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 /**
85 * Constructs a <code>SerialBlob</code> object that is a serialized version of
86 * the given <code>byte</code> array.
87 * <p>
88 * The new <code>SerialBlob</code> object is initialized with the data from the
89 * <code>byte</code> array, thus allowing disconnected <code>RowSet</code>
90 * objects to establish serialized <code>Blob</code> objects without
91 * touching the data source.
92 *
93 * @param b the <code>byte</code> array containing the data for the
94 * <code>Blob</code> object to be serialized
95 * @throws SerialException if an error occurs during serialization
96 * @throws SQLException if a SQL errors occurs
97 */
98 public SerialBlob(byte[] b) throws SerialException, SQLException {
99
100 len = b.length;
101 buf = new byte[(int)len];
102 for(int i = 0; i < len; i++) {
103 buf[i] = b[i];
143
144 /**
145 * Copies the specified number of bytes, starting at the given
146 * position, from this <code>SerialBlob</code> object to
147 * another array of bytes.
148 * <P>
149 * Note that if the given number of bytes to be copied is larger than
150 * the length of this <code>SerialBlob</code> object's array of
151 * bytes, the given number will be shortened to the array's length.
152 *
153 * @param pos the ordinal position of the first byte in this
154 * <code>SerialBlob</code> object to be copied;
155 * numbering starts at <code>1</code>; must not be less
156 * than <code>1</code> and must be less than or equal
157 * to the length of this <code>SerialBlob</code> object
158 * @param length the number of bytes to be copied
159 * @return an array of bytes that is a copy of a region of this
160 * <code>SerialBlob</code> object, starting at the given
161 * position and containing the given number of consecutive bytes
162 * @throws SerialException if the given starting position is out of bounds
163 */
164 public byte[] getBytes(long pos, int length) throws SerialException {
165 if (length > len) {
166 length = (int)len;
167 }
168
169 if (pos < 1 || len - pos < 0 ) {
170 throw new SerialException("Invalid arguments: position cannot be "
171 + "less than 1 or greater than the length of the SerialBlob");
172 }
173
174 pos--; // correct pos to array index
175
176 byte[] b = new byte[length];
177
178 for (int i = 0; i < length; i++) {
179 b[i] = this.buf[(int)pos];
180 pos++;
181 }
182 return b;
183 }
184
185 /**
186 * Retrieves the number of bytes in this <code>SerialBlob</code>
187 * object's array of bytes.
188 *
189 * @return a <code>long</code> indicating the length in bytes of this
190 * <code>SerialBlob</code> object's array of bytes
191 * @throws SerialException if an error occurs
192 */
193 public long length() throws SerialException {
194 return len;
195 }
196
197 /**
198 * Returns this <code>SerialBlob</code> object as an input stream.
199 * Unlike the related method, <code>setBinaryStream</code>,
200 * a stream is produced regardless of whether the <code>SerialBlob</code>
201 * was created with a <code>Blob</code> object or a <code>byte</code> array.
202 *
203 * @return a <code>java.io.InputStream</code> object that contains
204 * this <code>SerialBlob</code> object's array of bytes
205 * @throws SerialException if an error occurs
206 * @see #setBinaryStream
207 */
208 public java.io.InputStream getBinaryStream() throws SerialException {
209 InputStream stream = new ByteArrayInputStream(buf);
210 return stream;
211 }
212
213 /**
214 * Returns the position in this <code>SerialBlob</code> object where
215 * the given pattern of bytes begins, starting the search at the
216 * specified position.
217 *
218 * @param pattern the pattern of bytes for which to search
219 * @param start the position of the byte in this
220 * <code>SerialBlob</code> object from which to begin
221 * the search; the first position is <code>1</code>;
222 * must not be less than <code>1</code> nor greater than
223 * the length of this <code>SerialBlob</code> object
224 * @return the position in this <code>SerialBlob</code> object
225 * where the given pattern begins, starting at the specified
226 * position; <code>-1</code> if the pattern is not found
227 * or the given starting position is out of bounds; position
228 * numbering for the return value starts at <code>1</code>
229 * @throws SerialException if an error occurs when serializing the blob
230 * @throws SQLException if there is an error accessing the <code>BLOB</code>
231 * value from the database
232 */
233 public long position(byte[] pattern, long start)
234 throws SerialException, SQLException {
235 if (start < 1 || start > len) {
236 return -1;
237 }
238
239 int pos = (int)start-1; // internally Blobs are stored as arrays.
