/**************************************************************************************
* Copyright (c) Jonas Bon�r, Alexandre Vasseur. All rights reserved. *
* http://aspectwerkz.codehaus.org *
* ---------------------------------------------------------------------------------- *
* The software in this package is published under the terms of the LGPL license *
* a copy of which has been included with this distribution in the license.txt file. *
**************************************************************************************/
package org.codehaus.aspectwerkz.hook.impl;
import org.codehaus.aspectwerkz.hook.ClassLoaderPatcher;
import org.codehaus.aspectwerkz.hook.ClassLoaderPreProcessor;
import java.io.InputStream;
import javassist.CannotCompileException;
import javassist.ClassPool;
import javassist.CtClass;
import javassist.expr.ExprEditor;
import javassist.expr.MethodCall;
/**
* Instruments the java.lang.ClassLoader to plug in the Class PreProcessor mechanism using Javassist. <p/>We are using a
* lazy initialization of the class preprocessor to allow all class pre processor logic to be in system classpath and
* not in bootclasspath. <p/>This implementation should support IBM custom JRE
*
* @author <a href="mailto:alex@gnilux.com">Alexandre Vasseur </a>
*/
public class ClassLoaderPreProcessorImpl implements ClassLoaderPreProcessor {
public ClassLoaderPreProcessorImpl() {
}
public byte[] preProcess(final byte[] b) {
try {
ClassPool pool = ClassPool.getDefault();
CtClass klass = pool.get("java.lang.ClassLoader");
// patch caller side of defineClass0
// pre-call
// byte[] besee =
// com.gnilux.besee.hook.impl.ClassPreProcessorHelper.defineClass0Pre(this, $$);
// <call> c = defineClass0(name, besee, 0, besee.length, protectionDomain);
ExprEditor defineClass0Pre = new ExprEditor() {
public void edit(MethodCall m) throws CannotCompileException {
if ("defineClass0".equals(m.getMethodName())) {
int argsCount = 5;
// For SUN VM, argCount = 5: name, byte[], int, int, ProtectionDomain
// For IBM 1.3, argCount = 7: ... + Certificate + byte[] flatSource
try {
argsCount = m.getMethod().getParameterTypes().length;
} catch (Throwable t) {
throw new RuntimeException(t.toString());
}
if (argsCount == 5) {
m.replace(
'{'
+
" byte[] newBytes = org.codehaus.aspectwerkz.hook.impl.ClassPreProcessorHelper.defineClass0Pre($0, $$);"
+ " $_ = $proceed($1, newBytes, 0, newBytes.length, $5);"
+ '}'
);
} else if (argsCount == 7) {
m.replace(
'{'
+
" byte[] newBytes = org.codehaus.aspectwerkz.hook.impl.ClassPreProcessorHelper.defineClass0Pre($0, $1, $2, $3, $4, $5);"
+ " $_ = $proceed($1, newBytes, 0, newBytes.length, $5, $6, $7);"
+ '}'
);
}
}
}
};
klass.instrument(defineClass0Pre);
//
// pool.writeFile("java.lang.ClassLoader", "___");
// System.out.println("========DUMPED");
return klass.toBytecode();
// return pool.write("java.lang.ClassLoader");
} catch (Exception e) {
System.err.println("failed to patch ClassLoader:");
e.printStackTrace();
return b;
}
}
/**
* main test
*/
public static void main(String[] args) throws Exception {
ClassLoaderPreProcessor me = new ClassLoaderPreProcessorImpl();
InputStream is = ClassLoader.getSystemClassLoader().getParent().getResourceAsStream(
"java/lang/ClassLoader.class"
);
me.preProcess(ClassLoaderPatcher.inputStreamToByteArray(is));
is.close();
}
}