org.springframework/spring-beans/5.3.3 : org/springframework/beans/factory/BeanFactoryUtils.java

BeanFactoryUtils
https://github.com/spring-projects/spring-framework: Spring Beans (Spring IO)
Apache License, Version 2.0
Juergen Hoeller
/*
 * Copyright 2002-2019 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
 *
 *      https://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;

import java.lang.annotation.Annotation;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.LinkedHashMap;
import java.util.List;
import java.util.Map;
import java.util.concurrent.ConcurrentHashMap;

import org.springframework.beans.BeansException;
import org.springframework.core.ResolvableType;
import org.springframework.lang.Nullable;
import org.springframework.util.Assert;
import org.springframework.util.StringUtils;

Convenience methods operating on bean factories, in particular on the ListableBeanFactory interface. Returns bean counts, bean names or bean instances,
taking into account the nesting hierarchy of a bean factory
(which the methods defined on the ListableBeanFactory interface don't,
in contrast to the methods defined on the BeanFactory interface).
Author: Rod Johnson, Juergen Hoeller, Chris Beams
Since: 04.07.2003/**
 * Convenience methods operating on bean factories, in particular
 * on the {@link ListableBeanFactory} interface.
 *
 * <p>Returns bean counts, bean names or bean instances,
 * taking into account the nesting hierarchy of a bean factory
 * (which the methods defined on the ListableBeanFactory interface don't,
 * in contrast to the methods defined on the BeanFactory interface).
 *
 * @author Rod Johnson
 * @author Juergen Hoeller
 * @author Chris Beams
 * @since 04.07.2003
 */
public abstract class BeanFactoryUtils {

	Separator for generated bean names. If a class name or parent name is not
unique, "#1", "#2" etc will be appended, until the name becomes unique.
/**
	 * Separator for generated bean names. If a class name or parent name is not
	 * unique, "#1", "#2" etc will be appended, until the name becomes unique.
	 */
	public static final String GENERATED_BEAN_NAME_SEPARATOR = "#";

	Cache from name with factory bean prefix to stripped name without dereference.
See Also: BeanFactory.FACTORY_BEAN_PREFIX
Since: 5.1/**
	 * Cache from name with factory bean prefix to stripped name without dereference.
	 * @since 5.1
	 * @see BeanFactory#FACTORY_BEAN_PREFIX
	 */
	private static final Map<String, String> transformedBeanNameCache = new ConcurrentHashMap<>();


	Return whether the given name is a factory dereference
(beginning with the factory dereference prefix).
Params: name – the name of the bean
See Also: BeanFactory.FACTORY_BEAN_PREFIX
Returns: whether the given name is a factory dereference/**
	 * Return whether the given name is a factory dereference
	 * (beginning with the factory dereference prefix).
	 * @param name the name of the bean
	 * @return whether the given name is a factory dereference
	 * @see BeanFactory#FACTORY_BEAN_PREFIX
	 */
	public static boolean isFactoryDereference(@Nullable String name) {
		return (name != null && name.startsWith(BeanFactory.FACTORY_BEAN_PREFIX));
	}

	Return the actual bean name, stripping out the factory dereference
prefix (if any, also stripping repeated factory prefixes if found).
Params: name – the name of the bean
See Also: BeanFactory.FACTORY_BEAN_PREFIX
Returns: the transformed name/**
	 * Return the actual bean name, stripping out the factory dereference
	 * prefix (if any, also stripping repeated factory prefixes if found).
	 * @param name the name of the bean
	 * @return the transformed name
	 * @see BeanFactory#FACTORY_BEAN_PREFIX
	 */
	public static String transformedBeanName(String name) {
		Assert.notNull(name, "'name' must not be null");
		if (!name.startsWith(BeanFactory.FACTORY_BEAN_PREFIX)) {
			return name;
		}
		return transformedBeanNameCache.computeIfAbsent(name, beanName -> {
			do {
				beanName = beanName.substring(BeanFactory.FACTORY_BEAN_PREFIX.length());
			}
			while (beanName.startsWith(BeanFactory.FACTORY_BEAN_PREFIX));
			return beanName;
		});
	}

	Return whether the given name is a bean name which has been generated
by the default naming strategy (containing a "#..." part).
Params: name – the name of the bean
See Also: GENERATED_BEAN_NAME_SEPARATOR
BeanDefinitionReaderUtils.generateBeanName
DefaultBeanNameGenerator
Returns: whether the given name is a generated bean name/**
	 * Return whether the given name is a bean name which has been generated
	 * by the default naming strategy (containing a "#..." part).
	 * @param name the name of the bean
	 * @return whether the given name is a generated bean name
	 * @see #GENERATED_BEAN_NAME_SEPARATOR
	 * @see org.springframework.beans.factory.support.BeanDefinitionReaderUtils#generateBeanName
	 * @see org.springframework.beans.factory.support.DefaultBeanNameGenerator
	 */
	public static boolean isGeneratedBeanName(@Nullable String name) {
		return (name != null && name.contains(GENERATED_BEAN_NAME_SEPARATOR));
	}