240 int i = 0;
241 long patlen = pattern.length;
242
243 while (pos < len) {
244 if (pattern[i] == buf[pos]) {
245 if (i + 1 == patlen) {
246 return (pos + 1) - (patlen - 1);
247 }
248 i++; pos++; // increment pos, and i
249 } else if (pattern[i] != buf[pos]) {
250 pos++; // increment pos only
251 }
252 }
253 return -1; // not found
254 }
255
256 /**
257 * Returns the position in this <code>SerialBlob</code> object where
258 * the given <code>Blob</code> object begins, starting the search at the
259 * specified position.
260 *
261 * @param pattern the <code>Blob</code> object for which to search;
262 * @param start the position of the byte in this
263 * <code>SerialBlob</code> object from which to begin
264 * the search; the first position is <code>1</code>;
265 * must not be less than <code>1</code> nor greater than
266 * the length of this <code>SerialBlob</code> object
267 * @return the position in this <code>SerialBlob</code> object
268 * where the given <code>Blob</code> object begins, starting
269 * at the specified position; <code>-1</code> if the pattern is
270 * not found or the given starting position is out of bounds;
271 * position numbering for the return value starts at <code>1</code>
272 * @throws SerialException if an error occurs when serializing the blob
273 * @throws SQLException if there is an error accessing the <code>BLOB</code>
274 * value from the database
275 */
276 public long position(Blob pattern, long start)
277 throws SerialException, SQLException {
278 return position(pattern.getBytes(1, (int)(pattern.length())), start);
279 }
280
281 /**
282 * Writes the given array of bytes to the <code>BLOB</code> value that
283 * this <code>Blob</code> object represents, starting at position
284 * <code>pos</code>, and returns the number of bytes written.
285 *
286 * @param pos the position in the SQL <code>BLOB</code> value at which
287 * to start writing. The first position is <code>1</code>;
288 * must not be less than <code>1</code> nor greater than
289 * the length of this <code>SerialBlob</code> object.
290 * @param bytes the array of bytes to be written to the <code>BLOB</code>
291 * value that this <code>Blob</code> object represents
292 * @return the number of bytes written
293 * @throws SerialException if there is an error accessing the
294 * <code>BLOB</code> value; or if an invalid position is set; if an
295 * invalid offset value is set
296 * @throws SQLException if there is an error accessing the <code>BLOB</code>
297 * value from the database
298 * @see #getBytes
299 */
300 public int setBytes(long pos, byte[] bytes)
301 throws SerialException, SQLException {
302 return (setBytes(pos, bytes, 0, bytes.length));
303 }
304
305 /**
306 * Writes all or part of the given <code>byte</code> array to the
307 * <code>BLOB</code> value that this <code>Blob</code> object represents
308 * and returns the number of bytes written.
309 * Writing starts at position <code>pos</code> in the <code>BLOB</code>
310 * value; <i>len</i> bytes from the given byte array are written.
311 *
312 * @param pos the position in the <code>BLOB</code> object at which
313 * to start writing. The first position is <code>1</code>;
314 * must not be less than <code>1</code> nor greater than
315 * the length of this <code>SerialBlob</code> object.
316 * @param bytes the array of bytes to be written to the <code>BLOB</code>
317 * value
318 * @param offset the offset in the <code>byte</code> array at which
319 * to start reading the bytes. The first offset position is
320 * <code>0</code>; must not be less than <code>0</code> nor greater
321 * than the length of the <code>byte</code> array
322 * @param length the number of bytes to be written to the
323 * <code>BLOB</code> value from the array of bytes <i>bytes</i>.
324 *
325 * @return the number of bytes written
326 * @throws SerialException if there is an error accessing the
327 * <code>BLOB</code> value; if an invalid position is set; if an
328 * invalid offset value is set; if number of bytes to be written
329 * is greater than the <code>SerialBlob</code> length; or the combined
330 * values of the length and offset is greater than the Blob buffer
331 * @throws SQLException if there is an error accessing the <code>BLOB</code>
332 * value from the database.
