/*
* 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.aop.aspectj.annotation;
import org.springframework.util.Assert;
/**
* Decorator to cause a {@link MetadataAwareAspectInstanceFactory} to instantiate only once.
*
* @author Rod Johnson
* @author Juergen Hoeller
* @since 2.0
*/
public class LazySingletonAspectInstanceFactoryDecorator implements MetadataAwareAspectInstanceFactory {
private final MetadataAwareAspectInstanceFactory maaif;
private volatile Object materialized;
/**
* Create a new lazily initializing decorator for the given AspectInstanceFactory.
* @param maaif the MetadataAwareAspectInstanceFactory to decorate
*/
public LazySingletonAspectInstanceFactoryDecorator(MetadataAwareAspectInstanceFactory maaif) {
Assert.notNull(maaif, "AspectInstanceFactory must not be null");
this.maaif = maaif;
}
public synchronized Object getAspectInstance() {
if (this.materialized == null) {
synchronized (this) {
if (this.materialized == null) {
this.materialized = this.maaif.getAspectInstance();
}
}
}
return this.materialized;
}
public boolean isMaterialized() {
return (this.materialized != null);
}
public ClassLoader getAspectClassLoader() {
return this.maaif.getAspectClassLoader();
}
public AspectMetadata getAspectMetadata() {
return this.maaif.getAspectMetadata();
}
public int getOrder() {
return this.maaif.getOrder();
}
@Override
public String toString() {
return "LazySingletonAspectInstanceFactoryDecorator: decorating " + this.maaif;
}
}
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