	Extract the "raw" bean name from the given (potentially generated) bean name,
excluding any "#..." suffixes which might have been added for uniqueness.
Params: name – the potentially generated bean name
See Also: GENERATED_BEAN_NAME_SEPARATOR
Returns: the raw bean name/**
	 * Extract the "raw" bean name from the given (potentially generated) bean name,
	 * excluding any "#..." suffixes which might have been added for uniqueness.
	 * @param name the potentially generated bean name
	 * @return the raw bean name
	 * @see #GENERATED_BEAN_NAME_SEPARATOR
	 */
	public static String originalBeanName(String name) {
		Assert.notNull(name, "'name' must not be null");
		int separatorIndex = name.indexOf(GENERATED_BEAN_NAME_SEPARATOR);
		return (separatorIndex != -1 ? name.substring(0, separatorIndex) : name);
	}


	// Retrieval of bean names

	Count all beans in any hierarchy in which this factory participates.
Includes counts of ancestor bean factories.
Beans that are "overridden" (specified in a descendant factory
with the same name) are only counted once.
Params: lbf – the bean factory
See Also: beanNamesIncludingAncestors
Returns: count of beans including those defined in ancestor factories/**
	 * Count all beans in any hierarchy in which this factory participates.
	 * Includes counts of ancestor bean factories.
	 * <p>Beans that are "overridden" (specified in a descendant factory
	 * with the same name) are only counted once.
	 * @param lbf the bean factory
	 * @return count of beans including those defined in ancestor factories
	 * @see #beanNamesIncludingAncestors
	 */
	public static int countBeansIncludingAncestors(ListableBeanFactory lbf) {
		return beanNamesIncludingAncestors(lbf).length;
	}

	Return all bean names in the factory, including ancestor factories.
Params: lbf – the bean factory
See Also: beanNamesForTypeIncludingAncestors
Returns: the array of matching bean names, or an empty array if none/**
	 * Return all bean names in the factory, including ancestor factories.
	 * @param lbf the bean factory
	 * @return the array of matching bean names, or an empty array if none
	 * @see #beanNamesForTypeIncludingAncestors
	 */
	public static String[] beanNamesIncludingAncestors(ListableBeanFactory lbf) {
		return beanNamesForTypeIncludingAncestors(lbf, Object.class);
	}

	Get all bean names for the given type, including those defined in ancestor
factories. Will return unique names in case of overridden bean definitions.
Does consider objects created by FactoryBeans, which means that FactoryBeans
will get initialized. If the object created by the FactoryBean doesn't match,
the raw FactoryBean itself will be matched against the type.
This version of beanNamesForTypeIncludingAncestors automatically includes prototypes and FactoryBeans. 
Params: lbf – the bean factory
type – the type that beans must match (as a ResolvableType)
See Also: ListableBeanFactory.getBeanNamesForType(ResolvableType)
Returns: the array of matching bean names, or an empty array if none
Since: 4.2/**
	 * Get all bean names for the given type, including those defined in ancestor
	 * factories. Will return unique names in case of overridden bean definitions.
	 * <p>Does consider objects created by FactoryBeans, which means that FactoryBeans
	 * will get initialized. If the object created by the FactoryBean doesn't match,
	 * the raw FactoryBean itself will be matched against the type.
	 * <p>This version of {@code beanNamesForTypeIncludingAncestors} automatically
	 * includes prototypes and FactoryBeans.
	 * @param lbf the bean factory
	 * @param type the type that beans must match (as a {@code ResolvableType})
	 * @return the array of matching bean names, or an empty array if none
	 * @since 4.2
	 * @see ListableBeanFactory#getBeanNamesForType(ResolvableType)
	 */
	public static String[] beanNamesForTypeIncludingAncestors(ListableBeanFactory lbf, ResolvableType type) {
		Assert.notNull(lbf, "ListableBeanFactory must not be null");
		String[] result = lbf.getBeanNamesForType(type);
		if (lbf instanceof HierarchicalBeanFactory) {
			HierarchicalBeanFactory hbf = (HierarchicalBeanFactory) lbf;
			if (hbf.getParentBeanFactory() instanceof ListableBeanFactory) {
				String[] parentResult = beanNamesForTypeIncludingAncestors(
						(ListableBeanFactory) hbf.getParentBeanFactory(), type);
				result = mergeNamesWithParent(result, parentResult, hbf);
			}
		}
		return result;
	}

