| 1 | /* |
| 2 | Copyright (C) 2002-2004 MySQL AB |
| 3 | |
| 4 | This program is free software; you can redistribute it and/or modify |
| 5 | it under the terms of version 2 of the GNU General Public License as |
| 6 | published by the Free Software Foundation. |
| 7 | |
| 8 | There are special exceptions to the terms and conditions of the GPL |
| 9 | as it is applied to this software. View the full text of the |
| 10 | exception in file EXCEPTIONS-CONNECTOR-J in the directory of this |
| 11 | software distribution. |
| 12 | |
| 13 | This program is distributed in the hope that it will be useful, |
| 14 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 15 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 16 | GNU General Public License for more details. |
| 17 | |
| 18 | You should have received a copy of the GNU General Public License |
| 19 | along with this program; if not, write to the Free Software |
| 20 | Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA |
| 21 | |
| 22 | |
| 23 | |
| 24 | */ |
| 25 | package com.mysql.jdbc; |
| 26 | |
| 27 | import java.io.ByteArrayInputStream; |
| 28 | import java.io.OutputStream; |
| 29 | |
| 30 | import java.sql.SQLException; |
| 31 | |
| 32 | import java.util.ArrayList; |
| 33 | import java.util.List; |
| 34 | |
| 35 | /** |
| 36 | * The representation (mapping) in the JavaTM programming language of an SQL |
| 37 | * BLOB value. An SQL BLOB is a built-in type that stores a Binary Large Object |
| 38 | * as a column value in a row of a database table. The driver implements Blob |
| 39 | * using an SQL locator(BLOB), which means that a Blob object contains a logical |
| 40 | * pointer to the SQL BLOB data rather than the data itself. A Blob object is |
| 41 | * valid for the duration of the transaction in which is was created. Methods in |
| 42 | * the interfaces ResultSet, CallableStatement, and PreparedStatement, such as |
| 43 | * getBlob and setBlob allow a programmer to access an SQL BLOB value. The Blob |
| 44 | * interface provides methods for getting the length of an SQL BLOB (Binary |
| 45 | * Large Object) value, for materializing a BLOB value on the client, and for |
| 46 | * determining the position of a pattern of bytes within a BLOB value. This |
| 47 | * class is new in the JDBC 2.0 API. |
| 48 | * |
| 49 | * @author Mark Matthews |
| 50 | * |
| 51 | * @version $Id: BlobFromLocator.java,v 1.1.2.1 2005/05/13 18:58:38 mmatthews |
| 52 | * Exp $ |
| 53 | */ |
| 54 | public class BlobFromLocator implements java.sql.Blob { |
| 55 | private String blobColumnName = null; |
| 56 | |
| 57 | /** The ResultSet that created this BLOB */ |
| 58 | private ResultSet creatorResultSet; |
| 59 | |
| 60 | private int numColsInResultSet = 0; |
| 61 | |
| 62 | private int numPrimaryKeys = 0; |
| 63 | |
| 64 | private List primaryKeyColumns = null; |
| 65 | |
| 66 | private List primaryKeyValues = null; |
| 67 | |
| 68 | private String quotedId; |
| 69 | |
| 70 | private String tableName = null; |
| 71 | |
| 72 | /** |
| 73 | * Creates an updatable BLOB that can update in-place |
| 74 | */ |
