/*
* Copyright 2002-2015 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.framework.autoproxy;
import org.springframework.beans.factory.config.BeanDefinition;
import org.springframework.beans.factory.config.ConfigurableListableBeanFactory;
import org.springframework.core.Conventions;
/**
* Utilities for auto-proxy aware components.
* Mainly for internal use within the framework.
*
* @author Juergen Hoeller
* @since 2.0.3
* @see AbstractAutoProxyCreator
*/
public abstract class AutoProxyUtils {
/**
* Bean definition attribute that may indicate whether a given bean is supposed
* to be proxied with its target class (in case of it getting proxied in the first
* place). The value is {@code Boolean.TRUE} or {@code Boolean.FALSE}.
* <p>Proxy factories can set this attribute if they built a target class proxy
* for a specific bean, and want to enforce that bean can always be cast
* to its target class (even if AOP advices get applied through auto-proxying).
* @see #shouldProxyTargetClass
*/
public static final String PRESERVE_TARGET_CLASS_ATTRIBUTE =
Conventions.getQualifiedAttributeName(AutoProxyUtils.class, "preserveTargetClass");
/**
* Bean definition attribute that indicates the original target class of an
* auto-proxied bean, e.g. to be used for the introspection of annotations
* on the target class behind an interface-based proxy.
* @since 4.2.3
* @see #determineTargetClass
*/
public static final String ORIGINAL_TARGET_CLASS_ATTRIBUTE =
Conventions.getQualifiedAttributeName(AutoProxyUtils.class, "originalTargetClass");
/**
* Determine whether the given bean should be proxied with its target
* class rather than its interfaces. Checks the
* {@link #PRESERVE_TARGET_CLASS_ATTRIBUTE "preserveTargetClass" attribute}
* of the corresponding bean definition.
* @param beanFactory the containing ConfigurableListableBeanFactory
* @param beanName the name of the bean
* @return whether the given bean should be proxied with its target class
*/
public static boolean shouldProxyTargetClass(ConfigurableListableBeanFactory beanFactory, String beanName) {
if (beanName != null && beanFactory.containsBeanDefinition(beanName)) {
BeanDefinition bd = beanFactory.getBeanDefinition(beanName);
return Boolean.TRUE.equals(bd.getAttribute(PRESERVE_TARGET_CLASS_ATTRIBUTE));
}
return false;
}
/**
* Determine the original target class for the specified bean, if possible,
* otherwise falling back to a regular {@code getType} lookup.
* @param beanFactory the containing ConfigurableListableBeanFactory
* @param beanName the name of the bean
* @return the original target class as stored in the bean definition, if any
* @since 4.2.3
* @see org.springframework.beans.factory.BeanFactory#getType(String)
*/
public static Class<?> determineTargetClass(ConfigurableListableBeanFactory beanFactory, String beanName) {
if (beanName == null) {
return null;
}
if (beanFactory.containsBeanDefinition(beanName)) {
BeanDefinition bd = beanFactory.getMergedBeanDefinition(beanName);
Class<?> targetClass = (Class<?>) bd.getAttribute(ORIGINAL_TARGET_CLASS_ATTRIBUTE);
if (targetClass != null) {
return targetClass;
}
}
return beanFactory.getType(beanName);
}
/**
* Expose the given target class for the specified bean, if possible.
* @param beanFactory the containing ConfigurableListableBeanFactory
* @param beanName the name of the bean
* @param targetClass the corresponding target class
* @since 4.2.3
*/
static void exposeTargetClass(ConfigurableListableBeanFactory beanFactory, String beanName, Class<?> targetClass) {
if (beanName != null && beanFactory.containsBeanDefinition(beanName)) {
beanFactory.getMergedBeanDefinition(beanName).setAttribute(ORIGINAL_TARGET_CLASS_ATTRIBUTE, targetClass);
}
}
}