	Get all bean names for the given type, including those defined in ancestor
factories. Will return unique names in case of overridden bean definitions.
Does consider objects created by FactoryBeans if the "allowEagerInit"
flag is set, which means that FactoryBeans will get initialized. If the
object created by the FactoryBean doesn't match, the raw FactoryBean itself
will be matched against the type. If "allowEagerInit" is not set,
only raw FactoryBeans will be checked (which doesn't require initialization
of each FactoryBean).
Params: lbf – the bean factory
type – the type that beans must match (as a ResolvableType)
includeNonSingletons – whether to include prototype or scoped beans too
or just singletons (also applies to FactoryBeans)
allowEagerInit – whether to initialize lazy-init singletons and
objects created by FactoryBeans (or by factory methods with a
"factory-bean" reference) for the type check. Note that FactoryBeans need to be
eagerly initialized to determine their type: So be aware that passing in "true"
for this flag will initialize FactoryBeans and "factory-bean" references.
See Also: ListableBeanFactory.getBeanNamesForType(ResolvableType, boolean, boolean)
Returns: the array of matching bean names, or an empty array if none
Since: 5.2/**
	 * Get all bean names for the given type, including those defined in ancestor
	 * factories. Will return unique names in case of overridden bean definitions.
	 * <p>Does consider objects created by FactoryBeans if the "allowEagerInit"
	 * flag is set, which means that FactoryBeans will get initialized. If the
	 * object created by the FactoryBean doesn't match, the raw FactoryBean itself
	 * will be matched against the type. If "allowEagerInit" is not set,
	 * only raw FactoryBeans will be checked (which doesn't require initialization
	 * of each FactoryBean).
	 * @param lbf the bean factory
	 * @param type the type that beans must match (as a {@code ResolvableType})
	 * @param includeNonSingletons whether to include prototype or scoped beans too
	 * or just singletons (also applies to FactoryBeans)
	 * @param allowEagerInit whether to initialize <i>lazy-init singletons</i> and
	 * <i>objects created by FactoryBeans</i> (or by factory methods with a
	 * "factory-bean" reference) for the type check. Note that FactoryBeans need to be
	 * eagerly initialized to determine their type: So be aware that passing in "true"
	 * for this flag will initialize FactoryBeans and "factory-bean" references.
	 * @return the array of matching bean names, or an empty array if none
	 * @since 5.2
	 * @see ListableBeanFactory#getBeanNamesForType(ResolvableType, boolean, boolean)
	 */
	public static String[] beanNamesForTypeIncludingAncestors(
			ListableBeanFactory lbf, ResolvableType type, boolean includeNonSingletons, boolean allowEagerInit) {

		Assert.notNull(lbf, "ListableBeanFactory must not be null");
		String[] result = lbf.getBeanNamesForType(type, includeNonSingletons, allowEagerInit);
		if (lbf instanceof HierarchicalBeanFactory) {
			HierarchicalBeanFactory hbf = (HierarchicalBeanFactory) lbf;
			if (hbf.getParentBeanFactory() instanceof ListableBeanFactory) {
				String[] parentResult = beanNamesForTypeIncludingAncestors(
						(ListableBeanFactory) hbf.getParentBeanFactory(), type, includeNonSingletons, allowEagerInit);
				result = mergeNamesWithParent(result, parentResult, hbf);
			}
		}
		return result;
	}

	Get all bean names for the given type, including those defined in ancestor
factories. Will return unique names in case of overridden bean definitions.
Does consider objects created by FactoryBeans, which means that FactoryBeans
will get initialized. If the object created by the FactoryBean doesn't match,
the raw FactoryBean itself will be matched against the type.
This version of beanNamesForTypeIncludingAncestors automatically includes prototypes and FactoryBeans. 
Params: lbf – the bean factory
type – the type that beans must match (as a Class)
See Also: ListableBeanFactory.getBeanNamesForType(Class<?>)
Returns: the array of matching bean names, or an empty array if none/**
	 * Get all bean names for the given type, including those defined in ancestor
	 * factories. Will return unique names in case of overridden bean definitions.
	 * <p>Does consider objects created by FactoryBeans, which means that FactoryBeans
	 * will get initialized. If the object created by the FactoryBean doesn't match,
	 * the raw FactoryBean itself will be matched against the type.
	 * <p>This version of {@code beanNamesForTypeIncludingAncestors} automatically
	 * includes prototypes and FactoryBeans.
	 * @param lbf the bean factory
	 * @param type the type that beans must match (as a {@code Class})
	 * @return the array of matching bean names, or an empty array if none
	 * @see ListableBeanFactory#getBeanNamesForType(Class)
	 */
	public static String[] beanNamesForTypeIncludingAncestors(ListableBeanFactory lbf, Class<?> type) {
		Assert.notNull(lbf, "ListableBeanFactory must not be null");
		String[] result = lbf.getBeanNamesForType(type);
		if (lbf instanceof HierarchicalBeanFactory) {
			HierarchicalBeanFactory hbf = (HierarchicalBeanFactory) lbf;
			if (hbf.getParentBeanFactory() instanceof ListableBeanFactory) {
				String[] parentResult = beanNamesForTypeIncludingAncestors(
						(ListableBeanFactory) hbf.getParentBeanFactory(), type);
				result = mergeNamesWithParent(result, parentResult, hbf);
			}
		}
		return result;
	}

