/*
* 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.context.weaving;
import java.lang.instrument.ClassFileTransformer;
import java.lang.instrument.IllegalClassFormatException;
import java.security.ProtectionDomain;
import org.aspectj.weaver.loadtime.ClassPreProcessorAgentAdapter;
import org.springframework.beans.BeansException;
import org.springframework.beans.factory.BeanClassLoaderAware;
import org.springframework.beans.factory.config.BeanFactoryPostProcessor;
import org.springframework.beans.factory.config.ConfigurableListableBeanFactory;
import org.springframework.core.Ordered;
import org.springframework.instrument.classloading.InstrumentationLoadTimeWeaver;
import org.springframework.instrument.classloading.LoadTimeWeaver;
/**
* Post-processor that registers AspectJ's
* {@link org.aspectj.weaver.loadtime.ClassPreProcessorAgentAdapter}
* with the Spring application context's default
* {@link org.springframework.instrument.classloading.LoadTimeWeaver}.
*
* @author Juergen Hoeller
* @author Ramnivas Laddad
* @since 2.5
*/
public class AspectJWeavingEnabler
implements BeanFactoryPostProcessor, BeanClassLoaderAware, LoadTimeWeaverAware, Ordered {
private ClassLoader beanClassLoader;
private LoadTimeWeaver loadTimeWeaver;
public void setBeanClassLoader(ClassLoader classLoader) {
this.beanClassLoader = classLoader;
}
public void setLoadTimeWeaver(LoadTimeWeaver loadTimeWeaver) {
this.loadTimeWeaver = loadTimeWeaver;
}
public int getOrder() {
return HIGHEST_PRECEDENCE;
}
public void postProcessBeanFactory(ConfigurableListableBeanFactory beanFactory) throws BeansException {
LoadTimeWeaver weaverToUse = this.loadTimeWeaver;
if (weaverToUse == null) {
if (InstrumentationLoadTimeWeaver.isInstrumentationAvailable()) {
weaverToUse = new InstrumentationLoadTimeWeaver(this.beanClassLoader);
}
else {
throw new IllegalStateException("No LoadTimeWeaver available");
}
}
weaverToUse.addTransformer(new AspectJClassBypassingClassFileTransformer(
new ClassPreProcessorAgentAdapter()));
}
/*
* Decorator to suppress processing AspectJ classes, hence avoiding potential LinkageErrors.
* OC4J and Tomcat (in Glassfish) definitely need such bypassing of AspectJ classes.
*/
private static class AspectJClassBypassingClassFileTransformer implements ClassFileTransformer {
private final ClassFileTransformer delegate;
public AspectJClassBypassingClassFileTransformer(ClassFileTransformer delegate) {
this.delegate = delegate;
}
public byte[] transform(ClassLoader loader, String className, Class<?> classBeingRedefined,
ProtectionDomain protectionDomain, byte[] classfileBuffer) throws IllegalClassFormatException {
if (className.startsWith("org.aspectj") || className.startsWith("org/aspectj")) {
return classfileBuffer;
}
return this.delegate.transform(loader, className, classBeingRedefined, protectionDomain, classfileBuffer);
}
}
}
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