Spring Framework example source code file (EventPublicationInterceptor.java)

This example Spring Framework source code file (EventPublicationInterceptor.java) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" ^TM.

Java - Spring Framework tags/keywords

applicationevent, applicationevent, applicationeventpublisher, constructor, eventpublicationinterceptor, illegalargumentexception, illegalargumentexception, initializingbean, methodinterceptor, nosuchmethodexception, nosuchmethodexception, object, object, reflection, throwable

The Spring Framework EventPublicationInterceptor.java source code

/*
 * Copyright 2002-2006 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 ApplicationListeners
 * registered with an <code>ApplicationEventPublisher after each
 * <i>successful method invocation.
 *
 * <p>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.
	 * <p>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 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.equals(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);
		}
	}

	public void setApplicationEventPublisher(ApplicationEventPublisher applicationEventPublisher) {
		this.applicationEventPublisher = applicationEventPublisher;
	}

	public void afterPropertiesSet() throws Exception {
		if (this.applicationEventClassConstructor == null) {
			throw new IllegalArgumentException("applicationEventClass is required");
		}
	}


	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;
	}

}