/*
* Copyright 2002-2008 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;
import org.springframework.aop.TargetSource;
import org.springframework.aop.framework.adapter.AdvisorAdapterRegistry;
import org.springframework.aop.framework.adapter.GlobalAdvisorAdapterRegistry;
import org.springframework.aop.target.SingletonTargetSource;
import org.springframework.beans.factory.BeanClassLoaderAware;
import org.springframework.beans.factory.FactoryBean;
import org.springframework.beans.factory.FactoryBeanNotInitializedException;
import org.springframework.beans.factory.InitializingBean;
import org.springframework.util.ClassUtils;
/**
* Convenient proxy factory bean superclass for proxy factory
* beans that create only singletons.
*
* <p>Manages pre- and post-interceptors (references, rather than
* interceptor names, as in {@link ProxyFactoryBean}) and provides
* consistent interface management.
*
* @author Juergen Hoeller
* @since 2.0
*/
public abstract class AbstractSingletonProxyFactoryBean extends ProxyConfig
implements FactoryBean, BeanClassLoaderAware, InitializingBean {
private Object target;
private Class[] proxyInterfaces;
private Object[] preInterceptors;
private Object[] postInterceptors;
/** Default is global AdvisorAdapterRegistry */
private AdvisorAdapterRegistry advisorAdapterRegistry = GlobalAdvisorAdapterRegistry.getInstance();
private transient ClassLoader proxyClassLoader;
private Object proxy;
/**
* Set the target object, that is, the bean to be wrapped with a transactional proxy.
* <p>The target may be any object, in which case a SingletonTargetSource will
* be created. If it is a TargetSource, no wrapper TargetSource is created:
* This enables the use of a pooling or prototype TargetSource etc.
* @see org.springframework.aop.TargetSource
* @see org.springframework.aop.target.SingletonTargetSource
* @see org.springframework.aop.target.LazyInitTargetSource
* @see org.springframework.aop.target.PrototypeTargetSource
* @see org.springframework.aop.target.CommonsPoolTargetSource
*/
public void setTarget(Object target) {
this.target = target;
}
/**
* Specify the set of interfaces being proxied.
* <p>If not specified (the default), the AOP infrastructure works
* out which interfaces need proxying by analyzing the target,
* proxying all the interfaces that the target object implements.
*/
public void setProxyInterfaces(Class[] proxyInterfaces) {
this.proxyInterfaces = proxyInterfaces;
}
/**
* Set additional interceptors (or advisors) to be applied before the
* implicit transaction interceptor, e.g. a PerformanceMonitorInterceptor.
* <p>You may specify any AOP Alliance MethodInterceptors or other
* Spring AOP Advices, as well as Spring AOP Advisors.
* @see org.springframework.aop.interceptor.PerformanceMonitorInterceptor
*/
public void setPreInterceptors(Object[] preInterceptors) {
this.preInterceptors = preInterceptors;
}
/**
* Set additional interceptors (or advisors) to be applied after the
* implicit transaction interceptor.
* <p>You may specify any AOP Alliance MethodInterceptors or other
* Spring AOP Advices, as well as Spring AOP Advisors.
*/
public void setPostInterceptors(Object[] postInterceptors) {
this.postInterceptors = postInterceptors;
}
/**
* Specify the AdvisorAdapterRegistry to use.
* Default is the global AdvisorAdapterRegistry.
* @see org.springframework.aop.framework.adapter.GlobalAdvisorAdapterRegistry
*/
public void setAdvisorAdapterRegistry(AdvisorAdapterRegistry advisorAdapterRegistry) {
this.advisorAdapterRegistry = advisorAdapterRegistry;
}
/**
* Set the ClassLoader to generate the proxy class in.
* <p>Default is the bean ClassLoader, i.e. the ClassLoader used by the
* containing BeanFactory for loading all bean classes. This can be
* overridden here for specific proxies.
*/
public void setProxyClassLoader(ClassLoader classLoader) {
this.proxyClassLoader = classLoader;
}
public void setBeanClassLoader(ClassLoader classLoader) {
if (this.proxyClassLoader == null) {
this.proxyClassLoader = classLoader;
}
}
public void afterPropertiesSet() {
if (this.target == null) {
throw new IllegalArgumentException("Property 'target' is required");
}
if (this.target instanceof String) {
throw new IllegalArgumentException("'target' needs to be a bean reference, not a bean name as value");
}
if (this.proxyClassLoader == null) {
this.proxyClassLoader = ClassUtils.getDefaultClassLoader();
}
ProxyFactory proxyFactory = new ProxyFactory();
if (this.preInterceptors != null) {
for (int i = 0; i < this.preInterceptors.length; i++) {
proxyFactory.addAdvisor(this.advisorAdapterRegistry.wrap(this.preInterceptors[i]));
}
}
// Add the main interceptor (typically an Advisor).
proxyFactory.addAdvisor(this.advisorAdapterRegistry.wrap(createMainInterceptor()));
if (this.postInterceptors != null) {
for (int i = 0; i < this.postInterceptors.length; i++) {
proxyFactory.addAdvisor(this.advisorAdapterRegistry.wrap(this.postInterceptors[i]));
}
}
proxyFactory.copyFrom(this);
TargetSource targetSource = createTargetSource(this.target);
proxyFactory.setTargetSource(targetSource);
if (this.proxyInterfaces != null) {
proxyFactory.setInterfaces(this.proxyInterfaces);
}
else if (!isProxyTargetClass()) {
// Rely on AOP infrastructure to tell us what interfaces to proxy.
proxyFactory.setInterfaces(
ClassUtils.getAllInterfacesForClass(targetSource.getTargetClass(), this.proxyClassLoader));
}
this.proxy = getProxy(proxyFactory);
}
/**
* Determine a TargetSource for the given target (or TargetSource).
* @param target target. If this is an implementation of TargetSource it is
* used as our TargetSource; otherwise it is wrapped in a SingletonTargetSource.
* @return a TargetSource for this object
*/
protected TargetSource createTargetSource(Object target) {
if (target instanceof TargetSource) {
return (TargetSource) target;
}
else {
return new SingletonTargetSource(target);
}
}
/**
* Return the proxy object to expose.
* <p>The default implementation uses a <code>getProxy</code> call with
* the factory's bean class loader. Can be overridden to specify a
* custom class loader.
* @param aopProxy the prepared AopProxy instance to get the proxy from
* @return the proxy object to expose
* @see AopProxy#getProxy(ClassLoader)
*/
protected Object getProxy(AopProxy aopProxy) {
return aopProxy.getProxy(this.proxyClassLoader);
}
public Object getObject() {
if (this.proxy == null) {
throw new FactoryBeanNotInitializedException();
}
return this.proxy;
}
public Class getObjectType() {
if (this.proxy != null) {
return this.proxy.getClass();
}
if (this.proxyInterfaces != null && this.proxyInterfaces.length == 1) {
return this.proxyInterfaces[0];
}
if (this.target instanceof TargetSource) {
return ((TargetSource) this.target).getTargetClass();
}
if (this.target != null) {
return this.target.getClass();
}
return null;
}
public final boolean isSingleton() {
return true;
}
/**
* Create the "main" interceptor for this proxy factory bean.
* Typically an Advisor, but can also be any type of Advice.
* <p>Pre-interceptors will be applied before, post-interceptors
* will be applied after this interceptor.
*/
protected abstract Object createMainInterceptor();
}