1 /* 2 * Copyright (c) 2003, 2011, Oracle and/or its affiliates. All rights reserved. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4 * 5 * This code is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License version 2 only, as 7 * published by the Free Software Foundation. Oracle designates this 8 * particular file as subject to the "Classpath" exception as provided 9 * by Oracle in the LICENSE file that accompanied this code. 10 * 11 * This code is distributed in the hope that it will be useful, but WITHOUT 12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 14 * version 2 for more details (a copy is included in the LICENSE file that 15 * accompanied this code). 16 * 17 * You should have received a copy of the GNU General Public License version 18 * 2 along with this work; if not, write to the Free Software Foundation, 19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 20 * 21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 22 * or visit www.oracle.com if you need additional information or have any 23 * questions. 24 */ 25 26 package javax.sql.rowset.serial; 27 28 import java.sql.*; 29 import java.io.*; 30 import java.lang.reflect.*; 31 32 33 /** 34 * A serialized mapping in the Java programming language of an SQL 35 * <code>BLOB</code> value. 36 * <P> 37 * The <code>SerialBlob</code> class provides a constructor for creating 38 * an instance from a <code>Blob</code> object. Note that the 39 * <code>Blob</code> 40 * object should have brought the SQL <code>BLOB</code> value's data over 41 * to the client before a <code>SerialBlob</code> object 42 * is constructed from it. The data of an SQL <code>BLOB</code> value can 43 * be materialized on the client as an array of bytes (using the method 44 * <code>Blob.getBytes</code>) or as a stream of uninterpreted bytes 45 * (using the method <code>Blob.getBinaryStream</code>). 46 * <P> 47 * <code>SerialBlob</code> methods make it possible to make a copy of a 48 * <code>SerialBlob</code> object as an array of bytes or as a stream. 49 * They also make it possible to locate a given pattern of bytes or a 50 * <code>Blob</code> object within a <code>SerialBlob</code> object 51 * and to update or truncate a <code>Blob</code> object. 52 * 53 * @author Jonathan Bruce 54 */ 55 public class SerialBlob implements Blob, Serializable, Cloneable { 56 57 /** 58 * A serialized array of uninterpreted bytes representing the 59 * value of this <code>SerialBlob</code> object. 60 * @serial 61 */ 62 private byte buf[]; 63 64 /** 65 * The internal representation of the <code>Blob</code> object on which this 66 * <code>SerialBlob</code> object is based. 67 */ 68 private Blob blob; 69 70 /** 71 * The number of bytes in this <code>SerialBlob</code> object's 72 * array of bytes. 73 * @serial 74 */ 75 private long len; 76 77 /** 78 * The orginal number of bytes in this <code>SerialBlob</code> object's 79 * array of bytes when it was first established. 80 * @serial 81 */ 82 private long origLen; 83 84 private transient boolean isFree = false; 85 86 /** 87 * Constructs a <code>SerialBlob</code> object that is a serialized version of 88 * the given <code>byte</code> array. 89 * <p> 90 * The new <code>SerialBlob</code> object is initialized with the data from the 91 * <code>byte</code> array, thus allowing disconnected <code>RowSet</code> 92 * objects to establish serialized <code>Blob</code> objects without 93 * touching the data source. 94 * 95 * @param b the <code>byte</code> array containing the data for the 96 * <code>Blob</code> object to be serialized 97 * @throws SerialException if an error occurs during serialization 98 * @throws SQLException if a SQL errors occurs 99 */ 100 public SerialBlob(byte[] b) throws SerialException, SQLException { 101 102 len = b.length; 103 buf = new byte[(int)len]; 104 for(int i = 0; i < len; i++) { 105 buf[i] = b[i]; 106 } 107 origLen = len; 108 } 109 110 111 /** 112 * Constructs a <code>SerialBlob</code> object that is a serialized 113 * version of the given <code>Blob</code> object. 114 * <P> 115 * The new <code>SerialBlob</code> object is initialized with the 116 * data from the <code>Blob</code> object; therefore, the 117 * <code>Blob</code> object should have previously brought the 118 * SQL <code>BLOB</code> value's data over to the client from 119 * the database. Otherwise, the new <code>SerialBlob</code> object 120 * will contain no data. 121 * 122 * @param blob the <code>Blob</code> object from which this 123 * <code>SerialBlob</code> object is to be constructed; 124 * cannot be null. 125 * @throws SerialException if an error occurs during serialization 126 * @throws SQLException if the <code>Blob</code> passed to this 127 * to this constructor is a <code>null</code>. 