333 * @see #getBytes
334 */
335 public int setBytes(long pos, byte[] bytes, int offset, int length)
336 throws SerialException, SQLException {
337
338 if (offset < 0 || offset > bytes.length) {
339 throw new SerialException("Invalid offset in byte array set");
340 }
341
342 if (pos < 1 || pos > this.length()) {
343 throw new SerialException("Invalid position in BLOB object set");
344 }
345
346 if ((long)(length) > origLen) {
347 throw new SerialException("Buffer is not sufficient to hold the value");
348 }
349
350 if ((length + offset) > bytes.length) {
351 throw new SerialException("Invalid OffSet. Cannot have combined offset " +
352 "and length that is greater that the Blob buffer");
353 }
354
355 int i = 0;
356 pos--; // correct to array indexing
361 return i;
362 }
363
364 /**
365 * Retrieves a stream that can be used to write to the <code>BLOB</code>
366 * value that this <code>Blob</code> object represents. The stream begins
367 * at position <code>pos</code>. This method forwards the
368 * <code>setBinaryStream()</code> call to the underlying <code>Blob</code> in
369 * the event that this <code>SerialBlob</code> object is instantiated with a
370 * <code>Blob</code>. If this <code>SerialBlob</code> is instantiated with
371 * a <code>byte</code> array, a <code>SerialException</code> is thrown.
372 *
373 * @param pos the position in the <code>BLOB</code> value at which
374 * to start writing
375 * @return a <code>java.io.OutputStream</code> object to which data can
376 * be written
377 * @throws SQLException if there is an error accessing the
378 * <code>BLOB</code> value
379 * @throws SerialException if the SerialBlob in not instantiated with a
380 * <code>Blob</code> object that supports <code>setBinaryStream()</code>
381 * @see #getBinaryStream
382 */
383 public java.io.OutputStream setBinaryStream(long pos)
384 throws SerialException, SQLException {
385 if (this.blob != null) {
386 return this.blob.setBinaryStream(pos);
387 } else {
388 throw new SerialException("Unsupported operation. SerialBlob cannot " +
389 "return a writable binary stream, unless instantiated with a Blob object " +
390 "that provides a setBinaryStream() implementation");
391 }
392 }
393
394 /**
395 * Truncates the <code>BLOB</code> value that this <code>Blob</code>
396 * object represents to be <code>len</code> bytes in length.
397 *
398 * @param length the length, in bytes, to which the <code>BLOB</code>
399 * value that this <code>Blob</code> object represents should be
400 * truncated
401 * @throws SerialException if there is an error accessing the Blob value;
402 * or the length to truncate is greater that the SerialBlob length
403 */
404 public void truncate(long length) throws SerialException {
405
406 if (length > len) {
407 throw new SerialException
408 ("Length more than what can be truncated");
409 } else if((int)length == 0) {
410 buf = new byte[0];
411 len = length;
412 } else {
413 len = length;
414 buf = this.getBytes(1, (int)len);
415 }
416 }
417
418
419 /**
420 * Returns an <code>InputStream</code> object that contains a partial <code>Blob</code> value,
421 * starting with the byte specified by pos, which is length bytes in length.
422 *
423 * @param pos the offset to the first byte of the partial value to be retrieved.
424 * The first byte in the <code>Blob</code> is at position 1
425 * @param length the length in bytes of the partial value to be retrieved
426 * @return <code>InputStream</code> through which the partial <code>Blob</code> value can be read.
427 * @throws SQLException if pos is less than 1 or if pos is greater than the number of bytes
428 * in the <code>Blob</code> or if pos + length is greater than the number of bytes
429 * in the <code>Blob</code>
430 *
431 * @since 1.6
432 */
433 public InputStream getBinaryStream(long pos,long length) throws SQLException {
434 throw new java.lang.UnsupportedOperationException("Not supported");
435 }
436
437
438 /**
439 * This method frees the <code>Blob</code> object and releases the resources that it holds.
440 * <code>Blob</code> object. The object is invalid once the <code>free</code>
441 * method is called. If <code>free</code> is called multiple times, the subsequent
442 * calls to <code>free</code> are treated as a no-op.
443 *
444 * @throws SQLException if an error occurs releasing
445 * the Blob's resources
446 * @since 1.6
447 */
448 public void free() throws SQLException {
449 throw new java.lang.UnsupportedOperationException("Not supported");
450 }
451 /**
452 * The identifier that assists in the serialization of this <code>SerialBlob</code>
453 * object.
