| /* |
| * Copyright (c) 2013, 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. |
| */ |
| import java.security.*; |
| import java.lang.instrument.*; |
| import java.lang.reflect.*; |
| |
| public class Agent implements ClassFileTransformer { |
| public synchronized byte[] transform(final ClassLoader classLoader, |
| final String className, |
| Class<?> classBeingRedefined, |
| ProtectionDomain protectionDomain, |
| byte[] classfileBuffer) { |
| System.out.println("Transforming class " + className); |
| return classfileBuffer; |
| } |
| |
| public static void redefine(String agentArgs, Instrumentation instrumentation, Class to_redefine) { |
| |
| try { |
| instrumentation.retransformClasses(to_redefine); |
| } catch (Exception e) { |
| e.printStackTrace(); |
| } |
| |
| } |
| |
| public static void premain(String agentArgs, Instrumentation instrumentation) { |
| Agent transformer = new Agent(); |
| instrumentation.addTransformer(transformer, true); |
| |
| // Redefine java/lang/Object and java/lang/reflect/Method.invoke and |
| // java/lang/ClassLoader |
| Class object_class = Object.class; |
| redefine(agentArgs, instrumentation, object_class); |
| |
| Class method_class = Method.class; |
| redefine(agentArgs, instrumentation, method_class); |
| |
| Class loader_class = ClassLoader.class; |
| redefine(agentArgs, instrumentation, loader_class); |
| |
| instrumentation.removeTransformer(transformer); |
| } |
| |
| public static void main(String[] args) { |
| byte[] ba = new byte[0]; |
| |
| // If it survives 1000 GC's, it's good. |
| for (int i = 0; i < 1000 ; i++) { |
| System.gc(); |
| ba.clone(); |
| } |
| try { |
| // Use java/lang/reflect/Method.invoke to call |
| WalkThroughInvoke a = new WalkThroughInvoke(); |
| Class aclass = WalkThroughInvoke.class; |
| Method m = aclass.getMethod("stackWalk"); |
| m.invoke(a); |
| } catch (Exception x) { |
| x.printStackTrace(); |
| } |
| } |
| } |