| 1 | /* |
| 2 | |
| 3 | Derby - Class org.apache.derby.impl.jdbc.EmbedClob |
| 4 | |
| 5 | Copyright 2000, 2004 The Apache Software Foundation or its licensors, as applicable. |
| 6 | |
| 7 | Licensed under the Apache License, Version 2.0 (the "License"); |
| 8 | you may not use this file except in compliance with the License. |
| 9 | You may obtain a copy of the License at |
| 10 | |
| 11 | http://www.apache.org/licenses/LICENSE-2.0 |
| 12 | |
| 13 | Unless required by applicable law or agreed to in writing, software |
| 14 | distributed under the License is distributed on an "AS IS" BASIS, |
| 15 | WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| 16 | See the License for the specific language governing permissions and |
| 17 | limitations under the License. |
| 18 | |
| 19 | */ |
| 20 | |
| 21 | |
| 22 | package org.apache.derby.impl.jdbc; |
| 23 | |
| 24 | import org.apache.derby.iapi.reference.SQLState; |
| 25 | import org.apache.derby.iapi.error.StandardException; |
| 26 | import org.apache.derby.iapi.services.sanity.SanityManager; |
| 27 | import org.apache.derby.iapi.types.DataValueDescriptor; |
| 28 | import org.apache.derby.iapi.types.Resetable; |
| 29 | import org.apache.derby.impl.jdbc.ConnectionChild; |
| 30 | import org.apache.derby.impl.jdbc.EmbedConnection; |
| 31 | import org.apache.derby.impl.jdbc.Util; |
| 32 | import org.apache.derby.impl.jdbc.UTF8Reader; |
| 33 | import org.apache.derby.impl.jdbc.ReaderToAscii; |
| 34 | |
| 35 | import java.io.InputStream; |
| 36 | import java.io.InputStreamReader; |
| 37 | import java.io.StringReader; |
| 38 | import java.io.Reader; |
| 39 | import java.io.IOException; |
| 40 | import java.io.EOFException; |
| 41 | import java.sql.SQLException; |
| 42 | import java.sql.Clob; |
| 43 | |
| 44 | /** |
| 45 | Implements java.sql.Clob (see the JDBC 2.0 spec). |
| 46 | A clob sits on top of a CHAR, VARCHAR or LONG VARCHAR column. |
| 47 | If its data is small (less than 1 page) it is a byte array taken from |
| 48 | the SQLChar class. If it is large (more than 1 page) it is a long column |
| 49 | in the database. The long column is accessed as a stream, and is implemented |
| 50 | in store as an OverflowInputStream. The Resetable interface allows sending |
| 51 | messages to that stream to initialize itself (reopen its container and |
| 52 | lock the corresponding row) and to reset itself to the beginning. |
| 53 | |
| 54 | NOTE: In the case that the data is large, it is represented as a stream. |
| 55 | This stream can be returned to the user in the getAsciiStream() method. |
| 56 | This means that we have limited control over the state of the stream, |
| 57 | since the user can read bytes from it at any time. Thus all methods |
| 58 | here reset the stream to the beginning before doing any work. |
| 59 | CAVEAT: The methods may not behave correctly if a user sets up |
| 60 | multiple threads and sucks data from the stream (returned from |
| 61 | getAsciiStream()) at the same time as calling the Clob methods. |
| 62 | |
| 63 | <P><B>Supports</B> |
| 64 | <UL> |
| 65 | <LI> JSR169 - no subsetting for java.sql.Clob |
| 66 | <LI> JDBC 2.0 |
| 67 | <LI> JDBC 3.0 - no new dependencies on new JDBC 3.0 or JDK 1.4 classes, |
| 68 | new update methods can safely be added into implementation. |
| 69 | </UL> |
| 70 | */ |
| 71 | final class EmbedClob extends ConnectionChild implements Clob |
| 72 | { |
| 73 | // clob is either a string or stream |
| 74 | private boolean isString; |
| 75 | private InputStream myStream; |
| 76 | private String myString; |
| 77 | |
| 78 | //This boolean variable indicates whether the Clob object has |
| 79 | //been invalidated by calling free() on it |
| 80 | private boolean isValid = true; |
| 81 | |
| 82 | /** |
| 83 | * This constructor is used to create a empty Clob object. It is used by the |