454 */
455
456 static final long serialVersionUID = -8144641928112860441L;
457 }
|
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 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];
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 * or called after free() has been called.
166 */
167 public byte[] getBytes(long pos, int length) throws SerialException {
168 isFreed();
169
170 if (length > len) {
171 length = (int)len;
172 }
173
174 if (pos < 1 || len - pos < 0 ) {
175 throw new SerialException("Invalid arguments: position cannot be "
176 + "less than 1 or greater than the length of the SerialBlob");
177 }
178
179 pos--; // correct pos to array index
180
181 byte[] b = new byte[length];
182
183 for (int i = 0; i < length; i++) {
184 b[i] = this.buf[(int)pos];
185 pos++;
186 }
187 return b;
188 }
189
190 /**
191 * Retrieves the number of bytes in this <code>SerialBlob</code>
192 * object's array of bytes.
193 *
194 * @return a <code>long</code> indicating the length in bytes of this
195 * <code>SerialBlob</code> object's array of bytes
196 * @throws SerialException if an error occurs or called after free() has been called.
197 */
198 public long length() throws SerialException {
199 isFreed();
200 return len;
201 }
202
203 /**
204 * Returns this <code>SerialBlob</code> object as an input stream.
205 * Unlike the related method, <code>setBinaryStream</code>,
206 * a stream is produced regardless of whether the <code>SerialBlob</code>
207 * was created with a <code>Blob</code> object or a <code>byte</code> array.
208 *
209 * @return a <code>java.io.InputStream</code> object that contains
210 * this <code>SerialBlob</code> object's array of bytes
211 * @throws SerialException if an error occurs or called after free() has
212 * been called.
213 * @see #setBinaryStream
214 */
215 public java.io.InputStream getBinaryStream() throws SerialException {
216 isFreed();
217
218 InputStream stream = new ByteArrayInputStream(buf);
219 return stream;
220 }
221
222 /**
223 * Returns the position in this <code>SerialBlob</code> object where
224 * the given pattern of bytes begins, starting the search at the
225 * specified position.
226 *
227 * @param pattern the pattern of bytes for which to search
228 * @param start the position of the byte in this
229 * <code>SerialBlob</code> object from which to begin
230 * the search; the first position is <code>1</code>;
231 * must not be less than <code>1</code> nor greater than
232 * the length of this <code>SerialBlob</code> object
233 * @return the position in this <code>SerialBlob</code> object
234 * where the given pattern begins, starting at the specified
235 * position; <code>-1</code> if the pattern is not found
236 * or the given starting position is out of bounds; position
237 * numbering for the return value starts at <code>1</code>
238 * @throws SerialException if an error occurs when serializing the blob or
239 * called after free() has been called.
240 * @throws SQLException if there is an error accessing the <code>BLOB</code>
241 * value from the database
242 */
243 public long position(byte[] pattern, long start)
244 throws SerialException, SQLException {
245 isFreed();
246
247 if (start < 1 || start > len) {
248 return -1;
249 }
250
251 int pos = (int)start-1; // internally Blobs are stored as arrays.
252 int i = 0;
253 long patlen = pattern.length;
254
255 while (pos < len) {
256 if (pattern[i] == buf[pos]) {
257 if (i + 1 == patlen) {
258 return (pos + 1) - (patlen - 1);
259 }
260 i++; pos++; // increment pos, and i
261 } else if (pattern[i] != buf[pos]) {
262 pos++; // increment pos only
263 }
264 }
265 return -1; // not found
266 }
267
268 /**
269 * Returns the position in this <code>SerialBlob</code> object where
270 * the given <code>Blob</code> object begins, starting the search at the
271 * specified position.
272 *
273 * @param pattern the <code>Blob</code> object for which to search;
274 * @param start the position of the byte in this
275 * <code>SerialBlob</code> object from which to begin
276 * the search; the first position is <code>1</code>;
277 * must not be less than <code>1</code> nor greater than
278 * the length of this <code>SerialBlob</code> object
279 * @return the position in this <code>SerialBlob</code> object
280 * where the given <code>Blob</code> object begins, starting
281 * at the specified position; <code>-1</code> if the pattern is
282 * not found or the given starting position is out of bounds;
283 * position numbering for the return value starts at <code>1</code>
284 * @throws SerialException if an error occurs when serializing the blob or
285 * called after free() has been called.
