org.springframework.aop.target.LazyInitTargetSource Maven / Gradle / Ivy
/*
* Copyright 2002-2005 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.target;
import org.springframework.beans.BeansException;
/**
* TargetSource that lazily accesses a singleton from a BeanFactory.
*
* Useful when a proxy reference is needed on initialization but
* the actual target object should not be initialized until first use.
* The target bean must me marked as "lazy-init" too, else it would get
* instantiated by the BeanFactory on startup. For example:
*
*
* <bean id="serviceTarget" class="example.MyService" lazy-init="true">
* ...
* </bean>
*
* <bean id="service" class="org.springframework.aop.framework.ProxyFactoryBean">
* <property name="targetSource">
* <bean class="org.springframework.aop.target.LazyInitTargetSource">
* <property name="targetBeanName"><idref local="serviceTarget"/></property>
* </bean>
* </property>
* </bean>
*
* The "serviceTarget" bean will not get initialized until a method on the
* "service" proxy gets invoked.
*
* @author Juergen Hoeller
* @since 1.1.4
*/
public class LazyInitTargetSource extends AbstractBeanFactoryBasedTargetSource {
private Object target;
public synchronized Object getTarget() throws BeansException {
if (this.target == null) {
this.target = getBeanFactory().getBean(getTargetBeanName());
}
return this.target;
}
}