1 /* SystemProperties.java -- Manage the System properties.
2 Copyright (C) 2004, 2005 Free Software Foundation
4 This file is part of GNU Classpath.
6 GNU Classpath is free software; you can redistribute it and/or modify
7 it under the terms of the GNU General Public License as published by
8 the Free Software Foundation; either version 2, or (at your option)
11 GNU Classpath is distributed in the hope that it will be useful, but
12 WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 General Public License for more details.
16 You should have received a copy of the GNU General Public License
17 along with GNU Classpath; see the file COPYING. If not, write to the
18 Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
21 Linking this library statically or dynamically with other modules is
22 making a combined work based on this library. Thus, the terms and
23 conditions of the GNU General Public License cover the whole
26 As a special exception, the copyright holders of this library give you
27 permission to link this library with independent modules to produce an
28 executable, regardless of the license terms of these independent
29 modules, and to copy and distribute the resulting executable under
30 terms of your choice, provided that you also meet, for each linked
31 independent module, the terms and conditions of the license of that
32 module. An independent module is a module which is not derived from
33 or based on this library. If you modify this library, you may extend
34 this exception to your version of the library, but you are not
35 obligated to do so. If you do not wish to do so, delete this
36 exception statement from your version. */
39 package gnu.classpath;
41 import java.util.Properties;
44 * The class manages the System properties. This class is only available to
45 * privileged code (i.e. code loaded by the bootstrap class loader) and
46 * therefore doesn't do any security checks.
47 * This class is separated out from java.lang.System to simplify bootstrap
48 * dependencies and to allow trusted code a simple and efficient mechanism
49 * to access the system properties.
51 public class SystemProperties
54 * Stores the current system properties. This can be modified by
55 * {@link #setProperties(Properties)}, but will never be null, because
56 * setProperties(null) sucks in the default properties.
58 private static Properties properties;
61 * The default properties. Once the default is stabilized,
62 * it should not be modified;
63 * instead it is cloned when calling <code>setProperties(null)</code>.
65 private static final Properties defaultProperties = new Properties();
67 private static native void insertSystemProperties(Properties properties);
71 insertSystemProperties(defaultProperties);
73 // Set base URL if not already set.
74 if (defaultProperties.get("gnu.classpath.home.url") == null)
75 defaultProperties.put("gnu.classpath.home.url",
77 + defaultProperties.get("gnu.classpath.home")
80 // Set short name if not already set.
81 if (defaultProperties.get("gnu.classpath.vm.shortname") == null)
83 String value = defaultProperties.getProperty("java.vm.name");
84 int index = value.lastIndexOf(' ');
86 value = value.substring(index + 1);
87 defaultProperties.put("gnu.classpath.vm.shortname", value);
91 if (defaultProperties.get("http.agent") == null)
93 String userAgent = ("gnu-classpath/"
94 + defaultProperties.getProperty("gnu.classpath.version")
96 + defaultProperties.getProperty("gnu.classpath.vm.shortname")
98 + defaultProperties.getProperty("java.vm.version")
100 defaultProperties.put("http.agent", userAgent);
103 defaultProperties.put("gnu.cpu.endian",
104 isWordsBigEndian() ? "big" : "little");
106 // XXX FIXME - Temp hack for old systems that set the wrong property
107 if (defaultProperties.get("java.io.tmpdir") == null)
108 defaultProperties.put("java.io.tmpdir",
109 defaultProperties.get("java.tmpdir"));
111 // Note that we use clone here and not new. Some programs assume
112 // that the system properties do not have a parent.
113 properties = (Properties) defaultProperties.clone();
116 public static String getProperty(String name)
118 return properties.getProperty(name);
121 public static String getProperty(String name, String defaultValue)
123 return properties.getProperty(name, defaultValue);
126 public static String setProperty(String name, String value)
128 return (String) properties.setProperty(name, value);
131 public static Properties getProperties()
136 public static void setProperties(Properties properties)
138 if (properties == null)
140 // Note that we use clone here and not new. Some programs
141 // assume that the system properties do not have a parent.
142 properties = (Properties)defaultProperties.clone();
145 SystemProperties.properties = properties;
149 * Detect big-endian systems.
151 * @return true if the system is big-endian.
153 private static native boolean isWordsBigEndian();