	Get all bean names for the given type, including those defined in ancestor
factories. Will return unique names in case of overridden bean definitions.
Does consider objects created by FactoryBeans if the "allowEagerInit"
flag is set, which means that FactoryBeans will get initialized. If the
object created by the FactoryBean doesn't match, the raw FactoryBean itself
will be matched against the type. If "allowEagerInit" is not set,
only raw FactoryBeans will be checked (which doesn't require initialization
of each FactoryBean).
Params: lbf – the bean factory
includeNonSingletons – whether to include prototype or scoped beans too
or just singletons (also applies to FactoryBeans)
allowEagerInit – whether to initialize lazy-init singletons and
objects created by FactoryBeans (or by factory methods with a
"factory-bean" reference) for the type check. Note that FactoryBeans need to be
eagerly initialized to determine their type: So be aware that passing in "true"
for this flag will initialize FactoryBeans and "factory-bean" references.
type – the type that beans must match
See Also: ListableBeanFactory.getBeanNamesForType(Class<?>, boolean, boolean)
Returns: the array of matching bean names, or an empty array if none/**
	 * Get all bean names for the given type, including those defined in ancestor
	 * factories. Will return unique names in case of overridden bean definitions.
	 * <p>Does consider objects created by FactoryBeans if the "allowEagerInit"
	 * flag is set, which means that FactoryBeans will get initialized. If the
	 * object created by the FactoryBean doesn't match, the raw FactoryBean itself
	 * will be matched against the type. If "allowEagerInit" is not set,
	 * only raw FactoryBeans will be checked (which doesn't require initialization
	 * of each FactoryBean).
	 * @param lbf the bean factory
	 * @param includeNonSingletons whether to include prototype or scoped beans too
	 * or just singletons (also applies to FactoryBeans)
	 * @param allowEagerInit whether to initialize <i>lazy-init singletons</i> and
	 * <i>objects created by FactoryBeans</i> (or by factory methods with a
	 * "factory-bean" reference) for the type check. Note that FactoryBeans need to be
	 * eagerly initialized to determine their type: So be aware that passing in "true"
	 * for this flag will initialize FactoryBeans and "factory-bean" references.
	 * @param type the type that beans must match
	 * @return the array of matching bean names, or an empty array if none
	 * @see ListableBeanFactory#getBeanNamesForType(Class, boolean, boolean)
	 */
	public static String[] beanNamesForTypeIncludingAncestors(
			ListableBeanFactory lbf, Class<?> type, boolean includeNonSingletons, boolean allowEagerInit) {

		Assert.notNull(lbf, "ListableBeanFactory must not be null");
		String[] result = lbf.getBeanNamesForType(type, includeNonSingletons, allowEagerInit);
		if (lbf instanceof HierarchicalBeanFactory) {
			HierarchicalBeanFactory hbf = (HierarchicalBeanFactory) lbf;
			if (hbf.getParentBeanFactory() instanceof ListableBeanFactory) {
				String[] parentResult = beanNamesForTypeIncludingAncestors(
						(ListableBeanFactory) hbf.getParentBeanFactory(), type, includeNonSingletons, allowEagerInit);
				result = mergeNamesWithParent(result, parentResult, hbf);
			}
		}
		return result;
	}

	Get all bean names whose Class has the supplied Annotation type, including those defined in ancestor factories, without creating any bean instances yet. Will return unique names in case of overridden bean definitions. 
Params: lbf – the bean factory
annotationType – the type of annotation to look for
See Also: ListableBeanFactory.getBeanNamesForAnnotation(Class<? extends Annotation>)
Returns: the array of matching bean names, or an empty array if none
Since: 5.0/**
	 * Get all bean names whose {@code Class} has the supplied {@link Annotation}
	 * type, including those defined in ancestor factories, without creating any bean
	 * instances yet. Will return unique names in case of overridden bean definitions.
	 * @param lbf the bean factory
	 * @param annotationType the type of annotation to look for
	 * @return the array of matching bean names, or an empty array if none
	 * @since 5.0
	 * @see ListableBeanFactory#getBeanNamesForAnnotation(Class)
	 */
	public static String[] beanNamesForAnnotationIncludingAncestors(
			ListableBeanFactory lbf, Class<? extends Annotation> annotationType) {

		Assert.notNull(lbf, "ListableBeanFactory must not be null");
		String[] result = lbf.getBeanNamesForAnnotation(annotationType);
		if (lbf instanceof HierarchicalBeanFactory) {
			HierarchicalBeanFactory hbf = (HierarchicalBeanFactory) lbf;
			if (hbf.getParentBeanFactory() instanceof ListableBeanFactory) {
				String[] parentResult = beanNamesForAnnotationIncludingAncestors(
						(ListableBeanFactory) hbf.getParentBeanFactory(), annotationType);
				result = mergeNamesWithParent(result, parentResult, hbf);
			}
		}
		return result;
	}


	// Retrieval of bean instances

	Return all beans of the given type or subtypes, also picking up beans defined in
ancestor bean factories if the current bean factory is a HierarchicalBeanFactory.
The returned Map will only contain beans of this type.
Does consider objects created by FactoryBeans, which means that FactoryBeans
will get initialized. If the object created by the FactoryBean doesn't match,
the raw FactoryBean itself will be matched against the type.
Note: Beans of the same name will take precedence at the 'lowest' factory level,
i.e. such beans will be returned from the lowest factory that they are being found in,
hiding corresponding beans in ancestor factories. This feature allows for
'replacing' beans by explicitly choosing the same bean name in a child factory;
the bean in the ancestor factory won't be visible then, not even for by-type lookups.
Params: lbf – the bean factory
type – type of bean to match
Throws: BeansException – if a bean could not be created
See Also: ListableBeanFactory.getBeansOfType(Class<Object>)
Returns: the Map of matching bean instances, or an empty Map if none/**
	 * Return all beans of the given type or subtypes, also picking up beans defined in
	 * ancestor bean factories if the current bean factory is a HierarchicalBeanFactory.
	 * The returned Map will only contain beans of this type.
	 * <p>Does consider objects created by FactoryBeans, which means that FactoryBeans
	 * will get initialized. If the object created by the FactoryBean doesn't match,
	 * the raw FactoryBean itself will be matched against the type.
	 * <p><b>Note: Beans of the same name will take precedence at the 'lowest' factory level,
	 * i.e. such beans will be returned from the lowest factory that they are being found in,
	 * hiding corresponding beans in ancestor factories.</b> This feature allows for
	 * 'replacing' beans by explicitly choosing the same bean name in a child factory;
	 * the bean in the ancestor factory won't be visible then, not even for by-type lookups.
	 * @param lbf the bean factory
	 * @param type type of bean to match
	 * @return the Map of matching bean instances, or an empty Map if none
	 * @throws BeansException if a bean could not be created
	 * @see ListableBeanFactory#getBeansOfType(Class)
	 */
	public static <T> Map<String, T> beansOfTypeIncludingAncestors(ListableBeanFactory lbf, Class<T> type)
			throws BeansException {

