1 /* 2 * Copyright (c) 2016, Oracle and/or its affiliates. All rights reserved. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4 * 5 * This code is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License version 2 only, as 7 * published by the Free Software Foundation. 8 * 9 * This code is distributed in the hope that it will be useful, but WITHOUT 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 12 * version 2 for more details (a copy is included in the LICENSE file that 13 * accompanied this code). 14 * 15 * You should have received a copy of the GNU General Public License version 16 * 2 along with this work; if not, write to the Free Software Foundation, 17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 18 * 19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 20 * or visit www.oracle.com if you need additional information or have any 21 * questions. 22 */ 23 24 import java.lang.instrument.ClassFileTransformer; 25 import java.lang.instrument.Instrumentation; 26 import java.lang.instrument.IllegalClassFormatException; 27 import java.security.ProtectionDomain; 28 import java.util.HashMap; 29 30 // This is a test ulitilty class used to transform 31 // specified classes via initial transformation (CFLH). 32 // Names of classes to be transformed are supplied as arguments, 33 // the phrase to be transformed is a hard-coded predefined 34 // fairly unique phrase. 35 36 public class TransformerAgent { 37 private static String[] classesToTransform; 38 39 40 private static void log(String msg) { 41 System.out.println("TransformerAgent: " + msg); 42 } 43 44 45 // arguments are comma-separated list of classes to transform 46 public static void premain(String agentArguments, Instrumentation instrumentation) { 47 log("premain() is called, arguments = " + agentArguments); 48 classesToTransform = agentArguments.split(","); 49 instrumentation.addTransformer(new SimpleTransformer(), /*canRetransform=*/true); 50 } 51 52 53 public static void agentmain(String args, Instrumentation inst) throws Exception { 54 log("agentmain() is called"); 55 premain(args, inst); 56 } 57 58 59 static class SimpleTransformer implements ClassFileTransformer { 60 public byte[] transform(ClassLoader loader, String name, Class<?> classBeingRedefined, 61 ProtectionDomain pd, byte[] buffer) throws IllegalClassFormatException { 62 63 log("SimpleTransformer called for: " + name + "@" + incrCounter(name)); 64 if (!shouldTransform(name)) 65 return null; 66 67 log("transforming: class name = " + name); 68 int nrOfReplacements = TransformUtil.replace(buffer, "this-should-be-transformed", "this-has-been--transformed"); 69 log("replaced the string, nrOfReplacements = " + nrOfReplacements); 70 return buffer; 71 } 72 73 // Check class name pattern, since test should only transform certain classes 74 private static boolean shouldTransform(String name) { 75 for (String match : classesToTransform) { 76 if (name.matches(match)) { 77 log("shouldTransform: match-found, match = " + match); 78 return true; 79 } 80 } 81 82 return false; 83 } 84 } 85 86 87 static HashMap<String, Integer> counterMap = new HashMap<>(); 88 89 static Integer incrCounter(String className) { 90 Integer i = counterMap.get(className); 91 if (i == null) { 92 i = new Integer(1); 93 } else { 94 i = new Integer(i.intValue() + 1); 95 } 96 counterMap.put(className, i); 97 return i; 98 } 99 }