| 75 | BlobFromLocator(ResultSet creatorResultSetToSet, int blobColumnIndex) |
| 76 | throws SQLException { |
| 77 | this.creatorResultSet = creatorResultSetToSet; |
| 78 | |
| 79 | this.numColsInResultSet = this.creatorResultSet.fields.length; |
| 80 | this.quotedId = this.creatorResultSet.connection.getMetaData() |
| 81 | .getIdentifierQuoteString(); |
| 82 | |
| 83 | if (this.numColsInResultSet > 1) { |
| 84 | this.primaryKeyColumns = new ArrayList(); |
| 85 | this.primaryKeyValues = new ArrayList(); |
| 86 | |
| 87 | for (int i = 0; i < this.numColsInResultSet; i++) { |
| 88 | if (this.creatorResultSet.fields[i].isPrimaryKey()) { |
| 89 | StringBuffer keyName = new StringBuffer(); |
| 90 | keyName.append(quotedId); |
| 91 | |
| 92 | String originalColumnName = this.creatorResultSet.fields[i] |
| 93 | .getOriginalName(); |
| 94 | |
| 95 | if (this.creatorResultSet.connection.getIO() |
| 96 | .hasLongColumnInfo() |
| 97 | && (originalColumnName != null) |
| 98 | && (originalColumnName.length() > 0)) { |
| 99 | keyName.append(originalColumnName); |
| 100 | } else { |
| 101 | keyName.append(this.creatorResultSet.fields[i] |
| 102 | .getName()); |
| 103 | } |
| 104 | |
| 105 | keyName.append(quotedId); |
| 106 | |
| 107 | this.primaryKeyColumns.add(keyName.toString()); |
| 108 | this.primaryKeyValues.add(this.creatorResultSet |
| 109 | .getString(i + 1)); |
| 110 | } |
| 111 | } |
| 112 | } else { |
| 113 | notEnoughInformationInQuery(); |
| 114 | } |
| 115 | |
| 116 | this.numPrimaryKeys = this.primaryKeyColumns.size(); |
| 117 | |
| 118 | if (this.numPrimaryKeys == 0) { |
| 119 | notEnoughInformationInQuery(); |
| 120 | } |
| 121 | |
| 122 | if (this.creatorResultSet.fields[0].getOriginalTableName() != null) { |
| 123 | StringBuffer tableNameBuffer = new StringBuffer(); |
| 124 | |
| 125 | String databaseName = this.creatorResultSet.fields[0] |
| 126 | .getDatabaseName(); |
| 127 | |
| 128 | if ((databaseName != null) && (databaseName.length() > 0)) { |
| 129 | tableNameBuffer.append(quotedId); |
| 130 | tableNameBuffer.append(databaseName); |
| 131 | tableNameBuffer.append(quotedId); |
| 132 | tableNameBuffer.append('.'); |
| 133 | } |
| 134 | |
| 135 | tableNameBuffer.append(quotedId); |
| 136 | tableNameBuffer.append(this.creatorResultSet.fields[0] |
| 137 | .getOriginalTableName()); |
| 138 | tableNameBuffer.append(quotedId); |
| 139 | |
| 140 | this.tableName = tableNameBuffer.toString(); |
| 141 | } else { |
| 142 | StringBuffer tableNameBuffer = new StringBuffer(); |
| 143 | |
| 144 | tableNameBuffer.append(quotedId); |
| 145 | tableNameBuffer.append(this.creatorResultSet.fields[0] |
| 146 | .getTableName()); |
| 147 | tableNameBuffer.append(quotedId); |
| 148 | |
| 149 | this.tableName = tableNameBuffer.toString(); |
| 150 | } |
| 151 | |
| 152 | this.blobColumnName = this.creatorResultSet.getString(blobColumnIndex); |
| 153 | } |
| 154 | |
| 155 | /** |
| 156 | * Retrieves the BLOB designated by this Blob instance as a stream. |
| 157 | * |
| 158 | * @return this BLOB represented as a binary stream of bytes. |
| 159 | * |
| 160 | * @throws SQLException |
