1 /**
2 * Licensed under the Artistic License; you may not use this file
3 * except in compliance with the License.
4 * You may obtain a copy of the License at
5 *
6 * http://displaytag.sourceforge.net/license.html
7 *
8 * THIS PACKAGE IS PROVIDED "AS IS" AND WITHOUT ANY EXPRESS OR
9 * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
10 * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
11 */
12 package org.displaytag.localization;
13
14 import java.util.Locale;
15
16 import javax.servlet.http.HttpServletRequest;
17 import javax.servlet.http.HttpSession;
18 import javax.servlet.jsp.PageContext;
19 import javax.servlet.jsp.tagext.Tag;
20
21 import org.apache.struts.Globals;
22 import org.apache.struts.config.ModuleConfig;
23 import org.apache.struts.util.MessageResources;
24
25
26 /**
27 * Struts implementation of a resource provider and locale resolver. Uses Struts
28 * <code>RequestUtils.getUserLocale()</code> and <code>TagUtils.message()</code> for the lookup.
29 * @author Fabrizio Giustina
30 * @version $Revision: 1081 $ ($Author: fgiust $)
31 */
32 public class I18nStrutsAdapter implements I18nResourceProvider, LocaleResolver
33 {
34
35 /**
36 * prefix/suffix for missing entries.
37 */
38 public static final String UNDEFINED_KEY = "???"; //$NON-NLS-1$
39
40 /**
41 * @see LocaleResolver#resolveLocale(HttpServletRequest)
42 */
43 public Locale resolveLocale(HttpServletRequest request)
44 {
45 Locale userLocale = null;
46 HttpSession session = request.getSession(false);
47
48 // Only check session if sessions are enabled
49 if (session != null)
50 {
51 userLocale = (Locale) session.getAttribute(Globals.LOCALE_KEY);
52 }
53
54 if (userLocale == null)
55 {
56 // Returns Locale based on Accept-Language header or the server default
57 userLocale = request.getLocale();
58 }
59
60 return userLocale;
61 }
62
63 /**
64 * @see I18nResourceProvider#getResource(String, String, Tag, PageContext)
65 */
66 public String getResource(String resourceKey, String defaultValue, Tag tag, PageContext pageContext)
67 {
68
69 // if titleKey isn't defined either, use property
70 String key = (resourceKey != null) ? resourceKey : defaultValue;
71
72 // retrieve MessageResources. Don't use TagUtils to mantain Struts 1.1 compatibility
73 MessageResources resources = (MessageResources) pageContext.getAttribute(
74 Globals.MESSAGES_KEY,
75 PageContext.REQUEST_SCOPE);
76
77 if (resources == null)
78 {
79 ModuleConfig moduleConfig = (ModuleConfig) pageContext.getRequest().getAttribute(Globals.MODULE_KEY);
80
81 if (moduleConfig == null)
82 {
83 moduleConfig = (ModuleConfig) pageContext.getServletContext().getAttribute(Globals.MODULE_KEY);
84 pageContext.getRequest().setAttribute(Globals.MODULE_KEY, moduleConfig);
85 }
86
87 resources = (MessageResources) pageContext.getAttribute(
88 Globals.MESSAGES_KEY + moduleConfig.getPrefix(),
89 PageContext.APPLICATION_SCOPE);
90 }
91
92 if (resources == null)
93 {
94 resources = (MessageResources) pageContext
95 .getAttribute(Globals.MESSAGES_KEY, PageContext.APPLICATION_SCOPE);
96 }
97
98 String title = null;
99 if (resources != null)
100 {
101 Locale userLocale = resolveLocale((HttpServletRequest) pageContext.getRequest());
102 title = resources.getMessage(userLocale, key);
103 }
104
105 // if user explicitely added a titleKey we guess this is an error
106 if (title == null && resourceKey != null)
107 {
108 title = UNDEFINED_KEY + resourceKey + UNDEFINED_KEY;
109 }
110
111 return title;
112 }
113
114 }
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