/*
* Copyright 2002-2010 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.springframework.aop.config;
import java.util.List;
import org.w3c.dom.Node;
import org.springframework.aop.framework.ProxyFactoryBean;
import org.springframework.beans.factory.config.BeanDefinition;
import org.springframework.beans.factory.config.BeanDefinitionHolder;
import org.springframework.beans.factory.support.AbstractBeanDefinition;
import org.springframework.beans.factory.support.BeanDefinitionReaderUtils;
import org.springframework.beans.factory.support.BeanDefinitionRegistry;
import org.springframework.beans.factory.support.ManagedList;
import org.springframework.beans.factory.support.RootBeanDefinition;
import org.springframework.beans.factory.xml.BeanDefinitionDecorator;
import org.springframework.beans.factory.xml.ParserContext;
import org.springframework.util.ClassUtils;
import org.springframework.util.StringUtils;
/**
* Base implementation for
* {@link org.springframework.beans.factory.xml.BeanDefinitionDecorator BeanDefinitionDecorators}
* wishing to add an {@link org.aopalliance.intercept.MethodInterceptor interceptor}
* to the resulting bean.
*
* <p>This base class controls the creation of the {@link ProxyFactoryBean} bean definition
* and wraps the original as an inner-bean definition for the <code>target</code> property
* of {@link ProxyFactoryBean}.
*
* <p>Chaining is correctly handled, ensuring that only one {@link ProxyFactoryBean} definition
* is created. If a previous {@link org.springframework.beans.factory.xml.BeanDefinitionDecorator}
* already created the {@link org.springframework.aop.framework.ProxyFactoryBean} then the
* interceptor is simply added to the existing definition.
*
* <p>Subclasses have only to create the <code>BeanDefinition</code> to the interceptor that
* they wish to add.
*
* @author Rob Harrop
* @author Juergen Hoeller
* @since 2.0
* @see org.aopalliance.intercept.MethodInterceptor
*/
public abstract class AbstractInterceptorDrivenBeanDefinitionDecorator implements BeanDefinitionDecorator {
public final BeanDefinitionHolder decorate(Node node, BeanDefinitionHolder definitionHolder, ParserContext parserContext) {
BeanDefinitionRegistry registry = parserContext.getRegistry();
// get the root bean name - will be the name of the generated proxy factory bean
String existingBeanName = definitionHolder.getBeanName();
BeanDefinition targetDefinition = definitionHolder.getBeanDefinition();
BeanDefinitionHolder targetHolder = new BeanDefinitionHolder(targetDefinition, existingBeanName + ".TARGET");
// delegate to subclass for interceptor definition
BeanDefinition interceptorDefinition = createInterceptorDefinition(node);
// generate name and register the interceptor
String interceptorName = existingBeanName + "." + getInterceptorNameSuffix(interceptorDefinition);
BeanDefinitionReaderUtils.registerBeanDefinition(
new BeanDefinitionHolder(interceptorDefinition, interceptorName), registry);
BeanDefinitionHolder result = definitionHolder;
if (!isProxyFactoryBeanDefinition(targetDefinition)) {
// create the proxy definition
RootBeanDefinition proxyDefinition = new RootBeanDefinition();
// create proxy factory bean definition
proxyDefinition.setBeanClass(ProxyFactoryBean.class);
proxyDefinition.setScope(targetDefinition.getScope());
proxyDefinition.setLazyInit(targetDefinition.isLazyInit());
// set the target
proxyDefinition.setDecoratedDefinition(targetHolder);
proxyDefinition.getPropertyValues().add("target", targetHolder);
// create the interceptor names list
proxyDefinition.getPropertyValues().add("interceptorNames", new ManagedList<String>());
// copy autowire settings from original bean definition.
proxyDefinition.setAutowireCandidate(targetDefinition.isAutowireCandidate());
proxyDefinition.setPrimary(targetDefinition.isPrimary());
if (targetDefinition instanceof AbstractBeanDefinition) {
proxyDefinition.copyQualifiersFrom((AbstractBeanDefinition) targetDefinition);
}
// wrap it in a BeanDefinitionHolder with bean name
result = new BeanDefinitionHolder(proxyDefinition, existingBeanName);
}
addInterceptorNameToList(interceptorName, result.getBeanDefinition());
return result;
}
@SuppressWarnings("unchecked")
private void addInterceptorNameToList(String interceptorName, BeanDefinition beanDefinition) {
List<String> list = (List<String>)
beanDefinition.getPropertyValues().getPropertyValue("interceptorNames").getValue();
list.add(interceptorName);
}
private boolean isProxyFactoryBeanDefinition(BeanDefinition existingDefinition) {
return ProxyFactoryBean.class.getName().equals(existingDefinition.getBeanClassName());
}
protected String getInterceptorNameSuffix(BeanDefinition interceptorDefinition) {
return StringUtils.uncapitalize(ClassUtils.getShortName(interceptorDefinition.getBeanClassName()));
}
/**
* Subclasses should implement this method to return the <code>BeanDefinition</code>
* for the interceptor they wish to apply to the bean being decorated.
*/
protected abstract BeanDefinition createInterceptorDefinition(Node node);
}