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 import java.security.AccessController; 29 import java.security.PrivilegedAction; 30 import java.util.Properties; 31 32 /** 33 * A convenience class for retrieving the string value of a system 34 * property as a privileged action. 35 * 36 * <p>An instance of this class can be used as the argument of 37 * <code>AccessController.doPrivileged</code>. 38 * 39 * <p>The following code retrieves the value of the system 40 * property named <code>"prop"</code> as a privileged action: 41 * 42 * <pre> 43 * String s = java.security.AccessController.doPrivileged 44 * (new GetPropertyAction("prop")); 45 * </pre> 46 * 47 * @author Roland Schemers 48 * @see java.security.PrivilegedAction 49 * @see java.security.AccessController 50 * @since 1.2 51 */ 52 53 public class GetPropertyAction implements PrivilegedAction<String> { 54 private String theProp; 55 private String defaultVal; 56 57 /** 58 * Constructor that takes the name of the system property whose 59 * string value needs to be determined. 60 * 61 * @param theProp the name of the system property. 62 */ 63 public GetPropertyAction(String theProp) { 64 this.theProp = theProp; 65 } 66 67 /** 68 * Constructor that takes the name of the system property and the default 69 * value of that property. 70 * 71 * @param theProp the name of the system property. 72 * @param defaultVal the default value. 73 */ 74 public GetPropertyAction(String theProp, String defaultVal) { 75 this.theProp = theProp; 76 this.defaultVal = defaultVal; 77 } 78 79 /** 80 * Determines the string value of the system property whose 81 * name was specified in the constructor. 82 * 83 * @return the string value of the system property, 84 * or the default value if there is no property with that key. 85 */ 86 public String run() { 87 String value = System.getProperty(theProp); 88 return (value == null) ? defaultVal : value; 89 } 90 91 /** 92 * Convenience method to get a property without going through doPrivileged 93 * if no security manager is present. This is unsafe for inclusion in a 94 * public API but allowable here since this class is now encapsulated. 95 * 96 * @param theProp the name of the system property. 97 */ 98 public static String getProperty(String theProp) { 99 if (System.getSecurityManager() == null) { 100 return System.getProperty(theProp); 101 } else { 102 return AccessController.doPrivileged( 103 new GetPropertyAction(theProp)); 104 } 105 } 106 107 /** 108 * Convenience method to get a property without going through doPrivileged 109 * if no security manager is present. This is unsafe for inclusion in a 110 * public API but allowable here since this class is now encapsulated. 111 * 112 * @param theProp the name of the system property. 113 * @param defaultVal the default value. 114 */ 115 public static String getProperty(String theProp, String defaultVal) { 116 if (System.getSecurityManager() == null) { 117 return System.getProperty(theProp, defaultVal); 118 } else { 119 return AccessController.doPrivileged( 120 new GetPropertyAction(theProp, defaultVal)); 121 } 122 } 123 124 /** 125 * Convenience method to call <code>System.getProperties</code> without 126 * having to go through doPrivileged if no security manager is present. 127 * This is unsafe for inclusion in a public API but allowable here since 128 * this class is now encapsulated. 129 */ 130 public static Properties getProperties() { 131 if (System.getSecurityManager() == null) { 132 return System.getProperties(); 133 } else { 134 return AccessController.doPrivileged( 135 new PrivilegedAction<Properties>() { 136 public Properties run() { 137 return System.getProperties(); 138 } 139 } 140 ); 141 } 142 } 143 }