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1
16 package org.apache.cocoon.components.source.impl;
17
18 import java.io.ByteArrayInputStream  ;
19 import java.io.FilterInputStream ;
20 import java.io.IOException ;
21 import java.io.InputStream ;
22 import java.net.MalformedURLException ;
23 import java.sql.Blob ;
24 import java.sql.Clob ;
25 import java.sql.Connection ;
26 import java.sql.ResultSet ;
27 import java.sql.SQLException ;
28 import java.sql.Statement ;
29 import java.sql.Types ;
30 import java.util.Iterator ;
31
32 import org.apache.avalon.framework.logger.AbstractLogEnabled;
33 import org.apache.avalon.framework.service.ServiceManager;
34 import org.apache.avalon.framework.service.ServiceSelector;
35 import org.apache.avalon.framework.service.Serviceable;
36
37 import org.apache.avalon.excalibur.datasource.DataSourceComponent;
38
39 import org.apache.cocoon.CascadingIOException;
40
41 import org.apache.excalibur.source.Source;
42 import org.apache.excalibur.source.SourceException;
43 import org.apache.excalibur.source.SourceValidity;
44
45
65 public class BlobSource extends AbstractLogEnabled implements Source, Serviceable {
66
67
68 private ServiceManager manager = null;
69
70
73 private String systemId;
74
75 private String datasourceName;
76
77 private String tableName;
78
79 private String columnName;
80
81 private String condition;
82
83 private final static String URL_PREFIX = "blob:/";
84 private final static int URL_PREFIX_LEN = URL_PREFIX.length();
85
86
90 public BlobSource(String url) throws MalformedURLException {
91
92 this.systemId = url;
93
94 int start = URL_PREFIX_LEN;
96 int end;
97
98 end = url.indexOf('/', start);
100 if (end == -1) {
101 throw new MalformedURLException ("Malformed blob source (cannot find datasource) : " + url);
102 }
103
104 this.datasourceName = url.substring(start, end);
105
106 start = end + 1;
108 end = url.indexOf('/', start);
109 if (end == -1) {
110 throw new MalformedURLException ("Malformed blob source (cannot find table name) : " + url);
111 }
112
113 this.tableName = url.substring(start, end);
114
115 start = end + 1;
117 end = url.indexOf('[', start);
118 if (end == -1) {
119 this.columnName = url.substring(start);
120 } else {
121 this.columnName = url.substring(start, end);
122
123 start = end + 1;
125 end = url.length() - 1;
126 if (url.charAt(end) != ']') {
127 throw new MalformedURLException ("Malformed url for a blob source (cannot find condition) : " + url);
128 } else {
129 this.condition = url.substring(start, end);
130 }
131 }
132 }
133
134
138 public void service(ServiceManager manager) {
139 this.manager = manager;
140 }
141
142
145 public String getScheme() {
146 return URL_PREFIX;
147 }
148
149
152 public String getURI() {
153 return this.systemId;
154 }
155
156
159 public InputStream getInputStream() throws IOException , SourceException {
160 if (getLogger().isDebugEnabled()) {
161 getLogger().debug("Opening stream for datasource " + this.datasourceName +
162 ", table " + this.tableName + ", column " + this.columnName +
163 (this.condition == null ? ", no condition" : ", condition " + this.condition)
164 );
165 }
166
167 Connection cnx = null;
168 Statement stmt = null;
169
170 try {
171 cnx = getConnection();
172 stmt = cnx.createStatement();
