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1   /*
2    * Copyright 2012-2013 smartics, Kronseder & Reiner GmbH
3    *
4    * Licensed under the Apache License, Version 2.0 (the "License");
5    * you may not use this file except in compliance with the License.
6    * You may obtain a copy of the License at
7    *
8    *     http://www.apache.org/licenses/LICENSE-2.0
9    *
10   * Unless required by applicable law or agreed to in writing, software
11   * distributed under the License is distributed on an "AS IS" BASIS,
12   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13   * See the License for the specific language governing permissions and
14   * limitations under the License.
15   */
16  package de.smartics.properties.spi.core.context;
17  
18  import java.util.ArrayList;
19  import java.util.Collections;
20  import java.util.Comparator;
21  import java.util.HashSet;
22  import java.util.List;
23  import java.util.Locale;
24  import java.util.Set;
25  
26  import org.apache.commons.io.FilenameUtils;
27  import org.apache.commons.lang.LocaleUtils;
28  
29  import de.smartics.properties.api.core.domain.ConfigException;
30  import de.smartics.properties.api.core.domain.PropertiesContext;
31  import de.smartics.util.lang.ClassPathContext;
32  import de.smartics.util.util.GenericServiceFactory;
33  
34  /**
35   * Finds all supported locales.
36   */
37  final class LocaleFinder
38  {
39    // ********************************* Fields *********************************
40  
41    // --- constants ------------------------------------------------------------
42  
43    /**
44     * Helper to get listing of a folder on the class path.
45     */
46    private static final ClassPathListing CLASS_PATH_LISTING;
47  
48    // --- members --------------------------------------------------------------
49  
50    /**
51     * Locale comparator.
52     */
53    private static final Comparator<Locale> COMPARATOR = new Comparator<Locale>()
54    {
55      @Override
56      public int compare(final Locale o1, final Locale o2)
57      {
58        return o1.toString().compareTo(o2.toString());
59      }
60    };
61  
62    // ****************************** Initializer *******************************
63  
64    static
65    {
66      ClassPathListing service = null;
67      try
68      {
69        service =
70            new GenericServiceFactory<ClassPathListing>(ClassPathListing.class)
71                .create();
72      }
73      catch (final IllegalStateException e)
74      {
75        service = new JarAndFileClassPathListing();
76      }
77  
78      CLASS_PATH_LISTING = service;
79    }
80  
81    // ****************************** Constructors ******************************
82  
83    /**
84     * Default constructor.
85     */
86    LocaleFinder()
87    {
88    }
89  
90    // ****************************** Inner Classes *****************************
91  
92    // ********************************* Methods ********************************
93  
94    // --- init -----------------------------------------------------------------
95  
96    // --- get&set --------------------------------------------------------------
97  
98    // --- business -------------------------------------------------------------
99  
100   List<Locale> find(final String systemId, final ClassPathContext context)
101     throws ConfigException
102   {
103     final Set<Locale> locales = new HashSet<Locale>();
104     locales.add(new Locale(""));
105 
106     final List<String> listing =
107         CLASS_PATH_LISTING.list(context,
108             PropertiesContext.META_INF_PROPERTY_SET_REPORT);
109 
110     for (final String path : listing)
111     {
112       final Locale locale = calcLocale(path);
113       if (locale != null)
114       {
115         locales.add(locale);
116       }
117     }
118 
119     final List<Locale> list = new ArrayList<Locale>(locales);
120     Collections.sort(list, COMPARATOR);
121     return list;
122   }
123 
124   Locale calcLocale(final String urlString)
125   {
126     final String fileName = FilenameUtils.getBaseName(urlString);
127     final int urlStringLength = urlString.length();
128     int separatorIndex = fileName.indexOf('_');
129     Locale locale = null;
130 
131     while (separatorIndex != -1)
132     {
133       final String localeString = fileName.substring(separatorIndex + 1);
134       locale = constructLocale(localeString);
135       separatorIndex =
136           locale != null || separatorIndex + 1 >= urlStringLength ? -1
137               : fileName.indexOf('_', separatorIndex + 1);
138     }
139     return locale;
140   }
141 
142   private Locale constructLocale(final String localeString)
143   {
144     try
145     {
146       final Locale locale = LocaleUtils.toLocale(localeString);
147       return locale;
148     }
149     catch (final IllegalArgumentException e)
150     {
151       return null;
152     }
153   }
154 
155   // --- object basics --------------------------------------------------------
156 
157 }