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 31 /** 32 * A serialized mapping in the Java programming language of an SQL 33 * <code>CLOB</code> value. 34 * <P> 35 * The <code>SerialClob</code> class provides a constructor for creating 36 * an instance from a <code>Clob</code> object. Note that the <code>Clob</code> 37 * object should have brought the SQL <code>CLOB</code> value's data over 38 * to the client before a <code>SerialClob</code> object 39 * is constructed from it. The data of an SQL <code>CLOB</code> value can 40 * be materialized on the client as a stream of Unicode characters. 41 * <P> 42 * <code>SerialClob</code> methods make it possible to get a substring 43 * from a <code>SerialClob</code> object or to locate the start of 44 * a pattern of characters. 45 * 46 * @author Jonathan Bruce 47 */ 48 public class SerialClob implements Clob, Serializable, Cloneable { 49 50 /** 51 * A serialized array of characters containing the data of the SQL 52 * <code>CLOB</code> value that this <code>SerialClob</code> object 53 * represents. 54 * 55 * @serial 56 */ 57 private char buf[]; 58 59 /** 60 * Internal Clob representation if SerialClob is initialized with a 61 * Clob. Null if SerialClob is initialized with a char[]. 62 */ 63 private final Clob clob; 64 65 /** 66 * The length in characters of this <code>SerialClob</code> object's 67 * internal array of characters. 68 * 69 * @serial 70 */ 71 private long len; 72 73 /** 74 * The original length in characters of this <code>SerialClob</code> 75 * object's internal array of characters. 76 * 77 * @serial 78 */ 79 private final long origLen; 80 81 /** 82 * Constructs a <code>SerialClob</code> object that is a serialized version of 83 * the given <code>char</code> array. 84 * <p> 85 * The new <code>SerialClob</code> object is initialized with the data from the 86 * <code>char</code> array, thus allowing disconnected <code>RowSet</code> 87 * objects to establish a serialized <code>Clob</code> object without touching 88 * the data source. 89 * 90 * @param ch the char array representing the <code>Clob</code> object to be 91 * serialized 92 * @throws SerialException if an error occurs during serialization 93 * @throws SQLException if a SQL error occurs 94 */ 95 public SerialClob(char ch[]) throws SerialException, SQLException { 96 97 // %%% JMB. Agreed. Add code here to throw a SQLException if no 98 // support is available for locatorsUpdateCopy=false 99 // Serializing locators is not supported. 100 101 len = ch.length; 102 buf = new char[(int)len]; 103 for (int i = 0; i < len ; i++){ 104 buf[i] = ch[i]; 105 } 106 origLen = len; 107 clob = null; 108 } 109 110 /** 111 * Constructs a <code>SerialClob</code> object that is a serialized 112 * version of the given <code>Clob</code> object. 113 * <P> 114 * The new <code>SerialClob</code> object is initialized with the 115 * data from the <code>Clob</code> object; therefore, the 116 * <code>Clob</code> object should have previously brought the 117 * SQL <code>CLOB</code> value's data over to the client from 118 * the database. Otherwise, the new <code>SerialClob</code> object 119 * object will contain no data. 120 * <p> 121 * Note: The <code>Clob</code> object supplied to this constructor must 122 * return non-null for both the <code>Clob.getCharacterStream()</code> 123 * and <code>Clob.getAsciiStream</code> methods. This <code>SerialClob</code> 124 * constructor cannot serialize a <code>Clob</code> object in this instance 125 * and will throw an <code>SQLException</code> object. 126 * 127 * @param clob the <code>Clob</code> object from which this 128 * <code>SerialClob</code> object is to be constructed; cannot be null 129 * @throws SerialException if an error occurs during serialization 130 * @throws SQLException if a SQL error occurs in capturing the CLOB; 131 * if the <code>Clob</code> object is a null; or if either of the 132 * <code>Clob.getCharacterStream()</code> and <code>Clob.getAsciiStream()</code> 133 * methods on the <code>Clob</code> returns a null 134 * @see java.sql.Clob 135 */ 136 public SerialClob(Clob clob) throws SerialException, SQLException { 137 138 if (clob == null) { 139 throw new SQLException("Cannot instantiate a SerialClob " + 140 "object with a null Clob object"); 141 } 142 len = clob.length(); 143 this.clob = clob; 144 buf = new char[(int)len]; 145 int read = 0; 146 int offset = 0; 147 148 try (Reader charStream = clob.getCharacterStream()) { 149 if (charStream == null) { 150 throw new SQLException("Invalid Clob object. The call to getCharacterStream " + 151 "returned null which cannot be serialized."); 152 } 153 154 // Note: get an ASCII stream in order to null-check it, 155 // even though we don't do anything with it. 156 try (InputStream asciiStream = clob.getAsciiStream()) { 157 if (asciiStream == null) { 158 throw new SQLException("Invalid Clob object. The call to getAsciiStream " + 159 "returned null which cannot be serialized."); 160 } 161 } 162 163 try (Reader reader = new BufferedReader(charStream)) { 164 do { 165 read = reader.read(buf, offset, (int)(len - offset)); 166 offset += read; 167 } while (read > 0); 168 } 169 } catch (java.io.IOException ex) { 170 throw new SerialException("SerialClob: " + ex.getMessage()); 171 } 172 173 origLen = len; 174 } 175 176 /** 177 * Retrieves the number of characters in this <code>SerialClob</code> 178 * object's array of characters. 