| 84 | * Connection interface method createClob(). |
| 85 | * |
| 86 | * @param clobString A String object containing the data to be stores in the |
| 87 | * Clob. |
| 88 | * |
| 89 | * @param con The Connection object associated with this EmbedClob object. |
| 90 | * |
| 91 | */ |
| 92 | |
| 93 | EmbedClob(String clobString,EmbedConnection con) { |
| 94 | super(con); |
| 95 | myString = clobString; |
| 96 | isString = true; |
| 97 | } |
| 98 | |
| 99 | /* |
| 100 | This constructor should only be called by EmbedResultSet.getClob |
| 101 | */ |
| 102 | protected EmbedClob(DataValueDescriptor dvd, EmbedConnection con) |
| 103 | throws StandardException |
| 104 | { |
| 105 | super(con); |
| 106 | // if the underlying column is null, ResultSet.getClob will return null, |
| 107 | // never should get this far |
| 108 | if (SanityManager.DEBUG) |
| 109 | SanityManager.ASSERT(!dvd.isNull(), "clob is created on top of a null column"); |
| 110 | |
| 111 | myStream = dvd.getStream(); |
| 112 | if (myStream == null) |
| 113 | { |
| 114 | isString = true; |
| 115 | myString = dvd.getString(); |
| 116 | if (SanityManager.DEBUG) |
| 117 | SanityManager.ASSERT(myString != null,"clob has a null value underneath"); |
| 118 | } |
| 119 | else |
| 120 | { |
| 121 | /* |
| 122 | We are expecting this stream to be a FormatIdInputStream with an |
| 123 | OverflowInputStream inside. FormatIdInputStream implements |
| 124 | Resetable, as does OverflowInputStream. This should be the case |
| 125 | when retrieving data from a long column. However, SQLChar, which is |
| 126 | the class implementing the getStream() method for dvd.getStream(), |
| 127 | does not guarantee this for us. In particular, the logging system |
| 128 | (see StoredPage.logColumn) calls setStream with an argument that |
| 129 | is sometimes a RememberBytesInputStream on a SQLChar object |
| 130 | (e.g. see test repStreaming.sql). However, such a SQLChar |
| 131 | object is going to the log buffer, NOT back to the user, so it |
| 132 | should not break the ASSERT below. |
| 133 | */ |
| 134 | if (SanityManager.DEBUG) |
| 135 | SanityManager.ASSERT(myStream instanceof Resetable); |
| 136 | |
| 137 | try { |
| 138 | ((Resetable) myStream).initStream(); |
| 139 | } catch (StandardException se) { |
| 140 | if (se.getMessageId().equals(SQLState.DATA_CONTAINER_CLOSED)) { |
| 141 | throw StandardException |
| 142 | .newException(SQLState.BLOB_ACCESSED_AFTER_COMMIT); |
| 143 | } |
| 144 | } |
| 145 | } |
| 146 | } |
| 147 | |
| 148 | |
| 149 | /** |
| 150 | * Returns the number of characters |
| 151 | * in the <code>CLOB</code> value |
| 152 | * designated by this <code>Clob</code> object. |
| 153 | * @return length of the <code>CLOB</code> in characters |
| 154 | * @exception SQLException if there is an error accessing the |
| 155 | * length of the <code>CLOB</code> |
| 156 | */ |
| 157 | |
| 158 | public long length() throws SQLException |
| 159 | { |
| 160 | //call checkValidity to exit by throwing a SQLException if |
| 161 | //the Clob object has been freed by calling free() on it |
| 162 | checkValidity(); |
| 163 | // if we have a string, not a stream |
| 164 | if (isString) |
| 165 | return myString.length(); |
| 166 | |
| 167 | |
| 168 | Object synchronization = getConnectionSynchronization(); |
| 169 | synchronized (synchronization) |
| 170 | { |
| 171 | Reader clobReader = null; |
| 172 | setupContextStack(); |
| 173 | try { |
| 174 | |
| 175 | clobReader = getCharacterStream(); |
| 176 | long clobLength = 0; |
| 177 | for (;;) |
| 178 | { |
| 179 | long size = clobReader.skip(32 * 1024); |
| 180 | if (size == -1) |
| 181 | break; |
| 182 | clobLength += size; |
| 183 | } |
| 184 | clobReader.close(); |
| 185 | clobReader = null; |
| 186 | |
| 187 | return clobLength; |
| 188 | } |
| 189 | catch (Throwable t) |
