1 /* 2 * Copyright (c) 1998, 2017, 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 31 /** 32 * A convenience class for retrieving the string value of a system 33 * property as a privileged action. 34 * 35 * <p>An instance of this class can be used as the argument of 36 * <code>AccessController.doPrivileged</code>. 37 * 38 * <p>The following code retrieves the value of the system 39 * property named <code>"prop"</code> as a privileged action: <p> 40 * 41 * <pre> 42 * String s = java.security.AccessController.doPrivileged 43 * (new GetPropertyAction("prop")); 44 * </pre> 45 * 46 * @author Roland Schemers 47 * @see java.security.PrivilegedAction 48 * @see java.security.AccessController 49 * @since 1.2 50 */ 51 52 public class GetPropertyAction implements PrivilegedAction<String> { 53 private String theProp; 54 private String defaultVal; 55 56 /** 57 * Constructor that takes the name of the system property whose 58 * string value needs to be determined. 59 * 60 * @param theProp the name of the system property. 61 */ GetPropertyAction(String theProp)62 public GetPropertyAction(String theProp) { 63 this.theProp = theProp; 64 } 65 66 /** 67 * Constructor that takes the name of the system property and the default 68 * value of that property. 69 * 70 * @param theProp the name of the system property. 71 * @param defaulVal the default value. 72 */ GetPropertyAction(String theProp, String defaultVal)73 public GetPropertyAction(String theProp, String defaultVal) { 74 this.theProp = theProp; 75 this.defaultVal = defaultVal; 76 } 77 78 /** 79 * Determines the string value of the system property whose 80 * name was specified in the constructor. 81 * 82 * @return the string value of the system property, 83 * or the default value if there is no property with that key. 84 */ run()85 public String run() { 86 String value = System.getProperty(theProp); 87 return (value == null) ? defaultVal : value; 88 } 89 90 /** 91 * Convenience method to get a property without going through doPrivileged 92 * if no security manager is present. This is unsafe for inclusion in a 93 * public API but allowable here since this class is by default restricted 94 * by the package.access security property. 95 * 96 * Note that this method performs a privileged action using caller-provided 97 * inputs. The caller of this method should take care to ensure that the 98 * inputs are not tainted and the returned property is not made accessible 99 * to untrusted code if it contains sensitive information. 100 * 101 * @param theProp the name of the system property. 102 */ privilegedGetProperty(String theProp)103 public static String privilegedGetProperty(String theProp) { 104 if (System.getSecurityManager() == null) { 105 return System.getProperty(theProp); 106 } else { 107 return AccessController.doPrivileged( 108 new GetPropertyAction(theProp)); 109 } 110 } 111 112 /** 113 * Convenience method to get a property without going through doPrivileged 114 * if no security manager is present. This is unsafe for inclusion in a 115 * public API but allowable here since this class is now encapsulated. 116 * 117 * Note that this method performs a privileged action using caller-provided 118 * inputs. The caller of this method should take care to ensure that the 119 * inputs are not tainted and the returned property is not made accessible 120 * to untrusted code if it contains sensitive information. 121 * 122 * @param theProp the name of the system property. 123 * @param defaultVal the default value. 124 */ privilegedGetProperty(String theProp, String defaultVal)125 public static String privilegedGetProperty(String theProp, 126 String defaultVal) { 127 if (System.getSecurityManager() == null) { 128 return System.getProperty(theProp, defaultVal); 129 } else { 130 return AccessController.doPrivileged( 131 new GetPropertyAction(theProp, defaultVal)); 132 } 133 } 134 } 135