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Java > Open Source Codes > org > displaytag > export > ExportViewFactory


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.export;
13
14 import java.util.HashMap JavaDoc;
15 import java.util.Map JavaDoc;
16
17 import org.apache.commons.lang.ArrayUtils;
18 import org.apache.commons.logging.Log;
19 import org.apache.commons.logging.LogFactory;
20 import org.displaytag.Messages;
21 import org.displaytag.exception.WrappedRuntimeException;
22 import org.displaytag.model.TableModel;
23 import org.displaytag.properties.MediaTypeEnum;
24 import org.displaytag.properties.TableProperties;
25 import org.displaytag.util.ReflectHelper;
26
27
28 /**
29  * Factory for export views.
30  * @author Fabrizio Giustina
31  * @version $Revision: 934 $ ($Author: fgiust $)
32  */
33 public final class ExportViewFactory
34 {
35
36     /**
37      * Singleton.
38      */
39     private static ExportViewFactory instance;
40
41     /**
42      * logger.
43      */
44     private static Log log = LogFactory.getLog(ExportViewFactory.class);
45
46     /**
47      * Map containing MediaTypeEnum - View class.
48      */
49     private final Map JavaDoc viewClasses = new HashMap JavaDoc();
50
51     /**
52      * Private constructor.
53      */
54     private ExportViewFactory()
55     {
56         TableProperties properties = TableProperties.getInstance(null);
57         String JavaDoc[] exportTypes = properties.getExportTypes();
58
59         if (log.isInfoEnabled())
60         {
61             log.info(Messages.getString("ExportViewFactory.initializing", //$NON-NLS-1$
62 new Object JavaDoc[]{ArrayUtils.toString(exportTypes)}));
63         }
64         for (int j = 0; j < exportTypes.length; j++)
65         {
66             String JavaDoc className = properties.getExportClass(exportTypes[j]);
67             registerExportView(exportTypes[j], className);
68         }
69     }
70
71     /**
72      * Returns the simgleton for this class.
73      * @return ExportViewFactory instance
74      */
75     public static synchronized ExportViewFactory getInstance()
76     {
77         if (instance == null)
78         {
79             instance = new ExportViewFactory();
80         }
81         return instance;
82     }
83
84     /**
85      * Register a new Export View, associated with a Media Type. If another export view is currently associated with the
86      * given media type it's replaced.
87      * @param name media name
88      * @param viewClassName export view class name
89      */
90     public void registerExportView(String JavaDoc name, String JavaDoc viewClassName)
91     {
92         Class JavaDoc exportClass;
93         try
94         {
95             exportClass = ReflectHelper.classForName(viewClassName);
96         }
97         catch (ClassNotFoundException JavaDoc e)
98         {
99             log.error(Messages.getString("ExportViewFactory.classnotfound", //$NON-NLS-1$
100 new Object JavaDoc[]{name, viewClassName}));
101             return;
102         }
103         catch (NoClassDefFoundError JavaDoc e)
104         {
105             log.warn(Messages.getString("ExportViewFactory.noclassdef" //$NON-NLS-1$
106 , new Object JavaDoc[]{name, viewClassName, e.getMessage()}));
107             return;
108         }
109
110         try
111         {
112             exportClass.newInstance();
113         }
114         catch (InstantiationException JavaDoc e)
115         {
116             log.error(Messages.getString("ExportViewFactory.instantiationexception", //$NON-NLS-1$
117 new Object JavaDoc[]{name, viewClassName, e.getMessage()}));
118             return;
119         }
120         catch (IllegalAccessException JavaDoc e)
121         {
122             log.error(Messages.getString("ExportViewFactory.illegalaccess", //$NON-NLS-1$
123 new Object JavaDoc[]{name, viewClassName, e.getMessage()}));
124             return;
125         }
126         catch (NoClassDefFoundError JavaDoc e)
127         {
128             log.warn(Messages.getString("ExportViewFactory.noclassdef" //$NON-NLS-1$
129 , new Object JavaDoc[]{name, viewClassName, e.getMessage()}));
130             return;
131         }
132
133         MediaTypeEnum media = MediaTypeEnum.registerMediaType(name);
134         viewClasses.put(media, exportClass);
135
136         if (log.isDebugEnabled())
137         {
138             log.debug(Messages.getString("ExportViewFactory.added", //$NON-NLS-1$
139 new Object JavaDoc[]{media, viewClassName}));
140         }
141     }
142
143     /**
144      * returns an instance of export view associated with the given export type.
145      * @param exportType MediaTypeEnum
146      * @param tableModel table model containing data to render
147      * @param exportFullList should the complete list be exported?
148      * @param includeHeader should header be included in export?
149      * @param decorateValues should ouput be decorated?
150      * @return specialized instance of BaseExportView
151      */
152     public ExportView getView(MediaTypeEnum exportType, TableModel tableModel, boolean exportFullList,
153         boolean includeHeader, boolean decorateValues)
154     {
155         ExportView view;
156
157         Class JavaDoc viewClass = (Class JavaDoc) viewClasses.get(exportType);
158
159         try
160         {
161             view = (ExportView) viewClass.newInstance();
162         }
163         catch (InstantiationException JavaDoc e)
164         {
165             // should not happen (class has already been instantiated before)
166 throw new WrappedRuntimeException(getClass(), e);
167         }
168         catch (IllegalAccessException JavaDoc e)
169         {
170             // should not happen (class has already been instantiated before)
171 throw new WrappedRuntimeException(getClass(), e);
172         }
173
174         view.setParameters(tableModel, exportFullList, includeHeader, decorateValues);
175         return view;
176     }
177
178 }
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