Source code: gnu/classpath/SystemProperties.java
1 /* SystemProperties.java -- Manage the System properties.
2 Copyright (C) 2004, 2005 Free Software Foundation
3
4 This file is part of GNU Classpath.
5
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)
9 any later version.
10
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.
15
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., 51 Franklin Street, Fifth Floor, Boston, MA
19 02110-1301 USA.
20
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
24 combination.
25
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. */
37
38
39 package gnu.classpath;
40
41 import java.util.Properties;
42
43 /**
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.
50 */
51 public class SystemProperties
52 {
53 /**
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.
57 */
58 private static Properties properties;
59
60 /**
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>.
64 */
65 private static final Properties defaultProperties = new Properties();
66
67 static
68 {
69 VMSystemProperties.preInit(defaultProperties);
70
71 defaultProperties.put("gnu.classpath.home", Configuration.CLASSPATH_HOME);
72 defaultProperties.put("gnu.classpath.version",
73 Configuration.CLASSPATH_VERSION);
74
75 // Set base URL if not already set.
76 if (defaultProperties.get("gnu.classpath.home.url") == null)
77 defaultProperties.put("gnu.classpath.home.url",
78 "file://"
79 + Configuration.CLASSPATH_HOME
80 + "/lib");
81
82 // Set short name if not already set.
83 if (defaultProperties.get("gnu.classpath.vm.shortname") == null)
84 {
85 String value = defaultProperties.getProperty("java.vm.name");
86 int index = value.lastIndexOf(' ');
87 if (index != -1)
88 value = value.substring(index + 1);
89 defaultProperties.put("gnu.classpath.vm.shortname", value);
90 }
91
92 // Network properties
93 if (defaultProperties.get("http.agent") == null)
94 {
95 String userAgent = ("gnu-classpath/"
96 + defaultProperties.getProperty("gnu.classpath.version")
97 + " ("
98 + defaultProperties.getProperty("gnu.classpath.vm.shortname")
99 + "/"
100 + defaultProperties.getProperty("java.vm.version")
101 + ")");
102 defaultProperties.put("http.agent", userAgent);
103 }
104
105 // 8859_1 is a safe default encoding to use when not explicitly set
106 if (defaultProperties.get("file.encoding") == null)
107 defaultProperties.put("file.encoding", "8859_1");
108
109 // Default to the Swing FocusManager so that the old-style Swing API
110 // for FocusManager can be supported without hardcoding it in AWT.
111 if (defaultProperties.get("gnu.java.awt.FocusManager") == null)
112 defaultProperties.put("gnu.java.awt.FocusManager",
113 "gnu.java.awt.FocusManager");
114
115 // XXX FIXME - Temp hack for old systems that set the wrong property
116 if (defaultProperties.get("java.io.tmpdir") == null)
117 defaultProperties.put("java.io.tmpdir",
118 defaultProperties.get("java.tmpdir"));
119
120 VMSystemProperties.postInit(defaultProperties);
121
122 // Note that we use clone here and not new. Some programs assume
123 // that the system properties do not have a parent.
124 properties = (Properties) defaultProperties.clone();
125 }
126
127 public static String getProperty(String name)
128 {
129 return properties.getProperty(name);
130 }
131
132 public static String getProperty(String name, String defaultValue)
133 {
134 return properties.getProperty(name, defaultValue);
135 }
136
137 public static String setProperty(String name, String value)
138 {
139 return (String) properties.setProperty(name, value);
140 }
141
142 public static Properties getProperties()
143 {
144 return properties;
145 }
146
147 public static void setProperties(Properties properties)
148 {
149 if (properties == null)
150 {
151 // Note that we use clone here and not new. Some programs
152 // assume that the system properties do not have a parent.
153 properties = (Properties)defaultProperties.clone();
154 }
155
156 SystemProperties.properties = properties;
157 }
158 }