173
174 StringBuffer selectBuf = new StringBuffer ("SELECT ").append(this.columnName).
175 append(" FROM ").append(this.tableName);
176
177 if (this.condition != null) {
178 selectBuf.append(" WHERE ").append(this.condition);
179 }
180
181 String select = selectBuf.toString();
182 if (getLogger().isDebugEnabled()) {
183 getLogger().debug("Executing statement " + select);
184 }
185
186 ResultSet rs = stmt.executeQuery(select);
187 rs.next();
188
189 int colType = rs.getMetaData().getColumnType(1);
190
191 switch(colType) {
192 case Types.BLOB :
193 Blob blob = rs.getBlob(1);
194 return new JDBCInputStream(blob.getBinaryStream(), cnx);
195
197 case Types.CLOB :
198 Clob clob = rs.getClob(1);
199 return new JDBCInputStream(clob.getAsciiStream(), cnx);
200
202 default :
203 String value = rs.getString(1);
204 return new ByteArrayInputStream (value.getBytes());
205 }
206 } catch(SQLException sqle) {
207 String msg = "Cannot retrieve content from " + this.systemId;
208 getLogger().error(msg, sqle);
209 throw new SourceException(msg, sqle);
211 } finally {
212 try {
213 if (stmt != null) {
214 stmt.close();
215 }
216 if (cnx != null) {
217 cnx.close();
218 }
219 } catch(SQLException sqle2) {
220 throw new SourceException("Cannot close connection", sqle2);
222 }
223 }
224 }
225
226
232 public SourceValidity getValidity() {
233 return null;
234 }
235
236
240 public void refresh() {
241 }
242
243
247 public boolean exists() {
248 return true;
250 }
251
252
257 public String getMimeType() {
258 return null;
259 }
260
261
265 public long getContentLength() {
266 return -1;
267 }
268
269
274 public long getLastModified() {
275 return 0;
276 }
277
278
283 public String getParameter(String name) {
284 return null;
285 }
286
287
292 public long getParameterAsLong(String name) {
293 return 0;
294 }
295
296
301 public Iterator getParameterNames() {
302 return new EmptyIterator();
303 }
304
305 static class EmptyIterator implements Iterator {
306 public boolean hasNext() { return false; }
307 public Object next() { return null; }
308 public void remove() {}
309 }
310
311 private Connection getConnection() throws SourceException {
312
313 ServiceSelector selector = null;
314 DataSourceComponent datasource = null;
315
316 try {
317 try {
318 selector = (ServiceSelector)this.manager.lookup(DataSourceComponent.ROLE + "Selector");
319
320 datasource = (DataSourceComponent)selector.select(this.datasourceName);
321
322 } catch(Exception e) {
323 String msg = "Cannot get datasource '" + this.datasourceName + "'";
324 getLogger().error(msg);
325 throw new SourceException(msg, e);
326 }
327
328 try {
329 return datasource.getConnection();
330 } catch(Exception e) {
331 String msg = "Cannot get connection for datasource '" + this .datasourceName + "'";
332 getLogger().error(msg);
333 throw new SourceException(msg, e);
334 }
335
336 } finally {
337 if (datasource != null) {
338 selector.release(datasource);
339 }
340 }
341 }
342
343
347 private class JDBCInputStream extends FilterInputStream {
348
349 Connection cnx;
350
351 private final void closeCnx() throws IOException {
352 if (this.cnx != null) {
353 try {
354 Connection tmp = cnx;
355 cnx = null;
356 tmp.close();
357 } catch(Exception e) {
358 String msg = "Error closing the connection for " + BlobSource.this.getURI();
359 BlobSource.this.getLogger().warn(msg, e);
360 throw new CascadingIOException(msg + " : " + e.getMessage(), e);
361 }
362 }
363 }
364
365 public JDBCInputStream(InputStream stream, Connection cnx) {
366 super(stream);
367 this.cnx = cnx;
368 }
369
370 public int read() throws IOException {
371 try {
372 int result = in.read();
373 if (result == -1) {
374 closeCnx();
375 }
376 return result;
377 } catch(IOException e) {
378 closeCnx();
379 throw e;
380 }
381 }
382
383 public int read(byte[] b) throws IOException {
384 try {
385 int result = in.read(b);
386 if (result == -1) {
387 closeCnx();
388 }
389 return result;
390 } catch(IOException e) {
391 closeCnx();
392 throw e;
393 }
394 }
395
396 public int read(byte[] b, int off, int len) throws IOException {
397 try {
398 int result = in.read(b, off, len);
399 if (result == -1) {
400 closeCnx();
401 }
402 return result;
403 } catch(IOException e) {
404 closeCnx();
405 throw e;
406 }
407 }
408
409 public void close() throws IOException {
410 super.close();
411 closeCnx();
412 }
413 }
414 }
415
416 |
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