1 /*
   2  * Copyright (c) 1996, 2019, 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.InputStreamReader;
  44 import java.io.Reader;
  45 import java.io.IOException;
  46 import java.nio.charset.MalformedInputException;
  47 import java.nio.charset.UnmappableCharacterException;
  48 import sun.nio.cs.ISO_8859_1;
  49 import sun.security.action.GetPropertyAction;
  50 import sun.util.PropertyResourceBundleCharset;
  51 import sun.util.ResourceBundleEnumeration;
  52 
  53 /**
  54  * {@code PropertyResourceBundle} is a concrete subclass of
  55  * {@code ResourceBundle} that manages resources for a locale
  56  * using a set of static strings from a property file. See
  57  * {@link ResourceBundle ResourceBundle} for more information about resource
  58  * bundles.
  59  *
  60  * <p>
  61  * Unlike other types of resource bundle, you don't subclass
  62  * {@code PropertyResourceBundle}.  Instead, you supply properties
  63  * files containing the resource data.  {@code ResourceBundle.getBundle}
  64  * will automatically look for the appropriate properties file and create a
  65  * {@code PropertyResourceBundle} that refers to it. See
  66  * {@link ResourceBundle#getBundle(String, Locale, ClassLoader) ResourceBundle.getBundle}
  67  * for a complete description of the search and instantiation strategy.
  68  *
  69  * <p>
  70  * The following <a id="sample">example</a> shows a member of a resource
  71  * bundle family with the base name "MyResources".
  72  * The text defines the bundle "MyResources_de",
  73  * the German member of the bundle family.
  74  * This member is based on {@code PropertyResourceBundle}, and the text
  75  * therefore is the content of the file "MyResources_de.properties"
  76  * (a related <a href="ListResourceBundle.html#sample">example</a> shows
  77  * how you can add bundles to this family that are implemented as subclasses
  78  * of {@code ListResourceBundle}).
  79  * The keys in this example are of the form "s1" etc. The actual
  80  * keys are entirely up to your choice, so long as they are the same as
  81  * the keys you use in your program to retrieve the objects from the bundle.
  82  * Keys are case-sensitive.
  83  * <blockquote>
  84  * <pre>
  85  * # MessageFormat pattern
  86  * s1=Die Platte \"{1}\" enth&auml;lt {0}.
  87  *
  88  * # location of {0} in pattern
  89  * s2=1
  90  *
  91  * # sample disk name
  92  * s3=Meine Platte
  93  *
  94  * # first ChoiceFormat choice
  95  * s4=keine Dateien
  96  *
  97  * # second ChoiceFormat choice
  98  * s5=eine Datei
  99  *
 100  * # third ChoiceFormat choice
 101  * s6={0,number} Dateien
 102  *
 103  * # sample date
 104  * s7=3. M&auml;rz 1996
 105  * </pre>
 106  * </blockquote>
 107  *
 108  * @apiNote
 109  * {@code PropertyResourceBundle} can be constructed either
 110  * from an {@code InputStream} or a {@code Reader}, which represents a property file.
 111  * Constructing a {@code PropertyResourceBundle} instance from an {@code InputStream}
 112  * requires that the input stream be encoded in {@code UTF-8}. By default, if a
 113  * {@link java.nio.charset.MalformedInputException} or an
 114  * {@link java.nio.charset.UnmappableCharacterException} occurs on reading the
 115  * input stream, then the {@code PropertyResourceBundle} instance resets to the state
 116  * before the exception, re-reads the input stream in {@code ISO-8859-1}, and
 117  * continues reading. If the system property
 118  * {@systemProperty java.util.PropertyResourceBundle.encoding} is set to either
 119  * "ISO-8859-1" or "UTF-8", the input stream is solely read in that encoding,
 120  * and throws the exception if it encounters an invalid sequence.
 121  * If "ISO-8859-1" is specified, characters that cannot be represented in
 122  * ISO-8859-1 encoding must be represented by Unicode Escapes as defined in section
 123  * 3.3 of <cite>The Java Language Specification</cite>
 124  * whereas the other constructor which takes a {@code Reader} does not have that limitation.
 125  * Other encoding values are ignored for this system property.
 126  * The system property is read and evaluated when initializing this class.
 127  * Changing or removing the property has no effect after the initialization.
 128  *
 129  * @implSpec
 130  * The implementation of a {@code PropertyResourceBundle} subclass must be
 131  * thread-safe if it's simultaneously used by multiple threads. The default
 132  * implementations of the non-abstract methods in this class are thread-safe.
 133  *
 134  * @see ResourceBundle
 135  * @see ListResourceBundle
 136  * @see Properties
 137  * @since 1.1
 138  */
 139 public class PropertyResourceBundle extends ResourceBundle {
 140 
 141     // Check whether the strict encoding is specified.
