1/*
2 * Copyright (c) 1998, 2006, 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.  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.
20 *
21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22 * or visit www.oracle.com if you need additional information or have any
23 * questions.
24 */
25
26package 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 * @see java.security.PrivilegedAction
45 * @see java.security.AccessController
46 * @since 1.2
47 */
48
49public class GetPropertyAction
50        implements java.security.PrivilegedAction<String> {
51    private String theProp;
52    private String defaultVal;
53
54    /**
55     * Constructor that takes the name of the system property whose
56     * string value needs to be determined.
57     *
58     * @param theProp the name of the system property.
59     */
60    public GetPropertyAction(String theProp) {
61        this.theProp = theProp;
62    }
63
64    /**
65     * Constructor that takes the name of the system property and the default
66     * value of that property.
67     *
68     * @param theProp the name of the system property.
69     * @param defaulVal the default value.
70     */
71    public GetPropertyAction(String theProp, String defaultVal) {
72        this.theProp = theProp;
73        this.defaultVal = defaultVal;
74    }
75
76    /**
77     * Determines the string value of the system property whose
78     * name was specified in the constructor.
79     *
80     * @return the string value of the system property,
81     *         or the default value if there is no property with that key.
82     */
83    public String run() {
84        String value = System.getProperty(theProp);
85        return (value == null) ? defaultVal : value;
86    }
87}
88