1 /*
2 * Copyright 1996-2006 Sun Microsystems, Inc. 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. Sun designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Sun 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
22 * CA 95054 USA or visit www.sun.com if you need additional information or
23 * have any questions.
24 */
25
26 /*
27 * (C) Copyright Taligent, Inc. 1996, 1997 - All Rights Reserved
28 * (C) Copyright IBM Corp. 1996 - 1998 - All Rights Reserved
29 *
30 * The original version of this source code and documentation
31 * is copyrighted and owned by Taligent, Inc., a wholly-owned
32 * subsidiary of IBM. These materials are provided under terms
33 * of a License Agreement between Taligent and Sun. This technology
34 * is protected by multiple US and International patents.
35 *
36 * This notice and attribution to Taligent may not be removed.
37 * Taligent is a registered trademark of Taligent, Inc.
38 */
39
40 package java.util;
41
42 import java.io.InputStream;
43 import java.io.Reader;
44 import java.io.IOException;
45 import sun.util.ResourceBundleEnumeration;
46
47 /**
48 * <code>PropertyResourceBundle</code> is a concrete subclass of
49 * <code>ResourceBundle</code> that manages resources for a locale
50 * using a set of static strings from a property file. See
51 * {@link ResourceBundle ResourceBundle} for more information about resource
52 * bundles.
53 *
54 * <p>
55 * Unlike other types of resource bundle, you don't subclass
56 * <code>PropertyResourceBundle</code>. Instead, you supply properties
57 * files containing the resource data. <code>ResourceBundle.getBundle</code>
58 * will automatically look for the appropriate properties file and create a
59 * <code>PropertyResourceBundle</code> that refers to it. See
60 * {@link ResourceBundle#getBundle(java.lang.String, java.util.Locale, java.lang.ClassLoader) ResourceBundle.getBundle}
61 * for a complete description of the search and instantiation strategy.
62 *
63 * <p>
64 * The following <a name="sample">example</a> shows a member of a resource
65 * bundle family with the base name "MyResources".
66 * The text defines the bundle "MyResources_de",
67 * the German member of the bundle family.
68 * This member is based on <code>PropertyResourceBundle</code>, and the text
69 * therefore is the content of the file "MyResources_de.properties"
70 * (a related <a href="ListResourceBundle.html#sample">example</a> shows
71 * how you can add bundles to this family that are implemented as subclasses
72 * of <code>ListResourceBundle</code>).
73 * The keys in this example are of the form "s1" etc. The actual
74 * keys are entirely up to your choice, so long as they are the same as
75 * the keys you use in your program to retrieve the objects from the bundle.
76 * Keys are case-sensitive.
77 * <blockquote>
78 * <pre>
79 * # MessageFormat pattern
80 * s1=Die Platte \"{1}\" enthält {0}.
81 *
82 * # location of {0} in pattern
83 * s2=1
84 *
85 * # sample disk name
86 * s3=Meine Platte
87 *
88 * # first ChoiceFormat choice
89 * s4=keine Dateien
90 *
91 * # second ChoiceFormat choice
92 * s5=eine Datei
93 *
94 * # third ChoiceFormat choice
95 * s6={0,number} Dateien
96 *
97 * # sample date
98 * s7=3. März 1996
99 * </pre>
100 * </blockquote>
101 *
102 * <p>
103 * <strong>Note:</strong> PropertyResourceBundle can be constructed either
104 * from an InputStream or a Reader, which represents a property file.
105 * Constructing a PropertyResourceBundle instance from an InputStream requires
106 * that the input stream be encoded in ISO-8859-1. In that case, characters
107 * that cannot be represented in ISO-8859-1 encoding must be represented by
108 * <a href="http://java.sun.com/docs/books/jls/third_edition/html/lexical.html#3.3">Unicode Escapes</a>,
109 * whereas the other constructor which takes a Reader does not have that limitation.
110 *
111 * @see ResourceBundle
112 * @see ListResourceBundle
113 * @see Properties
114 * @since JDK1.1
115 */
116 public class PropertyResourceBundle extends ResourceBundle {
117 /**
118 * Creates a property resource bundle from an {@link java.io.InputStream
119 * InputStream}. The property file read with this constructor
120 * must be encoded in ISO-8859-1.
121 *
122 * @param stream an InputStream that represents a property file
123 * to read from.
124 * @throws IOException if an I/O error occurs
125 * @throws NullPointerException if <code>stream</code> is null
126 */
127 public PropertyResourceBundle (InputStream stream) throws IOException {
128 Properties properties = new Properties();
129 properties.load(stream);
130 lookup = new HashMap(properties);
131 }
132
133 /**
134 * Creates a property resource bundle from a {@link java.io.Reader
135 * Reader}. Unlike the constructor
136 * {@link #PropertyResourceBundle(java.io.InputStream) PropertyResourceBundle(InputStream)},
137 * there is no limitation as to the encoding of the input property file.
138 *
139 * @param reader a Reader that represents a property file to
140 * read from.
141 * @throws IOException if an I/O error occurs
142 * @throws NullPointerException if <code>reader</code> is null
143 * @since 1.6
144 */
145 public PropertyResourceBundle (Reader reader) throws IOException {
146 Properties properties = new Properties();
147 properties.load(reader);
148 lookup = new HashMap(properties);
149 }
150
151 // Implements java.util.ResourceBundle.handleGetObject; inherits javadoc specification.
152 public Object handleGetObject(String key) {
153 if (key == null) {
154 throw new NullPointerException();
155 }
156 return lookup.get(key);
157 }
158
159 /**
160 * Returns an <code>Enumeration</code> of the keys contained in
161 * this <code>ResourceBundle</code> and its parent bundles.
162 *
163 * @return an <code>Enumeration</code> of the keys contained in
164 * this <code>ResourceBundle</code> and its parent bundles.
165 * @see #keySet()
166 */
167 public Enumeration<String> getKeys() {
168 ResourceBundle parent = this.parent;
169 return new ResourceBundleEnumeration(lookup.keySet(),
170 (parent != null) ? parent.getKeys() : null);
171 }
172
173 /**
174 * Returns a <code>Set</code> of the keys contained
175 * <em>only</em> in this <code>ResourceBundle</code>.
176 *
177 * @return a <code>Set</code> of the keys contained only in this
178 * <code>ResourceBundle</code>
179 * @since 1.6
180 * @see #keySet()
181 */
182 protected Set<String> handleKeySet() {
183 return lookup.keySet();
184 }
185
186 // ==================privates====================
187
188 private Map<String,Object> lookup;
189 }
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