		Assert.notNull(lbf, "ListableBeanFactory must not be null");
		Map<String, T> result = new LinkedHashMap<>(4);
		result.putAll(lbf.getBeansOfType(type));
		if (lbf instanceof HierarchicalBeanFactory) {
			HierarchicalBeanFactory hbf = (HierarchicalBeanFactory) lbf;
			if (hbf.getParentBeanFactory() instanceof ListableBeanFactory) {
				Map<String, T> parentResult = beansOfTypeIncludingAncestors(
						(ListableBeanFactory) hbf.getParentBeanFactory(), type);
				parentResult.forEach((beanName, beanInstance) -> {
					if (!result.containsKey(beanName) && !hbf.containsLocalBean(beanName)) {
						result.put(beanName, beanInstance);
					}
				});
			}
		}
		return result;
	}

	Return all beans of the given type or subtypes, also picking up beans defined in
ancestor bean factories if the current bean factory is a HierarchicalBeanFactory.
The returned Map will only contain beans of this type.
Does consider objects created by FactoryBeans if the "allowEagerInit" flag is set,
which means that FactoryBeans will get initialized. If the object created by the
FactoryBean doesn't match, the raw FactoryBean itself will be matched against the
type. If "allowEagerInit" is not set, only raw FactoryBeans will be checked
(which doesn't require initialization of each FactoryBean).
Note: Beans of the same name will take precedence at the 'lowest' factory level,
i.e. such beans will be returned from the lowest factory that they are being found in,
hiding corresponding beans in ancestor factories. This feature allows for
'replacing' beans by explicitly choosing the same bean name in a child factory;
the bean in the ancestor factory won't be visible then, not even for by-type lookups.
Params: lbf – the bean factory
type – type of bean to match
includeNonSingletons – whether to include prototype or scoped beans too
or just singletons (also applies to FactoryBeans)
allowEagerInit – whether to initialize lazy-init singletons and
objects created by FactoryBeans (or by factory methods with a
"factory-bean" reference) for the type check. Note that FactoryBeans need to be
eagerly initialized to determine their type: So be aware that passing in "true"
for this flag will initialize FactoryBeans and "factory-bean" references.
Throws: BeansException – if a bean could not be created
See Also: ListableBeanFactory.getBeansOfType(Class<Object>, boolean, boolean)
Returns: the Map of matching bean instances, or an empty Map if none/**
	 * Return all beans of the given type or subtypes, also picking up beans defined in
	 * ancestor bean factories if the current bean factory is a HierarchicalBeanFactory.
	 * The returned Map will only contain beans of this type.
	 * <p>Does consider objects created by FactoryBeans if the "allowEagerInit" flag is set,
	 * which means that FactoryBeans will get initialized. If the object created by the
	 * FactoryBean doesn't match, the raw FactoryBean itself will be matched against the
	 * type. If "allowEagerInit" is not set, only raw FactoryBeans will be checked
	 * (which doesn't require initialization of each FactoryBean).
	 * <p><b>Note: Beans of the same name will take precedence at the 'lowest' factory level,
	 * i.e. such beans will be returned from the lowest factory that they are being found in,
	 * hiding corresponding beans in ancestor factories.</b> This feature allows for
	 * 'replacing' beans by explicitly choosing the same bean name in a child factory;
	 * the bean in the ancestor factory won't be visible then, not even for by-type lookups.
	 * @param lbf the bean factory
	 * @param type type of bean to match
	 * @param includeNonSingletons whether to include prototype or scoped beans too
	 * or just singletons (also applies to FactoryBeans)
	 * @param allowEagerInit whether to initialize <i>lazy-init singletons</i> and
	 * <i>objects created by FactoryBeans</i> (or by factory methods with a
	 * "factory-bean" reference) for the type check. Note that FactoryBeans need to be
	 * eagerly initialized to determine their type: So be aware that passing in "true"
	 * for this flag will initialize FactoryBeans and "factory-bean" references.
	 * @return the Map of matching bean instances, or an empty Map if none
	 * @throws BeansException if a bean could not be created
	 * @see ListableBeanFactory#getBeansOfType(Class, boolean, boolean)
	 */
	public static <T> Map<String, T> beansOfTypeIncludingAncestors(
			ListableBeanFactory lbf, Class<T> type, boolean includeNonSingletons, boolean allowEagerInit)
			throws BeansException {

