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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.CAL10NPropertyResourceBundle;
32  import ch.qos.cal10n.util.PropertyResourceBundleFinder;
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, CAL10NPropertyResourceBundle> cache = new ConcurrentHashMap<String, CAL10NPropertyResourceBundle>();
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) throws MessageConveyorException {
72  
73      String declararingClassName = key.getDeclaringClass().getName();
74      CAL10NPropertyResourceBundle  rb = cache.get(declararingClassName);
75      if (rb == null || rb.hasChanged()) {
76        rb = lookup(key);
77        cache.put(declararingClassName, rb);
78      }
79  
80      String keyAsStr = key.toString();
81      String value = rb.getString(keyAsStr);
82      if (value == null) {
83        return "No key found for " + keyAsStr;
84      } else {
85        if (args == null || args.length == 0) {
86          return value;
87        } else {
88          return MessageFormat.format(value, args);
89        }
90      }
91    }
92  
93    private <E extends Enum<?>> CAL10NPropertyResourceBundle lookup(E key) throws MessageConveyorException {
94      String baseName = AnnotationExtractor.getBaseName(key.getDeclaringClass());
95      if (baseName == null) {
96        throw new MessageConveyorException(
97            "Missing @BaseName annotation in enum type ["
98                + key.getClass().getName() + "]. See also "
99                + Cal10nConstants.MISSING_BN_ANNOTATION_URL);
100     }
101     CAL10NPropertyResourceBundle rb = PropertyResourceBundleFinder.getBundle(this.getClass()
102         .getClassLoader(), baseName, locale);
103 
104     if(rb == null) {
105       throw new MessageConveyorException("Failed to locate resource bundle [" + baseName
106         + "] for locale [" + locale + "] for enum type [" + key.getDeclaringClass().getName()
107         + "]");
108     }
109     return rb;
110   }
111 
112   public String getMessage(MessageParameterObj mpo) throws MessageConveyorException {
113     if (mpo == null) {
114       throw new IllegalArgumentException(
115           "MessageParameterObj argumument cannot be null");
116     }
117     return getMessage(mpo.getKey(), mpo.getArgs());
118   }
119 
120 }