| 161 | * if a database error occurs |
| 162 | */ |
| 163 | public java.io.InputStream getBinaryStream() throws SQLException { |
| 164 | return new ByteArrayInputStream(getBytes(1L, (int) length())); |
| 165 | } |
| 166 | |
| 167 | /** |
| 168 | * Returns as an array of bytes, part or all of the BLOB value that this |
| 169 | * Blob object designates. |
| 170 | * |
| 171 | * @param pos |
| 172 | * where to start the part of the BLOB |
| 173 | * @param length |
| 174 | * the length of the part of the BLOB you want returned. |
| 175 | * |
| 176 | * @return the bytes stored in the blob starting at position |
| 177 | * <code>pos</code> and having a length of <code>length</code>. |
| 178 | * |
| 179 | * @throws SQLException |
| 180 | * if a database error occurs |
| 181 | */ |
| 182 | public byte[] getBytes(long pos, int length) throws SQLException { |
| 183 | java.sql.ResultSet blobRs = null; |
| 184 | java.sql.PreparedStatement pStmt = null; |
| 185 | |
| 186 | // FIXME: Needs to use identifiers for column/table names |
| 187 | StringBuffer query = new StringBuffer("SELECT SUBSTRING("); |
| 188 | query.append(this.blobColumnName); |
| 189 | query.append(", "); |
| 190 | query.append(pos); |
| 191 | query.append(", "); |
| 192 | query.append(length); |
| 193 | query.append(") FROM "); |
| 194 | query.append(this.tableName); |
| 195 | query.append(" WHERE "); |
| 196 | |
| 197 | query.append((String) this.primaryKeyColumns.get(0)); |
| 198 | query.append(" = ?"); |
| 199 | |
| 200 | for (int i = 1; i < this.numPrimaryKeys; i++) { |
| 201 | query.append(" AND "); |
| 202 | query.append((String) this.primaryKeyColumns.get(i)); |
| 203 | query.append(" = ?"); |
| 204 | } |
| 205 | |
| 206 | try { |
| 207 | // FIXME: Have this passed in instead |
| 208 | pStmt = this.creatorResultSet.connection.prepareStatement(query |
| 209 | .toString()); |
| 210 | |
| 211 | for (int i = 0; i < this.numPrimaryKeys; i++) { |
| 212 | pStmt.setString(i + 1, (String) this.primaryKeyValues.get(i)); |
| 213 | } |
| 214 | |
| 215 | blobRs = pStmt.executeQuery(); |
| 216 | |
| 217 | if (blobRs.next()) { |
| 218 | return ((com.mysql.jdbc.ResultSet) blobRs).getBytes(1, true); |
| 219 | } |
| 220 | |
| 221 | throw new SQLException( |
| 222 | "BLOB data not found! Did primary keys change?", |
| 223 | SQLError.SQL_STATE_GENERAL_ERROR); |
| 224 | } finally { |
| 225 | if (blobRs != null) { |
| 226 | try { |
| 227 | blobRs.close(); |
| 228 | } catch (SQLException sqlEx) { |
| 229 | ; // do nothing |
| 230 | } |
| 231 | |
| 232 | blobRs = null; |
| 233 | } |
| 234 | |
| 235 | if (pStmt != null) { |
| 236 | try { |
| 237 | pStmt.close(); |
| 238 | } catch (SQLException sqlEx) { |
| 239 | ; // do nothing |
| 240 | } |
| 241 | |
| 242 | pStmt = null; |
| 243 | } |
| 244 | } |
| 245 | } |
| 246 | |
| 247 | /** |
| 248 | * Returns the number of bytes in the BLOB value designated by this Blob |
| 249 | * object. |
| 250 | * |
| 251 | * @return the length of this blob |
| 252 | * |
| 253 | * @throws SQLException |
| 254 | * if a database error occurs |
| 255 | */ |