| 190 | { |
| 191 | throw noStateChangeLOB(t); |
| 192 | } |
| 193 | finally |
| 194 | { |
| 195 | if (clobReader != null) { |
| 196 | try { |
| 197 | clobReader.close(); |
| 198 | } catch (IOException ioe) { |
| 199 | } |
| 200 | } |
| 201 | restoreContextStack(); |
| 202 | } |
| 203 | } |
| 204 | } |
| 205 | |
| 206 | /** |
| 207 | * Returns a copy of the specified substring |
| 208 | * in the <code>CLOB</code> value |
| 209 | * designated by this <code>Clob</code> object. |
| 210 | * The substring begins at position |
| 211 | * <code>pos</code> and has up to <code>length</code> consecutive |
| 212 | * characters. |
| 213 | * @param pos the first character of the substring to be extracted. |
| 214 | * The first character is at position 1. |
| 215 | * @param length the number of consecutive characters to be copied |
| 216 | * @return a <code>String</code> that is the specified substring in |
| 217 | * the <code>CLOB</code> value designated by this <code>Clob</code> object |
| 218 | * @exception SQLException if there is an error accessing the |
| 219 | * <code>CLOB</code> |
| 220 | |
| 221 | NOTE: return the empty string if pos is too large |
| 222 | */ |
| 223 | |
| 224 | public String getSubString(long pos, int length) throws SQLException |
| 225 | { |
| 226 | //call checkValidity to exit by throwing a SQLException if |
| 227 | //the Clob object has been freed by calling free() on it |
| 228 | checkValidity(); |
| 229 | |
| 230 | if (pos < 1) |
| 231 | throw Util.generateCsSQLException( |
| 232 | SQLState.BLOB_BAD_POSITION, new Long(pos)); |
| 233 | if (length <= 0) |
| 234 | throw Util.generateCsSQLException( |
| 235 | SQLState.BLOB_NONPOSITIVE_LENGTH, new Integer(length)); |
| 236 | |
| 237 | // if we have a string, not a stream |
| 238 | if (isString) |
| 239 | { |
| 240 | int sLength = myString.length(); |
| 241 | if (sLength < pos) |
| 242 | throw Util.generateCsSQLException( |
| 243 | SQLState.BLOB_POSITION_TOO_LARGE, new Long(pos)); |
| 244 | int endIndex = ((int) pos) + length - 1; |
| 245 | // cannot go over length of string, or we get an exception |
| 246 | return myString.substring(((int) pos) - 1, (sLength > endIndex ? endIndex : sLength)); |
| 247 | } |
| 248 | |
| 249 | Object synchronization = getConnectionSynchronization(); |
| 250 | synchronized (synchronization) |
| 251 | { |
| 252 | setupContextStack(); |
| 253 | |
| 254 | UTF8Reader clobReader = null; |
| 255 | try { |
| 256 | |
| 257 | clobReader = getCharacterStreamAtPos(pos, synchronization); |
| 258 | if (clobReader == null) |
| 259 | throw StandardException.newException(SQLState.BLOB_POSITION_TOO_LARGE, new Long(pos)); |
| 260 | |
| 261 | StringBuffer sb = new StringBuffer(length); |
| 262 | int remainToRead = length; |
| 263 | while (remainToRead > 0) { |
| 264 | |
| 265 | int read = clobReader.readInto(sb, remainToRead); |
| 266 | if (read == -1) |
| 267 | break; |
| 268 | |
| 269 | remainToRead -= read; |
| 270 | } |
| 271 | clobReader.close(); |
| 272 | clobReader = null; |
| 273 | |
| 274 | return sb.toString(); |
| 275 | } |
| 276 | catch (Throwable t) |
| 277 | { |
| 278 | throw noStateChangeLOB(t); |
| 279 | } |
| 280 | finally |
| 281 | { |
| 282 | if (clobReader != null) |
| 283 | clobReader.close(); |
| 284 | restoreContextStack(); |
| 285 | } |
| 286 | } |
| 287 | } |
| 288 | |
| 289 | |
| 290 | /** |
| 291 | * Gets the <code>Clob</code> contents as a Unicode stream. |
| 292 | * @return a Unicode stream containing the <code>CLOB</code> data |
| 293 | * @exception SQLException if there is an error accessing the |
| 294 | * <code>CLOB</code> |
| 295 | */ |
| 296 | |
| 297 | public java.io.Reader getCharacterStream() throws SQLException |
| 298 | { |
| 299 | //call checkValidity to exit by throwing a SQLException if |
| 300 | //the Clob object has been freed by calling free() on it |
