/*
* Copyright 2002-2007 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.instrument.classloading.glassfish;
import java.lang.instrument.ClassFileTransformer;
import com.sun.enterprise.loader.InstrumentableClassLoader;
import org.springframework.instrument.classloading.LoadTimeWeaver;
import org.springframework.util.Assert;
import org.springframework.util.ClassUtils;
/**
* {@link LoadTimeWeaver} implementation for GlassFish's
* {@link InstrumentableClassLoader}.
*
* @author Costin Leau
* @author Juergen Hoeller
* @since 2.0.1
* @see com.sun.enterprise.loader.InstrumentableClassLoader
*/
public class GlassFishLoadTimeWeaver implements LoadTimeWeaver {
private final InstrumentableClassLoader classLoader;
/**
* Create a new instance of the <code>GlassFishLoadTimeWeaver</code> class
* using the default {@link ClassLoader}.
* @see #GlassFishLoadTimeWeaver(ClassLoader)
*/
public GlassFishLoadTimeWeaver() {
this(ClassUtils.getDefaultClassLoader());
}
/**
* Create a new instance of the <code>GlassFishLoadTimeWeaver</code> class.
* @param classLoader the specific {@link ClassLoader} to use; must not be <code>null</code>
* @throws IllegalArgumentException if the supplied <code>classLoader</code> is <code>null</code>;
* or if the supplied <code>classLoader</code> is not an {@link InstrumentableClassLoader}
*/
public GlassFishLoadTimeWeaver(ClassLoader classLoader) {
Assert.notNull(classLoader, "ClassLoader must not be null");
InstrumentableClassLoader icl = determineClassLoader(classLoader);
if (icl == null) {
throw new IllegalArgumentException(classLoader + " and its parents are not suitable ClassLoaders: " +
"An [" + InstrumentableClassLoader.class.getName() + "] implementation is required.");
}
this.classLoader = icl;
}
/**
* Determine the GlassFish {@link InstrumentableClassLoader} for the given
* {@link ClassLoader}.
* @param classLoader the <code>ClassLoader</code> to check
* @return the <code>InstrumentableClassLoader</code>, or <code>null</code> if none found
*/
protected InstrumentableClassLoader determineClassLoader(ClassLoader classLoader) {
// Detect transformation-aware ClassLoader by traversing the hierarchy
// (as in GlassFish, Spring can be loaded by the WebappClassLoader).
for (ClassLoader cl = classLoader; cl != null; cl = cl.getParent()) {
if (cl instanceof InstrumentableClassLoader) {
return (InstrumentableClassLoader) cl;
}
}
return null;
}
public void addTransformer(ClassFileTransformer transformer) {
this.classLoader.addTransformer(new ClassTransformerAdapter(transformer));
}
public ClassLoader getInstrumentableClassLoader() {
return (ClassLoader) this.classLoader;
}
public ClassLoader getThrowawayClassLoader() {
return this.classLoader.copy();
}
}