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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
60  	 * the 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
99  				.getDeclaringClass());
100 		if (baseName == null) {
101 			throw new MessageConveyorException(
102 					"Missing @BaseName annotation in enum type ["
103 							+ key.getClass().getName() + "]. See also "
104 							+ Cal10nConstants.MISSING_BN_ANNOTATION_URL);
105 		}
106 
107 		String charset = AnnotationExtractor.getCharset(declaringClass, locale);
108 		// use the declaring class' loader instead of
109 		// this.getClass().getClassLoader()
110 		// see also http://jira.qos.ch/browse/CAL-8
111 		CAL10NResourceBundle rb = CAL10NResourceBundleFinder.getBundle(
112 				declaringClass.getClassLoader(), baseName, locale, charset);
113 
114 		if (rb == null) {
115 			throw new MessageConveyorException(
116 					"Failed to locate resource bundle [" + baseName
117 							+ "] for locale [" + locale + "] for enum type ["
118 							+ key.getDeclaringClass().getName() + "]");
119 		}
120 		return rb;
121 	}
122 
123 	public String getMessage(MessageParameterObj mpo)
124 			throws MessageConveyorException {
125 		if (mpo == null) {
126 			throw new IllegalArgumentException(
127 					"MessageParameterObj argumument cannot be null");
128 		}
129 		return getMessage(mpo.getKey(), mpo.getArgs());
130 	}
131 }