286 * @throws SQLException if there is an error accessing the <code>BLOB</code>
287 * value from the database
288 */
289 public long position(Blob pattern, long start)
290 throws SerialException, SQLException {
291 isFreed();
292 return position(pattern.getBytes(1, (int)(pattern.length())), start);
293 }
294
295 /**
296 * Writes the given array of bytes to the <code>BLOB</code> value that
297 * this <code>Blob</code> object represents, starting at position
298 * <code>pos</code>, and returns the number of bytes written.
299 *
300 * @param pos the position in the SQL <code>BLOB</code> value at which
301 * to start writing. The first position is <code>1</code>;
302 * must not be less than <code>1</code> nor greater than
303 * the length of this <code>SerialBlob</code> object.
304 * @param bytes the array of bytes to be written to the <code>BLOB</code>
305 * value that this <code>Blob</code> object represents
306 * @return the number of bytes written
307 * @throws SerialException if there is an error accessing the
308 * <code>BLOB</code> value; or if an invalid position is set; if an
309 * invalid offset value is set or called after free() has been called.
310 * @throws SQLException if there is an error accessing the <code>BLOB</code>
311 * value from the database
312 * @see #getBytes
313 */
314 public int setBytes(long pos, byte[] bytes)
315 throws SerialException, SQLException {
316 isFreed();
317 return (setBytes(pos, bytes, 0, bytes.length));
318 }
319
320 /**
321 * Writes all or part of the given <code>byte</code> array to the
322 * <code>BLOB</code> value that this <code>Blob</code> object represents
323 * and returns the number of bytes written.
324 * Writing starts at position <code>pos</code> in the <code>BLOB</code>
325 * value; <i>len</i> bytes from the given byte array are written.
326 *
327 * @param pos the position in the <code>BLOB</code> object at which
328 * to start writing. The first position is <code>1</code>;
329 * must not be less than <code>1</code> nor greater than
330 * the length of this <code>SerialBlob</code> object.
331 * @param bytes the array of bytes to be written to the <code>BLOB</code>
332 * value
333 * @param offset the offset in the <code>byte</code> array at which
334 * to start reading the bytes. The first offset position is
335 * <code>0</code>; must not be less than <code>0</code> nor greater
336 * than the length of the <code>byte</code> array
337 * @param length the number of bytes to be written to the
338 * <code>BLOB</code> value from the array of bytes <i>bytes</i>.
339 *
340 * @return the number of bytes written
341 * @throws SerialException if there is an error accessing the
342 * <code>BLOB</code> value; if an invalid position is set; if an
343 * invalid offset value is set; if number of bytes to be written
344 * is greater than the <code>SerialBlob</code> length; or the combined
345 * values of the length and offset is greater than the Blob buffer or
346 * called after free() has been called.
347 * @throws SQLException if there is an error accessing the <code>BLOB</code>
348 * value from the database.
349 * @see #getBytes
350 */
351 public int setBytes(long pos, byte[] bytes, int offset, int length)
352 throws SerialException, SQLException {
353 isFreed();
354
355 if (offset < 0 || offset > bytes.length) {
356 throw new SerialException("Invalid offset in byte array set");
357 }
358
359 if (pos < 1 || pos > this.length()) {
360 throw new SerialException("Invalid position in BLOB object set");
361 }
362
363 if ((long)(length) > origLen) {
364 throw new SerialException("Buffer is not sufficient to hold the value");
365 }
366
367 if ((length + offset) > bytes.length) {
368 throw new SerialException("Invalid OffSet. Cannot have combined offset " +
369 "and length that is greater that the Blob buffer");
370 }
371
372 int i = 0;
373 pos--; // correct to array indexing
378 return i;
379 }
380
381 /**
382 * Retrieves a stream that can be used to write to the <code>BLOB</code>
383 * value that this <code>Blob</code> object represents. The stream begins
384 * at position <code>pos</code>. This method forwards the
385 * <code>setBinaryStream()</code> call to the underlying <code>Blob</code> in
386 * the event that this <code>SerialBlob</code> object is instantiated with a
387 * <code>Blob</code>. If this <code>SerialBlob</code> is instantiated with
388 * a <code>byte</code> array, a <code>SerialException</code> is thrown.
