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1   /*
2    * Copyright (c) 2001-2017, Zoltan Farkas All Rights Reserved.
3    *
4    * This library is free software; you can redistribute it and/or
5    * modify it under the terms of the GNU Lesser General Public
6    * License as published by the Free Software Foundation; either
7    * version 2.1 of the License, or (at your option) any later version.
8    *
9    * This library is distributed in the hope that it will be useful,
10   * but WITHOUT ANY WARRANTY; without even the implied warranty of
11   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
12   * GNU General Public License for more details.
13   *
14   * You should have received a copy of the GNU Lesser General Public
15   * License along with this program; if not, write to the Free Software
16   * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
17   *
18   * Additionally licensed with:
19   *
20   * Licensed under the Apache License, Version 2.0 (the "License");
21   * you may not use this file except in compliance with the License.
22   * You may obtain a copy of the License at
23   *
24   *      http://www.apache.org/licenses/LICENSE-2.0
25   *
26   * Unless required by applicable law or agreed to in writing, software
27   * distributed under the License is distributed on an "AS IS" BASIS,
28   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
29   * See the License for the specific language governing permissions and
30   * limitations under the License.
31   */
32  package org.spf4j.base;
33  
34  import java.lang.reflect.Field;
35  import java.security.AccessController;
36  import java.security.PrivilegedAction;
37  import java.util.Collections;
38  import java.util.List;
39  import javax.annotation.ParametersAreNonnullByDefault;
40  
41  /**
42   *
43   * @author Zoltan Farkas
44   */
45  @ParametersAreNonnullByDefault
46  public final class UnsafeThrowable {
47  
48    private UnsafeThrowable() { }
49  
50    private static final Field SUPPRESSED_FIELD;
51  
52    static {
53      SUPPRESSED_FIELD = AccessController.doPrivileged((PrivilegedAction<Field>) () -> {
54        Field suppressedField;
55        try {
56          suppressedField = Throwable.class.getDeclaredField("suppressedExceptions");
57        } catch (NoSuchFieldException | SecurityException ex) {
58          throw new ExceptionInInitializerError(ex);
59        }
60        suppressedField.setAccessible(true);
61        return suppressedField;
62      });
63    }
64  
65    public static List<Throwable> getSuppressedNoCopy(final Throwable t) {
66          try {
67        final List<Throwable> suppressedExceptions = (List<Throwable>) SUPPRESSED_FIELD.get(t);
68        if (suppressedExceptions == null) {
69          return Collections.emptyList();
70        } else {
71          return suppressedExceptions;
72        }
73      } catch (IllegalArgumentException | IllegalAccessException ex) {
74        throw new RuntimeException(ex);
75      }
76    }
77  
78  
79  }