128 * @see java.sql.Blob 129 */ 130 public SerialBlob (Blob blob) throws SerialException, SQLException { 131 132 if (blob == null) { 133 throw new SQLException("Cannot instantiate a SerialBlob " + 134 "object with a null Blob object"); 135 } 136 137 len = blob.length(); 138 buf = blob.getBytes(1, (int)len ); 139 this.blob = blob; 140 141 //if ( len < 10240000) 142 // len = 10240000; 143 origLen = len; 144 } 145 146 /** 147 * Copies the specified number of bytes, starting at the given 148 * position, from this <code>SerialBlob</code> object to 149 * another array of bytes. 150 * <P> 151 * Note that if the given number of bytes to be copied is larger than 152 * the length of this <code>SerialBlob</code> object's array of 153 * bytes, the given number will be shortened to the array's length. 154 * 155 * @param pos the ordinal position of the first byte in this 156 * <code>SerialBlob</code> object to be copied; 157 * numbering starts at <code>1</code>; must not be less 158 * than <code>1</code> and must be less than or equal 159 * to the length of this <code>SerialBlob</code> object 160 * @param length the number of bytes to be copied 161 * @return an array of bytes that is a copy of a region of this 162 * <code>SerialBlob</code> object, starting at the given 163 * position and containing the given number of consecutive bytes 164 * @throws SerialException if the given starting position is out of bounds 165 */ 166 public byte[] getBytes(long pos, int length) throws SerialException { 167 if (isFree == true) { 168 throw new SerialException( 169 "Unsupported operation. SerialBlob cannot " 170 + "get bytes when it has already been freed with free()"); 171 } 172 173 if (length > len) { 174 length = (int)len; 175 } 176 177 if (pos < 1 || len - pos < 0 ) { 178 throw new SerialException("Invalid arguments: position cannot be " 179 + "less than 1 or greater than the length of the SerialBlob"); 180 } 181 182 pos--; // correct pos to array index 183 184 byte[] b = new byte[length]; 185 186 for (int i = 0; i < length; i++) { 187 b[i] = this.buf[(int)pos]; 188 pos++; 189 } 190 return b; 191 } 192 193 /** 194 * Retrieves the number of bytes in this <code>SerialBlob</code> 195 * object's array of bytes. 196 * 197 * @return a <code>long</code> indicating the length in bytes of this 198 * <code>SerialBlob</code> object's array of bytes 199 * @throws SerialException if an error occurs 200 */ 201 public long length() throws SerialException { 202 return len; 203 } 204 205 /** 206 * Returns this <code>SerialBlob</code> object as an input stream. 207 * Unlike the related method, <code>setBinaryStream</code>, 208 * a stream is produced regardless of whether the <code>SerialBlob</code> 209 * was created with a <code>Blob</code> object or a <code>byte</code> array. 210 * 211 * @return a <code>java.io.InputStream</code> object that contains 212 * this <code>SerialBlob</code> object's array of bytes 213 * @throws SerialException if an error occurs 214 * @see #setBinaryStream 215 */ 216 public java.io.InputStream getBinaryStream() throws SerialException { 217 if (isFree == true) { 218 throw new SerialException( 219 "Unsupported operation. SerialBlob cannot " 220 + "return a binary stream when it has already been freed with free()"); 221 } 222 223 InputStream stream = new ByteArrayInputStream(buf); 224 return stream; 225 } 226 227 /** 228 * Returns the position in this <code>SerialBlob</code> object where 229 * the given pattern of bytes begins, starting the search at the 230 * specified position. 231 * 232 * @param pattern the pattern of bytes for which to search 233 * @param start the position of the byte in this 234 * <code>SerialBlob</code> object from which to begin 235 * the search; the first position is <code>1</code>; 236 * must not be less than <code>1</code> nor greater than 237 * the length of this <code>SerialBlob</code> object 238 * @return the position in this <code>SerialBlob</code> object 239 * where the given pattern begins, starting at the specified 240 * position; <code>-1</code> if the pattern is not found 241 * or the given starting position is out of bounds; position 242 * numbering for the return value starts at <code>1</code> 243 * @throws SerialException if an error occurs when serializing the blob 244 * @throws SQLException if there is an error accessing the <code>BLOB</code> 245 * value from the database 246 */ 247 public long position(byte[] pattern, long start) 248 throws SerialException, SQLException { 249 if (isFree == true) { 250 throw new SerialException( 251 "Unsupported operation. SerialBlob has already been freed "); 252 } 253 254 if (start < 1 || start > len) { 255 return -1; 256 } 257 258 int pos = (int)start-1; // internally Blobs are stored as arrays. 