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