		Assert.notNull(lbf, "ListableBeanFactory must not be null");
		Map<String, T> result = new LinkedHashMap<>(4);
		result.putAll(lbf.getBeansOfType(type, includeNonSingletons, allowEagerInit));
		if (lbf instanceof HierarchicalBeanFactory) {
			HierarchicalBeanFactory hbf = (HierarchicalBeanFactory) lbf;
			if (hbf.getParentBeanFactory() instanceof ListableBeanFactory) {
				Map<String, T> parentResult = beansOfTypeIncludingAncestors(
						(ListableBeanFactory) hbf.getParentBeanFactory(), type, includeNonSingletons, allowEagerInit);
				parentResult.forEach((beanName, beanInstance) -> {
					if (!result.containsKey(beanName) && !hbf.containsLocalBean(beanName)) {
						result.put(beanName, beanInstance);
					}
				});
			}
		}
		return result;
	}

	Return a single bean of the given type or subtypes, also picking up beans
defined in ancestor bean factories if the current bean factory is a
HierarchicalBeanFactory. Useful convenience method when we expect a
single bean and don't care about the bean name.
Does consider objects created by FactoryBeans, which means that FactoryBeans
will get initialized. If the object created by the FactoryBean doesn't match,
the raw FactoryBean itself will be matched against the type.
This version of beanOfTypeIncludingAncestors automatically includes prototypes and FactoryBeans. 
Note: Beans of the same name will take precedence at the 'lowest' factory level,
i.e. such beans will be returned from the lowest factory that they are being found in,
hiding corresponding beans in ancestor factories. This feature allows for
'replacing' beans by explicitly choosing the same bean name in a child factory;
the bean in the ancestor factory won't be visible then, not even for by-type lookups.
Params: lbf – the bean factory
type – type of bean to match
Throws: NoSuchBeanDefinitionException – if no bean of the given type was found
NoUniqueBeanDefinitionException – if more than one bean of the given type was found
BeansException – if the bean could not be created
See Also: beansOfTypeIncludingAncestors(ListableBeanFactory, Class<Object>)
Returns: the matching bean instance/**
	 * Return a single bean of the given type or subtypes, also picking up beans
	 * defined in ancestor bean factories if the current bean factory is a
	 * HierarchicalBeanFactory. Useful convenience method when we expect a
	 * single bean and don't care about the bean name.
	 * <p>Does consider objects created by FactoryBeans, which means that FactoryBeans
	 * will get initialized. If the object created by the FactoryBean doesn't match,
	 * the raw FactoryBean itself will be matched against the type.
	 * <p>This version of {@code beanOfTypeIncludingAncestors} automatically includes
	 * prototypes and FactoryBeans.
	 * <p><b>Note: Beans of the same name will take precedence at the 'lowest' factory level,
	 * i.e. such beans will be returned from the lowest factory that they are being found in,
	 * hiding corresponding beans in ancestor factories.</b> This feature allows for
	 * 'replacing' beans by explicitly choosing the same bean name in a child factory;
	 * the bean in the ancestor factory won't be visible then, not even for by-type lookups.
	 * @param lbf the bean factory
	 * @param type type of bean to match
	 * @return the matching 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
	 * @see #beansOfTypeIncludingAncestors(ListableBeanFactory, Class)
	 */
	public static <T> T beanOfTypeIncludingAncestors(ListableBeanFactory lbf, Class<T> type)
			throws BeansException {

		Map<String, T> beansOfType = beansOfTypeIncludingAncestors(lbf, type);
		return uniqueBean(type, beansOfType);
	}

	Return a single bean of the given type or subtypes, also picking up beans
defined in ancestor bean factories if the current bean factory is a
HierarchicalBeanFactory. Useful convenience method when we expect a
single bean and don't care about the bean name.
Does consider objects created by FactoryBeans if the "allowEagerInit" flag is set,
which means that FactoryBeans will get initialized. If the object created by the
FactoryBean doesn't match, the raw FactoryBean itself will be matched against the
type. If "allowEagerInit" is not set, only raw FactoryBeans will be checked
(which doesn't require initialization of each FactoryBean).
Note: Beans of the same name will take precedence at the 'lowest' factory level,
i.e. such beans will be returned from the lowest factory that they are being found in,
hiding corresponding beans in ancestor factories. This feature allows for
'replacing' beans by explicitly choosing the same bean name in a child factory;
the bean in the ancestor factory won't be visible then, not even for by-type lookups.
Params: lbf – the bean factory
type – type of bean to match
includeNonSingletons – whether to include prototype or scoped beans too
or just singletons (also applies to FactoryBeans)
allowEagerInit – whether to initialize lazy-init singletons and
objects created by FactoryBeans (or by factory methods with a
"factory-bean" reference) for the type check. Note that FactoryBeans need to be
eagerly initialized to determine their type: So be aware that passing in "true"
for this flag will initialize FactoryBeans and "factory-bean" references.
Throws: NoSuchBeanDefinitionException – if no bean of the given type was found
NoUniqueBeanDefinitionException – if more than one bean of the given type was found
BeansException – if the bean could not be created
See Also: beansOfTypeIncludingAncestors(ListableBeanFactory, Class<Object>, boolean, boolean)
Returns: the matching bean instance/**
	 * Return a single bean of the given type or subtypes, also picking up beans
	 * defined in ancestor bean factories if the current bean factory is a
	 * HierarchicalBeanFactory. Useful convenience method when we expect a
	 * single bean and don't care about the bean name.
	 * <p>Does consider objects created by FactoryBeans if the "allowEagerInit" flag is set,
	 * which means that FactoryBeans will get initialized. If the object created by the
	 * FactoryBean doesn't match, the raw FactoryBean itself will be matched against the
	 * type. If "allowEagerInit" is not set, only raw FactoryBeans will be checked
	 * (which doesn't require initialization of each FactoryBean).
	 * <p><b>Note: Beans of the same name will take precedence at the 'lowest' factory level,
	 * i.e. such beans will be returned from the lowest factory that they are being found in,
	 * hiding corresponding beans in ancestor factories.</b> This feature allows for
	 * 'replacing' beans by explicitly choosing the same bean name in a child factory;
	 * the bean in the ancestor factory won't be visible then, not even for by-type lookups.
	 * @param lbf the bean factory
	 * @param type type of bean to match
	 * @param includeNonSingletons whether to include prototype or scoped beans too
	 * or just singletons (also applies to FactoryBeans)
	 * @param allowEagerInit whether to initialize <i>lazy-init singletons</i> and
	 * <i>objects created by FactoryBeans</i> (or by factory methods with a
	 * "factory-bean" reference) for the type check. Note that FactoryBeans need to be
	 * eagerly initialized to determine their type: So be aware that passing in "true"
	 * for this flag will initialize FactoryBeans and "factory-bean" references.
	 * @return the matching 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
	 * @see #beansOfTypeIncludingAncestors(ListableBeanFactory, Class, boolean, boolean)
	 */
	public static <T> T beanOfTypeIncludingAncestors(
			ListableBeanFactory lbf, Class<T> type, boolean includeNonSingletons, boolean allowEagerInit)
			throws BeansException {

