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


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.io.IOException JavaDoc;
15 import java.io.Writer JavaDoc;
16 import java.util.Iterator JavaDoc;
17
18 import javax.servlet.jsp.JspException JavaDoc;
19
20 import org.apache.commons.lang.StringUtils;
21 import org.apache.commons.logging.Log;
22 import org.apache.commons.logging.LogFactory;
23 import org.displaytag.model.Column;
24 import org.displaytag.model.ColumnIterator;
25 import org.displaytag.model.HeaderCell;
26 import org.displaytag.model.Row;
27 import org.displaytag.model.RowIterator;
28 import org.displaytag.model.TableModel;
29
30
31 /**
32  * <p>
33  * Base abstract class for simple export views.
34  * </p>
35  * <p>
36  * A class that extends BaseExportView simply need to provide delimiters for rows and columns.
37  * </p>
38  * @author Fabrizio Giustina
39  * @version $Revision: 720 $ ($Author: fgiust $)
40  */
41 public abstract class BaseExportView implements TextExportView
42 {
43
44     /**
45      * logger.
46      */
47     private static Log log = LogFactory.getLog(BaseExportView.class);
48
49     /**
50      * TableModel to render.
51      */
52     private TableModel model;
53
54     /**
55      * export full list?
56      */
57     private boolean exportFull;
58
59     /**
60      * include header in export?
61      */
62     private boolean header;
63
64     /**
65      * decorate export?
66      */
67     private boolean decorated;
68
69     /**
70      * @see org.displaytag.export.ExportView#setParameters(org.displaytag.model.TableModel, boolean, boolean, boolean)
71      */
72     public void setParameters(TableModel tableModel, boolean exportFullList, boolean includeHeader,
73         boolean decorateValues)
74     {
75         this.model = tableModel;
76         this.exportFull = exportFullList;
77         this.header = includeHeader;
78         this.decorated = decorateValues;
79     }
80
81     /**
82      * String to add before a row.
83      * @return String
84      */
85     protected String JavaDoc getRowStart()
86     {
87         return null;
88     }
89
90     /**
91      * String to add after a row.
92      * @return String
93      */
94     protected String JavaDoc getRowEnd()
95     {
96         return null;
97     }
98
99     /**
100      * String to add before a cell.
101      * @return String
102      */
103     protected String JavaDoc getCellStart()
104     {
105         return null;
106     }
107
108     /**
109      * String to add after a cell.
110      * @return String
111      */
112     protected abstract String JavaDoc getCellEnd();
113
114     /**
115      * String to add to the top of document.
116      * @return String
117      */
118     protected String JavaDoc getDocumentStart()
119     {
120         return null;
121     }
122
123     /**
124      * String to add to the end of document.
125      * @return String
126      */
127     protected String JavaDoc getDocumentEnd()
128     {
129         return null;
130     }
131
132     /**
133      * always append cell end string?
134      * @return boolean
135      */
136     protected abstract boolean getAlwaysAppendCellEnd();
137
138     /**
139      * always append row end string?
140      * @return boolean
141      */
142     protected abstract boolean getAlwaysAppendRowEnd();
143
144     /**
145      * can be implemented to escape values for different output.
146      * @param value original column value
147      * @return escaped column value
148      */
149     protected abstract String JavaDoc escapeColumnValue(Object JavaDoc value);
150
151     /**
152      * Write table header.
