1 /*
   2  * Copyright (c) 1996, 2012, 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 
  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}\" enth&auml;lt {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. M&auml;rz 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 Unicode Escapes
 108  * as defined in section 3.3 of
 109  * <cite>The Java&trade; Language Specification</cite>
 110  * whereas the other constructor which takes a Reader does not have that limitation.
 111  *
 112  * @see ResourceBundle
 113  * @see ListResourceBundle
 114  * @see Properties
 115  * @since JDK1.1
 116  */
 117 public class PropertyResourceBundle extends ResourceBundle {
 118     /**
 119      * Creates a property resource bundle from an {@link java.io.InputStream
 120      * InputStream}.  The property file read with this constructor
 121      * must be encoded in ISO-8859-1.
 122      *
 123      * @param stream an InputStream that represents a property file
 124      *        to read from.
 125      * @throws IOException if an I/O error occurs
 126      * @throws NullPointerException if <code>stream</code> is null
 127      */
 128     @SuppressWarnings({"unchecked", "rawtypes"})
 129     public PropertyResourceBundle (InputStream stream) throws IOException {
 130         Properties properties = new Properties();
 131         properties.load(stream);
 132         lookup = new HashMap(properties);
 133     }
 134 
 135     /**
 136      * Creates a property resource bundle from a {@link java.io.Reader
 137      * Reader}.  Unlike the constructor
 138      * {@link #PropertyResourceBundle(java.io.InputStream) PropertyResourceBundle(InputStream)},
 139      * there is no limitation as to the encoding of the input property file.
 140      *
 141      * @param reader a Reader that represents a property file to
 142      *        read from.
 143      * @throws IOException if an I/O error occurs
 144      * @throws NullPointerException if <code>reader</code> is null
 145      * @since 1.6
 146      */
 147     @SuppressWarnings({"unchecked", "rawtypes"})
 148     public PropertyResourceBundle (Reader reader) throws IOException {
 149         Properties properties = new Properties();
 150         properties.load(reader);
 151         lookup = new HashMap(properties);
 152     }
 153 
 154     // Implements java.util.ResourceBundle.handleGetObject; inherits javadoc specification.
 155     public Object handleGetObject(String key) {
 156         if (key == null) {
 157             throw new NullPointerException();
 158         }
 159         return lookup.get(key);
 160     }
 161 
 162     /**
 163      * Returns an <code>Enumeration</code> of the keys contained in
 164      * this <code>ResourceBundle</code> and its parent bundles.
 165      *
 166      * @return an <code>Enumeration</code> of the keys contained in
 167      *         this <code>ResourceBundle</code> and its parent bundles.
 168      * @see #keySet()
 169      */
 170     public Enumeration<String> getKeys() {
 171         ResourceBundle parent = this.parent;
 172         return new ResourceBundleEnumeration(lookup.keySet(),
 173                 (parent != null) ? parent.getKeys() : null);
 174     }
 175 
 176     /**
 177      * Returns a <code>Set</code> of the keys contained
 178      * <em>only</em> in this <code>ResourceBundle</code>.
 179      *
 180      * @return a <code>Set</code> of the keys contained only in this
 181      *         <code>ResourceBundle</code>
 182      * @since 1.6
 183      * @see #keySet()
 184      */
 185     protected Set<String> handleKeySet() {
 186         return lookup.keySet();
 187     }
 188 
 189     // ==================privates====================
 190 
 191     private Map<String,Object> lookup;
 192 }