1/* 2 * Copyright (c) 2003, 2014, 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 26package javax.sql.rowset.serial; 27 28import java.sql.*; 29import java.io.*; 30import java.util.Map; 31import java.net.URL; 32import java.util.Arrays; 33 34 35/** 36 * A serialized version of an <code>Array</code> 37 * object, which is the mapping in the Java programming language of an SQL 38 * <code>ARRAY</code> value. 39 * <P> 40 * The <code>SerialArray</code> class provides a constructor for creating 41 * a <code>SerialArray</code> instance from an <code>Array</code> object, 42 * methods for getting the base type and the SQL name for the base type, and 43 * methods for copying all or part of a <code>SerialArray</code> object. 44 * <P> 45 * 46 * Note: In order for this class to function correctly, a connection to the 47 * data source 48 * must be available in order for the SQL <code>Array</code> object to be 49 * materialized (have all of its elements brought to the client server) 50 * if necessary. At this time, logical pointers to the data in the data source, 51 * such as locators, are not currently supported. 52 * 53 * <h3> Thread safety </h3> 54 * 55 * A SerialArray is not safe for use by multiple concurrent threads. If a 56 * SerialArray is to be used by more than one thread then access to the 57 * SerialArray should be controlled by appropriate synchronization. 58 * 59 * @since 1.5 60 */ 61public class SerialArray implements Array, Serializable, Cloneable { 62 63 /** 64 * A serialized array in which each element is an <code>Object</code> 65 * in the Java programming language that represents an element 66 * in the SQL <code>ARRAY</code> value. 67 * @serial 68 */ 69 private Object[] elements; 70 71 /** 72 * The SQL type of the elements in this <code>SerialArray</code> object. The 73 * type is expressed as one of the constants from the class 74 * <code>java.sql.Types</code>. 75 * @serial 76 */ 77 private int baseType; 78 79 /** 80 * The type name used by the DBMS for the elements in the SQL <code>ARRAY</code> 81 * value that this <code>SerialArray</code> object represents. 82 * @serial 83 */ 84 private String baseTypeName; 85 86 /** 87 * The number of elements in this <code>SerialArray</code> object, which 88 * is also the number of elements in the SQL <code>ARRAY</code> value 89 * that this <code>SerialArray</code> object represents. 90 * @serial 91 */ 92 private int len; 93 94 /** 95 * Constructs a new <code>SerialArray</code> object from the given 96 * <code>Array</code> object, using the given type map for the custom 97 * mapping of each element when the elements are SQL UDTs. 98 * <P> 99 * This method does custom mapping if the array elements are a UDT 100 * and the given type map has an entry for that UDT. 101 * Custom mapping is recursive, 102 * meaning that if, for instance, an element of an SQL structured type 103 * is an SQL structured type that itself has an element that is an SQL 104 * structured type, each structured type that has a custom mapping will be 105 * mapped according to the given type map. 106 * <P> 107 * The new <code>SerialArray</code> 108 * object contains the same elements as the <code>Array</code> object 109 * from which it is built, except when the base type is the SQL type 110 * <code>STRUCT</code>, <code>ARRAY</code>, <code>BLOB</code>, 111 * <code>CLOB</code>, <code>DATALINK</code> or <code>JAVA_OBJECT</code>. 112 * In this case, each element in the new 113 * <code>SerialArray</code> object is the appropriate serialized form, 114 * that is, a <code>SerialStruct</code>, <code>SerialArray</code>, 115 * <code>SerialBlob</code>, <code>SerialClob</code>, 116 * <code>SerialDatalink</code>, or <code>SerialJavaObject</code> object. 117 * <P> 118 * Note: (1) The <code>Array</code> object from which a <code>SerialArray</code> 119 * object is created must have materialized the SQL <code>ARRAY</code> value's 120 * data on the client before it is passed to the constructor. Otherwise, 121 * the new <code>SerialArray</code> object will contain no data. 122 * <p> 123 * Note: (2) If the <code>Array</code> contains <code>java.sql.Types.JAVA_OBJECT</code> 124 * types, the <code>SerialJavaObject</code> constructor is called where checks 125 * are made to ensure this object is serializable. 