259 int i = 0; 260 long patlen = pattern.length; 261 262 while (pos < len) { 263 if (pattern[i] == buf[pos]) { 264 if (i + 1 == patlen) { 265 return (pos + 1) - (patlen - 1); 266 } 267 i++; pos++; // increment pos, and i 268 } else if (pattern[i] != buf[pos]) { 269 pos++; // increment pos only 270 } 271 } 272 return -1; // not found 273 } 274 275 /** 276 * Returns the position in this <code>SerialBlob</code> object where 277 * the given <code>Blob</code> object begins, starting the search at the 278 * specified position. 279 * 280 * @param pattern the <code>Blob</code> object for which to search; 281 * @param start the position of the byte in this 282 * <code>SerialBlob</code> object from which to begin 283 * the search; the first position is <code>1</code>; 284 * must not be less than <code>1</code> nor greater than 285 * the length of this <code>SerialBlob</code> object 286 * @return the position in this <code>SerialBlob</code> object 287 * where the given <code>Blob</code> object begins, starting 288 * at the specified position; <code>-1</code> if the pattern is 289 * not found or the given starting position is out of bounds; 290 * position numbering for the return value starts at <code>1</code> 291 * @throws SerialException if an error occurs when serializing the blob 292 * @throws SQLException if there is an error accessing the <code>BLOB</code> 293 * value from the database 294 */ 295 public long position(Blob pattern, long start) 296 throws SerialException, SQLException { 297 return position(pattern.getBytes(1, (int)(pattern.length())), start); 298 } 299 300 /** 301 * Writes the given array of bytes to the <code>BLOB</code> value that 302 * this <code>Blob</code> object represents, starting at position 303 * <code>pos</code>, and returns the number of bytes written. 304 * 305 * @param pos the position in the SQL <code>BLOB</code> value at which 306 * to start writing. The first position is <code>1</code>; 307 * must not be less than <code>1</code> nor greater than 308 * the length of this <code>SerialBlob</code> object. 309 * @param bytes the array of bytes to be written to the <code>BLOB</code> 310 * value that this <code>Blob</code> object represents 311 * @return the number of bytes written 312 * @throws SerialException if there is an error accessing the 313 * <code>BLOB</code> value; or if an invalid position is set; if an 314 * invalid offset value is set 315 * @throws SQLException if there is an error accessing the <code>BLOB</code> 316 * value from the database 317 * @see #getBytes 318 */ 319 public int setBytes(long pos, byte[] bytes) 320 throws SerialException, SQLException { 321 return (setBytes(pos, bytes, 0, bytes.length)); 322 } 323 324 /** 325 * Writes all or part of the given <code>byte</code> array to the 326 * <code>BLOB</code> value that this <code>Blob</code> object represents 327 * and returns the number of bytes written. 328 * Writing starts at position <code>pos</code> in the <code>BLOB</code> 329 * value; <i>len</i> bytes from the given byte array are written. 330 * 331 * @param pos the position in the <code>BLOB</code> object at which 332 * to start writing. The first position is <code>1</code>; 333 * must not be less than <code>1</code> nor greater than 334 * the length of this <code>SerialBlob</code> object. 335 * @param bytes the array of bytes to be written to the <code>BLOB</code> 336 * value 337 * @param offset the offset in the <code>byte</code> array at which 338 * to start reading the bytes. The first offset position is 339 * <code>0</code>; must not be less than <code>0</code> nor greater 340 * than the length of the <code>byte</code> array 341 * @param length the number of bytes to be written to the 342 * <code>BLOB</code> value from the array of bytes <i>bytes</i>. 343 * 344 * @return the number of bytes written 345 * @throws SerialException if there is an error accessing the 346 * <code>BLOB</code> value; if an invalid position is set; if an 347 * invalid offset value is set; if number of bytes to be written 348 * is greater than the <code>SerialBlob</code> length; or the combined 349 * values of the length and offset is greater than the Blob buffer 350 * @throws SQLException if there is an error accessing the <code>BLOB</code> 351 * value from the database. 352 * @see #getBytes 353 */ 354 public int setBytes(long pos, byte[] bytes, int offset, int length) 355 throws SerialException, SQLException { 356 if (isFree == true) { 357 throw new SerialException( 358 "Unsupported operation. SerialBlob cannot " 359 + "set a binary stream when it has already been freed with free()"); 360 } 361 362 if (offset < 0 || offset > bytes.length) { 363 throw new SerialException("Invalid offset in byte array set"); 364 } 365 366 if (pos < 1 || pos > this.length()) { 367 throw new SerialException("Invalid position in BLOB object set"); 368 } 369 370 if ((long)(length) > origLen) { 371 throw new SerialException("Buffer is not sufficient to hold the value"); 372 } 373 374 if ((length + offset) > bytes.length) { 375 throw new SerialException("Invalid OffSet. Cannot have combined