| 301 | checkValidity(); |
| 302 | |
| 303 | // if we have a string, not a stream |
| 304 | if (isString) |
| 305 | { |
| 306 | return new StringReader(myString); |
| 307 | } |
| 308 | |
| 309 | |
| 310 | Object synchronization = getConnectionSynchronization(); |
| 311 | synchronized (synchronization) |
| 312 | { |
| 313 | setupContextStack(); |
| 314 | |
| 315 | try { |
| 316 | return getCharacterStreamAtPos(1, synchronization); |
| 317 | } |
| 318 | catch (Throwable t) |
| 319 | { |
| 320 | throw noStateChangeLOB(t); |
| 321 | } |
| 322 | finally |
| 323 | { |
| 324 | restoreContextStack(); |
| 325 | } |
| 326 | } |
| 327 | } |
| 328 | |
| 329 | |
| 330 | /** |
| 331 | * Gets the <code>CLOB</code> value designated by this <code>Clob</code> |
| 332 | * object as a stream of Ascii bytes. |
| 333 | * @return an ascii stream containing the <code>CLOB</code> data |
| 334 | * @exception SQLException if there is an error accessing the |
| 335 | * <code>CLOB</code> value |
| 336 | */ |
| 337 | |
| 338 | public java.io.InputStream getAsciiStream() throws SQLException |
| 339 | { |
| 340 | //call checkValidity to exit by throwing a SQLException if |
| 341 | //the Clob object has been freed by calling free() on it |
| 342 | checkValidity(); |
| 343 | return new ReaderToAscii(getCharacterStream()); |
| 344 | } |
| 345 | |
| 346 | private UTF8Reader getCharacterStreamAtPos(long position, Object synchronization) |
| 347 | throws IOException, StandardException |
| 348 | { |
| 349 | ((Resetable)myStream).resetStream(); |
| 350 | UTF8Reader clobReader = new UTF8Reader(myStream, 0, this, synchronization); |
| 351 | |
| 352 | // skip to the correct position (pos is one based) |
| 353 | long remainToSkip = position - 1; |
| 354 | while (remainToSkip > 0) { |
| 355 | long skipBy = clobReader.skip(remainToSkip); |
| 356 | if (skipBy == -1) |
| 357 | return null; |
| 358 | |
| 359 | remainToSkip -= skipBy; |
| 360 | } |
| 361 | |
| 362 | return clobReader; |
| 363 | } |
| 364 | |
| 365 | |
| 366 | /** |
| 367 | * Determines the character position at which the specified substring |
| 368 | * <code>searchstr</code> appears in the <code>CLOB</code>. The search |
| 369 | * begins at position <code>start</code>. |
| 370 | * @param searchStr the substring for which to search |
| 371 | * @param start the position at which to begin searching; the first position |
| 372 | * is 1 |
| 373 | * @return the position at which the substring appears, else -1; the first |
| 374 | * position is 1 |
| 375 | * @exception SQLException if there is an error accessing the |
| 376 | * <code>CLOB</code> value |
| 377 | */ |
| 378 | public long position(String searchStr, long start) |
| 379 | throws SQLException |
| 380 | { |
| 381 | //call checkValidity to exit by throwing a SQLException if |
| 382 | //the Clob object has been freed by calling free() on it |
| 383 | checkValidity(); |
| 384 | |
| 385 | boolean pushStack = false; |
| 386 | try |
| 387 | { |
| 388 | if (start < 1) |
| 389 | throw StandardException.newException( |
| 390 | SQLState.BLOB_BAD_POSITION, new Long(start)); |
| 391 | if (searchStr == null) |
| 392 | throw StandardException.newException(SQLState.BLOB_NULL_PATTERN_OR_SEARCH_STR); |
| 393 | if (searchStr == "") |
| 394 | return start; // match DB2's SQL LOCATE function |
| 395 | |
| 396 | // if we have a string, not a stream |
| 397 | if (isString) |
| 398 | { |
| 399 | // avoid truncation errors in the cast of start to an int. |
| 400 | if (start > myString.length()) |
| 401 | return -1; |
| 402 | |
| 403 | int result = myString.indexOf(searchStr, (int) start-1); |
| 404 | return result < 0 ? -1 : result + 1; |
| 405 | } |
| 406 | else // we have a stream |
| 407 | { |
| 408 | Object synchronization = getConnectionSynchronization(); |
| 409 | synchronized (synchronization) |
| 410 | { |
