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1   /*
2    * Copyright (c) 2005, 2011, 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  package com.sun.rowset;
27  
28  import java.io.*;
29  import java.util.*;
30  
31  /**
32   * This class is used to help in localization of resources,
33   * especially the exception strings.
34   *
35   * @author Amit Handa
36   */
37  
38  public class JdbcRowSetResourceBundle implements Serializable {
39  
40      /**
41       * This <code>String</code> variable stores the location
42       * of the resource bundle location.
43       */
44      private static String fileName;
45  
46      /**
47       * This variable will hold the <code>PropertyResourceBundle</code>
48       * of the text to be internationalized.
49       */
50      private transient PropertyResourceBundle propResBundle;
51  
52      /**
53       * The constructor initializes to this object
54       *
55       */
56      private static volatile JdbcRowSetResourceBundle jpResBundle;
57  
58      /**
59       * The variable which will represent the properties
60       * the suffix or extension of the resource bundle.
61       **/
62      private static final String PROPERTIES = "properties";
63  
64      /**
65       * The variable to represent underscore
66       **/
67      private static final String UNDERSCORE = "_";
68  
69      /**
70       * The variable which will represent dot
71       **/
72      private static final String DOT = ".";
73  
74      /**
75       * The variable which will represent the slash.
76       **/
77      private static final String SLASH = "/";
78  
79      /**
80       * The variable where the default resource bundle will
81       * be placed.
82       **/
83      private static final String PATH = "com/sun/rowset/RowSetResourceBundle";
84  
85      /**
86       * The constructor which initializes the resource bundle.
87       * Note this is a private constructor and follows Singleton
88       * Design Pattern.
89       *
90       * @throws IOException if unable to load the ResourceBundle
91       * according to locale or the default one.
92       */
93      private JdbcRowSetResourceBundle () throws IOException {
94          // Try to load the resource bundle according
95          // to the locale. Else if no bundle found according
96          // to the locale load the default.
97  
98          // In default case the default locale resource bundle
99          // should always be loaded else it
100         // will be difficult to throw appropriate
101         // exception string messages.
102         Locale locale = Locale.getDefault();
103 
104         // Load appropriate bundle according to locale
105          propResBundle = (PropertyResourceBundle) ResourceBundle.getBundle(PATH,
106                            locale, Thread.currentThread().getContextClassLoader());
107 
108    }
109 
110     /**
111      * This method is used to get a handle to the
112      * initialized instance of this class. Note that
113      * at any time there is only one instance of this
114      * class initialized which will be returned.
115      *
116      * @throws IOException if unable to find the RowSetResourceBundle.properties
117      */
118     public static JdbcRowSetResourceBundle getJdbcRowSetResourceBundle()
119     throws IOException {
120 
121          if(jpResBundle == null){
122              synchronized(JdbcRowSetResourceBundle.class) {
123                 if(jpResBundle == null){
124                     jpResBundle = new JdbcRowSetResourceBundle();
125                 } //end if
126              } //end synchronized block
127          } //end if
128          return jpResBundle;
129     }
130 
131     /**
132      * This method returns an enumerated handle of the keys
133      * which correspond to values translated to various locales.
134      *
135      * @return an enumeration of keys which have messages tranlated to
136      * corresponding locales.
137      */
138     @SuppressWarnings("rawtypes")
139     public Enumeration getKeys() {
140        return propResBundle.getKeys();
141     }
142 
143 
144     /**
145      * This method takes the key as an argument and
146      * returns the corresponding value reading it
147      * from the Resource Bundle loaded earlier.
148      *
149      * @return value in locale specific language
150      * according to the key passed.
151      */
152     public Object handleGetObject(String key) {
153        return propResBundle.handleGetObject(key);
154     }
155 
156     static final long serialVersionUID = 436199386225359954L;
157 }