/*
* Copyright 2002-2010 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 org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.springframework.beans.factory.BeanClassLoaderAware;
import org.springframework.beans.factory.DisposableBean;
import org.springframework.instrument.InstrumentationSavingAgent;
import org.springframework.instrument.classloading.InstrumentationLoadTimeWeaver;
import org.springframework.instrument.classloading.LoadTimeWeaver;
import org.springframework.instrument.classloading.ReflectiveLoadTimeWeaver;
import org.springframework.instrument.classloading.glassfish.GlassFishLoadTimeWeaver;
import org.springframework.instrument.classloading.jboss.JBossLoadTimeWeaver;
import org.springframework.instrument.classloading.oc4j.OC4JLoadTimeWeaver;
import org.springframework.instrument.classloading.weblogic.WebLogicLoadTimeWeaver;
/**
* Default {@link LoadTimeWeaver} bean for use in an application context,
* decorating an automatically detected internal <code>LoadTimeWeaver</code>.
*
* <p>Typically registered for the default bean name
* "<code>loadTimeWeaver</code>"; the most convenient way to achieve this is
* Spring's <code><context:load-time-weaver></code> XML tag.
*
* <p>This class implements a runtime environment check for obtaining the
* appropriate weaver implementation: As of Spring 2.5, it detects Sun's
* GlassFish, Oracle's OC4J, BEA's WebLogic 10,
* {@link InstrumentationSavingAgent Spring's VM agent} and any
* {@link ClassLoader} supported by Spring's {@link ReflectiveLoadTimeWeaver}
* (for example the
* {@link org.springframework.instrument.classloading.tomcat.TomcatInstrumentableClassLoader}).
*
* @author Juergen Hoeller
* @author Ramnivas Laddad
* @since 2.5
* @see org.springframework.context.ConfigurableApplicationContext#LOAD_TIME_WEAVER_BEAN_NAME
*/
public class DefaultContextLoadTimeWeaver implements LoadTimeWeaver, BeanClassLoaderAware, DisposableBean {
protected final Log logger = LogFactory.getLog(getClass());
private LoadTimeWeaver loadTimeWeaver;
public void setBeanClassLoader(ClassLoader classLoader) {
LoadTimeWeaver serverSpecificLoadTimeWeaver = createServerSpecificLoadTimeWeaver(classLoader);
if (serverSpecificLoadTimeWeaver != null) {
if (logger.isInfoEnabled()) {
logger.info("Determined server-specific load-time weaver: " +
serverSpecificLoadTimeWeaver.getClass().getName());
}
this.loadTimeWeaver = serverSpecificLoadTimeWeaver;
}
else if (InstrumentationLoadTimeWeaver.isInstrumentationAvailable()) {
logger.info("Found Spring's JVM agent for instrumentation");
this.loadTimeWeaver = new InstrumentationLoadTimeWeaver(classLoader);
}
else {
try {
this.loadTimeWeaver = new ReflectiveLoadTimeWeaver(classLoader);
logger.info("Using a reflective load-time weaver for class loader: " +
this.loadTimeWeaver.getInstrumentableClassLoader().getClass().getName());
}
catch (IllegalStateException ex) {
throw new IllegalStateException(ex.getMessage() + " Specify a custom LoadTimeWeaver or start your " +
"Java virtual machine with Spring's agent: -javaagent:org.springframework.instrument.jar");
}
}
}
/*
* This method never fails, allowing to try other possible ways to use an
* server-agnostic weaver. This non-failure logic is required since
* determining a load-time weaver based on the ClassLoader name alone may
* legitimately fail due to other mismatches. Specific case in point: the
* use of WebLogicLoadTimeWeaver works for WLS 10 but fails due to the lack
* of a specific method (addInstanceClassPreProcessor) for any earlier
* versions even though the ClassLoader name is the same.
*/
protected LoadTimeWeaver createServerSpecificLoadTimeWeaver(ClassLoader classLoader) {
String name = classLoader.getClass().getName();
try {
if (name.startsWith("weblogic")) {
return new WebLogicLoadTimeWeaver(classLoader);
}
else if (name.startsWith("oracle")) {
return new OC4JLoadTimeWeaver(classLoader);
}
else if (name.startsWith("com.sun.enterprise") || name.startsWith("org.glassfish")) {
return new GlassFishLoadTimeWeaver(classLoader);
}
else if (name.startsWith("org.jboss")) {
return new JBossLoadTimeWeaver(classLoader);
}
}
catch (IllegalStateException ex) {
logger.info("Could not obtain server-specific LoadTimeWeaver: " + ex.getMessage());
}
return null;
}
public void destroy() {
if (this.loadTimeWeaver instanceof InstrumentationLoadTimeWeaver) {
logger.info("Removing all registered transformers for class loader: " +
this.loadTimeWeaver.getInstrumentableClassLoader().getClass().getName());
((InstrumentationLoadTimeWeaver) this.loadTimeWeaver).removeTransformers();
}
}
public void addTransformer(ClassFileTransformer transformer) {
this.loadTimeWeaver.addTransformer(transformer);
}
public ClassLoader getInstrumentableClassLoader() {
return this.loadTimeWeaver.getInstrumentableClassLoader();
}
public ClassLoader getThrowawayClassLoader() {
return this.loadTimeWeaver.getThrowawayClassLoader();
}
}
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