/*
* Copyright 2002-2009 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.ejb.interceptor;
import java.util.Map;
import java.util.WeakHashMap;
import javax.annotation.PostConstruct;
import javax.annotation.PreDestroy;
import javax.ejb.EJBException;
import javax.ejb.PostActivate;
import javax.ejb.PrePassivate;
import javax.interceptor.InvocationContext;
import org.springframework.beans.factory.BeanFactory;
import org.springframework.beans.factory.access.BeanFactoryLocator;
import org.springframework.beans.factory.access.BeanFactoryReference;
import org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor;
import org.springframework.context.ApplicationContext;
import org.springframework.context.access.ContextSingletonBeanFactoryLocator;
/**
* EJB3-compliant interceptor class that injects Spring beans into
* fields and methods which are annotated with <code>@Autowired</code>.
* Performs injection after construction as well as after activation
* of a passivated bean.
*
* <p>To be applied through an <code>@Interceptors</code> annotation in
* the EJB Session Bean or Message-Driven Bean class, or through an
* <code>interceptor-binding</code> XML element in the EJB deployment descriptor.
*
* <p>Delegates to Spring's {@link AutowiredAnnotationBeanPostProcessor}
* underneath, allowing for customization of its specific settings through
* overriding the {@link #configureBeanPostProcessor} template method.
*
* <p>The actual BeanFactory to obtain Spring beans from is determined
* by the {@link #getBeanFactory} template method. The default implementation
* obtains the Spring {@link ContextSingletonBeanFactoryLocator}, initialized
* from the default resource location <strong>classpath*:beanRefContext.xml</strong>,
* and obtains the single ApplicationContext defined there.
*
* <p><b>NOTE: If you have more than one shared ApplicationContext definition available
* in your EJB class loader, you need to override the {@link #getBeanFactoryLocatorKey}
* method and provide a specific locator key for each autowired EJB.</b>
* Alternatively, override the {@link #getBeanFactory} template method and
* obtain the target factory explicitly.
*
* <p><b>WARNING: Do not define the same bean as Spring-managed bean and as
* EJB3 session bean in the same deployment unit.</b> In particular, be
* careful when using the <code><context:component-scan></code> feature
* in combination with the deployment of Spring-based EJB3 session beans:
* Make sure that the EJB3 session beans are <i>not</i> autodetected as
* Spring-managed beans as well, using appropriate package restrictions.
*
* @author Juergen Hoeller
* @since 2.5.1
* @see org.springframework.beans.factory.annotation.Autowired
* @see org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor
* @see org.springframework.context.access.ContextSingletonBeanFactoryLocator
* @see #getBeanFactoryLocatorKey
* @see org.springframework.ejb.support.AbstractEnterpriseBean#setBeanFactoryLocator
* @see org.springframework.ejb.support.AbstractEnterpriseBean#setBeanFactoryLocatorKey
*/
public class SpringBeanAutowiringInterceptor {
/*
* We're keeping the BeanFactoryReference per target object in order to
* allow for using a shared interceptor instance on pooled target beans.
* This is not strictly necessary for EJB3 Session Beans and Message-Driven
* Beans, where interceptor instances get created per target bean instance.
* It simply protects against future usage of the interceptor in a shared scenario.
*/
private final Map<Object, BeanFactoryReference> beanFactoryReferences =
new WeakHashMap<Object, BeanFactoryReference>();
/**
* Autowire the target bean after construction as well as after passivation.
* @param invocationContext the EJB3 invocation context
*/
@PostConstruct
@PostActivate
public void autowireBean(InvocationContext invocationContext) {
doAutowireBean(invocationContext.getTarget());
try {
invocationContext.proceed();
}
catch (RuntimeException ex) {
throw ex;
}
catch (Exception ex) {
// Cannot declare a checked exception on WebSphere here - so we need to wrap.
throw new EJBException(ex);
}
}
/**
* Actually autowire the target bean after construction/passivation.
