/*
* Hibernate, Relational Persistence for Idiomatic Java
*
* Copyright (c) 2009, Red Hat Middleware LLC 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 Middleware LLC.
*
* 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.buildtime;
import java.io.ByteArrayInputStream;
import java.io.DataInputStream;
import java.io.IOException;
import java.util.Set;
import javassist.bytecode.ClassFile;
import org.hibernate.bytecode.ClassTransformer;
import org.hibernate.bytecode.javassist.BytecodeProviderImpl;
import org.hibernate.bytecode.javassist.FieldHandled;
import org.hibernate.bytecode.util.BasicClassFilter;
import org.hibernate.bytecode.util.ClassDescriptor;
/**
* Strategy for performing build-time instrumentation of persistent classes in order to enable
* field-level interception using Javassist.
*
* @author Steve Ebersole
* @author Muga Nishizawa
*/
public class JavassistInstrumenter extends AbstractInstrumenter {
private static final BasicClassFilter CLASS_FILTER = new BasicClassFilter();
private final BytecodeProviderImpl provider = new BytecodeProviderImpl();
public JavassistInstrumenter(Logger logger, Options options) {
super( logger, options );
}
protected ClassDescriptor getClassDescriptor(byte[] bytecode) throws IOException {
return new CustomClassDescriptor( bytecode );
}
protected ClassTransformer getClassTransformer(ClassDescriptor descriptor, Set classNames) {
if ( descriptor.isInstrumented() ) {
logger.debug( "class [" + descriptor.getName() + "] already instrumented" );
return null;
}
else {
return provider.getTransformer( CLASS_FILTER, new CustomFieldFilter( descriptor, classNames ) );
}
}
private static class CustomClassDescriptor implements ClassDescriptor {
private final byte[] bytes;
private final ClassFile classFile;
public CustomClassDescriptor(byte[] bytes) throws IOException {
this.bytes = bytes;
this.classFile = new ClassFile( new DataInputStream( new ByteArrayInputStream( bytes ) ) );
}
public String getName() {
return classFile.getName();
}
public boolean isInstrumented() {
String[] intfs = classFile.getInterfaces();
for ( int i = 0; i < intfs.length; i++ ) {
if ( FieldHandled.class.getName().equals( intfs[i] ) ) {
return true;
}
}
return false;
}
public byte[] getBytes() {
return bytes;
}
}
}