/*
 * Copyright 2002-2018 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
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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;
import org.springframework.lang.Nullable;

Post-processor that registers AspectJ's ClassPreProcessorAgentAdapter with the Spring application context's default LoadTimeWeaver.
Author:Juergen Hoeller, Ramnivas Laddad
Since:2.5
/** * 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 {
The aop.xml resource location.
/** * The {@code aop.xml} resource location. */
public static final String ASPECTJ_AOP_XML_RESOURCE = "META-INF/aop.xml"; @Nullable private ClassLoader beanClassLoader; @Nullable private LoadTimeWeaver loadTimeWeaver; @Override public void setBeanClassLoader(ClassLoader classLoader) { this.beanClassLoader = classLoader; } @Override public void setLoadTimeWeaver(LoadTimeWeaver loadTimeWeaver) { this.loadTimeWeaver = loadTimeWeaver; } @Override public int getOrder() { return HIGHEST_PRECEDENCE; } @Override public void postProcessBeanFactory(ConfigurableListableBeanFactory beanFactory) throws BeansException { enableAspectJWeaving(this.loadTimeWeaver, this.beanClassLoader); }
Enable AspectJ weaving with the given LoadTimeWeaver.
Params:
  • weaverToUse – the LoadTimeWeaver to apply to (or null for a default weaver)
  • beanClassLoader – the class loader to create a default weaver for (if necessary)
/** * Enable AspectJ weaving with the given {@link LoadTimeWeaver}. * @param weaverToUse the LoadTimeWeaver to apply to (or {@code null} for a default weaver) * @param beanClassLoader the class loader to create a default weaver for (if necessary) */
public static void enableAspectJWeaving( @Nullable LoadTimeWeaver weaverToUse, @Nullable ClassLoader beanClassLoader) { if (weaverToUse == null) { if (InstrumentationLoadTimeWeaver.isInstrumentationAvailable()) { weaverToUse = new InstrumentationLoadTimeWeaver(beanClassLoader); } else { throw new IllegalStateException("No LoadTimeWeaver available"); } } weaverToUse.addTransformer( new AspectJClassBypassingClassFileTransformer(new ClassPreProcessorAgentAdapter())); }
ClassFileTransformer decorator that suppresses processing of AspectJ classes in order to avoid potential LinkageErrors.
See Also:
  • LoadTimeWeavingConfiguration
/** * ClassFileTransformer decorator that suppresses processing of AspectJ * classes in order to avoid potential LinkageErrors. * @see org.springframework.context.annotation.LoadTimeWeavingConfiguration */
private static class AspectJClassBypassingClassFileTransformer implements ClassFileTransformer { private final ClassFileTransformer delegate; public AspectJClassBypassingClassFileTransformer(ClassFileTransformer delegate) { this.delegate = delegate; } @Override 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); } } }