offset " + 376 "and length that is greater that the Blob buffer"); 377 } 378 379 int i = 0; 380 pos--; // correct to array indexing 381 while ( i < length || (offset + i +1) < (bytes.length-offset) ) { 382 this.buf[(int)pos + i] = bytes[offset + i ]; 383 i++; 384 } 385 return i; 386 } 387 388 /** 389 * Retrieves a stream that can be used to write to the <code>BLOB</code> 390 * value that this <code>Blob</code> object represents. The stream begins 391 * at position <code>pos</code>. This method forwards the 392 * <code>setBinaryStream()</code> call to the underlying <code>Blob</code> in 393 * the event that this <code>SerialBlob</code> object is instantiated with a 394 * <code>Blob</code>. If this <code>SerialBlob</code> is instantiated with 395 * a <code>byte</code> array, a <code>SerialException</code> is thrown. 396 * 397 * @param pos the position in the <code>BLOB</code> value at which 398 * to start writing 399 * @return a <code>java.io.OutputStream</code> object to which data can 400 * be written 401 * @throws SQLException if there is an error accessing the 402 * <code>BLOB</code> value 403 * @throws SerialException if the SerialBlob in not instantiated with a 404 * <code>Blob</code> object that supports <code>setBinaryStream()</code> 405 * @see #getBinaryStream 406 */ 407 public java.io.OutputStream setBinaryStream(long pos) 408 throws SerialException, SQLException { 409 if (this.blob != null) { 410 return this.blob.setBinaryStream(pos); 411 } else { 412 throw new SerialException("Unsupported operation. SerialBlob cannot " + 413 "return a writable binary stream, unless instantiated with a Blob object " + 414 "that provides a setBinaryStream() implementation"); 415 } 416 } 417 418 /** 419 * Truncates the <code>BLOB</code> value that this <code>Blob</code> 420 * object represents to be <code>len</code> bytes in length. 421 * 422 * @param length the length, in bytes, to which the <code>BLOB</code> 423 * value that this <code>Blob</code> object represents should be 424 * truncated 425 * @throws SerialException if there is an error accessing the Blob value; 426 * or the length to truncate is greater that the SerialBlob length 427 */ 428 public void truncate(long length) throws SerialException { 429 if (isFree == true) { 430 throw new SerialException( 431 "Unsupported operation. SerialBlob cannot " 432 + "truncate a SerialBlob when it has already been freed with free()"); 433 } 434 435 if (length > len) { 436 throw new SerialException 437 ("Length more than what can be truncated"); 438 } else if((int)length == 0) { 439 buf = new byte[0]; 440 len = length; 441 } else { 442 len = length; 443 buf = this.getBytes(1, (int)len); 444 } 445 } 446 447 448 /** 449 * Returns an <code>InputStream</code> object that contains a partial <code>Blob</code> value, 450 * starting with the byte specified by pos, which is length bytes in length. 451 * 452 * @param pos the offset to the first byte of the partial value to be retrieved. 453 * The first byte in the <code>Blob</code> is at position 1 454 * @param length the length in bytes of the partial value to be retrieved 455 * @return <code>InputStream</code> through which the partial <code>Blob</code> value can be read. 456 * @throws SQLException if pos is less than 1 or if pos is greater than the number of bytes 457 * in the <code>Blob</code> or if pos + length is greater than the number of bytes 458 * in the <code>Blob</code> 459 * 460 * @since 1.6 461 */ 462 public InputStream getBinaryStream(long pos,long length) throws SQLException { 463 if (isFree == true) { 464 throw new SerialException( 465 "Unsupported operation. SerialBlob cannot " 466 + "return a binary stream when it has already been freed with free()"); 467 } 468 469 if (pos < 1 || pos > len || length > len - pos + 1) { 470 throw new SerialException("Invalid pos in getBinaryStream"); 471 } 472 if (length > len - pos + 1) { 473 throw new SerialException("pos + length greater than total number of bytes"); 474 } 475 return new ByteArrayInputStream(buf, (int) pos - 1, (int) length); 476 } 477 478 479 /** 480 * This method frees the <code>Blob</code> object and releases the resources that it holds. 481 * <code>Blob</code> object. The object is invalid once the <code>free</code> 482 * method is called. If <code>free</code> is called multiple times, the subsequent 483 * calls to <code>free</code> are treated as a no-op. 484 * 485 * @throws SQLException if an error occurs releasing 486 * the Blob's resources 487 * @since 1.6 488 */ 489 public void free() throws SQLException { 490 if (isFree == false) { 491 len = -1; 492 origLen = -1; 493 buf = null; 494 blob = null; 495 496 isFree = true; 497 } 498 } 499 /** 500 * The identifier that assists in the serialization of this <code>SerialBlob</code> 501 * object. 502 */ 503 504 static final long serialVersionUID = -8144641928112860441L; 505 }