/*
* Copyright 2007-2010 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.impalaframework.spring.service;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.impalaframework.exception.InvalidStateException;
import org.impalaframework.service.ServiceBeanReference;
import org.springframework.beans.factory.BeanFactory;
import org.springframework.beans.factory.FactoryBean;
import org.springframework.beans.factory.ListableBeanFactory;
import org.springframework.beans.factory.config.BeanDefinition;
import org.springframework.beans.factory.support.BeanDefinitionRegistry;
import org.springframework.util.Assert;
/**
* {@link FactoryBean} which simply injects bean obtained from parent bean factory
* @author Phil Zoio
*/
public class SpringServiceBeanUtils {
private static final Log logger = LogFactory.getLog(SpringServiceBeanUtils.class);
/**
* Returns instance of {@link StaticSpringServiceBeanReference} if bean is represented by a singleton
* and {@link SpringServiceBeanReference} if not.
* @see SpringServiceBeanUtils#isSingleton(BeanFactory, String)
*/
public static ServiceBeanReference newServiceBeanReference(BeanFactory beanFactory, String beanName) {
Object bean = beanFactory.getBean(beanName);
boolean singleton = SpringServiceBeanUtils.isSingleton(beanFactory, beanName);
if (singleton) {
return new StaticSpringServiceBeanReference(bean);
}
return new SpringServiceBeanReference(beanFactory, beanName);
}
/**
* Checks that the bean with given name contained in the specified bean factory is a singleton.
* Will return true if bean represented by a bean registered under the scope <code>singletone</code>.
* If the bean is also a factory bean (see {@link FactoryBean}), then the {@link FactoryBean}
* instance also needs to be a singleton.
*
* Note that in order to work properly the {@link BeanFactory} must be able to recover the {@link BeanDefinition}
* for a particular bean name. This in particular must mean implementing {@link BeanDefinitionRegistry} or
* {@link BeanDefinitionExposing}. In the latter case, if null is returned, then the bean will be treated as a singleton.
*
* @return true if bean is singleton registered bean and, if applicable, a singleton {@link FactoryBean}.
*/
public static boolean isSingleton(
BeanFactory beanFactory,
String beanName) {
Assert.notNull(beanFactory, "beanFactory cannot be null");
Assert.notNull(beanName, "beanName cannot be null");
boolean singleton = true;
boolean isBeanFactory = beanFactory.containsBean(BeanFactory.FACTORY_BEAN_PREFIX + beanName);
if (isBeanFactory) {
FactoryBean factoryBean = (FactoryBean) beanFactory.getBean(BeanFactory.FACTORY_BEAN_PREFIX + beanName);
singleton = factoryBean.isSingleton();
}
if (singleton) {
//ApplicationContext implements this implements this
ListableBeanFactory registry = (ListableBeanFactory) beanFactory;
//we're only interested in top level definitions
//inner beans won't appear here, so
boolean containsBeanDefinition = registry.containsBeanDefinition(beanName);
if (containsBeanDefinition) {
BeanDefinition beanDefinition = getBeanDefinition(registry, beanName);
if (beanDefinition != null) {
singleton = beanDefinition.isSingleton();
}
} else {
if (logger.isDebugEnabled()) {
logger.debug("Cannot check whether bean definition " + beanName + " is singleton as it is not available as a top level bean");
}
}
}
return singleton;
}
static BeanDefinition getBeanDefinition(BeanFactory beanFactory, String beanName) {
if (beanFactory instanceof BeanDefinitionRegistry) {
return ((BeanDefinitionRegistry) beanFactory).getBeanDefinition(beanName);
}
if (beanFactory instanceof BeanDefinitionExposing) {
BeanDefinition beanDefinition = ((BeanDefinitionExposing) beanFactory).getBeanDefinition(beanName);
return beanDefinition;
}
throw new InvalidStateException("Cannot get bean definition as bean factory ["
+ beanFactory.getClass().getName()
+ "] does not implement [" + BeanDefinitionRegistry.class
+ "] or " + BeanDefinitionExposing.class.getName() + "]");
}
}