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/*
* Copyright 2002-2012 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.context.event;
import java.lang.reflect.Constructor;
import org.aopalliance.intercept.MethodInterceptor;
import org.aopalliance.intercept.MethodInvocation;
import org.springframework.beans.factory.InitializingBean;
import org.springframework.context.ApplicationEvent;
import org.springframework.context.ApplicationEventPublisher;
import org.springframework.context.ApplicationEventPublisherAware;
/**
* {@link MethodInterceptor Interceptor} that publishes an
* {@code ApplicationEvent} to all {@code ApplicationListeners}
* registered with an {@code ApplicationEventPublisher} after each
* successful method invocation.
*
* Note that this interceptor is only capable of publishing stateless
* events configured via the
* {@link #setApplicationEventClass "applicationEventClass"} property.
*
* @author Dmitriy Kopylenko
* @author Juergen Hoeller
* @author Rick Evans
* @see #setApplicationEventClass
* @see org.springframework.context.ApplicationEvent
* @see org.springframework.context.ApplicationListener
* @see org.springframework.context.ApplicationEventPublisher
* @see org.springframework.context.ApplicationContext
*/
public class EventPublicationInterceptor
implements MethodInterceptor, ApplicationEventPublisherAware, InitializingBean {
private Constructor applicationEventClassConstructor;
private ApplicationEventPublisher applicationEventPublisher;
/**
* Set the application event class to publish.
*
The event class must have a constructor with a single
* {@code Object} argument for the event source. The interceptor
* will pass in the invoked object.
* @throws IllegalArgumentException if the supplied {@code Class} is
* {@code null} or if it is not an {@code ApplicationEvent} subclass or
* if it does not expose a constructor that takes a single {@code Object} argument
*/
public void setApplicationEventClass(Class applicationEventClass) {
if (ApplicationEvent.class == applicationEventClass ||
!ApplicationEvent.class.isAssignableFrom(applicationEventClass)) {
throw new IllegalArgumentException("applicationEventClass needs to extend ApplicationEvent");
}
try {
this.applicationEventClassConstructor =
applicationEventClass.getConstructor(new Class[] {Object.class});
}
catch (NoSuchMethodException ex) {
throw new IllegalArgumentException("applicationEventClass [" +
applicationEventClass.getName() + "] does not have the required Object constructor: " + ex);
}
}
@Override
public void setApplicationEventPublisher(ApplicationEventPublisher applicationEventPublisher) {
this.applicationEventPublisher = applicationEventPublisher;
}
@Override
public void afterPropertiesSet() throws Exception {
if (this.applicationEventClassConstructor == null) {
throw new IllegalArgumentException("applicationEventClass is required");
}
}
@Override
public Object invoke(MethodInvocation invocation) throws Throwable {
Object retVal = invocation.proceed();
ApplicationEvent event = (ApplicationEvent)
this.applicationEventClassConstructor.newInstance(new Object[] {invocation.getThis()});
this.applicationEventPublisher.publishEvent(event);
return retVal;
}
}