| 411 | pushStack = !getEmbedConnection().isClosed(); |
| 412 | if (pushStack) |
| 413 | setupContextStack(); |
| 414 | |
| 415 | char[] tmpClob = new char[256]; |
| 416 | int patternLength = searchStr.length(); |
| 417 | |
| 418 | restartPattern: |
| 419 | for (;;) { |
| 420 | |
| 421 | //System.out.println("RESET " + start); |
| 422 | UTF8Reader clobReader = getCharacterStreamAtPos(start, synchronization); |
| 423 | if (clobReader == null) |
| 424 | return -1; |
| 425 | |
| 426 | |
| 427 | |
| 428 | // start of any match of the complete pattern. |
| 429 | |
| 430 | int patternIndex = 0; |
| 431 | char[] tmpPattern = null; |
| 432 | boolean needPattern = true; |
| 433 | |
| 434 | // how many characters of the patter segment we have matched |
| 435 | int matchCount = 0; |
| 436 | |
| 437 | long currentPosition = start; |
| 438 | int clobOffset = -1; |
| 439 | int read = -1; |
| 440 | |
| 441 | // absolute position of a possible match |
| 442 | long matchPosition = -1; |
| 443 | |
| 444 | |
| 445 | // absolute position of the next possible match |
| 446 | long nextBestMatchPosition = -1; |
| 447 | //System.out.println("restartPattern: " + start); |
| 448 | |
| 449 | |
| 450 | search: |
| 451 | for (;;) |
| 452 | { |
| 453 | //System.out.println("search: " + needPattern + " -- " + clobOffset); |
| 454 | if (needPattern) { |
| 455 | |
| 456 | String tmpPatternS; |
| 457 | if ((patternLength - patternIndex) > 256) |
| 458 | tmpPatternS = searchStr.substring(patternIndex, 256); |
| 459 | else |
| 460 | tmpPatternS = searchStr; |
| 461 | |
| 462 | tmpPattern = tmpPatternS.toCharArray(); |
| 463 | needPattern = false; |
| 464 | matchCount = 0; |
| 465 | |
| 466 | } |
| 467 | |
| 468 | if (clobOffset == -1) { |
| 469 | |
| 470 | read = clobReader.read(tmpClob, 0, tmpClob.length); |
| 471 | //System.out.println("MORE DATA " + read); |
| 472 | if (read == -1) |
| 473 | return -1; |
| 474 | |
| 475 | if (read == 0) |
| 476 | continue search; |
| 477 | |
| 478 | clobOffset = 0; |
| 479 | } |
| 480 | |
| 481 | |
| 482 | // find matches within our two temp arrays. |
| 483 | compareArrays: |
| 484 | for (; clobOffset < read; clobOffset++) { |
| 485 | |
| 486 | //System.out.println("compareArrays " + clobOffset); |
| 487 | |
| 488 | char clobC = tmpClob[clobOffset]; |
| 489 | |
| 490 | |
| 491 | if (clobC == tmpPattern[matchCount]) |
| 492 | { |
| 493 | if (matchPosition == -1) { |
| 494 | matchPosition = currentPosition + clobOffset; |
| 495 | } |
| 496 | |
| 497 | matchCount++; |
| 498 | |
| 499 | // have we matched the entire pattern segment |
| 500 | if (matchCount == tmpPattern.length) |
| 501 | { |
| 502 | // move onto the next segment. |
| 503 | patternIndex += tmpPattern.length; |
| 504 | if (patternIndex == patternLength) { |
| 505 | // complete match !! |
| 506 | clobReader.close(); |
| 507 | //System.out.println("COMPLETE@" + matchPosition); |
| 508 | return matchPosition; |
| 509 | } |
| 510 | |
| 511 | needPattern = true; |
| 512 | continue search; |
| 513 | |
| 514 | } |
| 515 | |
| 516 | if (clobC == tmpPattern[0]) { |
| 517 | |
| 518 | // save the next best start position. |
| 519 | |
| 520 | // must be the first character of the actual pattern |
| 521 | if (patternIndex == 0) { |
| 522 | |
| 523 | // must not be just a repeat of the match of the first character |
| 524 | if (matchCount != 1) { |
| 525 | |
| 526 | // must not have a previous next best. |
| 527 | |
| 528 | if (nextBestMatchPosition == -1) { |
| 529 | nextBestMatchPosition = currentPosition + clobOffset; |
| 530 | } |
| 531 | |
| 532 | } |
| 533 | |
| 534 | } |
| 535 | } |
| 536 | |
| 537 | continue compareArrays; |
| 538 | } |
| 539 | else |
| 540 | { |
| 541 | // not a match |
| 542 | // |
| 543 | // |
| 544 | if (matchPosition != -1) { |
| 545 | // failed after we matched some amount of the pattern |