126 * <p> 127 * Note: (3) The <code>Array</code> object supplied to this constructor cannot 128 * return <code>null</code> for any <code>Array.getArray()</code> methods. 129 * <code>SerialArray</code> cannot serialize null array values. 130 * 131 * 132 * @param array the <code>Array</code> object to be serialized 133 * @param map a <code>java.util.Map</code> object in which 134 * each entry consists of 1) a <code>String</code> object 135 * giving the fully qualified name of a UDT (an SQL structured type or 136 * distinct type) and 2) the 137 * <code>Class</code> object for the <code>SQLData</code> implementation 138 * that defines how the UDT is to be mapped. The <i>map</i> 139 * parameter does not have any effect for <code>Blob</code>, 140 * <code>Clob</code>, <code>DATALINK</code>, or 141 * <code>JAVA_OBJECT</code> types. 142 * @throws SerialException if an error occurs serializing the 143 * <code>Array</code> object 144 * @throws SQLException if a database access error occurs or if the 145 * <i>array</i> or the <i>map</i> values are <code>null</code> 146 */ 147 public SerialArray(Array array, Map<String,Class<?>> map) 148 throws SerialException, SQLException 149 { 150 151 if ((array == null) || (map == null)) { 152 throw new SQLException("Cannot instantiate a SerialArray " + 153 "object with null parameters"); 154 } 155 156 if ((elements = (Object[])array.getArray()) == null) { 157 throw new SQLException("Invalid Array object. Calls to Array.getArray() " + 158 "return null value which cannot be serialized"); 159 } 160 161 elements = (Object[])array.getArray(map); 162 baseType = array.getBaseType(); 163 baseTypeName = array.getBaseTypeName(); 164 len = elements.length; 165 166 switch (baseType) { 167 case java.sql.Types.STRUCT: 168 for (int i = 0; i < len; i++) { 169 elements[i] = new SerialStruct((Struct)elements[i], map); 170 } 171 break; 172 173 case java.sql.Types.ARRAY: 174 for (int i = 0; i < len; i++) { 175 elements[i] = new SerialArray((Array)elements[i], map); 176 } 177 break; 178 179 case java.sql.Types.BLOB: 180 for (int i = 0; i < len; i++) { 181 elements[i] = new SerialBlob((Blob)elements[i]); 182 } 183 break; 184 185 case java.sql.Types.CLOB: 186 for (int i = 0; i < len; i++) { 187 elements[i] = new SerialClob((Clob)elements[i]); 188 } 189 break; 190 191 case java.sql.Types.DATALINK: 192 for (int i = 0; i < len; i++) { 193 elements[i] = new SerialDatalink((URL)elements[i]); 194 } 195 break; 196 197 case java.sql.Types.JAVA_OBJECT: 198 for (int i = 0; i < len; i++) { 199 elements[i] = new SerialJavaObject(elements[i]); 200 } 201 } 202 } 203 204 /** 205 * This method frees the {@code SerialArray} object and releases the 206 * resources that it holds. The object is invalid once the {@code free} 207 * method is called. <p> If {@code free} is called multiple times, the 208 * subsequent calls to {@code free} are treated as a no-op. </P> 209 * 210 * @throws SQLException if an error occurs releasing the SerialArray's resources 211 * @since 1.6 212 */ 213 public void free() throws SQLException { 214 if (elements != null) { 215 elements = null; 216 baseTypeName= null; 217 } 218 } 219 220 /** 221 * Constructs a new <code>SerialArray</code> object from the given 222 * <code>Array</code> object. 223 * <P> 224 * This constructor does not do custom mapping. If the base type of the array 225 * is an SQL structured type and custom mapping is desired, the constructor 226 * <code>SerialArray(Array array, Map map)</code> should be used. 227 * <P> 228 * The new <code>SerialArray</code> 229 * object contains the same elements as the <code>Array</code> object 230 * from which it is built, except when the base type is the SQL type 231 * <code>BLOB</code>, 232 * <code>CLOB</code>, <code>DATALINK</code> or <code>JAVA_OBJECT</code>. 233 * In this case, each element in the new 234 * <code>SerialArray</code> object is the appropriate serialized form, 235 * that is, a <code>SerialBlob</code>, <code>SerialClob</code>, 236 * <code>SerialDatalink</code>, or <code>SerialJavaObject</code> object. 