/*
* Hibernate, Relational Persistence for Idiomatic Java
*
* Copyright (c) 2008-2013, Red Hat Inc. or third-party contributors as
* indicated by the @author tags or express copyright attribution
* statements applied by the authors. All third-party contributions are
* distributed under license by Red Hat Inc.
*
* This copyrighted material is made available to anyone wishing to use, modify,
* copy, or redistribute it subject to the terms and conditions of the GNU
* Lesser General Public License, as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
* or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License
* for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with this distribution; if not, write to:
* Free Software Foundation, Inc.
* 51 Franklin Street, Fifth Floor
* Boston, MA 02110-1301 USA
*/
package org.hibernate.bytecode.internal.javassist;
import java.io.IOException;
import javassist.CannotCompileException;
import javassist.ClassPool;
import javassist.CtClass;
import javassist.NotFoundException;
import org.hibernate.HibernateException;
/**
* A ClassLoader implementation applying Class transformations as they are being loaded.
*
* @author Steve Ebersole
*/
@SuppressWarnings("UnusedDeclaration")
public class TransformingClassLoader extends ClassLoader {
private ClassLoader parent;
private ClassPool classPool;
TransformingClassLoader(ClassLoader parent, String[] classpaths) {
this.parent = parent;
this.classPool = new ClassPool( true );
for ( String classpath : classpaths ) {
try {
classPool.appendClassPath( classpath );
}
catch (NotFoundException e) {
throw new HibernateException(
"Unable to resolve requested classpath for transformation [" +
classpath + "] : " + e.getMessage()
);
}
}
}
@Override
protected Class findClass(String name) throws ClassNotFoundException {
try {
final CtClass cc = classPool.get( name );
// todo : modify the class definition if not already transformed...
final byte[] b = cc.toBytecode();
return defineClass( name, b, 0, b.length );
}
catch (NotFoundException e) {
throw new ClassNotFoundException();
}
catch (IOException e) {
throw new ClassNotFoundException();
}
catch (CannotCompileException e) {
throw new ClassNotFoundException();
}
}
/**
* Used to release resources. Call when done with the ClassLoader
*/
public void release() {
classPool = null;
parent = null;
}
}