| 546 | matchPosition = -1; |
| 547 | |
| 548 | // See if we found a next best match |
| 549 | if (nextBestMatchPosition == -1) |
| 550 | { |
| 551 | // NO - just continue on, re-starting at this character |
| 552 | |
| 553 | if (patternIndex != 0) { |
| 554 | needPattern = true; |
| 555 | continue search; |
| 556 | } |
| 557 | } |
| 558 | else if (nextBestMatchPosition >= currentPosition) |
| 559 | { |
| 560 | // restart in the current array |
| 561 | clobOffset = (int) (nextBestMatchPosition - currentPosition); |
| 562 | nextBestMatchPosition = -1; |
| 563 | |
| 564 | if (patternIndex != 0) { |
| 565 | needPattern = true; |
| 566 | continue search; |
| 567 | } |
| 568 | } |
| 569 | else |
| 570 | { |
| 571 | clobReader.close(); |
| 572 | start = nextBestMatchPosition; |
| 573 | continue restartPattern; |
| 574 | } |
| 575 | |
| 576 | clobOffset--; // since the continue will increment it |
| 577 | matchCount = 0; |
| 578 | continue compareArrays; |
| 579 | } |
| 580 | |
| 581 | // no current match, just continue |
| 582 | } |
| 583 | } |
| 584 | |
| 585 | currentPosition += read; |
| 586 | |
| 587 | // indicates we need to read more data |
| 588 | clobOffset = -1; |
| 589 | } |
| 590 | } |
| 591 | } |
| 592 | } |
| 593 | } |
| 594 | catch (Throwable t) |
| 595 | { |
| 596 | throw noStateChangeLOB(t); |
| 597 | } |
| 598 | finally |
| 599 | { |
| 600 | if (pushStack) |
| 601 | restoreContextStack(); |
| 602 | } |
| 603 | |
| 604 | } |
| 605 | |
| 606 | |
| 607 | /** |
| 608 | * Determines the character position at which the specified |
| 609 | * <code>Clob</code> object <code>searchstr</code> appears in this |
| 610 | * <code>Clob</code> object. The search begins at position |
| 611 | * <code>start</code>. |
| 612 | * @param searchClob the <code>Clob</code> object for which to search |
| 613 | * @param start the position at which to begin searching; the first |
| 614 | * position is 1 |
| 615 | * @return the position at which the <code>Clob</code> object appears, |
| 616 | * else -1; the first position is 1 |
| 617 | * @exception SQLException if there is an error accessing the |
| 618 | * <code>CLOB</code> value |
| 619 | */ |
| 620 | |
| 621 | public long position(Clob searchClob, long start) |
| 622 | throws SQLException |
| 623 | { |
| 624 | //call checkValidity to exit by throwing a SQLException if |
| 625 | //the Clob object has been freed by calling free() on it |
| 626 | checkValidity(); |
| 627 | |
| 628 | boolean pushStack = false; |
| 629 | try |
| 630 | { |
| 631 | if (start < 1) |
| 632 | throw StandardException.newException( |
| 633 | SQLState.BLOB_BAD_POSITION, new Long(start)); |
| 634 | if (searchClob == null) |
| 635 | throw StandardException.newException(SQLState.BLOB_NULL_PATTERN_OR_SEARCH_STR); |
| 636 | |
| 637 | synchronized (getConnectionSynchronization()) |
| 638 | { |
| 639 | char[] subPatternChar = new char[256]; |
| 640 | |
| 641 | boolean seenOneCharacter = false; |
| 642 | |
| 643 | //System.out.println("BEGIN CLOB SEARCH @ " + start); |
| 644 | |
| 645 | restartScan: |
| 646 | for (;;) { |
| 647 | |
| 648 | long firstPosition = -1; |
| 649 | |
| 650 | Reader patternReader = searchClob.getCharacterStream(); |
| 651 | |
| 652 | //System.out.println("RESTART CLOB SEARCH @ " + start); |
| 653 | |
| 654 | try { |
| 655 | |
| 656 | for (;;) { |
| 657 | |
| 658 | int read = patternReader.read(subPatternChar, 0, subPatternChar.length); |
| 659 | if (read == -1) { |
| 660 | //empty pattern |
| 661 | if (!seenOneCharacter) |
| 662 | return start; // matches DB2 SQL LOCATE function |
| 663 | |
| 664 | return firstPosition; |
| 665 | } |
| 666 | if (read == 0) { |
| 667 | //System.out.println("STUCK IN READ 0 HELL"); |
| 668 | continue; |
| 669 | } |
| 670 | |
| 671 | seenOneCharacter = true; |
| 672 | |
