/*
* Copyright 2002-2018 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.support;
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.stream.Stream;
import org.springframework.beans.BeansException;
import org.springframework.beans.factory.BeanCreationException;
import org.springframework.beans.factory.BeanFactoryUtils;
import org.springframework.beans.factory.BeanIsNotAFactoryException;
import org.springframework.beans.factory.BeanNotOfRequiredTypeException;
import org.springframework.beans.factory.FactoryBean;
import org.springframework.beans.factory.ListableBeanFactory;
import org.springframework.beans.factory.NoSuchBeanDefinitionException;
import org.springframework.beans.factory.NoUniqueBeanDefinitionException;
import org.springframework.beans.factory.ObjectProvider;
import org.springframework.beans.factory.SmartFactoryBean;
import org.springframework.core.OrderComparator;
import org.springframework.core.ResolvableType;
import org.springframework.core.annotation.AnnotationUtils;
import org.springframework.lang.Nullable;
import org.springframework.util.Assert;
import org.springframework.util.ObjectUtils;
import org.springframework.util.StringUtils;
Static BeanFactory
implementation which allows to register existing singleton instances programmatically. Does not have support for prototype beans or aliases. Serves as example for a simple implementation of the ListableBeanFactory
interface, managing existing bean instances rather than creating new ones based on bean definitions, and not implementing any extended SPI interfaces (such as ConfigurableBeanFactory
).
For a full-fledged factory based on bean definitions, have a look at DefaultListableBeanFactory
.
Author: Rod Johnson, Juergen Hoeller See Also: Since: 06.01.2003
/**
* Static {@link org.springframework.beans.factory.BeanFactory} implementation
* which allows to register existing singleton instances programmatically.
* Does not have support for prototype beans or aliases.
*
* <p>Serves as example for a simple implementation of the
* {@link org.springframework.beans.factory.ListableBeanFactory} interface,
* managing existing bean instances rather than creating new ones based on bean
* definitions, and not implementing any extended SPI interfaces (such as
* {@link org.springframework.beans.factory.config.ConfigurableBeanFactory}).
*
* <p>For a full-fledged factory based on bean definitions, have a look
* at {@link DefaultListableBeanFactory}.
*
* @author Rod Johnson
* @author Juergen Hoeller
* @since 06.01.2003
* @see DefaultListableBeanFactory
*/
public class StaticListableBeanFactory implements ListableBeanFactory {
Map from bean name to bean instance. /** Map from bean name to bean instance. */
private final Map<String, Object> beans;
Create a regular StaticListableBeanFactory
, to be populated with singleton bean instances through addBean
calls. /**
* Create a regular {@code StaticListableBeanFactory}, to be populated
* with singleton bean instances through {@link #addBean} calls.
*/
public StaticListableBeanFactory() {
this.beans = new LinkedHashMap<>();
}
Create a StaticListableBeanFactory
wrapping the given Map
. Note that the given Map
may be pre-populated with beans; or new, still allowing for beans to be registered via addBean
; or Collections.emptyMap()
for a dummy factory which enforces operating against an empty set of beans.
Params: - beans – a
Map
for holding this factory's beans, with the bean name String as key and the corresponding singleton object as value
Since: 4.3
/**
* Create a {@code StaticListableBeanFactory} wrapping the given {@code Map}.
* <p>Note that the given {@code Map} may be pre-populated with beans;
* or new, still allowing for beans to be registered via {@link #addBean};
* or {@link java.util.Collections#emptyMap()} for a dummy factory which
* enforces operating against an empty set of beans.
* @param beans a {@code Map} for holding this factory's beans, with the
* bean name String as key and the corresponding singleton object as value
* @since 4.3
*/
public StaticListableBeanFactory(Map<String, Object> beans) {
Assert.notNull(beans, "Beans Map must not be null");
this.beans = beans;
}
Add a new singleton bean.
Will overwrite any existing instance for the given name.
Params: - name – the name of the bean
- bean – the bean instance
/**
* Add a new singleton bean.
* Will overwrite any existing instance for the given name.