179 * 180 * @return a <code>long</code> indicating the length in characters of this 181 * <code>SerialClob</code> object's array of character 182 * @throws SerialException if an error occurs 183 */ 184 public long length() throws SerialException { 185 return len; 186 } 187 188 /** 189 * Returns this <code>SerialClob</code> object's data as a stream 190 * of Unicode characters. Unlike the related method, <code>getAsciiStream</code>, 191 * a stream is produced regardless of whether the <code>SerialClob</code> object 192 * was created with a <code>Clob</code> object or a <code>char</code> array. 193 * 194 * @return a <code>java.io.Reader</code> object containing this 195 * <code>SerialClob</code> object's data 196 * @throws SerialException if an error occurs 197 */ 198 public java.io.Reader getCharacterStream() throws SerialException { 199 return (java.io.Reader) new CharArrayReader(buf); 200 } 201 202 /** 203 * Retrieves the <code>CLOB</code> value designated by this <code>SerialClob</code> 204 * object as an ascii stream. This method forwards the <code>getAsciiStream</code> 205 * call to the underlying <code>Clob</code> object in the event that this 206 * <code>SerialClob</code> object is instantiated with a <code>Clob</code> 207 * object. If this <code>SerialClob</code> object is instantiated with 208 * a <code>char</code> array, a <code>SerialException</code> object is thrown. 209 * 210 * @return a <code>java.io.InputStream</code> object containing 211 * this <code>SerialClob</code> object's data 212 * @throws SerialException if this <code>SerialClob</code> object was not instantiated 213 * with a <code>Clob</code> object 214 * @throws SQLException if there is an error accessing the 215 * <code>CLOB</code> value represented by the <code>Clob</code> object that was 216 * used to create this <code>SerialClob</code> object 217 */ 218 public java.io.InputStream getAsciiStream() throws SerialException, SQLException { 219 if (this.clob != null) { 220 return this.clob.getAsciiStream(); 221 } else { 222 throw new SerialException("Unsupported operation. SerialClob cannot " + 223 "return a the CLOB value as an ascii stream, unless instantiated " + 224 "with a fully implemented Clob object."); 225 } 226 } 227 228 /** 229 * Returns a copy of the substring contained in this 230 * <code>SerialClob</code> object, starting at the given position 231 * and continuing for the specified number or characters. 232 * 233 * @param pos the position of the first character in the substring 234 * to be copied; the first character of the 235 * <code>SerialClob</code> object is at position 236 * <code>1</code>; must not be less than <code>1</code>, 237 * and the sum of the starting position and the length 238 * of the substring must be less than the length of this 239 * <code>SerialClob</code> object 240 * @param length the number of characters in the substring to be 241 * returned; must not be greater than the length of 242 * this <code>SerialClob</code> object, and the 243 * sum of the starting position and the length 244 * of the substring must be less than the length of this 245 * <code>SerialClob</code> object 246 * @return a <code>String</code> object containing a substring of 247 * this <code>SerialClob</code> object beginning at the 248 * given position and containing the specified number of 249 * consecutive characters 250 * @throws SerialException if either of the arguments is out of bounds 251 */ 252 public String getSubString(long pos, int length) throws SerialException { 253 254 if (pos < 1 || pos > this.length()) { 255 throw new SerialException("Invalid position in BLOB object set"); 256 } 257 258 if ((pos-1) + length > this.length()) { 259 throw new SerialException("Invalid position and substring length"); 260 } 261 262 try { 263 return new String(buf, (int)pos - 1, length); 264 265 } catch (StringIndexOutOfBoundsException e) { 266 throw new SerialException("StringIndexOutOfBoundsException: " + 267 e.getMessage()); 268 } 269 270 } 271 272 /** 273 * Returns the position in this <code>SerialClob</code> object 274 * where the given <code>String</code> object begins, starting 275 * the search at the specified position. This method returns 276 * <code>-1</code> if the pattern is not found. 