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 
  26 package sun.security.action;
  27 
  28 /**
  29  * A convenience class for retrieving the <code>Long</code> 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 <code>Long</code> value of the system
  36  * property named <code>"prop"</code> as a privileged action. Since it does
  37  * not pass a default value to be used in case the property
  38  * <code>"prop"</code> is not defined, it has to check the result for
  39  * <code>null</code>: <p>
  40  *
  41  * <pre>
  42  * Long tmp = java.security.AccessController.doPrivileged
  43  *     (new sun.security.action.GetLongAction("prop"));
  44  * long l;
  45  * if (tmp != null) {
  46  *     l = tmp.longValue();
  47  * }
  48  * </pre>
  49  *
  50  * <p>The following code retrieves the <code>Long</code> value of the system
  51  * property named <code>"prop"</code> as a privileged action, and also passes
  52  * a default value to be used in case the property <code>"prop"</code> is not
  53  * defined: <p>
  54  *
  55  * <pre>
  56  * long l = java.security.AccessController.doPrivileged
  57  *      (new GetLongAction("prop")).longValue();
  58  * </pre>
  59  *
  60  * @author Roland Schemers
  61  * @see java.security.PrivilegedAction
  62  * @see java.security.AccessController
  63  * @since 1.2
  64  */
  65 
  66 public class GetLongAction implements java.security.PrivilegedAction<Long> {
  67     private String theProp;
  68     private long defaultVal;
  69     private boolean defaultSet = false;
  70 
  71     /**
  72      * Constructor that takes the name of the system property whose
  73      * <code>Long</code> value needs to be determined.
  74      *
  75      * @param theProp the name of the system property.
  76      */
  77     public GetLongAction(String theProp) {
  78         this.theProp = theProp;
  79     }
  80 
  81     /**
  82      * Constructor that takes the name of the system property and the default
  83      * value of that property.
  84      *
  85      * @param theProp the name of the system property.
  86      * @param defaulVal the default value.
  87      */
  88     public GetLongAction(String theProp, long defaultVal) {
  89         this.theProp = theProp;
  90         this.defaultVal = defaultVal;
  91         this.defaultSet = true;
  92     }
  93 
  94     /**
  95      * Determines the <code>Long</code> value of the system property whose
  96      * name was specified in the constructor.
  97      *
  98      * <p>If there is no property of the specified name, or if the property
  99      * does not have the correct numeric format, then a <code>Long</code>
 100      * object representing the default value that was specified in the
 101      * constructor is returned, or <code>null</code> if no default value was
 102      * specified.
 103      *
 104      * @return the <code>Long</code> value of the property.
 105      */
 106     public Long run() {
 107         Long value = Long.getLong(theProp);
 108         if ((value == null) && defaultSet)
 109             return new Long(defaultVal);
 110         return value;
 111     }
 112 }