| 256 | public long length() throws SQLException { |
| 257 | java.sql.ResultSet blobRs = null; |
| 258 | java.sql.PreparedStatement pStmt = null; |
| 259 | |
| 260 | // FIXME: Needs to use identifiers for column/table names |
| 261 | StringBuffer query = new StringBuffer("SELECT LENGTH("); |
| 262 | query.append(this.blobColumnName); |
| 263 | query.append(") FROM "); |
| 264 | query.append(this.tableName); |
| 265 | query.append(" WHERE "); |
| 266 | |
| 267 | query.append((String) this.primaryKeyColumns.get(0)); |
| 268 | query.append(" = ?"); |
| 269 | |
| 270 | for (int i = 1; i < this.numPrimaryKeys; i++) { |
| 271 | query.append(" AND "); |
| 272 | query.append((String) this.primaryKeyColumns.get(i)); |
| 273 | query.append(" = ?"); |
| 274 | } |
| 275 | |
| 276 | try { |
| 277 | // FIXME: Have this passed in instead |
| 278 | pStmt = this.creatorResultSet.connection.prepareStatement(query |
| 279 | .toString()); |
| 280 | |
| 281 | for (int i = 0; i < this.numPrimaryKeys; i++) { |
| 282 | pStmt.setString(i + 1, (String) this.primaryKeyValues.get(i)); |
| 283 | } |
| 284 | |
| 285 | blobRs = pStmt.executeQuery(); |
| 286 | |
| 287 | if (blobRs.next()) { |
| 288 | return blobRs.getLong(1); |
| 289 | } |
| 290 | |
| 291 | throw new SQLException( |
| 292 | "BLOB data not found! Did primary keys change?", |
| 293 | SQLError.SQL_STATE_GENERAL_ERROR); |
| 294 | } finally { |
| 295 | if (blobRs != null) { |
| 296 | try { |
| 297 | blobRs.close(); |
| 298 | } catch (SQLException sqlEx) { |
| 299 | ; // do nothing |
| 300 | } |
| 301 | |
| 302 | blobRs = null; |
| 303 | } |
| 304 | |
| 305 | if (pStmt != null) { |
| 306 | try { |
| 307 | pStmt.close(); |
| 308 | } catch (SQLException sqlEx) { |
| 309 | ; // do nothing |
| 310 | } |
| 311 | |
| 312 | pStmt = null; |
| 313 | } |
| 314 | } |
| 315 | } |
| 316 | |
| 317 | private void notEnoughInformationInQuery() throws SQLException { |
| 318 | throw new SQLException("Emulated BLOB locators must come from " |
| 319 | + "a ResultSet with only one table selected, and all primary " |
| 320 | + "keys selected", SQLError.SQL_STATE_GENERAL_ERROR); |
| 321 | } |
| 322 | |
| 323 | /** |
| 324 | * @see java.sql.Blob#position(byte[], long) |
| 325 | */ |
| 326 | public long position(byte[] pattern, long start) throws SQLException { |
| 327 | java.sql.ResultSet blobRs = null; |
| 328 | java.sql.PreparedStatement pStmt = null; |
| 329 | |
| 330 | // FIXME: Needs to use identifiers for column/table names |
| 331 | StringBuffer query = new StringBuffer("SELECT LOCATE("); |
| 332 | query.append("?, "); |
| 333 | query.append(this.blobColumnName); |
| 334 | query.append(", "); |
| 335 | query.append(start); |
| 336 | query.append(") FROM "); |
| 337 | query.append(this.tableName); |
| 338 | query.append(" WHERE "); |
| 339 | |
| 340 | query.append((String) this.primaryKeyColumns.get(0)); |
| 341 | query.append(" = ?"); |
| 342 | |
| 343 | for (int i = 1; i < this.numPrimaryKeys; i++) { |
| 344 | query.append(" AND "); |
| 345 | query.append((String) this.primaryKeyColumns.get(i)); |
| 346 | query.append(" = ?"); |
| 347 | } |
