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16 package org.apache.cocoon.reading;
17
18 import java.io.BufferedInputStream  ;
19 import java.io.IOException ;
20 import java.io.InputStream ;
21 import java.sql.Connection ;
22 import java.sql.PreparedStatement ;
23 import java.sql.ResultSet ;
24 import java.sql.SQLException ;
25 import java.sql.Timestamp ;
26 import java.util.Map ;
27
28 import org.apache.avalon.excalibur.datasource.DataSourceComponent;
29 import org.apache.avalon.framework.activity.Disposable;
30 import org.apache.avalon.framework.configuration.Configurable;
31 import org.apache.avalon.framework.configuration.Configuration;
32 import org.apache.avalon.framework.configuration.ConfigurationException;
33 import org.apache.avalon.framework.parameters.Parameters;
34 import org.apache.avalon.framework.service.ServiceException;
35 import org.apache.avalon.framework.service.ServiceManager;
36 import org.apache.avalon.framework.service.ServiceSelector;
37 import org.apache.cocoon.ProcessingException;
38 import org.apache.cocoon.ResourceNotFoundException;
39 import org.apache.cocoon.caching.CacheableProcessingComponent;
40 import org.apache.cocoon.environment.ObjectModelHelper;
41 import org.apache.cocoon.environment.Request;
42 import org.apache.cocoon.environment.Response;
43 import org.apache.cocoon.environment.SourceResolver;
44 import org.apache.excalibur.source.SourceValidity;
45 import org.apache.excalibur.source.impl.validity.NOPValidity;
46 import org.apache.excalibur.source.impl.validity.TimeStampValidity;
47 import org.xml.sax.SAXException ;
48
49
57 public class DatabaseReader extends ServiceableReader
58 implements Configurable, Disposable, CacheableProcessingComponent
59 {
60
61 private ServiceSelector dbselector;
62 private String dsn;
63 private long lastModified = System.currentTimeMillis();
64 private InputStream resource = null; private Connection con = null;
66 private DataSourceComponent datasource = null;
67 private String mimeType = null;
68 private int typeColumn = 0;
69 private boolean doCommit = false;
70 private boolean defaultCache = true;
71
72 public void service(final ServiceManager manager) throws ServiceException {
73 super.service(manager);
74 this.dbselector = (ServiceSelector) manager.lookup(DataSourceComponent.ROLE + "Selector");
75 }
76
77
81 public void configure(Configuration conf) throws ConfigurationException {
82 this.dsn = conf.getChild("use-connection").getValue();
83 this.defaultCache = conf.getChild("invalidate").getValue("never").equals("always");
84 }
85
86
90 public void setup(SourceResolver resolver, Map objectModel, String src, Parameters par)
91 throws ProcessingException, SAXException , IOException {
92 super.setup(resolver, objectModel, src, par);
93
94 PreparedStatement statement = null;
95 try {
96 this.datasource = (DataSourceComponent) dbselector.select(dsn);
97 this.con = datasource.getConnection();
98
99 if (this.con.getAutoCommit()) {
100 this.con.setAutoCommit(false);
101 }
102
103 statement = con.prepareStatement(getQuery());
104 statement.setString(1, this.source);
105 ResultSet set = statement.executeQuery();
106 if (!set.next()) throw new ResourceNotFoundException("There is no resource with that key");
107
108 Response response = ObjectModelHelper.getResponse(objectModel);
109 Request request = ObjectModelHelper.getRequest(objectModel);
110
111 if (this.modifiedSince(set, request, response)) {
112 this.resource = set.getBinaryStream(1);
113 if (this.typeColumn != 0) {
114 this.mimeType = set.getString(this.typeColumn);
115 }
116
117 if (this.resource == null) {
118 throw new ResourceNotFoundException("There is no resource with that key");
119 }
120 }
121
122 this.doCommit = true;
123 } catch (Exception e) {
124 this.doCommit = false;
125 throw new ResourceNotFoundException("DatabaseReader error:", e);
126 } finally {
127 try {
128 if (statement != null) {
129 statement.close();
130 }
131 } catch(SQLException sqle) {
132 throw new ResourceNotFoundException("Cannot close connection", sqle);
133 }
134 }
135 }
136
137
166 public void generate() throws ProcessingException, SAXException , IOException {
167 try {
168 Response response = ObjectModelHelper.getResponse(objectModel);
169 this.serialize(response);
170 } catch (IOException ioe) {
171 getLogger().warn("Assuming client reset stream");
172