| 673 | String subPattern = new String(subPatternChar, 0, read); |
| 674 | //System.out.println("START CLOB SEARCH @ " + start + " -- " + subPattern); |
| 675 | long position = position(subPattern, start); |
| 676 | //System.out.println("DONE SUB CLOB SEARCH @ " + start + " -- " + position); |
| 677 | if (position == -1) { |
| 678 | // never seen any match |
| 679 | if (firstPosition == -1) |
| 680 | return -1; |
| 681 | |
| 682 | start = firstPosition + 1; |
| 683 | continue restartScan; |
| 684 | } |
| 685 | |
| 686 | if (firstPosition == -1) |
| 687 | firstPosition = position; |
| 688 | else if (position != start) { |
| 689 | // must match at the first character of the segment |
| 690 | start = firstPosition + 1; |
| 691 | continue restartScan; |
| 692 | } |
| 693 | |
| 694 | // read is the length of the subPattern string |
| 695 | start = position + read; |
| 696 | } |
| 697 | } finally { |
| 698 | patternReader.close(); |
| 699 | } |
| 700 | } |
| 701 | } |
| 702 | } |
| 703 | catch (Throwable t) |
| 704 | { |
| 705 | throw noStateChangeLOB(t); |
| 706 | } |
| 707 | finally |
| 708 | { |
| 709 | if (pushStack) |
| 710 | restoreContextStack(); |
| 711 | } |
| 712 | |
| 713 | } |
| 714 | |
| 715 | |
| 716 | /* |
| 717 | If we have a stream, release the resources associated with it. |
| 718 | */ |
| 719 | protected void finalize() |
| 720 | { |
| 721 | // System.out.println("finalizer called"); |
| 722 | if (!isString) |
| 723 | ((Resetable)myStream).closeStream(); |
| 724 | } |
| 725 | |
| 726 | |
| 727 | /** |
| 728 | Following methods are for the new JDBC 3.0 methods in java.sql.Clob |
| 729 | (see the JDBC 3.0 spec). We have the JDBC 3.0 methods in Local20 |
| 730 | package, so we don't have to have a new class in Local30. |
| 731 | The new JDBC 3.0 methods don't make use of any new JDBC3.0 classes and |
| 732 | so this will work fine in jdbc2.0 configuration. |
| 733 | */ |
| 734 | |
| 735 | ///////////////////////////////////////////////////////////////////////// |
| 736 | // |
| 737 | // JDBC 3.0 - New public methods |
| 738 | // |
| 739 | ///////////////////////////////////////////////////////////////////////// |
| 740 | |
| 741 | /** |
| 742 | * JDBC 3.0 |
| 743 | * |
| 744 | * Writes the given Java String to the CLOB value that this Clob object designates |
| 745 | * at the position pos. |
| 746 | * |
| 747 | * @param pos - the position at which to start writing to the CLOB value that |
| 748 | * this Clob object represents |
| 749 | * @return the number of characters written |
| 750 | * @exception SQLException Feature not implemented for now. |
| 751 | */ |
| 752 | public int setString(long pos, String parameterName) |
| 753 | throws SQLException |
| 754 | { |
| 755 | throw Util.notImplemented(); |
| 756 | } |
| 757 | |
| 758 | /** |
| 759 | * JDBC 3.0 |
| 760 | * |
| 761 | * Writes len characters of str, starting at character offset, to the CLOB value |
| 762 | * that this Clob represents. |
| 763 | * |
| 764 | * @param pos - the position at which to start writing to this Clob object |
| 765 | * @param str - the string to be written to the CLOB value that this Clob designates |
| 766 | * @param offset - the offset into str to start reading the characters to be written |
| 767 | * @param len - the number of characters to be written |
| 768 | * @return the number of characters written |
| 769 | * @exception SQLException Feature not implemented for now. |
| 770 | */ |
| 771 | public int setString(long pos, String str, int offset, int len) |
| 772 | throws SQLException |
| 773 | { |
| 774 | throw Util.notImplemented(); |
| 775 | } |
| 776 | |
| 777 | /** |
| 778 | * JDBC 3.0 |
| 779 | * |
| 780 | * Retrieves a stream to be used to write Ascii characters to the CLOB |
| 781 | * value that this Clob object represents, starting at position pos. |
| 782 | * |
