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 }