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1   /*
2    * Copyright (c) 2009 QOS.ch All rights reserved.
3    * 
4    * Permission is hereby granted, free of charge, to any person obtaining a copy
5    * of this software and associated documentation files (the "Software"), to deal
6    * in the Software without restriction, including without limitation the rights
7    * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
8    * copies of the Software, and to permit persons to whom the Software is
9    * furnished to do so, subject to the following conditions:
10   * 
11   * The above copyright notice and this permission notice shall be included in
12   * all copies or substantial portions of the Software.
13   * 
14   * THE SOFTWARE IS PROVIDED "AS  IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
15   * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
16   * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
17   * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
18   * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
19   * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
20   * SOFTWARE.
21   */
22  
23  package ch.qos.cal10n;
24  
25  import java.text.MessageFormat;
26  import java.util.Locale;
27  import java.util.Map;
28  import java.util.concurrent.ConcurrentHashMap;
29  
30  import ch.qos.cal10n.util.AnnotationExtractor;
31  import ch.qos.cal10n.util.CAL10NResourceBundle;
32  import ch.qos.cal10n.util.CAL10NResourceBundleFinder;
33  
34  /**
35   * The default implementation for {@link IMessageConveyor} based on resource
36   * bundles.
37   * 
38   * <p>
39   * See also {@link #getMessage(Enum, Object...)} for details.
40   * 
41   * @author Ceki G&uuml;lc&uuml;
42   */
43  public class MessageConveyor implements IMessageConveyor {
44  
45    final Locale locale;
46  
47    final Map<String, CAL10NResourceBundle> cache = new ConcurrentHashMap<String, CAL10NResourceBundle>();
48  
49    /**
50     * The {@link Locale} associated with this instance.
51     * 
52     * @param locale
53     */
54    public MessageConveyor(Locale locale) {
55      this.locale = locale;
56    }
57  
58    /**
59     * Given an enum as key, find the corresponding resource bundle and return the
60     * corresponding internationalized.
61     * 
62     * <p>
63     * The name of the resource bundle is defined via the {@link BaseName}
64     * annotation whereas the locale is specified in this MessageConveyor
65     * instance's constructor.
66     * 
67     * @param key
68     *          an enum instance used as message key
69     * 
70     */
71    public <E extends Enum<?>> String getMessage(E key, Object... args)
72        throws MessageConveyorException {
73  
74      String declararingClassName = key.getDeclaringClass().getName();
75      CAL10NResourceBundle rb = cache.get(declararingClassName);
76      if (rb == null || rb.hasChanged()) {
77        rb = lookup(key);
78        cache.put(declararingClassName, rb);
79      }
80  
81      String keyAsStr = key.toString();
82      String value = rb.getString(keyAsStr);
83      if (value == null) {
84        return "No key found for " + keyAsStr;
85      } else {
86        if (args == null || args.length == 0) {
87          return value;
88        } else {
89          return MessageFormat.format(value, args);
90        }
91      }
92    }
93  
94    private <E extends Enum<?>> CAL10NResourceBundle lookup(E key)
95        throws MessageConveyorException {
96      Class<?> declaringClass = key.getDeclaringClass();
97  
98      String baseName = AnnotationExtractor.getBaseName(key.getDeclaringClass());
99      if (baseName == null) {
100       throw new MessageConveyorException(
101           "Missing @BaseName annotation in enum type ["
102               + key.getClass().getName() + "]. See also "
103               + Cal10nConstants.MISSING_BN_ANNOTATION_URL);
104     }
105 
106     String charset = AnnotationExtractor.getCharset(declaringClass, locale);
107     CAL10NResourceBundle rb = CAL10NResourceBundleFinder.getBundle(this
108         .getClass().getClassLoader(), baseName, locale, charset);
109 
110     if (rb == null) {
111       throw new MessageConveyorException("Failed to locate resource bundle ["
112           + baseName + "] for locale [" + locale + "] for enum type ["
113           + key.getDeclaringClass().getName() + "]");
114     }
115     return rb;
116   }
117 
118   public String getMessage(MessageParameterObj mpo)
119       throws MessageConveyorException {
120     if (mpo == null) {
121       throw new IllegalArgumentException(
122           "MessageParameterObj argumument cannot be null");
123     }
124     return getMessage(mpo.getKey(), mpo.getArgs());
125   }
126 
127 }