Spring Framework example source code file (BeanFactoryAspectJAdvisorsBuilder.java)

This example Spring Framework source code file (BeanFactoryAspectJAdvisorsBuilder.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

aspectjadvisorfactory, aspectmetadata, beanfactoryaspectjadvisorsbuilder, beanfactoryaspectjadvisorsbuilder, hashmap, linkedlist, list, list, listablebeanfactory, map, metadataawareaspectinstancefactory, metadataawareaspectinstancefactory, string, string, util

The Spring Framework BeanFactoryAspectJAdvisorsBuilder.java source code

/*
 * Copyright 2002-2007 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.aspectj.annotation;

import java.util.Collections;
import java.util.HashMap;
import java.util.Iterator;
import java.util.LinkedList;
import java.util.List;
import java.util.Map;

import org.aspectj.lang.reflect.PerClauseKind;

import org.springframework.aop.Advisor;
import org.springframework.beans.factory.BeanFactoryUtils;
import org.springframework.beans.factory.ListableBeanFactory;
import org.springframework.util.Assert;

/**
 * Helper for retrieving @AspectJ beans from a BeanFactory and building
 * Spring Advisors based on them, for use with auto-proxying.
 *
 * @author Juergen Hoeller
 * @since 2.0.2
 * @see AnnotationAwareAspectJAutoProxyCreator
 */
public class BeanFactoryAspectJAdvisorsBuilder {

	private final ListableBeanFactory beanFactory;

	private final AspectJAdvisorFactory advisorFactory;

	private List<String> aspectBeanNames;

	private final Map<String, List advisorsCache = new HashMap>();

	private final Map<String, MetadataAwareAspectInstanceFactory> aspectFactoryCache =
			new HashMap<String, MetadataAwareAspectInstanceFactory>();


	/**
	 * Create a new BeanFactoryAspectJAdvisorsBuilder for the given BeanFactory.
	 * @param beanFactory the ListableBeanFactory to scan
	 */
	public BeanFactoryAspectJAdvisorsBuilder(ListableBeanFactory beanFactory) {
		this(beanFactory, new ReflectiveAspectJAdvisorFactory());
	}

	/**
	 * Create a new BeanFactoryAspectJAdvisorsBuilder for the given BeanFactory.
	 * @param beanFactory the ListableBeanFactory to scan
	 * @param advisorFactory the AspectJAdvisorFactory to build each Advisor with
	 */
	public BeanFactoryAspectJAdvisorsBuilder(ListableBeanFactory beanFactory, AspectJAdvisorFactory advisorFactory) {
		Assert.notNull(beanFactory, "ListableBeanFactory must not be null");
		Assert.notNull(advisorFactory, "AspectJAdvisorFactory must not be null");
		this.beanFactory = beanFactory;
		this.advisorFactory = advisorFactory;
	}


	/**
	 * Look for AspectJ-annotated aspect beans in the current bean factory,
	 * and return to a list of Spring AOP Advisors representing them.
	 * <p>Creates a Spring Advisor for each AspectJ advice method.
	 * @return the list of {@link org.springframework.aop.Advisor} beans
	 * @see #isEligibleBean
	 */
	public List<Advisor> buildAspectJAdvisors() {
		List<String> aspectNames = null;

		synchronized (this) {
			aspectNames = this.aspectBeanNames;
			if (aspectNames == null) {
				List<Advisor> advisors = new LinkedList();
				aspectNames = new LinkedList<String>();
				String[] beanNames =
						BeanFactoryUtils.beanNamesForTypeIncludingAncestors(this.beanFactory, Object.class, true, false);
				for (String beanName : beanNames) {
					if (!isEligibleBean(beanName)) {
						continue;
					}
					// We must be careful not to instantiate beans eagerly as in this
					// case they would be cached by the Spring container but would not
					// have been weaved
					Class beanType = this.beanFactory.getType(beanName);
					if (beanType == null) {
						continue;
					}
					if (this.advisorFactory.isAspect(beanType)) {
						aspectNames.add(beanName);
						AspectMetadata amd = new AspectMetadata(beanType, beanName);
						if (amd.getAjType().getPerClause().getKind() == PerClauseKind.SINGLETON) {
							MetadataAwareAspectInstanceFactory factory =
									new BeanFactoryAspectInstanceFactory(this.beanFactory, beanName);
							List<Advisor> classAdvisors = this.advisorFactory.getAdvisors(factory);
							if (this.beanFactory.isSingleton(beanName)) {
								this.advisorsCache.put(beanName, classAdvisors);
							}
							else {
								this.aspectFactoryCache.put(beanName, factory);
							}
							advisors.addAll(classAdvisors);
						}
						else {
							// Per target or per this.
							if (this.beanFactory.isSingleton(beanName)) {
								throw new IllegalArgumentException("Bean with name '" + beanName +
										"' is a singleton, but aspect instantiation model is not singleton");
							}
							MetadataAwareAspectInstanceFactory factory =
									new PrototypeAspectInstanceFactory(this.beanFactory, beanName);
							this.aspectFactoryCache.put(beanName, factory);
							advisors.addAll(this.advisorFactory.getAdvisors(factory));
						}
					}
				}
				this.aspectBeanNames = aspectNames;
				return advisors;
			}
		}

		if (aspectNames.isEmpty()) {
			return Collections.EMPTY_LIST;
		}
		List<Advisor> advisors = new LinkedList();
		for (Iterator it = aspectNames.iterator(); it.hasNext();) {
			String aspectName = (String) it.next();
			List<Advisor> cachedAdvisors = this.advisorsCache.get(aspectName);
			if (cachedAdvisors != null) {
				advisors.addAll(cachedAdvisors);
			}
			else {
				MetadataAwareAspectInstanceFactory factory = this.aspectFactoryCache.get(aspectName);
				advisors.addAll(this.advisorFactory.getAdvisors(factory));
			}
		}
		return advisors;
	}

	/**
	 * Return whether the aspect bean with the given name is eligible.
	 * @param beanName the name of the aspect bean
	 * @return whether the bean is eligible
	 */
	protected boolean isEligibleBean(String beanName) {
		return true;
	}

}