| 348 | |
| 349 | try { |
| 350 | // FIXME: Have this passed in instead |
| 351 | pStmt = this.creatorResultSet.connection.prepareStatement(query |
| 352 | .toString()); |
| 353 | pStmt.setBytes(1, pattern); |
| 354 | |
| 355 | for (int i = 0; i < this.numPrimaryKeys; i++) { |
| 356 | pStmt.setString(i + 2, (String) this.primaryKeyValues.get(i)); |
| 357 | } |
| 358 | |
| 359 | blobRs = pStmt.executeQuery(); |
| 360 | |
| 361 | if (blobRs.next()) { |
| 362 | return blobRs.getLong(1); |
| 363 | } |
| 364 | |
| 365 | throw new SQLException( |
| 366 | "BLOB data not found! Did primary keys change?", |
| 367 | SQLError.SQL_STATE_GENERAL_ERROR); |
| 368 | } finally { |
| 369 | if (blobRs != null) { |
| 370 | try { |
| 371 | blobRs.close(); |
| 372 | } catch (SQLException sqlEx) { |
| 373 | ; // do nothing |
| 374 | } |
| 375 | |
| 376 | blobRs = null; |
| 377 | } |
| 378 | |
| 379 | if (pStmt != null) { |
| 380 | try { |
| 381 | pStmt.close(); |
| 382 | } catch (SQLException sqlEx) { |
| 383 | ; // do nothing |
| 384 | } |
| 385 | |
| 386 | pStmt = null; |
| 387 | } |
| 388 | } |
| 389 | } |
| 390 | |
| 391 | /** |
| 392 | * Finds the position of the given pattern in this BLOB. |
| 393 | * |
| 394 | * @param pattern |
| 395 | * the pattern to find |
| 396 | * @param start |
| 397 | * where to start finding the pattern |
| 398 | * |
| 399 | * @return the position where the pattern is found in the BLOB, -1 if not |
| 400 | * found |
| 401 | * |
| 402 | * @throws SQLException |
| 403 | * if a database error occurs |
| 404 | */ |
| 405 | public long position(java.sql.Blob pattern, long start) throws SQLException { |
| 406 | return position(pattern.getBytes(0, (int) pattern.length()), start); |
| 407 | } |
| 408 | |
| 409 | /** |
| 410 | * @see Blob#setBinaryStream(long) |
| 411 | */ |
| 412 | public OutputStream setBinaryStream(long indexToWriteAt) |
| 413 | throws SQLException { |
| 414 | throw new NotImplemented(); |
| 415 | } |
| 416 | |
| 417 | /** |
| 418 | * @see Blob#setBytes(long, byte[]) |
| 419 | */ |
| 420 | public int setBytes(long writeAt, byte[] bytes) throws SQLException { |
| 421 | return setBytes(writeAt, bytes, 0, bytes.length); |
| 422 | } |
| 423 | |
| 424 | /** |
| 425 | * @see Blob#setBytes(long, byte[], int, int) |
| 426 | */ |
| 427 | public int setBytes(long writeAt, byte[] bytes, int offset, int length) |
| 428 | throws SQLException { |
| 429 | java.sql.PreparedStatement pStmt = null; |
| 430 | |
| 431 | if ((offset + length) > bytes.length) { |
| 432 | length = bytes.length - offset; |
| 433 | } |
| 434 | |
| 435 | byte[] bytesToWrite = new byte[length]; |
| 436 | System.arraycopy(bytes, offset, bytesToWrite, 0, length); |
| 437 | |
| 438 | // FIXME: Needs to use identifiers for column/table names |
| 439 | StringBuffer query = new StringBuffer("UPDATE "); |
| 440 | query.append(this.tableName); |
| 441 | query.append(" SET "); |
| 442 | query.append(this.blobColumnName); |
| 443 | query.append(" = INSERT("); |
| 444 | query.append(this.blobColumnName); |
| 445 | query.append(", "); |
| 446 | query.append(writeAt); |