389 *
390 * @param pos the position in the <code>BLOB</code> value at which
391 * to start writing
392 * @return a <code>java.io.OutputStream</code> object to which data can
393 * be written
394 * @throws SQLException if there is an error accessing the
395 * <code>BLOB</code> value
396 * @throws SerialException if the SerialBlob in not instantiated with a
397 * <code>Blob</code> object that supports <code>setBinaryStream()</code>
398 * or called after free() has been called.
399 * @see #getBinaryStream
400 */
401 public java.io.OutputStream setBinaryStream(long pos)
402 throws SerialException, SQLException {
403 isFreed();
404
405 if (this.blob != null) {
406 return this.blob.setBinaryStream(pos);
407 } else {
408 throw new SerialException("Unsupported operation. SerialBlob cannot " +
409 "return a writable binary stream, unless instantiated with a Blob object " +
410 "that provides a setBinaryStream() implementation");
411 }
412 }
413
414 /**
415 * Truncates the <code>BLOB</code> value that this <code>Blob</code>
416 * object represents to be <code>len</code> bytes in length.
417 *
418 * @param length the length, in bytes, to which the <code>BLOB</code>
419 * value that this <code>Blob</code> object represents should be
420 * truncated
421 * @throws SerialException if there is an error accessing the Blob value;
422 * or the length to truncate is greater that the SerialBlob length or
423 * called after free() has been called.
424 */
425 public void truncate(long length) throws SerialException {
426 isFreed();
427
428 if (length > len) {
429 throw new SerialException
430 ("Length more than what can be truncated");
431 } else if((int)length == 0) {
432 buf = new byte[0];
433 len = length;
434 } else {
435 len = length;
436 buf = this.getBytes(1, (int)len);
437 }
438 }
439
440
441 /**
442 * Returns an <code>InputStream</code> object that contains a partial <code>Blob</code> value,
443 * starting with the byte specified by pos, which is length bytes in length.
444 *
445 * @param pos the offset to the first byte of the partial value to be retrieved.
446 * The first byte in the <code>Blob</code> is at position 1
447 * @param length the length in bytes of the partial value to be retrieved
448 * @return <code>InputStream</code> through which the partial <code>Blob</code> value can be read.
449 * @throws SerialException if called after free() has been called.
450 * @throws SQLException if pos is less than 1 or if pos is greater than the number of bytes
451 * in the <code>Blob</code> or if pos + length is greater than the number of bytes
452 * in the <code>Blob</code>
453 *
454 * @since 1.6
455 */
456 public InputStream getBinaryStream(long pos,long length) throws SerialException, SQLException {
457 isFreed();
458
459 if (pos < 1 || pos > len) {
460 throw new SerialException("Invalid pos in getBinaryStream");
461 }
462 if ((pos - 1) + length > len) {
463 throw new SerialException(
464 "pos + length greater than total number of bytes");
465 }
466 return new ByteArrayInputStream(buf, (int) pos - 1, (int) length);
467 }
468
469
470 /**
471 * This method frees the <code>Blob</code> object and releases the
472 * resources that it holds. <code>Blob</code> object. The object is
473 * invalid once the <code>free</code> method is called. After
474 * <code>free</code> has been called, any attempt to invoke a method
475 * other than <code>free</code> will result in a
476 * <code>SerialException</code> being thrown. If <code>free</code> is
477 * called multiple times, the subsequent calls to <code>free</code>
478 * are treated as a no-op.
479 *
480 * @throws SQLException if an error occurs releasing the Blob's resources
481 * @since 1.6
482 */
483 public void free() throws SQLException {
484 if (isFree == false) {
485 len = -1;
486 origLen = -1;
487 buf = null;
488
489 if (blob != null) {
490 blob.free();
491 blob = null;
492 }
493
494 isFree = true;
495 }
496 }
497
498 private void isFreed() throws SerialException {
499 if (isFree == true) {
500 throw new SerialException(
501 "Unsupported operation. SerialBlob cannot "
502 + "execute this operation when it"
503 + "has already been freed by free()");
504 }
505 }
506
507 /**
508 * The identifier that assists in the serialization of this <code>SerialBlob</code>
509 * object.
510 */
511
512 static final long serialVersionUID = -8144641928112860441L;
513 }
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