NetProperties.java revision 12745:f068a4ffddd2 
1/*
2 * Copyright (c) 2004, 2008, 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 */
25package sun.net;
26
27import java.io.*;
28import java.security.AccessController;
29import java.security.PrivilegedAction;
30import java.util.Properties;
31
32/*
33 * This class allows for centralized access to Networking properties.
34 * Default values are loaded from the file jre/lib/net.properties
35 *
36 *
37 * @author Jean-Christophe Collet
38 *
39 */
40
41public class NetProperties {
42    private static Properties props = new Properties();
43    static {
44        AccessController.doPrivileged(
45            new PrivilegedAction<Void>() {
46                public Void run() {
47                    loadDefaultProperties();
48                    return null;
49                }});
50    }
51
52    private NetProperties() { };
53
54
55    /*
56     * Loads the default networking system properties
57     * the file is in jre/lib/net.properties
58     */
59    private static void loadDefaultProperties() {
60        String fname = System.getProperty("java.home");
61        if (fname == null) {
62            throw new Error("Can't find java.home ??");
63        }
64        try {
65            File f = new File(fname, "conf");
66            f = new File(f, "net.properties");
67            fname = f.getCanonicalPath();
68            InputStream in = new FileInputStream(fname);
69            BufferedInputStream bin = new BufferedInputStream(in);
70            props.load(bin);
71            bin.close();
72        } catch (Exception e) {
73            // Do nothing. We couldn't find or access the file
74            // so we won't have default properties...
75        }
76    }
77
78    /**
79     * Get a networking system property. If no system property was defined
80     * returns the default value, if it exists, otherwise returns
81     * <code>null</code>.
82     * @param      key  the property name.
83     * @throws  SecurityException  if a security manager exists and its
84     *          <code>checkPropertiesAccess</code> method doesn't allow access
85     *          to the system properties.
86     * @return the <code>String</code> value for the property,
87     *         or <code>null</code>
88     */
89    public static String get(String key) {
90        String def = props.getProperty(key);
91        try {
92            return System.getProperty(key, def);
93        } catch (IllegalArgumentException e) {
94        } catch (NullPointerException e) {
95        }
96        return null;
97    }
98
99    /**
100     * Get an Integer networking system property. If no system property was
101     * defined returns the default value, if it exists, otherwise returns
102     * <code>null</code>.
103     * @param   key     the property name.
104     * @param   defval  the default value to use if the property is not found
105     * @throws  SecurityException  if a security manager exists and its
106     *          <code>checkPropertiesAccess</code> method doesn't allow access
107     *          to the system properties.
108     * @return the <code>Integer</code> value for the property,
109     *         or <code>null</code>
110     */
111    public static Integer getInteger(String key, int defval) {
112        String val = null;
113
114        try {
115            val = System.getProperty(key, props.getProperty(key));
116        } catch (IllegalArgumentException e) {
117        } catch (NullPointerException e) {
118        }
119
120        if (val != null) {
121            try {
122                return Integer.decode(val);
123            } catch (NumberFormatException ex) {
124            }
125        }
126        return defval;
127    }
128
129    /**
130     * Get a Boolean networking system property. If no system property was
131     * defined returns the default value, if it exists, otherwise returns
132     * <code>null</code>.
133     * @param   key     the property name.
134     * @throws  SecurityException  if a security manager exists and its
135     *          <code>checkPropertiesAccess</code> method doesn't allow access
136     *          to the system properties.
137     * @return the <code>Boolean</code> value for the property,
138     *         or <code>null</code>
139     */
140    public static Boolean getBoolean(String key) {
141        String val = null;
142
143        try {
144            val = System.getProperty(key, props.getProperty(key));
145        } catch (IllegalArgumentException e) {
146        } catch (NullPointerException e) {
147        }
148
149        if (val != null) {
150            try {
151                return Boolean.valueOf(val);
152            } catch (NumberFormatException ex) {
153            }
154        }
155        return null;
156    }
157
158}
159