277 * 278 * @param searchStr the <code>String</code> object for which to 279 * search 280 * @param start the position in this <code>SerialClob</code> object 281 * at which to start the search; the first position is 282 * <code>1</code>; must not be less than <code>1</code> nor 283 * greater than the length of this <code>SerialClob</code> object 284 * @return the position at which the given <code>String</code> object 285 * begins, starting the search at the specified position; 286 * <code>-1</code> if the given <code>String</code> object is 287 * not found or the starting position is out of bounds; position 288 * numbering for the return value starts at <code>1</code> 289 * @throws SerialException if an error occurs locating the String signature 290 * @throws SQLException if there is an error accessing the Blob value 291 * from the database. 292 */ 293 public long position(String searchStr, long start) 294 throws SerialException, SQLException { 295 296 if (start < 1 || start > len) { 297 return -1; 298 } 299 300 char pattern[] = searchStr.toCharArray(); 301 302 int pos = (int)start-1; 303 int i = 0; 304 long patlen = pattern.length; 305 306 while (pos < len) { 307 if (pattern[i] == buf[pos]) { 308 if (i + 1 == patlen) { 309 return (pos + 1) - (patlen - 1); 310 } 311 i++; pos++; // increment pos, and i 312 313 } else if (pattern[i] != buf[pos]) { 314 pos++; // increment pos only 315 } 316 } 317 return -1; // not found 318 } 319 320 /** 321 * Returns the position in this <code>SerialClob</code> object 322 * where the given <code>Clob</code> signature begins, starting 323 * the search at the specified position. This method returns 324 * <code>-1</code> if the pattern is not found. 325 * 326 * @param searchStr the <code>Clob</code> object for which to search 327 * @param start the position in this <code>SerialClob</code> object 328 * at which to begin the search; the first position is 329 * <code>1</code>; must not be less than <code>1</code> nor 330 * greater than the length of this <code>SerialClob</code> object 331 * @return the position at which the given <code>Clob</code> 332 * object begins in this <code>SerialClob</code> object, 333 * at or after the specified starting position 334 * @throws SerialException if an error occurs locating the Clob signature 335 * @throws SQLException if there is an error accessing the Blob value 336 * from the database 337 */ 338 public long position(Clob searchStr, long start) 339 throws SerialException, SQLException { 340 341 return position(searchStr.getSubString(1,(int)searchStr.length()), start); 342 } 343 344 /** 345 * Writes the given Java <code>String</code> to the <code>CLOB</code> 346 * value that this <code>SerialClob</code> object represents, at the position 347 * <code>pos</code>. 348 * 349 * @param pos the position at which to start writing to the <code>CLOB</code> 350 * value that this <code>SerialClob</code> object represents; the first 351 * position is <code>1</code>; must not be less than <code>1</code> nor 352 * greater than the length of this <code>SerialClob</code> object 353 * @param str the string to be written to the <code>CLOB</code> 354 * value that this <code>SerialClob</code> object represents 355 * @return the number of characters written 356 * @throws SerialException if there is an error accessing the 357 * <code>CLOB</code> value; if an invalid position is set; if an 358 * invalid offset value is set; if number of bytes to be written 359 * is greater than the <code>SerialClob</code> length; or the combined 360 * values of the length and offset is greater than the Clob buffer 361 */ 362 public int setString(long pos, String str) throws SerialException { 363 return (setString(pos, str, 0, str.length())); 364 } 365 366 /** 367 * Writes <code>len</code> characters of <code>str</code>, starting 368 * at character <code>offset</code>, to the <code>CLOB</code> value 369 * that this <code>Clob</code> represents. 370 * 371 * @param pos the position at which to start writing to the <code>CLOB</code> 372 * value that this <code>SerialClob</code> object represents; the first 373 * position is <code>1</code>; must not be less than <code>1</code> nor 374 * greater than the length of this <code>SerialClob</code> object 375 * @param str the string to be written to the <code>CLOB</code> 376 * value that this <code>Clob</code> object represents 377 * @param offset the offset into <code>str</code> to start reading 378 * the characters to be written 379 * @param length the number of characters to be written 380 * @return the number of characters written 381 * @throws SerialException if there is an error accessing the 382 * <code>CLOB</code> value; if an invalid position is set; if an 383 * invalid offset value is set; if number of bytes to be written 384 * is greater than the <code>SerialClob</code> length; or the combined 385 * values of the length and offset is greater than the Clob buffer 386 */ 387 public int setString(long pos, String str, int offset, int length) 388 throws SerialException { 389 String temp = str.substring(offset); 390 char cPattern[] = temp.toCharArray(); 391 392 if (offset < 0 || offset > str.length()) { 393 throw new SerialException("Invalid offset in byte array set"); 394 } 395 396 if (pos < 1 || pos > this.length()) { 397 throw new SerialException("Invalid position in BLOB object set"); 398 } 399 400 if ((long)(length) > origLen) { 401 throw new SerialException("Buffer is not sufficient to hold the value"); 402 } 403 404 if ((length + offset) > str.length()) { 405 // need check to ensure length + offset !