1 /*

     2  * Copyright (c) 2016, 2018, 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 

    25 import sun.hotspot.WhiteBox;

    26 

    27 // package access top-level class to avoid problem with RedefineClassHelper

    28 // and nested types.

    29 class RedefineBasic_B {

    30     public static void okToCallBeforeRedefine() {

    31         System.out.println("okToCallBeforeRedefine");

    32     }

    33     public static void okToCallAfterRedefine() {

    34         throw new RuntimeException("okToCallAfterRedefine is called before redefinition, test failed");

    35     }

    36 }

    37 

    38 public class RedefineBasic {

    39 

    40     public static String newB =

    41         " class RedefineBasic_B { " +

    42         " public static void okToCallBeforeRedefine() { " +

    43         "    throw new RuntimeException(\"newB: okToCallBeforeRedefine is " +

    44         "    called after redefinition, test failed\"); }" +

    45         " public static void okToCallAfterRedefine() { " +

    46         "     System.out.println(\"newB: okToCallAfterRedefine\"); } " +

    47         " } ";

    48 

    49 

    50 

    51     static class SubclassOfB extends RedefineBasic_B {

    52         public static void testAfterRedefine() {

    53             RedefineBasic_B.okToCallAfterRedefine();

    54         }

    55     }

    56 

    57     class Subclass2OfB extends RedefineBasic_B {

    58         public void testAfterRedefine() {

    59             super.okToCallAfterRedefine();

    60         }

    61     }

    62 

    63     // verify that a given class is shared, report error if necessary

    64     public static void

    65     verifyClassIsShared(WhiteBox wb, Class c) throws Exception {

    66         if (!wb.isSharedClass(c)) {

    67             throw new RuntimeException(

    68             "This class should be shared but isn't: " + c.getName());

    69         } else {

    70             System.out.println("The class is shared as expected: " +

    71                 c.getName());

    72         }

    73     }

    74 

    75     public static void main(String[] args) throws Exception {

    76         WhiteBox wb = WhiteBox.getWhiteBox();

    77 

    78         verifyClassIsShared(wb, RedefineBasic.class);

    79         verifyClassIsShared(wb, RedefineBasic_B.class);

    80         verifyClassIsShared(wb, SubclassOfB.class);

    81         verifyClassIsShared(wb, Subclass2OfB.class);

    82 

    83         // (1) Test case: verify that original B works as expected

    84         // and that redefined B is shared and works as expected,

    85         // with new behavior

    86         RedefineBasic_B.okToCallBeforeRedefine();

    87         RedefineClassHelper.redefineClass(RedefineBasic_B.class, newB);

    88         verifyClassIsShared(wb, RedefineBasic_B.class);

    89         RedefineBasic_B.okToCallAfterRedefine();

    90 

    91         // Static subclass of the super:

    92         // 1. Make sure it is still shared

    93         // 2. and it calls the correct super (the redefined one)

    94         verifyClassIsShared(wb, SubclassOfB.class);

    95         SubclassOfB.testAfterRedefine();

    96 

    97         // Same as above, but for non-static class

    98         verifyClassIsShared(wb, Subclass2OfB.class);

    99         RedefineBasic thisTest = new RedefineBasic();

   100         thisTest.testSubclass2OfB();

   101     }

   102 

   103     public void testSubclass2OfB() {

   104         Subclass2OfB sub = new Subclass2OfB();

   105         sub.testAfterRedefine();

   106     }

   107 }