 142     // The possible encoding is either "ISO-8859-1" or "UTF-8".
 143     private static final String encoding = GetPropertyAction
 144         .privilegedGetProperty("java.util.PropertyResourceBundle.encoding", "")
 145         .toUpperCase(Locale.ROOT);
 146 
 147     /**
 148      * Creates a property resource bundle from an {@link java.io.InputStream
 149      * InputStream}. This constructor reads the property file in UTF-8 by default.
 150      * If a {@link java.nio.charset.MalformedInputException} or an
 151      * {@link java.nio.charset.UnmappableCharacterException} occurs on reading the
 152      * input stream, then the PropertyResourceBundle instance resets to the state
 153      * before the exception, re-reads the input stream in {@code ISO-8859-1} and
 154      * continues reading. If the system property
 155      * {@code java.util.PropertyResourceBundle.encoding} is set to either
 156      * "ISO-8859-1" or "UTF-8", the input stream is solely read in that encoding,
 157      * and throws the exception if it encounters an invalid sequence. Other
 158      * encoding values are ignored for this system property.
 159      * The system property is read and evaluated when initializing this class.
 160      * Changing or removing the property has no effect after the initialization.
 161      *
 162      * @param stream an InputStream that represents a property file
 163      *        to read from.
 164      * @throws IOException if an I/O error occurs
 165      * @throws NullPointerException if {@code stream} is null
 166      * @throws IllegalArgumentException if {@code stream} contains a
 167      *     malformed Unicode escape sequence.
 168      * @throws MalformedInputException if the system property
 169      *     {@code java.util.PropertyResourceBundle.encoding} is set to "UTF-8"
 170      *     and {@code stream} contains an invalid UTF-8 byte sequence.
 171      * @throws UnmappableCharacterException if the system property
 172      *     {@code java.util.PropertyResourceBundle.encoding} is set to "UTF-8"
 173      *     and {@code stream} contains an unmappable UTF-8 byte sequence.
 174      */
 175     @SuppressWarnings({"unchecked", "rawtypes"})
 176     public PropertyResourceBundle (InputStream stream) throws IOException {
 177         this(new InputStreamReader(stream,
 178             "ISO-8859-1".equals(encoding) ?
 179                 ISO_8859_1.INSTANCE.newDecoder() :
 180                 new PropertyResourceBundleCharset("UTF-8".equals(encoding)).newDecoder()));
 181     }
 182 
 183     /**
 184      * Creates a property resource bundle from a {@link java.io.Reader
 185      * Reader}.  Unlike the constructor
 186      * {@link #PropertyResourceBundle(java.io.InputStream) PropertyResourceBundle(InputStream)},
 187      * there is no limitation as to the encoding of the input property file.
 188      *
 189      * @param reader a Reader that represents a property file to
 190      *        read from.
 191      * @throws IOException if an I/O error occurs
 192      * @throws NullPointerException if {@code reader} is null
 193      * @throws IllegalArgumentException if a malformed Unicode escape sequence appears
 194      *     from {@code reader}.
 195      * @since 1.6
 196      */
 197     @SuppressWarnings({"unchecked", "rawtypes"})
 198     public PropertyResourceBundle (Reader reader) throws IOException {
 199         Properties properties = new Properties();
 200         properties.load(reader);
 201         lookup = new HashMap(properties);
 202     }
 203 
 204     // Implements java.util.ResourceBundle.handleGetObject; inherits javadoc specification.
 205     public Object handleGetObject(String key) {
 206         if (key == null) {
 207             throw new NullPointerException();
 208         }
 209         return lookup.get(key);
 210     }
 211 
 212     /**
 213      * Returns an {@code Enumeration} of the keys contained in
 214      * this {@code ResourceBundle} and its parent bundles.
 215      *
 216      * @return an {@code Enumeration} of the keys contained in
 217      *         this {@code ResourceBundle} and its parent bundles.
 218      * @see #keySet()
 219      */
 220     public Enumeration<String> getKeys() {
 221         ResourceBundle parent = this.parent;
 222         return new ResourceBundleEnumeration(lookup.keySet(),
 223                 (parent != null) ? parent.getKeys() : null);
 224     }
 225 
 226     /**
 227      * Returns a {@code Set} of the keys contained
 228      * <em>only</em> in this {@code ResourceBundle}.
 229      *
 230      * @return a {@code Set} of the keys contained only in this
 231      *         {@code ResourceBundle}
 232      * @since 1.6
 233      * @see #keySet()
 234      */
 235     protected Set<String> handleKeySet() {
 236         return lookup.keySet();
 237     }
 238 
 239     // ==================privates====================
 240 
 241     private final Map<String,Object> lookup;
 242 }