* @param target the target bean to autowire
*/
protected void doAutowireBean(Object target) {
AutowiredAnnotationBeanPostProcessor bpp = new AutowiredAnnotationBeanPostProcessor();
configureBeanPostProcessor(bpp, target);
bpp.setBeanFactory(getBeanFactory(target));
bpp.processInjection(target);
}
/**
* Template method for configuring the
* {@link AutowiredAnnotationBeanPostProcessor} used for autowiring.
* @param processor the AutowiredAnnotationBeanPostProcessor to configure
* @param target the target bean to autowire with this processor
*/
protected void configureBeanPostProcessor(AutowiredAnnotationBeanPostProcessor processor, Object target) {
}
/**
* Determine the BeanFactory for autowiring the given target bean.
* @param target the target bean to autowire
* @return the BeanFactory to use (never <code>null</code>)
* @see #getBeanFactoryReference
*/
protected BeanFactory getBeanFactory(Object target) {
BeanFactory factory = getBeanFactoryReference(target).getFactory();
if (factory instanceof ApplicationContext) {
factory = ((ApplicationContext) factory).getAutowireCapableBeanFactory();
}
return factory;
}
/**
* Determine the BeanFactoryReference for the given target bean.
* <p>The default implementation delegates to {@link #getBeanFactoryLocator}
* and {@link #getBeanFactoryLocatorKey}.
* @param target the target bean to autowire
* @return the BeanFactoryReference to use (never <code>null</code>)
* @see #getBeanFactoryLocator
* @see #getBeanFactoryLocatorKey
* @see org.springframework.beans.factory.access.BeanFactoryLocator#useBeanFactory(String)
*/
protected BeanFactoryReference getBeanFactoryReference(Object target) {
String key = getBeanFactoryLocatorKey(target);
BeanFactoryReference ref = getBeanFactoryLocator(target).useBeanFactory(key);
this.beanFactoryReferences.put(target, ref);
return ref;
}
/**
* Determine the BeanFactoryLocator to obtain the BeanFactoryReference from.
* <p>The default implementation exposes Spring's default
* {@link ContextSingletonBeanFactoryLocator}.
* @param target the target bean to autowire
* @return the BeanFactoryLocator to use (never <code>null</code>)
* @see org.springframework.context.access.ContextSingletonBeanFactoryLocator#getInstance()
*/
protected BeanFactoryLocator getBeanFactoryLocator(Object target) {
return ContextSingletonBeanFactoryLocator.getInstance();
}
/**
* Determine the BeanFactoryLocator key to use. This typically indicates
* the bean name of the ApplicationContext definition in
* <strong>classpath*:beanRefContext.xml</strong> resource files.
* <p>The default is <code>null</code>, indicating the single
* ApplicationContext defined in the locator. This must be overridden
* if more than one shared ApplicationContext definition is available.
* @param target the target bean to autowire
* @return the BeanFactoryLocator key to use (or <code>null</code> for
* referring to the single ApplicationContext defined in the locator)
*/
protected String getBeanFactoryLocatorKey(Object target) {
return null;
}
/**
* Release the factory which has been used for autowiring the target bean.
* @param invocationContext the EJB3 invocation context
*/
@PreDestroy
@PrePassivate
public void releaseBean(InvocationContext invocationContext) {
doReleaseBean(invocationContext.getTarget());
try {
invocationContext.proceed();
}
catch (RuntimeException ex) {
throw ex;
}
catch (Exception ex) {
// Cannot declare a checked exception on WebSphere here - so we need to wrap.
throw new EJBException(ex);
}
}
/**
* Actually release the BeanFactoryReference for the given target bean.
* @param target the target bean to release
*/
protected void doReleaseBean(Object target) {
BeanFactoryReference ref = this.beanFactoryReferences.remove(target);
if (ref != null) {
ref.release();
}
}
}