153      * @return String rendered header
154      */
155     protected String JavaDoc doHeaders()
156     {
157
158         final String JavaDoc ROW_START = getRowStart();
159         final String JavaDoc ROW_END = getRowEnd();
160         final String JavaDoc CELL_START = getCellStart();
161         final String JavaDoc CELL_END = getCellEnd();
162         final boolean ALWAYS_APPEND_CELL_END = getAlwaysAppendCellEnd();
163
164         StringBuffer JavaDoc buffer = new StringBuffer JavaDoc(1000);
165
166         Iterator JavaDoc iterator = this.model.getHeaderCellList().iterator();
167
168         // start row
169 if (ROW_START != null)
170         {
171             buffer.append(ROW_START);
172         }
173
174         while (iterator.hasNext())
175         {
176             HeaderCell headerCell = (HeaderCell) iterator.next();
177
178             String JavaDoc columnHeader = headerCell.getTitle();
179
180             if (columnHeader == null)
181             {
182                 columnHeader = StringUtils.capitalize(headerCell.getBeanPropertyName());
183             }
184
185             columnHeader = escapeColumnValue(columnHeader);
186
187             if (CELL_START != null)
188             {
189                 buffer.append(CELL_START);
190             }
191
192             if (columnHeader != null)
193             {
194                 buffer.append(columnHeader);
195             }
196
197             if (CELL_END != null && (ALWAYS_APPEND_CELL_END || iterator.hasNext()))
198             {
199                 buffer.append(CELL_END);
200             }
201         }
202
203         // end row
204 if (ROW_END != null)
205         {
206             buffer.append(ROW_END);
207         }
208
209         return buffer.toString();
210
211     }
212
213     /**
214      * @see org.displaytag.export.TextExportView#doExport(java.io.Writer)
215      */
216     public void doExport(Writer JavaDoc out) throws IOException JavaDoc, JspException JavaDoc
217     {
218         if (log.isDebugEnabled())
219         {
220             log.debug(getClass().getName());
221         }
222
223         final String JavaDoc DOCUMENT_START = getDocumentStart();
224         final String JavaDoc DOCUMENT_END = getDocumentEnd();
225         final String JavaDoc ROW_START = getRowStart();
226         final String JavaDoc ROW_END = getRowEnd();
227         final String JavaDoc CELL_START = getCellStart();
228         final String JavaDoc CELL_END = getCellEnd();
229         final boolean ALWAYS_APPEND_CELL_END = getAlwaysAppendCellEnd();
230         final boolean ALWAYS_APPEND_ROW_END = getAlwaysAppendRowEnd();
231
232         // document start
233 write(out, DOCUMENT_START);
234
235         if (this.header)
236         {
237             write(out, doHeaders());
238         }
239
240         // get the correct iterator (full or partial list according to the exportFull field)
241 RowIterator rowIterator = this.model.getRowIterator(this.exportFull);
242
243         // iterator on rows
244 while (rowIterator.hasNext())
245         {
246             Row row = rowIterator.next();
247
248             if (this.model.getTableDecorator() != null)
249             {
250
251                 String JavaDoc stringStartRow = this.model.getTableDecorator().startRow();
252                 write(out, stringStartRow);
253             }
254
255             // iterator on columns
256 ColumnIterator columnIterator = row.getColumnIterator(this.model.getHeaderCellList());
257
258             write(out, ROW_START);
259
260             while (columnIterator.hasNext())
261             {
262                 Column column = columnIterator.nextColumn();
263
264                 // Get the value to be displayed for the column
265 String JavaDoc value = escapeColumnValue(column.getValue(this.decorated));
266
267                 write(out, CELL_START);
268
269                 write(out, value);
270
271                 if (ALWAYS_APPEND_CELL_END || columnIterator.hasNext())
272                 {
273                     write(out, CELL_END);
274                 }
275
276             }
277             if (ALWAYS_APPEND_ROW_END || rowIterator.hasNext())
278             {
279                 write(out, ROW_END);
280             }
281         }
282
283         // document end
284 write(out, DOCUMENT_END);
285
286     }
287
288     /**
289      * Write a String, checking for nulls value.
290      * @param out output writer
291      * @param string String to be written
292      * @throws IOException thrown by out.write
293      */
294     private void write(Writer JavaDoc out, String JavaDoc string) throws IOException JavaDoc
295     {
296         if (string != null)
297         {
298             out.write(string);
299         }
300     }
301
302     /**
303      * @see org.displaytag.export.TextExportView#outputPage()
304      */
305     public boolean outputPage()
306     {
307         return false;
308     }
309 }
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