| 447 | query.append(", "); |
| 448 | query.append(length); |
| 449 | query.append(", ?) WHERE "); |
| 450 | |
| 451 | query.append((String) this.primaryKeyColumns.get(0)); |
| 452 | query.append(" = ?"); |
| 453 | |
| 454 | for (int i = 1; i < this.numPrimaryKeys; i++) { |
| 455 | query.append(" AND "); |
| 456 | query.append((String) this.primaryKeyColumns.get(i)); |
| 457 | query.append(" = ?"); |
| 458 | } |
| 459 | |
| 460 | try { |
| 461 | // FIXME: Have this passed in instead |
| 462 | pStmt = this.creatorResultSet.connection.prepareStatement(query |
| 463 | .toString()); |
| 464 | |
| 465 | pStmt.setBytes(1, bytesToWrite); |
| 466 | |
| 467 | for (int i = 0; i < this.numPrimaryKeys; i++) { |
| 468 | pStmt.setString(i + 2, (String) this.primaryKeyValues.get(i)); |
| 469 | } |
| 470 | |
| 471 | int rowsUpdated = pStmt.executeUpdate(); |
| 472 | |
| 473 | if (rowsUpdated != 1) { |
| 474 | throw new SQLException( |
| 475 | "BLOB data not found! Did primary keys change?", |
| 476 | SQLError.SQL_STATE_GENERAL_ERROR); |
| 477 | } |
| 478 | } finally { |
| 479 | if (pStmt != null) { |
| 480 | try { |
| 481 | pStmt.close(); |
| 482 | } catch (SQLException sqlEx) { |
| 483 | ; // do nothing |
| 484 | } |
| 485 | |
| 486 | pStmt = null; |
| 487 | } |
| 488 | } |
| 489 | |
| 490 | return (int) length(); |
| 491 | } |
| 492 | |
| 493 | /** |
| 494 | * @see Blob#truncate(long) |
| 495 | */ |
| 496 | public void truncate(long length) throws SQLException { |
| 497 | java.sql.PreparedStatement pStmt = null; |
| 498 | |
| 499 | // FIXME: Needs to use identifiers for column/table names |
| 500 | StringBuffer query = new StringBuffer("UPDATE "); |
| 501 | query.append(this.tableName); |
| 502 | query.append(" SET "); |
| 503 | query.append(this.blobColumnName); |
| 504 | query.append(" = LEFT("); |
| 505 | query.append(this.blobColumnName); |
| 506 | query.append(", "); |
| 507 | query.append(length); |
| 508 | query.append(") WHERE "); |
| 509 | |
| 510 | query.append((String) this.primaryKeyColumns.get(0)); |
| 511 | query.append(" = ?"); |
| 512 | |
| 513 | for (int i = 1; i < this.numPrimaryKeys; i++) { |
| 514 | query.append(" AND "); |
| 515 | query.append((String) this.primaryKeyColumns.get(i)); |
| 516 | query.append(" = ?"); |
| 517 | } |
| 518 | |
| 519 | try { |
| 520 | // FIXME: Have this passed in instead |
| 521 | pStmt = this.creatorResultSet.connection.prepareStatement(query |
| 522 | .toString()); |
| 523 | |
| 524 | for (int i = 0; i < this.numPrimaryKeys; i++) { |
| 525 | pStmt.setString(i + 1, (String) this.primaryKeyValues.get(i)); |
| 526 | } |
| 527 | |
| 528 | int rowsUpdated = pStmt.executeUpdate(); |
| 529 | |
| 530 | if (rowsUpdated != 1) { |
| 531 | throw new SQLException( |
| 532 | "BLOB data not found! Did primary keys change?", |
| 533 | SQLError.SQL_STATE_GENERAL_ERROR); |
| 534 | } |
| 535 | } finally { |
| 536 | if (pStmt != null) { |
| 537 | try { |
| 538 | pStmt.close(); |
| 539 | } catch (SQLException sqlEx) { |
| 540 | ; // do nothing |
| 541 | } |
| 542 | |
| 543 | pStmt = null; |
| 544 | } |
| 545 | } |
| 546 | } |
| 547 | } |