| 783 | * @param pos - the position at which to start writing to this Clob object |
| 784 | * @return the stream to which ASCII encoded characters can be written |
| 785 | * @exception SQLException Feature not implemented for now. |
| 786 | */ |
| 787 | public java.io.OutputStream setAsciiStream(long pos) |
| 788 | throws SQLException |
| 789 | { |
| 790 | throw Util.notImplemented(); |
| 791 | } |
| 792 | |
| 793 | /** |
| 794 | * JDBC 3.0 |
| 795 | * |
| 796 | * Retrieves a stream to be used to write a stream of Unicode characters to the |
| 797 | * CLOB value that this Clob object represents, starting at position pos. |
| 798 | * |
| 799 | * @param pos - the position at which to start writing to this Clob object |
| 800 | * @return the stream to which Unicode encoded characters can be written |
| 801 | * @exception SQLException Feature not implemented for now. |
| 802 | */ |
| 803 | public java.io.Writer setCharacterStream(long pos) |
| 804 | throws SQLException |
| 805 | { |
| 806 | throw Util.notImplemented(); |
| 807 | } |
| 808 | |
| 809 | /** |
| 810 | * JDBC 3.0 |
| 811 | * |
| 812 | * Truncates the CLOB value that this Clob designates to have a length of len characters |
| 813 | * |
| 814 | * @param len - the length, in bytes, to which the CLOB value that this Blob |
| 815 | * value should be truncated |
| 816 | * @exception SQLException Feature not implemented for now. |
| 817 | */ |
| 818 | public void truncate(long len) |
| 819 | throws SQLException |
| 820 | { |
| 821 | throw Util.notImplemented(); |
| 822 | } |
| 823 | |
| 824 | ///////////////////////////////////////////////////////////////////////// |
| 825 | // |
| 826 | // JDBC 4.0 - New public methods |
| 827 | // |
| 828 | ///////////////////////////////////////////////////////////////////////// |
| 829 | /** |
| 830 | * This method frees the <code>Clob</code> object and releases the resources the resources |
| 831 | * that it holds. The object is invalid once the <code>free</code> method |
| 832 | * is called. If <code>free</code> is called multiple times, the |
| 833 | * subsequent calls to <code>free</code> are treated as a no-op. |
| 834 | * |
| 835 | * @throws SQLException if an error occurs releasing |
| 836 | * the Clob's resources |
| 837 | */ |
| 838 | public void free() |
| 839 | throws SQLException { |
| 840 | //calling free() on a already freed object is treated as a no-op |
| 841 | if (!isValid) return; |
| 842 | |
| 843 | //now that free has been called the Clob object is no longer |
| 844 | //valid |
| 845 | isValid = false; |
| 846 | |
| 847 | if (!isString) |
| 848 | ((Resetable)myStream).closeStream(); |
| 849 | else |
| 850 | myString = null; |
| 851 | } |
| 852 | |
| 853 | public java.io.Reader getCharacterStream(long pos, long length) |
| 854 | throws SQLException { |
| 855 | throw Util.notImplemented(); |
| 856 | } |
| 857 | |
| 858 | /* |
| 859 | ** |
| 860 | */ |
| 861 | |
| 862 | static SQLException noStateChangeLOB(Throwable t) { |
| 863 | if (t instanceof StandardException) |
| 864 | { |
| 865 | // container closed means the blob or clob was accessed after commit |
| 866 | if (((StandardException) t).getMessageId().equals(SQLState.DATA_CONTAINER_CLOSED)) |
| 867 | { |
| 868 | t = StandardException.newException(SQLState.BLOB_ACCESSED_AFTER_COMMIT); |
| 869 | } |
| 870 | } |
| 871 | return org.apache.derby.impl.jdbc.EmbedResultSet.noStateChangeException(t); |
| 872 | } |
| 873 | |
| 874 | /* |
| 875 | * Checks is isValid is true. If it is not true throws |
| 876 | * a SQLException stating that a method has been called on |
| 877 | * an invalid LOB object |
| 878 | * |
| 879 | * throws SQLException if isValid is not true. |
| 880 | */ |
| 881 | private void checkValidity() throws SQLException{ |
| 882 | if(!isValid) |
| 883 | throw newSQLException(SQLState.LOB_OBJECT_INVALID); |
| 884 | } |
| 885 | } |