173 this.doCommit = false;
174 } catch (Exception e) {
175 this.doCommit = false;
176
177 throw new ResourceNotFoundException("DatabaseReader error:", e);
178 }
179 }
180
181
186 public String getQuery() throws Exception {
187 String table = this.parameters.getParameter("table", null);
188 String column = this.parameters.getParameter("image", null);
189 String key = this.parameters.getParameter("key", null);
190 String where = this.parameters.getParameter("where", null);
191 String orderBy = this.parameters.getParameter("order-by", null);
192 String typeColumn = this.parameters.getParameter("type-column", null);
193 int columnNo = 1;
194
195 if (table == null || column == null || key==null) {
196 throw new ProcessingException("We are missing a required parameter. Please include 'table', 'image', and 'key'");
197 }
198
199 String date = this.parameters.getParameter("last-modified", null);
200 StringBuffer query = new StringBuffer ("SELECT ");
201
202 query.append(column);
203 columnNo++;
204
205 if (date != null) {
206 query.append(", ").append(date);
207 columnNo++;
208 }
209
210 if (null != orderBy) {
211 query.append(", ");
212
213 if (orderBy.endsWith(" DESC")) {
214 query.append(orderBy.substring(0, orderBy.length() - 5));
215 } else {
216 query.append(orderBy);
217 }
218 columnNo++;
219 }
220
221 if (null != typeColumn) {
222 query.append(", ").append(typeColumn);
223 this.typeColumn = columnNo;
224 columnNo++;
225 }
226
227 query.append(" FROM ").append(table);
228 query.append(" WHERE ").append(key).append(" = ?");
229
230 if (null != where) {
231 query.append(" AND ").append(where);
232 }
233
234 if (null != orderBy) {
235 query.append(" ORDER BY ").append(orderBy);
236 }
237
238 return query.toString();
239 }
240
241
253 public boolean modifiedSince(ResultSet set, Request request, Response response)
254 throws SQLException {
255 String lastModified = this.parameters.getParameter("last-modified", null);
256
257 if (lastModified != null) {
258 Timestamp modified = set.getTimestamp(lastModified, null);
259 if (null != modified) {
260 this.lastModified = modified.getTime();
261 } else {
262 }
264
265 response.setDateHeader("Last-Modified", this.lastModified);
266
267 return this.lastModified > request.getDateHeader("if-modified-since");
268 }
269
270 return true;
273 }
274
275
278 public void serialize(Response response)
279 throws IOException , SQLException {
280 if (this.resource == null) {
281 throw new SQLException ("The Blob is empty!");
282 }
283
284 InputStream is = new BufferedInputStream (this.resource);
285
286 long expires = parameters.getParameterAsInteger("expires", -1);
287
288 if (expires > 0) {
289 response.setDateHeader("Expires", System.currentTimeMillis() + expires);
290 }
291
292 response.setHeader("Accept-Ranges", "bytes");
293
294 byte[] buffer = new byte[8192];
295 int length = -1;
296
297 while ((length = is.read(buffer)) > -1) {
298 out.write(buffer, 0, length);
299 }
300 is.close();
301 out.flush();
302 }
303
304
310 public java.io.Serializable getKey() {
311 return this.source;
312 }
313
314
320 public SourceValidity getValidity() {
321 if (this.lastModified > 0) {
322 return new TimeStampValidity(this.lastModified);
323 } else {
324 if (this.defaultCache) {
325 return NOPValidity.SHARED_INSTANCE;
326 } else {
327 return null;
328 }
329 }
330 }
331
332 public void recycle() {
333 super.recycle();
334 this.resource = null;
335 this.lastModified = 0;
336 this.mimeType = null;
337 this.typeColumn = 0;
338
339 if (this.con != null) {
340 try {
341 if (this.doCommit) {
342 this.con.commit();
343 } else {
344 this.con.rollback();
345 }
346 } catch (SQLException se) {
347 getLogger().warn("Could not commit or rollback connection", se);
348 }
349
350 try {
351 this.con.close();
352 } catch (SQLException se) {
353 getLogger().warn("Could not close connection", se);
354 }
355
356 this.con = null;
357 }
358
359 if (this.datasource != null) {
360 this.dbselector.release(this.datasource);
361 this.datasource = null;
362 }
363 }
364
365
368 public void dispose()
369 {
370 this.manager.release(this.dbselector);
371 }
372
373 public String getMimeType() {
374 return (this.mimeType != null ?
375 this.mimeType :
376 this.parameters.getParameter("content-type", super.getMimeType()));
377 }
378
379 }
380 |
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