BootstrapClassPathAgent.java

/*
 * Copyright (c) 2016, Oracle and/or its affiliates. All rights reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.
 *
 * This code 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 General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
 * or visit www.oracle.com if you need additional information or have any
 * questions.
 */

package p;

import java.io.*;
import java.lang.instrument.ClassFileTransformer;
import java.lang.instrument.Instrumentation;
import java.security.ProtectionDomain;

public class BootstrapClassPathAgent {

    public static void premain(String args, Instrumentation inst) {
        System.out.println("agent loader=" + BootstrapClassPathAgent.class.getClassLoader());
        inst.addTransformer(new MyTransformer());
    }

    static class MyTransformer implements ClassFileTransformer {

        public byte[] transform(Module module,
                                String className,
                                Class<?> classBeingRedefined,
                                ProtectionDomain    protectionDomain,
                                byte[] classfileBuffer) {
            System.out.println(className + ", module=" + module);
            return null;
        }
    }
}