/* * Copyright (c) 2014, 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.io.DataInputStream; import java.io.File; import java.io.FileInputStream; import java.lang.instrument.ClassDefinition; import java.lang.instrument.Instrumentation; /* * This class is present during compilation, but will be deleted before execution. */ class MyUnresolvedClass { static void bar() { } } class MyRedefinedClass { static void foo() { MyUnresolvedClass.bar(); } } public class UnresolvedClassAgent { public static void main(String... args) { } public static void premain(String args, Instrumentation inst) throws Exception { try { MyRedefinedClass.foo(); } catch(NoClassDefFoundError err) { System.out.println("NoClassDefFoundError (expected)"); } File f = new File(System.getProperty("test.classes"), "MyRedefinedClass.class"); byte[] buf = new byte[(int)f.length()]; try (DataInputStream dis = new DataInputStream(new FileInputStream(f))) { dis.readFully(buf); } ClassDefinition cd = new ClassDefinition(MyRedefinedClass.class, buf); inst.redefineClasses(new ClassDefinition[] {cd}); try { MyRedefinedClass.foo(); } catch(NoClassDefFoundError err) { System.out.println("NoClassDefFoundError (expected again)"); } } }