		Map<String, T> beansOfType = beansOfTypeIncludingAncestors(lbf, type, includeNonSingletons, allowEagerInit);
		return uniqueBean(type, beansOfType);
	}

	Return a single bean of the given type or subtypes, not looking in ancestor
factories. Useful convenience method when we expect a single bean and
don't care about the bean name.
Does consider objects created by FactoryBeans, which means that FactoryBeans
will get initialized. If the object created by the FactoryBean doesn't match,
the raw FactoryBean itself will be matched against the type.
This version of beanOfType automatically includes prototypes and FactoryBeans. 
Params: lbf – the bean factory
type – type of bean to match
Throws: NoSuchBeanDefinitionException – if no bean of the given type was found
NoUniqueBeanDefinitionException – if more than one bean of the given type was found
BeansException – if the bean could not be created
See Also: ListableBeanFactory.getBeansOfType(Class<Object>)
Returns: the matching bean instance/**
	 * Return a single bean of the given type or subtypes, not looking in ancestor
	 * factories. Useful convenience method when we expect a single bean and
	 * don't care about the bean name.
	 * <p>Does consider objects created by FactoryBeans, which means that FactoryBeans
	 * will get initialized. If the object created by the FactoryBean doesn't match,
	 * the raw FactoryBean itself will be matched against the type.
	 * <p>This version of {@code beanOfType} automatically includes
	 * prototypes and FactoryBeans.
	 * @param lbf the bean factory
	 * @param type type of bean to match
	 * @return the matching 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
	 * @see ListableBeanFactory#getBeansOfType(Class)
	 */
	public static <T> T beanOfType(ListableBeanFactory lbf, Class<T> type) throws BeansException {
		Assert.notNull(lbf, "ListableBeanFactory must not be null");
		Map<String, T> beansOfType = lbf.getBeansOfType(type);
		return uniqueBean(type, beansOfType);
	}

	Return a single bean of the given type or subtypes, not looking in ancestor
factories. Useful convenience method when we expect a single bean and
don't care about the bean name.
Does consider objects created by FactoryBeans if the "allowEagerInit"
flag is set, which means that FactoryBeans will get initialized. If the
object created by the FactoryBean doesn't match, the raw FactoryBean itself
will be matched against the type. If "allowEagerInit" is not set,
only raw FactoryBeans will be checked (which doesn't require initialization
of each FactoryBean).
Params: lbf – the bean factory
type – type of bean to match
includeNonSingletons – whether to include prototype or scoped beans too
or just singletons (also applies to FactoryBeans)
allowEagerInit – whether to initialize lazy-init singletons and
objects created by FactoryBeans (or by factory methods with a
"factory-bean" reference) for the type check. Note that FactoryBeans need to be
eagerly initialized to determine their type: So be aware that passing in "true"
for this flag will initialize FactoryBeans and "factory-bean" references.
Throws: NoSuchBeanDefinitionException – if no bean of the given type was found
NoUniqueBeanDefinitionException – if more than one bean of the given type was found
BeansException – if the bean could not be created
See Also: ListableBeanFactory.getBeansOfType(Class<Object>, boolean, boolean)
Returns: the matching bean instance/**
	 * Return a single bean of the given type or subtypes, not looking in ancestor
	 * factories. Useful convenience method when we expect a single bean and
	 * don't care about the bean name.
	 * <p>Does consider objects created by FactoryBeans if the "allowEagerInit"
	 * flag is set, which means that FactoryBeans will get initialized. If the
	 * object created by the FactoryBean doesn't match, the raw FactoryBean itself
	 * will be matched against the type. If "allowEagerInit" is not set,
	 * only raw FactoryBeans will be checked (which doesn't require initialization
	 * of each FactoryBean).
	 * @param lbf the bean factory
	 * @param type type of bean to match
	 * @param includeNonSingletons whether to include prototype or scoped beans too
	 * or just singletons (also applies to FactoryBeans)
	 * @param allowEagerInit whether to initialize <i>lazy-init singletons</i> and
	 * <i>objects created by FactoryBeans</i> (or by factory methods with a
	 * "factory-bean" reference) for the type check. Note that FactoryBeans need to be
	 * eagerly initialized to determine their type: So be aware that passing in "true"
	 * for this flag will initialize FactoryBeans and "factory-bean" references.
	 * @return the matching 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
	 * @see ListableBeanFactory#getBeansOfType(Class, boolean, boolean)
	 */
	public static <T> T beanOfType(
			ListableBeanFactory lbf, Class<T> type, boolean includeNonSingletons, boolean allowEagerInit)
			throws BeansException {