> bytes.length 406 throw new SerialException("Invalid OffSet. Cannot have combined offset " + 407 " and length that is greater that the Blob buffer"); 408 } 409 410 int i = 0; 411 pos--; //values in the array are at position one less 412 while ( i < length || (offset + i +1) < (str.length() - offset ) ) { 413 this.buf[(int)pos + i ] = cPattern[offset + i ]; 414 i++; 415 } 416 return i; 417 } 418 419 /** 420 * Retrieves a stream to be used to write Ascii characters to the 421 * <code>CLOB</code> value that this <code>SerialClob</code> object represents, 422 * starting at position <code>pos</code>. This method forwards the 423 * <code>setAsciiStream()</code> call to the underlying <code>Clob</code> object in 424 * the event that this <code>SerialClob</code> object is instantiated with a 425 * <code>Clob</code> object. If this <code>SerialClob</code> object is instantiated 426 * with a <code>char</code> array, a <code>SerialException</code> object is thrown. 427 * 428 * @param pos the position at which to start writing to the 429 * <code>CLOB</code> object 430 * @return the stream to which ASCII encoded characters can be written 431 * @throws SerialException if SerialClob is not instantiated with a 432 * Clob object that supports <code>setAsciiStream</code> 433 * @throws SQLException if there is an error accessing the 434 * <code>CLOB</code> value 435 * @see #getAsciiStream 436 */ 437 public java.io.OutputStream setAsciiStream(long pos) 438 throws SerialException, SQLException { 439 if (this.clob != null) { 440 return this.clob.setAsciiStream(pos); 441 } else { 442 throw new SerialException("Unsupported operation. SerialClob cannot " + 443 "return a writable ascii stream\n unless instantiated with a Clob object " + 444 "that has a setAsciiStream() implementation"); 445 } 446 } 447 448 /** 449 * Retrieves a stream to be used to write a stream of Unicode characters 450 * to the <code>CLOB</code> value that this <code>SerialClob</code> object 451 * represents, at position <code>pos</code>. This method forwards the 452 * <code>setCharacterStream()</code> call to the underlying <code>Clob</code> 453 * object in the event that this <code>SerialClob</code> object is instantiated with a 454 * <code>Clob</code> object. If this <code>SerialClob</code> object is instantiated with 455 * a <code>char</code> array, a <code>SerialException</code> is thrown. 456 * 457 * @param pos the position at which to start writing to the 458 * <code>CLOB</code> value 459 * 460 * @return a stream to which Unicode encoded characters can be written 461 * @throws SerialException if the SerialClob is not instantiated with 462 * a Clob object that supports <code>setCharacterStream</code> 463 * @throws SQLException if there is an error accessing the 464 * <code>CLOB</code> value 465 * @see #getCharacterStream 466 */ 467 public java.io.Writer setCharacterStream(long pos) 468 throws SerialException, SQLException { 469 if (this.clob != null) { 470 return this.clob.setCharacterStream(pos); 471 } else { 472 throw new SerialException("Unsupported operation. SerialClob cannot " + 473 "return a writable character stream\n unless instantiated with a Clob object " + 474 "that has a setCharacterStream implementation"); 475 } 476 } 477 478 /** 479 * Truncates the <code>CLOB</code> value that this <code>SerialClob</code> 480 * object represents so that it has a length of <code>len</code> 481 * characters. 482 * <p> 483 * Truncating a <code>SerialClob</code> object to length 0 has the effect of 484 * clearing its contents. 485 * 486 * @param length the length, in bytes, to which the <code>CLOB</code> 487 * value should be truncated 488 * @throws SQLException if there is an error accessing the 489 * <code>CLOB</code> value 490 */ 491 public void truncate(long length) throws SerialException { 492 if (length > len) { 493 throw new SerialException 494 ("Length more than what can be truncated"); 495 } else { 496 len = length; 497 // re-size the buffer 498 499 if (len == 0) { 500 buf = new char[] {}; 501 } else { 502 buf = (this.getSubString(1, (int)len)).toCharArray(); 503 } 504 505 } 506 } 507 508 509 public Reader getCharacterStream(long pos, long length) throws SQLException { 510 throw new java.lang.UnsupportedOperationException("Not supported"); 511 } 512 513 public void free() throws SQLException { 514 throw new java.lang.UnsupportedOperationException("Not supported"); 515 } 516 517 /** 518 * The identifier that assists in the serialization of this <code>SerialClob</code> 519 * object. 520 */ 521 static final long serialVersionUID = -1662519690087375313L; 522 }