Source code: edu/emory/mathcs/util/security/action/GetPropertyAction.java
1 /* ***** BEGIN LICENSE BLOCK *****
2 * Version: MPL 1.1/GPL 2.0/LGPL 2.1
3 *
4 * The contents of this file are subject to the Mozilla Public License Version
5 * 1.1 (the "License"); you may not use this file except in compliance with
6 * the License. You may obtain a copy of the License at
7 * http://www.mozilla.org/MPL/
8 *
9 * Software distributed under the License is distributed on an "AS IS" basis,
10 * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
11 * for the specific language governing rights and limitations under the
12 * License.
13 *
14 * The Original Code is the Emory Utilities.
15 *
16 * The Initial Developer of the Original Code is
17 * The Distributed Computing Laboratory, Emory University.
18 * Portions created by the Initial Developer are Copyright (C) 2002
19 * the Initial Developer. All Rights Reserved.
20 *
21 * Alternatively, the contents of this file may be used under the terms of
22 * either the GNU General Public License Version 2 or later (the "GPL"), or
23 * the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
24 * in which case the provisions of the GPL or the LGPL are applicable instead
25 * of those above. If you wish to allow use of your version of this file only
26 * under the terms of either the GPL or the LGPL, and not to allow others to
27 * use your version of this file under the terms of the MPL, indicate your
28 * decision by deleting the provisions above and replace them with the notice
29 * and other provisions required by the GPL or the LGPL. If you do not delete
30 * the provisions above, a recipient may use your version of this file under
31 * the terms of any one of the MPL, the GPL or the LGPL.
32 *
33 * ***** END LICENSE BLOCK ***** */
34
35 package edu.emory.mathcs.util.security.action;
36
37 import java.security.*;
38
39 /**
40 * A convenience class for retrieving the string value of a system property
41 * as a privileged action.
42 *
43 * @see java.security.PrivilegedAction
44 * @see java.security.AccessController
45 */
46 public class GetPropertyAction implements PrivilegedAction {
47 private String prop;
48 private String defaultVal;
49
50 /**
51 * Constructor that takes the name of the system property whose
52 * string value needs to be determined.
53 *
54 * @param prop the name of the system property
55 */
56 public GetPropertyAction(String prop) {
57 this(prop, null);
58 }
59
60 /**
61 * Constructor that takes the name of the system property and the default
62 * value to be used when property is not set.
63 *
64 * @param prop the name of the system property
65 * @param defaultVal the default value
66 */
67 public GetPropertyAction(String prop, String defaultVal) {
68 this.prop = prop;
69 this.defaultVal = defaultVal;
70 }
71
72 /**
73 * Determines the string value of the system property whose
74 * name was specified in the constructor.
75 *
76 * @return the string value of the system property,
77 * or the default value if there is no property with that key.
78 */
79 public Object run() {
80 String val = System.getProperty(prop);
81 return (val != null) ? val : defaultVal;
82 }
83 }