org.springframework.beans.factory.annotation.BeanFactoryAnnotationUtils Maven / Gradle / Ivy
/*
* Copyright 2002-2012 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.annotation;
import java.lang.reflect.Method;
import java.util.Map;
import org.springframework.beans.factory.BeanFactory;
import org.springframework.beans.factory.BeanFactoryUtils;
import org.springframework.beans.factory.NoSuchBeanDefinitionException;
import org.springframework.beans.factory.config.BeanDefinition;
import org.springframework.beans.factory.config.ConfigurableListableBeanFactory;
import org.springframework.beans.factory.support.AbstractBeanDefinition;
import org.springframework.beans.factory.support.AutowireCandidateQualifier;
import org.springframework.beans.factory.support.RootBeanDefinition;
import org.springframework.util.ObjectUtils;
/**
* Convenience methods performing bean lookups related to annotations, for example
* Spring's {@link Qualifier @Qualifier} annotation.
*
* @author Chris Beams
* @since 3.1.2
* @see BeanFactoryUtils
*/
public class BeanFactoryAnnotationUtils {
/**
* Obtain a bean of type {@code T} from the given {@code BeanFactory} declaring a
* qualifier (e.g. via {@code } or {@code @Qualifier}) matching the given
* qualifier, or having a bean name matching the given qualifier.
* @param beanFactory the BeanFactory to get the target bean from
* @param beanType the type of bean to retrieve
* @param qualifier the qualifier for selecting between multiple bean matches
* @return the matching bean of type {@code T} (never {@code null})
* @throws NoSuchBeanDefinitionException if no matching bean of type {@code T} found
*/
public static T qualifiedBeanOfType(BeanFactory beanFactory, Class beanType, String qualifier) {
if (beanFactory instanceof ConfigurableListableBeanFactory) {
// Full qualifier matching supported.
return qualifiedBeanOfType((ConfigurableListableBeanFactory) beanFactory, beanType, qualifier);
}
else if (beanFactory.containsBean(qualifier)) {
// Fallback: target bean at least found by bean name.
return beanFactory.getBean(qualifier, beanType);
}
else {
throw new NoSuchBeanDefinitionException(qualifier, "No matching " + beanType.getSimpleName() +
" bean found for bean name '" + qualifier +
"'! (Note: Qualifier matching not supported because given " +
"BeanFactory does not implement ConfigurableListableBeanFactory.)");
}
}
/**
* Obtain a bean of type {@code T} from the given {@code BeanFactory} declaring a qualifier
* (e.g. {@code } or {@code @Qualifier}) matching the given qualifier).
* @param bf the BeanFactory to get the target bean from
* @param beanType the type of bean to retrieve
* @param qualifier the qualifier for selecting between multiple bean matches
* @return the matching bean of type {@code T} (never {@code null})
* @throws NoSuchBeanDefinitionException if no matching bean of type {@code T} found
*/
private static T qualifiedBeanOfType(ConfigurableListableBeanFactory bf, Class beanType, String qualifier) {
Map candidateBeans = BeanFactoryUtils.beansOfTypeIncludingAncestors(bf, beanType);
T matchingBean = null;
for (String beanName : candidateBeans.keySet()) {
if (isQualifierMatch(qualifier, beanName, bf)) {
if (matchingBean != null) {
throw new NoSuchBeanDefinitionException(qualifier, "No unique " + beanType.getSimpleName() +
" bean found for qualifier '" + qualifier + "'");
}
matchingBean = candidateBeans.get(beanName);
}
}
if (matchingBean != null) {
return matchingBean;
}
else {
throw new NoSuchBeanDefinitionException(qualifier, "No matching " + beanType.getSimpleName() +
" bean found for qualifier '" + qualifier + "' - neither qualifier " + "match nor bean name match!");
}
}
/**
* Check whether the named bean declares a qualifier of the given name.
* @param qualifier the qualifier to match
* @param beanName the name of the candidate bean
* @param bf the {@code BeanFactory} from which to retrieve the named bean
* @return {@code true} if either the bean definition (in the XML case)
* or the bean's factory method (in the {@code @Bean} case) defines a matching
* qualifier value (through {@code } or {@code @Qualifier})
*/
private static boolean isQualifierMatch(String qualifier, String beanName, ConfigurableListableBeanFactory bf) {
if (bf.containsBean(beanName)) {
try {
BeanDefinition bd = bf.getMergedBeanDefinition(beanName);
if (bd instanceof AbstractBeanDefinition) {
AbstractBeanDefinition abd = (AbstractBeanDefinition) bd;
AutowireCandidateQualifier candidate = abd.getQualifier(Qualifier.class.getName());
if ((candidate != null && qualifier.equals(candidate.getAttribute(AutowireCandidateQualifier.VALUE_KEY))) ||
qualifier.equals(beanName) || ObjectUtils.containsElement(bf.getAliases(beanName), qualifier)) {
return true;
}
}
if (bd instanceof RootBeanDefinition) {
Method factoryMethod = ((RootBeanDefinition) bd).getResolvedFactoryMethod();
if (factoryMethod != null) {
Qualifier targetAnnotation = factoryMethod.getAnnotation(Qualifier.class);
if (targetAnnotation != null && qualifier.equals(targetAnnotation.value())) {
return true;
}
}
}
}
catch (NoSuchBeanDefinitionException ex) {
// ignore - can't compare qualifiers for a manually registered singleton object
}
}
return false;
}
}