1 /* 2 * Copyright (c) 2014, 2015, 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.io.PrintWriter; 25 import java.lang.instrument.*; 26 import jdk.test.lib.*; 27 28 /* 29 * Helper class to write tests that redefine classes. 30 * When main method is run, it will create a redefineagent.jar that can be used 31 * with the -javaagent option to support redefining classes in jtreg tests. 32 * 33 * See sample test in test/testlibrary_tests/RedefineClassTest.java 34 */ 35 public class RedefineClassHelper { 36 37 public static Instrumentation instrumentation; 38 public static void premain(String agentArgs, Instrumentation inst) { 39 instrumentation = inst; 40 } 41 42 /** 43 * Redefine a class 44 * 45 * @param clazz Class to redefine 46 * @param javacode String with the new java code for the class to be redefined 47 */ 48 public static void redefineClass(Class clazz, String javacode) throws Exception { 49 byte[] bytecode = InMemoryJavaCompiler.compile(clazz.getName(), javacode); 50 redefineClass(clazz, bytecode); 51 } 52 53 /** 54 * Redefine a class 55 * 56 * @param clazz Class to redefine 57 * @param bytecode byte[] with the new class 58 */ 59 public static void redefineClass(Class clazz, byte[] bytecode) throws Exception { 60 instrumentation.redefineClasses(new ClassDefinition(clazz, bytecode)); 61 } 62 63 /** 64 * Main method to be invoked before test to create the redefineagent.jar 65 */ 66 public static void main(String[] args) throws Exception { 67 ClassFileInstaller.main("RedefineClassHelper"); 68 69 PrintWriter pw = new PrintWriter("MANIFEST.MF"); 70 pw.println("Premain-Class: RedefineClassHelper"); 71 pw.println("Can-Redefine-Classes: true"); 72 pw.close(); 73 74 sun.tools.jar.Main jarTool = new sun.tools.jar.Main(System.out, System.err, "jar"); 75 if (!jarTool.run(new String[] { "-cmf", "MANIFEST.MF", "redefineagent.jar", "RedefineClassHelper.class" })) { 76 throw new Exception("jar operation failed"); 77 } 78 } 79 }