCandidates = new ArrayList<>();
+			for (String beanName : beanNames) {
+				if (!containsBeanDefinition(beanName) || getBeanDefinition(beanName).isAutowireCandidate()) {
+					autowireCandidates.add(beanName);
+				}
+			}
+			if (!autowireCandidates.isEmpty()) {
+				beanNames = autowireCandidates.toArray(new String[autowireCandidates.size()]);
+			}
+		}
+		if (beanNames.length == 1) {
+			String beanName = beanNames[0];
+			return new NamedBeanHolder<>(beanName, getBean(beanName, requiredType, args));
+		}
+		else if (beanNames.length > 1) {
+			Map<String, Object> candidates = new LinkedHashMap<>();
+			for (String beanName : beanNames) {
+				candidates.put(beanName, getBean(beanName, requiredType, args));
+			}
+			String primaryCandidate = determinePrimaryCandidate(candidates, requiredType);
+			if (primaryCandidate != null) {
+				return new NamedBeanHolder<>(primaryCandidate, getBean(primaryCandidate, requiredType, args));
+			}
+			String priorityCandidate = determineHighestPriorityCandidate(candidates, requiredType);
+			if (priorityCandidate != null) {
+				return new NamedBeanHolder<>(priorityCandidate, getBean(priorityCandidate, requiredType, args));
+			}
+			throw new NoUniqueBeanDefinitionException(requiredType, candidates.keySet());
+		}
+		return null;
+	}
+
+	@Override
+	public Object resolveDependency(DependencyDescriptor descriptor, String requestingBeanName,
 			Set<String> autowiredBeanNames, TypeConverter typeConverter) throws BeansException {
 
 		descriptor.initParameterNameDiscovery(getParameterNameDiscoverer());
 		if (Optional.class == descriptor.getDependencyType()) {
-			return createOptionalDependency(descriptor, beanName);
+			return createOptionalDependency(descriptor, requestingBeanName);
 		}
 		else if (ObjectFactory.class == descriptor.getDependencyType() ||
 				ObjectProvider.class == descriptor.getDependencyType()) {
-			return new DependencyObjectProvider(descriptor, beanName);
+			return new DependencyObjectProvider(descriptor, requestingBeanName);
 		}
 		else if (javaxInjectProviderClass == descriptor.getDependencyType()) {
-			return new Jsr330ProviderFactory().createDependencyProvider(descriptor, beanName);
+			return new Jsr330ProviderFactory().createDependencyProvider(descriptor, requestingBeanName);
 		}
 		else {
-			Object result = getAutowireCandidateResolver().getLazyResolutionProxyIfNecessary(descriptor, beanName);
+			Object result = getAutowireCandidateResolver().getLazyResolutionProxyIfNecessary(
+					descriptor, requestingBeanName);
 			if (result == null) {
-				result = doResolveDependency(descriptor, beanName, autowiredBeanNames, typeConverter);
+				result = doResolveDependency(descriptor, requestingBeanName, autowiredBeanNames, typeConverter);
 			}
 			return result;
 		}
@@ -1337,9 +1362,9 @@ protected boolean isPrimary(String beanName, Object beanInstance) {
 		if (containsBeanDefinition(beanName)) {
 			return getMergedLocalBeanDefinition(beanName).isPrimary();
 		}
-		BeanFactory parentFactory = getParentBeanFactory();
-		return (parentFactory instanceof DefaultListableBeanFactory &&
-				((DefaultListableBeanFactory) parentFactory).isPrimary(beanName, beanInstance));
+		BeanFactory parent = getParentBeanFactory();
+		return (parent instanceof DefaultListableBeanFactory &&
+				((DefaultListableBeanFactory) parent).isPrimary(beanName, beanInstance));
 	}
 
 	/**
@@ -1415,8 +1440,9 @@ private void checkBeanNotOfRequiredType(Class<?> type, DependencyDescriptor desc
 			}
 		}
 
-		if (getParentBeanFactory() instanceof DefaultListableBeanFactory) {
-			((DefaultListableBeanFactory) getParentBeanFactory()).checkBeanNotOfRequiredType(type, descriptor);
+		BeanFactory parent = getParentBeanFactory();
+		if (parent instanceof DefaultListableBeanFactory) {
+			((DefaultListableBeanFactory) parent).checkBeanNotOfRequiredType(type, descriptor);
 		}
 	}