		Assert.notNull(lbf, "ListableBeanFactory must not be null");
		Map<String, T> beansOfType = lbf.getBeansOfType(type, includeNonSingletons, allowEagerInit);
		return uniqueBean(type, beansOfType);
	}


	Merge the given bean names result with the given parent result.
Params: result – the local bean name result
parentResult – the parent bean name result (possibly empty)
hbf – the local bean factory
Returns: the merged result (possibly the local result as-is)
Since: 4.3.15/**
	 * Merge the given bean names result with the given parent result.
	 * @param result the local bean name result
	 * @param parentResult the parent bean name result (possibly empty)
	 * @param hbf the local bean factory
	 * @return the merged result (possibly the local result as-is)
	 * @since 4.3.15
	 */
	private static String[] mergeNamesWithParent(String[] result, String[] parentResult, HierarchicalBeanFactory hbf) {
		if (parentResult.length == 0) {
			return result;
		}
		List<String> merged = new ArrayList<>(result.length + parentResult.length);
		merged.addAll(Arrays.asList(result));
		for (String beanName : parentResult) {
			if (!merged.contains(beanName) && !hbf.containsLocalBean(beanName)) {
				merged.add(beanName);
			}
		}
		return StringUtils.toStringArray(merged);
	}

	Extract a unique bean for the given type from the given Map of matching beans.
Params: type – type of bean to match
matchingBeans – all matching beans found
Throws: NoSuchBeanDefinitionException – if no bean of the given type was found
NoUniqueBeanDefinitionException – if more than one bean of the given type was found
Returns: the unique bean instance/**
	 * Extract a unique bean for the given type from the given Map of matching beans.
	 * @param type type of bean to match
	 * @param matchingBeans all matching beans found
	 * @return the unique 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
	 */
	private static <T> T uniqueBean(Class<T> type, Map<String, T> matchingBeans) {
		int count = matchingBeans.size();
		if (count == 1) {
			return matchingBeans.values().iterator().next();
		}
		else if (count > 1) {
			throw new NoUniqueBeanDefinitionException(type, matchingBeans.keySet());
		}
		else {
			throw new NoSuchBeanDefinitionException(type);
		}
	}

}
Author:	Rod Johnson, Juergen Hoeller, Chris Beams
Since:	04.07.2003
Params:	name – the name of the bean
See Also:	BeanFactory.FACTORY_BEAN_PREFIX
Returns:	whether the given name is a factory dereference
Params:	name – the potentially generated bean name
See Also:	GENERATED_BEAN_NAME_SEPARATOR
Returns:	the raw bean name
Params:	lbf – the bean factory
See Also:	beanNamesIncludingAncestors
Returns:	count of beans including those defined in ancestor factories
Params:	lbf – the bean factory type – the type that beans must match (as a `ResolvableType`)
See Also:	ListableBeanFactory.getBeanNamesForType(ResolvableType)
Returns:	the array of matching bean names, or an empty array if none
Since:	4.2
Params:	lbf – the bean factory includeNonSingletons – whether to include prototype or scoped beans too or just singletons (also applies to FactoryBeans) allowEagerInit – whether to initialize lazy-init singletons and objects created by FactoryBeans (or by factory methods with a "factory-bean" reference) for the type check. Note that FactoryBeans need to be eagerly initialized to determine their type: So be aware that passing in "true" for this flag will initialize FactoryBeans and "factory-bean" references. type – the type that beans must match
See Also:	ListableBeanFactory.getBeanNamesForType(Class<?>, boolean, boolean)
Returns:	the array of matching bean names, or an empty array if none
Params:	lbf – the bean factory annotationType – the type of annotation to look for
See Also:	ListableBeanFactory.getBeanNamesForAnnotation(Class<? extends Annotation>)
Returns:	the array of matching bean names, or an empty array if none
Since:	5.0
Params:	lbf – the bean factory type – type of bean to match
Throws:	BeansException – if a bean could not be created
See Also:	ListableBeanFactory.getBeansOfType(Class<Object>)
Returns:	the Map of matching bean instances, or an empty Map if none
Params:	result – the local bean name result parentResult – the parent bean name result (possibly empty) hbf – the local bean factory
Returns:	the merged result (possibly the local result as-is)
Since:	4.3.15
Params:	type – type of bean to match matchingBeans – all matching beans found
Throws:	NoSuchBeanDefinitionException – if no bean of the given type was found NoUniqueBeanDefinitionException – if more than one bean of the given type was found
Returns:	the unique bean instance
/

org.springframework/ spring-beans/ 5.3.3/ org/springframework/beans/factory/BeanFactoryUtils.java
