1 /*
   2  * Copyright (c) 2014, 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.DataInputStream;
  25 import java.io.File;
  26 import java.io.FileInputStream;
  27 import java.lang.instrument.ClassDefinition;
  28 import java.lang.instrument.Instrumentation;
  29 
  30 /*
  31  * This class is present during compilation, but will be deleted before execution.
  32  */
  33 class MyUnresolvedClass {
  34     static void bar() {
  35     }
  36 }
  37 
  38 class MyRedefinedClass {
  39     static void foo() {
  40         MyUnresolvedClass.bar();
  41     }
  42 }
  43 
  44 public class UnresolvedClassAgent {
  45     public static void main(String... args) {
  46     }
  47 
  48     public static void premain(String args, Instrumentation inst) throws Exception {
  49         try {
  50             MyRedefinedClass.foo();
  51         } catch(NoClassDefFoundError err) {
  52             System.out.println("NoClassDefFoundError (expected)");
  53         }
  54 
  55         File f = new File(System.getProperty("test.classes"), "MyRedefinedClass.class");
  56         byte[] buf = new byte[(int)f.length()];
  57         try (DataInputStream dis = new DataInputStream(new FileInputStream(f))) {
  58             dis.readFully(buf);
  59         }
  60         ClassDefinition cd = new ClassDefinition(MyRedefinedClass.class, buf);
  61         inst.redefineClasses(new ClassDefinition[] {cd});
  62 
  63         try {
  64             MyRedefinedClass.foo();
  65         } catch(NoClassDefFoundError err) {
  66             System.out.println("NoClassDefFoundError (expected again)");
  67         }
  68     }
  69 }