* @param name the name of the bean
* @param bean the bean instance
*/
public void addBean(String name, Object bean) {
this.beans.put(name, bean);
}
//---------------------------------------------------------------------
// Implementation of BeanFactory interface
//---------------------------------------------------------------------
@Override
public Object getBean(String name) throws BeansException {
String beanName = BeanFactoryUtils.transformedBeanName(name);
Object bean = this.beans.get(beanName);
if (bean == null) {
throw new NoSuchBeanDefinitionException(beanName,
"Defined beans are [" + StringUtils.collectionToCommaDelimitedString(this.beans.keySet()) + "]");
}
// Don't let calling code try to dereference the
// bean factory if the bean isn't a factory
if (BeanFactoryUtils.isFactoryDereference(name) && !(bean instanceof FactoryBean)) {
throw new BeanIsNotAFactoryException(beanName, bean.getClass());
}
if (bean instanceof FactoryBean && !BeanFactoryUtils.isFactoryDereference(name)) {
try {
Object exposedObject = ((FactoryBean<?>) bean).getObject();
if (exposedObject == null) {
throw new BeanCreationException(beanName, "FactoryBean exposed null object");
}
return exposedObject;
}
catch (Exception ex) {
throw new BeanCreationException(beanName, "FactoryBean threw exception on object creation", ex);
}
}
else {
return bean;
}
}
@Override
@SuppressWarnings("unchecked")
public <T> T getBean(String name, @Nullable Class<T> requiredType) throws BeansException {
Object bean = getBean(name);
if (requiredType != null && !requiredType.isInstance(bean)) {
throw new BeanNotOfRequiredTypeException(name, requiredType, bean.getClass());
}
return (T) bean;
}
@Override
public Object getBean(String name, Object... args) throws BeansException {
if (!ObjectUtils.isEmpty(args)) {
throw new UnsupportedOperationException(
"StaticListableBeanFactory does not support explicit bean creation arguments");
}
return getBean(name);
}
@Override
public <T> T getBean(Class<T> requiredType) throws BeansException {
String[] beanNames = getBeanNamesForType(requiredType);
if (beanNames.length == 1) {
return getBean(beanNames[0], requiredType);
}
else if (beanNames.length > 1) {
throw new NoUniqueBeanDefinitionException(requiredType, beanNames);
}
else {
throw new NoSuchBeanDefinitionException(requiredType);
}
}
@Override
public <T> T getBean(Class<T> requiredType, Object... args) throws BeansException {
if (!ObjectUtils.isEmpty(args)) {
throw new UnsupportedOperationException(
"StaticListableBeanFactory does not support explicit bean creation arguments");
}
return getBean(requiredType);
}
@Override
public <T> ObjectProvider<T> getBeanProvider(Class<T> requiredType) throws BeansException {
return getBeanProvider(ResolvableType.forRawClass(requiredType));
}
@SuppressWarnings("unchecked")
@Override
public <T> ObjectProvider<T> getBeanProvider(ResolvableType requiredType) {
return new ObjectProvider<T>() {
@Override
public T getObject() throws BeansException {
String[] beanNames = getBeanNamesForType(requiredType);
if (beanNames.length == 1) {
return (T) getBean(beanNames[0], requiredType);
}
else if (beanNames.length > 1) {
throw new NoUniqueBeanDefinitionException(requiredType, beanNames);
}
else {
throw new NoSuchBeanDefinitionException(requiredType);
}
}
@Override
public T getObject(Object... args) throws BeansException {
String[] beanNames = getBeanNamesForType(requiredType);
if (beanNames.length == 1) {
return (T) getBean(beanNames[0], args);
}
else if (beanNames.length > 1) {
throw new NoUniqueBeanDefinitionException(requiredType, beanNames);
}
else {
throw new NoSuchBeanDefinitionException(requiredType);
}
}
@Override
@Nullable
public T getIfAvailable() throws BeansException {
String[] beanNames = getBeanNamesForType(requiredType);
if (beanNames.length == 1) {
return (T) getBean(beanNames[0]);
}
else if (beanNames.length > 1) {
throw new NoUniqueBeanDefinitionException(requiredType, beanNames);
}
else {
return null;
}
}
@Override
@Nullable
public T getIfUnique() throws BeansException {
String[] beanNames = getBeanNamesForType(requiredType);
if (beanNames.length == 1) {
return (T) getBean(beanNames[0]);
}
else {
return null;
}
}
@Override
public Stream<T> stream() {
return Arrays.stream(getBeanNamesForType(requiredType)).map(name -> (T) getBean(name));
}
@Override
public Stream<T> orderedStream() {
return stream().sorted(OrderComparator.INSTANCE);
}
};
}
@Override
public boolean containsBean(String name) {
return this.beans.containsKey(name);
}
@Override
public boolean isSingleton(String name) throws NoSuchBeanDefinitionException {
Object bean = getBean(name);
// In case of FactoryBean, return singleton status of created object.
return (bean instanceof FactoryBean && ((FactoryBean<?>) bean).isSingleton());
}
@Override
public boolean isPrototype(String name) throws NoSuchBeanDefinitionException {
Object bean = getBean(name);
// In case of FactoryBean, return prototype status of created object.
