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25 
26 package sun.security.action;
27 
28 import java.security.AccessController;
29 
30 /**
31  * A convenience class for retrieving the integer value of a system property
32  * as a privileged action.
33  *
34  * <p>An instance of this class can be used as the argument of
35  * <code>AccessController.doPrivileged</code>.
36  *
37  * <p>The following code retrieves the integer value of the system
38  * property named <code>"prop"</code> as a privileged action. Since it does
39  * not pass a default value to be used in case the property
40  * <code>"prop"</code> is not defined, it has to check the result for
41  * <code>null</code>:
42  *
43  * <pre>
44  * Integer tmp = java.security.AccessController.doPrivileged
45  *     (new sun.security.action.GetIntegerAction("prop"));
46  * int i;
47  * if (tmp != null) {
48  *     i = tmp.intValue();
49  * }
50  * </pre>
51  *
52  * <p>The following code retrieves the integer value of the system
53  * property named <code>"prop"</code> as a privileged action, and also passes
54  * a default value to be used in case the property <code>"prop"</code> is not
55  * defined:
56  *
57  * <pre>
58  * int i = ((Integer)java.security.AccessController.doPrivileged(
59  *                         new GetIntegerAction("prop", 3))).intValue();
60  * </pre>
61  *
62  * @author Roland Schemers
63  * @see java.security.PrivilegedAction
64  * @see java.security.AccessController
65  * @since 1.2
66  */
67 
68 public class GetIntegerAction
69         implements java.security.PrivilegedAction<Integer> {
70     private String theProp;
71     private int defaultVal;
72     private boolean defaultSet;
73 
74     /**
75      * Constructor that takes the name of the system property whose integer
76      * value needs to be determined.
77      *
78      * @param theProp the name of the system property.
79      */
GetIntegerAction(String theProp)80     public GetIntegerAction(String theProp) {
81         this.theProp = theProp;
82     }
83 
84     /**
85      * Constructor that takes the name of the system property and the default
86      * value of that property.
87      *
88      * @param theProp the name of the system property.
89      * @param defaultVal the default value.
90      */
GetIntegerAction(String theProp, int defaultVal)91     public GetIntegerAction(String theProp, int defaultVal) {
92         this.theProp = theProp;
93         this.defaultVal = defaultVal;
94         this.defaultSet = true;
95     }
96 
97     /**
98      * Determines the integer value of the system property whose name was
99      * specified in the constructor.
100      *
101      * <p>If there is no property of the specified name, or if the property
102      * does not have the correct numeric format, then an <code>Integer</code>
103      * object representing the default value that was specified in the
104      * constructor is returned, or <code>null</code> if no default value was
105      * specified.
106      *
107      * @return the <code>Integer</code> value of the property.
108      */
run()109     public Integer run() {
110         Integer value = Integer.getInteger(theProp);
111         if ((value == null) && defaultSet)
112             return defaultVal;
113         return value;
114     }
115 
116     /**
117      * Convenience method to get a property without going through doPrivileged
118      * if no security manager is present. This is unsafe for inclusion in a
119      * public API but allowable here since this class is now encapsulated.
120      *
121      * Note that this method performs a privileged action using caller-provided
122      * inputs. The caller of this method should take care to ensure that the
123      * inputs are not tainted and the returned property is not made accessible
124      * to untrusted code if it contains sensitive information.
125      *
126      * @param theProp the name of the system property.
127      */
128     @SuppressWarnings("removal")
privilegedGetProperty(String theProp)129     public static Integer privilegedGetProperty(String theProp) {
130         if (System.getSecurityManager() == null) {
131             return Integer.getInteger(theProp);
132         } else {
133             return AccessController.doPrivileged(
134                     new GetIntegerAction(theProp));
135         }
136     }
137 
138     /**
139      * Convenience method to get a property without going through doPrivileged
140      * if no security manager is present. This is unsafe for inclusion in a
141      * public API but allowable here since this class is now encapsulated.
142      *
143      * Note that this method performs a privileged action using caller-provided
144      * inputs. The caller of this method should take care to ensure that the
145      * inputs are not tainted and the returned property is not made accessible
146      * to untrusted code if it contains sensitive information.
147      *
148      * @param theProp the name of the system property.
149      * @param defaultVal the default value.
150      */
151     @SuppressWarnings("removal")
privilegedGetProperty(String theProp, int defaultVal)152     public static Integer privilegedGetProperty(String theProp,
153             int defaultVal) {
154         Integer value;
155         if (System.getSecurityManager() == null) {
156             value = Integer.getInteger(theProp);
157         } else {
158             value = AccessController.doPrivileged(
159                     new GetIntegerAction(theProp));
160         }
161         return (value != null) ? value : defaultVal;
162     }
163 }
164