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1
64
65 package com.jcorporate.expresso.core.dbobj;
66
67 import com.jcorporate.expresso.core.db.DBConnection;
68 import com.jcorporate.expresso.core.db.DBConnectionPool;
69 import com.jcorporate.expresso.core.db.DBException;
70 import com.jcorporate.expresso.core.misc.StringUtil;
71 import com.jcorporate.expresso.kernel.util.FastStringBuffer;
72 import org.apache.log4j.Logger;
73
74 import java.io.InputStream  ;
75 import java.sql.PreparedStatement ;
76 import java.sql.SQLException ;
77
78
127
128 public class LOBSupport {
129 static protected LOBSupport theInstance = null;
130 static private Logger log = Logger.getLogger("com.jcorporate" +
131 ".expresso.core.dbobj.LOBSupport");
132
133
136 protected LOBSupport() {
137 }
138
139
144 public static synchronized LOBSupport getInstance() {
145 if (theInstance == null) {
146 theInstance = new LOBSupport();
147 }
148
149 return theInstance;
150 }
151
152
153 public String getCLOB(DBObject baseObject,
154 String fieldName) throws DBException {
155 DBConnectionPool aPool = DBConnectionPool.getInstance(baseObject.getDataContext());
156 DBConnection localConnection = aPool.getConnection();
157 String returnValue = null;
158 try {
159 returnValue = this.getCLOB(baseObject, fieldName, localConnection);
160 } finally {
161 aPool.release(localConnection);
162 }
163 return returnValue;
164 }
165
166
179 public String getCLOB(DBObject baseObject,
180 String fieldName,
181 DBConnection theConnection) throws DBException {
182 prepSelectResultSet(baseObject, fieldName, theConnection);
183
184 if (theConnection.next()) {
185 return StringUtil.notNull(theConnection.getString(1));
186 }
187
188 return "";
189 }
190
191
201 public void setCLOB(DBObject baseObject,
202 String fieldName,
203 String theData,
204 DBConnection theConnection) throws DBException {
205
206 PreparedStatement preparedStatement = prepUpdate(baseObject, fieldName, theConnection);
207
208 try {
209 if ("interbase.interclient.Driver".equals(theConnection.getDBDriver())) {
210 byte[] data = theData.getBytes();
214 java.io.ByteArrayInputStream bis = new java.io.ByteArrayInputStream (data);
215 preparedStatement.setAsciiStream(1, bis, data.length);
216 } else {
217 java.io.Reader r = new java.io.StringReader (theData);
218 preparedStatement.setCharacterStream(1, r, theData.length());
219 }
220 } catch (SQLException ex) {
221 throw new DBException("Unable to set CharacterStream to CLOB object.", ex);
222 }
223
224 finalizeUpdate(theConnection);
225 }
226
227
228
241 public byte[] getBLOB(DBObject baseObject,
242 String fieldName,
243 DBConnection theConnection) throws DBException {
244
245 prepSelectResultSet(baseObject, fieldName, theConnection);
246 if (theConnection.next()) {
247 byte retVal[] = theConnection.getBytes(1);
248 if (retVal == null) {
249 return new byte[0];
250 } else {
251 return retVal;
252 }
253 }
254
255 return new byte[0];
256 }
257
258
267 public void setBLOB(DBObject baseObject,
268 String fieldName,
269 byte theData[],
270 DBConnection theConnection) throws DBException {
271
272 PreparedStatement preparedStatement = prepUpdate(baseObject, fieldName, theConnection);
273
274
275 try {
276 preparedStatement.setBytes(1, theData);
277 } catch (SQLException ex) {
278 throw new DBException("Error setting BLOB object", ex);
279 }
280
281 finalizeUpdate(theConnection);
282 }
283
284
295 public void setBLOB(DBObject baseObject,
296 String fieldName,
297 InputStream theData,
298 int dataLength,
299 DBConnection theConnection) throws DBException {
300 PreparedStatement preparedStatement = prepUpdate(baseObject, fieldName, theConnection);
301
302
303 try {
304 preparedStatement.setBinaryStream(1, theData, dataLength);
305 } catch (SQLException ex) {
306 throw new DBException("Error setting BLOB object", ex);
307 }
308
309
310 finalizeUpdate(theConnection);
311 }
312
313
314
327 protected void prepSelectResultSet(DBObject baseObject,
328 String fieldName,
329 DBConnection theConnection) throws DBException {
330 FastStringBuffer prepStatement = FastStringBuffer.getInstance();
331 try {
332 prepStatement.append("SELECT ");
333 prepStatement.append(fieldName);
334 prepStatement.append(" from ");
335 prepStatement.append(baseObject.getJDBCMetaData().getTargetSQLTable(baseObject.getDataContext()));
336 String whereClause = baseObject.buildWhereClause(false);
337 prepStatement.append(whereClause);
338 String thePrepString = prepStatement.toString();
339 if (log.isDebugEnabled()) {
340 log.debug("Preparing prepared statement: " + thePrepString);
341 }
342
343 PreparedStatement prep = theConnection.createPreparedStatement(thePrepString);
344 if (prep == null) {
345 throw new DBException("Unable to create prepared statement for CLOB retrieval." +
346 " Check DBConnection log for details");
347 }
348 theConnection.execute();
349
350 if (log.isDebugEnabled()) {
351 log.debug("Succesfully executed prepared statement");
352 }
353 } finally {
354 prepStatement.release();
355 prepStatement = null;
356 }
357 }
358
359
369 protected PreparedStatement prepUpdate(DBObject baseObject,
370 String fieldName,
371 DBConnection theConnection) throws DBException {
372 String whereClause = baseObject.buildWhereClause(false);
373
374 FastStringBuffer prepStatement = FastStringBuffer.getInstance();
375 String theSQL = null;
376 try {
377 prepStatement.append("UPDATE ");
378 prepStatement.append(baseObject.getJDBCMetaData().getTargetSQLTable(baseObject.getDataContext()));
379 prepStatement.append(" SET ");
380 prepStatement.append(fieldName);
381 prepStatement.append(" = ? ");
382 prepStatement.append(whereClause);
383 theSQL = prepStatement.toString();
384 } finally {
385 prepStatement.release();
386 prepStatement = null;
387 }
388
389 return theConnection.createPreparedStatement(theSQL);
390 }
391
392 protected void finalizeUpdate(DBConnection theConnection) throws DBException {
393
394 boolean alreadyInTransaction = !(theConnection.getAutoCommit());
395 boolean success = false;
396
397 if (!alreadyInTransaction && theConnection.supportsTransactions()) {
403 if (log.isDebugEnabled()) {
404 log.debug("Turning off auto-commit");
405 }
406 theConnection.setAutoCommit(false);
407 }
408
409 try {
410 theConnection.executeUpdate(null);
411 success = true;
412 } finally {
413 if (success == false) {
414 if (!alreadyInTransaction && theConnection.supportsTransactions()) {
415 if (log.isDebugEnabled()) {
416 log.debug("rolling back");
417 }
418 theConnection.rollback();
419 }
420 }
421 if (!alreadyInTransaction && theConnection.supportsTransactions()) {
422 if (log.isDebugEnabled()) {
423 log.debug("Finishing commit and turning auto-commit back to true");
424 }
425 theConnection.commit();
426 theConnection.setAutoCommit(true);
427 }
428 }
429
430 }
431
432 }
433 |
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