return ((bean instanceof SmartFactoryBean && ((SmartFactoryBean<?>) bean).isPrototype()) ||
(bean instanceof FactoryBean && !((FactoryBean<?>) bean).isSingleton()));
}
@Override
public boolean isTypeMatch(String name, ResolvableType typeToMatch) throws NoSuchBeanDefinitionException {
Class<?> type = getType(name);
return (type != null && typeToMatch.isAssignableFrom(type));
}
@Override
public boolean isTypeMatch(String name, @Nullable Class<?> typeToMatch) throws NoSuchBeanDefinitionException {
Class<?> type = getType(name);
return (typeToMatch == null || (type != null && typeToMatch.isAssignableFrom(type)));
}
@Override
public Class<?> getType(String name) throws NoSuchBeanDefinitionException {
String beanName = BeanFactoryUtils.transformedBeanName(name);
Object bean = this.beans.get(beanName);
if (bean == null) {
throw new NoSuchBeanDefinitionException(beanName,
"Defined beans are [" + StringUtils.collectionToCommaDelimitedString(this.beans.keySet()) + "]");
}
if (bean instanceof FactoryBean && !BeanFactoryUtils.isFactoryDereference(name)) {
// If it's a FactoryBean, we want to look at what it creates, not the factory class.
return ((FactoryBean<?>) bean).getObjectType();
}
return bean.getClass();
}
@Override
public String[] getAliases(String name) {
return new String[0];
}
//---------------------------------------------------------------------
// Implementation of ListableBeanFactory interface
//---------------------------------------------------------------------
@Override
public boolean containsBeanDefinition(String name) {
return this.beans.containsKey(name);
}
@Override
public int getBeanDefinitionCount() {
return this.beans.size();
}
@Override
public String[] getBeanDefinitionNames() {
return StringUtils.toStringArray(this.beans.keySet());
}
@Override
public String[] getBeanNamesForType(@Nullable ResolvableType type) {
boolean isFactoryType = false;
if (type != null) {
Class<?> resolved = type.resolve();
if (resolved != null && FactoryBean.class.isAssignableFrom(resolved)) {
isFactoryType = true;
}
}
List<String> matches = new ArrayList<>();
for (Map.Entry<String, Object> entry : this.beans.entrySet()) {
String name = entry.getKey();
Object beanInstance = entry.getValue();
if (beanInstance instanceof FactoryBean && !isFactoryType) {
Class<?> objectType = ((FactoryBean<?>) beanInstance).getObjectType();
if (objectType != null && (type == null || type.isAssignableFrom(objectType))) {
matches.add(name);
}
}
else {
if (type == null || type.isInstance(beanInstance)) {
matches.add(name);
}
}
}
return StringUtils.toStringArray(matches);
}
@Override
public String[] getBeanNamesForType(@Nullable Class<?> type) {
return getBeanNamesForType(ResolvableType.forClass(type));
}
@Override
public String[] getBeanNamesForType(@Nullable Class<?> type, boolean includeNonSingletons, boolean allowEagerInit) {
return getBeanNamesForType(ResolvableType.forClass(type));
}
@Override
public <T> Map<String, T> getBeansOfType(@Nullable Class<T> type) throws BeansException {
return getBeansOfType(type, true, true);
}
@Override
@SuppressWarnings("unchecked")
public <T> Map<String, T> getBeansOfType(@Nullable Class<T> type, boolean includeNonSingletons, boolean allowEagerInit)
throws BeansException {
boolean isFactoryType = (type != null && FactoryBean.class.isAssignableFrom(type));
Map<String, T> matches = new LinkedHashMap<>();
for (Map.Entry<String, Object> entry : this.beans.entrySet()) {
String beanName = entry.getKey();
Object beanInstance = entry.getValue();
// Is bean a FactoryBean?
if (beanInstance instanceof FactoryBean && !isFactoryType) {
// Match object created by FactoryBean.
FactoryBean<?> factory = (FactoryBean<?>) beanInstance;
Class<?> objectType = factory.getObjectType();
if ((includeNonSingletons || factory.isSingleton()) &&
objectType != null && (type == null || type.isAssignableFrom(objectType))) {
matches.put(beanName, getBean(beanName, type));
}
}
else {
if (type == null || type.isInstance(beanInstance)) {
// If type to match is FactoryBean, return FactoryBean itself.
// Else, return bean instance.
if (isFactoryType) {
beanName = FACTORY_BEAN_PREFIX + beanName;
}
matches.put(beanName, (T) beanInstance);
}
}
}
return matches;
}
@Override
public String[] getBeanNamesForAnnotation(Class<? extends Annotation> annotationType) {
List<String> results = new ArrayList<>();
for (String beanName : this.beans.keySet()) {
if (findAnnotationOnBean(beanName, annotationType) != null) {
results.add(beanName);
}
}
return StringUtils.toStringArray(results);
}
@Override
public Map<String, Object> getBeansWithAnnotation(Class<? extends Annotation> annotationType)
throws BeansException {
Map<String, Object> results = new LinkedHashMap<>();
for (String beanName : this.beans.keySet()) {
if (findAnnotationOnBean(beanName, annotationType) != null) {
results.put(beanName, getBean(beanName));
}
}
return results;
}
@Override
@Nullable
public <A extends Annotation> A findAnnotationOnBean(String beanName, Class<A> annotationType)
throws NoSuchBeanDefinitionException {
Class<?> beanType = getType(beanName);
return (beanType != null ? AnnotationUtils.findAnnotation(beanType, annotationType) : null);
}
}