01: /*
02: * Copyright 1998-2006 Sun Microsystems, Inc. All Rights Reserved.
03: * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
04: *
05: * This code is free software; you can redistribute it and/or modify it
06: * under the terms of the GNU General Public License version 2 only, as
07: * published by the Free Software Foundation. Sun designates this
08: * particular file as subject to the "Classpath" exception as provided
09: * by Sun 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.
20: *
21: * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
22: * CA 95054 USA or visit www.sun.com if you need additional information or
23: * have any questions.
24: */
25:
26: package sun.security.action;
27:
28: /**
29: * A convenience class for retrieving the string value of a system
30: * property as a privileged action.
31: *
32: * <p>An instance of this class can be used as the argument of
33: * <code>AccessController.doPrivileged</code>.
34: *
35: * <p>The following code retrieves the value of the system
36: * property named <code>"prop"</code> as a privileged action: <p>
37: *
38: * <pre>
39: * String s = java.security.AccessController.doPrivileged
40: * (new GetPropertyAction("prop"));
41: * </pre>
42: *
43: * @author Roland Schemers
44: * @version 1.18, 05/05/07
45: * @see java.security.PrivilegedAction
46: * @see java.security.AccessController
47: * @since 1.2
48: */
49:
50: public class GetPropertyAction implements
51: java.security.PrivilegedAction<String> {
52: private String theProp;
53: private String defaultVal;
54:
55: /**
56: * Constructor that takes the name of the system property whose
57: * string value needs to be determined.
58: *
59: * @param theProp the name of the system property.
60: */
61: public GetPropertyAction(String theProp) {
62: this .theProp = theProp;
63: }
64:
65: /**
66: * Constructor that takes the name of the system property and the default
67: * value of that property.
68: *
69: * @param theProp the name of the system property.
70: * @param defaulVal the default value.
71: */
72: public GetPropertyAction(String theProp, String defaultVal) {
73: this .theProp = theProp;
74: this .defaultVal = defaultVal;
75: }
76:
77: /**
78: * Determines the string value of the system property whose
79: * name was specified in the constructor.
80: *
81: * @return the string value of the system property,
82: * or the default value if there is no property with that key.
83: */
84: public String run() {
85: String value = System.getProperty(theProp);
86: return (value == null) ? defaultVal : value;
87: }
88: }
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