/*
* JBoss, Home of Professional Open Source
* Copyright 2005, JBoss Inc., and individual contributors as indicated
* by the @authors tag. See the copyright.txt in the distribution for a
* full listing of individual contributors.
*
* This is free software; you can redistribute it and/or modify it
* under the terms of the GNU Lesser General Public License as
* published by the Free Software Foundation; either version 2.1 of
* the License, or (at your option) any later version.
*
* This software 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 software; if not, write to the Free
* Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
* 02110-1301 USA, or see the FSF site: http://www.fsf.org.
*/
package org.jboss.aop.hook;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import javassist.CannotCompileException;
import javassist.ClassPool;
import javassist.CtClass;
import javassist.CtMethod;
import javassist.CtNewMethod;
import javassist.LoaderClassPath;
import javassist.Modifier;
import javassist.NotFoundException;
/**
* Generate the instrumented version of the classloader and store it in the filesystem.
*
* @author kevin
*/
public class GenerateInstrumentedClassLoader
{
private static void declare5(CtClass clazz, CtMethod method) throws NotFoundException, CannotCompileException
{
method.setName("wrappedDefineClass");
CtMethod wrapper = CtNewMethod.make(Modifier.PROTECTED, method.getReturnType(), "defineClass", method.getParameterTypes(), method.getExceptionTypes(), null, clazz);
String code = "{"
+ " byte[] newBytes = org.jboss.aop.AspectManager.instance().translate($1, $0, $2) ;"
+ " if (newBytes != (byte[])null) {"
+ " return wrappedDefineClass($1, newBytes, 0, newBytes.length, $5); "
+ " } else {"
+ " return wrappedDefineClass($1, $2, $3, $4, $5); "
+ " }"
+ "}";
wrapper.setBody(code);
clazz.addMethod(wrapper);
}
/**
* Get the instrumented version of the class loader.
*
* @return The instrumented version of the class loader.
* @throws javassist.NotFoundException if the class loader cannot be found.
* @throws javassist.CannotCompileException
* if the class cannot be compiled.
* @throws java.io.IOException If the class bytecodes cannot be obtained.
*/
public static byte[] getInstrumentedClassLoader()
throws NotFoundException, IOException, CannotCompileException
{
ClassPool classpool = ClassPool.getDefault();
classpool = ClassPool.getDefault();
ClassLoader cl = Thread.currentThread().getContextClassLoader();
classpool.insertClassPath(new LoaderClassPath(cl));
final CtClass clazz = classpool.get(ClassLoader.class.getName());
CtMethod[] methods = clazz.getDeclaredMethods();
for (int i = 0; i < methods.length; i++)
{
if (methods[i].getName().equals("defineClass"))
{
if (methods[i].getParameterTypes().length == 5
&& methods[i].getParameterTypes()[1].isArray())
{
declare5(clazz, methods[i]);
}
}
}
return clazz.toBytecode();
}
/**
* Store the instrumented classloader in the filesystem.
*
* @param args The filename as the first argument.
*/
public static void main(final String[] args)
{
if (args.length != 1)
{
System.err.println("Usage: java " + GeneratePluggableInstrumentedClassLoader.class.getName() + " <output directory>");
System.exit(1);
}
final String filename = args[0] + File.separatorChar +
"java" + File.separatorChar +
"lang" + File.separatorChar +
"ClassLoader.class";
final File file = new File(filename);
if (file.exists())
{
if (!file.canWrite())
{
System.err.println("Cannot write to existing file: " + file.getAbsolutePath());
System.exit(2);
}
}
else
{
final File dir = file.getParentFile();
if (!dir.exists())
{
dir.mkdirs();
}
if (!dir.canWrite())
{
System.err.println("Cannot write to parent directory: " + dir.getAbsolutePath());
}
}
final byte[] bytes;
try
{
bytes = getInstrumentedClassLoader();
}
catch (final Throwable th)
{
System.err.println("Unexpected exception caught during instrumentation: " + th.getMessage());
th.printStackTrace(System.err);
System.exit(5);
return;
}
try
{
final FileOutputStream fos = new FileOutputStream(file);
fos.write(bytes);
fos.close();
}
catch (final IOException ioe)
{
System.err.println("Unexpected exception caught while writing class file: " + ioe.getMessage());
ioe.printStackTrace(System.err);
System.exit(6);
}
}
}