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1   /*
2    * Copyright (c) 1998, 2013, 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
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7    * published by the Free Software Foundation.  Oracle designates this
8    * particular file as subject to the "Classpath" exception as provided
9    * by Oracle in the LICENSE file that accompanied this code.
10   *
11   * This code is distributed in the hope that it will be useful, but WITHOUT
12   * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13   * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
14   * version 2 for more details (a copy is included in the LICENSE file that
15   * accompanied this code).
16   *
17   * You should have received a copy of the GNU General Public License version
18   * 2 along with this work; if not, write to the Free Software Foundation,
19   * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
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24   */
25  
26  package java.security;
27  
28  
29  /**
30   * A computation to be performed with privileges enabled.  The computation is
31   * performed by invoking {@code AccessController.doPrivileged} on the
32   * {@code PrivilegedAction} object.  This interface is used only for
33   * computations that do not throw checked exceptions; computations that
34   * throw checked exceptions must use {@code PrivilegedExceptionAction}
35   * instead.
36   *
37   * @see AccessController
38   * @see AccessController#doPrivileged(PrivilegedAction)
39   * @see PrivilegedExceptionAction
40   */
41  
42  public interface PrivilegedAction<T> {
43      /**
44       * Performs the computation.  This method will be called by
45       * {@code AccessController.doPrivileged} after enabling privileges.
46       *
47       * @return a class-dependent value that may represent the results of the
48       *         computation. Each class that implements
49       *         {@code PrivilegedAction}
50       *         should document what (if anything) this value represents.
51       * @see AccessController#doPrivileged(PrivilegedAction)
52       * @see AccessController#doPrivileged(PrivilegedAction,
53       *                                     AccessControlContext)
54       */
55      T run();
56  }