237 * <P> 238 * Note: (1) The <code>Array</code> object from which a <code>SerialArray</code> 239 * object is created must have materialized the SQL <code>ARRAY</code> value's 240 * data on the client before it is passed to the constructor. Otherwise, 241 * the new <code>SerialArray</code> object will contain no data. 242 * <p> 243 * Note: (2) The <code>Array</code> object supplied to this constructor cannot 244 * return <code>null</code> for any <code>Array.getArray()</code> methods. 245 * <code>SerialArray</code> cannot serialize <code>null</code> array values. 246 * 247 * @param array the <code>Array</code> object to be serialized 248 * @throws SerialException if an error occurs serializing the 249 * <code>Array</code> object 250 * @throws SQLException if a database access error occurs or the 251 * <i>array</i> parameter is <code>null</code>. 252 */ 253 public SerialArray(Array array) throws SerialException, SQLException { 254 if (array == null) { 255 throw new SQLException("Cannot instantiate a SerialArray " + 256 "object with a null Array object"); 257 } 258 259 if ((elements = (Object[])array.getArray()) == null) { 260 throw new SQLException("Invalid Array object. Calls to Array.getArray() " + 261 "return null value which cannot be serialized"); 262 } 263 264 //elements = (Object[])array.getArray(); 265 baseType = array.getBaseType(); 266 baseTypeName = array.getBaseTypeName(); 267 len = elements.length; 268 269 switch (baseType) { 270 271 case java.sql.Types.BLOB: 272 for (int i = 0; i < len; i++) { 273 elements[i] = new SerialBlob((Blob)elements[i]); 274 } 275 break; 276 277 case java.sql.Types.CLOB: 278 for (int i = 0; i < len; i++) { 279 elements[i] = new SerialClob((Clob)elements[i]); 280 } 281 break; 282 283 case java.sql.Types.DATALINK: 284 for (int i = 0; i < len; i++) { 285 elements[i] = new SerialDatalink((URL)elements[i]); 286 } 287 break; 288 289 case java.sql.Types.JAVA_OBJECT: 290 for (int i = 0; i < len; i++) { 291 elements[i] = new SerialJavaObject(elements[i]); 292 } 293 break; 294 295 } 296 297 298 } 299 300 /** 301 * Returns a new array that is a copy of this <code>SerialArray</code> 302 * object. 303 * 304 * @return a copy of this <code>SerialArray</code> object as an 305 * <code>Object</code> in the Java programming language 306 * @throws SerialException if an error occurs; 307 * if {@code free} had previously been called on this object 308 */ 309 public Object getArray() throws SerialException { 310 isValid(); 311 Object dst = new Object[len]; 312 System.arraycopy((Object)elements, 0, dst, 0, len); 313 return dst; 314 } 315 316 /** 317 * Returns a new array that is a copy of this <code>SerialArray</code> 318 * object, using the given type map for the custom 319 * mapping of each element when the elements are SQL UDTs. 320 * <P> 321 * This method does custom mapping if the array elements are a UDT 322 * and the given type map has an entry for that UDT. 323 * Custom mapping is recursive, 324 * meaning that if, for instance, an element of an SQL structured type 325 * is an SQL structured type that itself has an element that is an SQL 326 * structured type, each structured type that has a custom mapping will be 327 * mapped according to the given type map. 328 * 329 * @param map a <code>java.util.Map</code> object in which 330 * each entry consists of 1) a <code>String</code> object 331 * giving the fully qualified name of a UDT and 2) the 332 * <code>Class</code> object for the <code>SQLData</code> implementation 333 * that defines how the UDT is to be mapped 334 * @return a copy of this <code>SerialArray</code> object as an 335 * <code>Object</code> in the Java programming language 336 * @throws SerialException if an error occurs; 337 * if {@code free} had previously been called on this object 338 */ 339 public Object getArray(Map<String, Class<?>> map) throws SerialException { 340 isValid(); 341 Object dst[] = new Object[len]; 342 System.arraycopy((Object)elements, 0, dst, 0, len); 343 return dst; 344 } 345 346 /** 347 * Returns a new array that is a copy of a slice 348 * of this <code>SerialArray</code> object, starting with the 349 * element at the given index and containing the given number 350 * of consecutive elements. 351 * 352 * @param index the index into this <code>SerialArray</code> object 353 * of the first element to be copied; 354 * the index of the first element is <code>0</code> 355 * @param count the number of consecutive elements to be copied, starting 356 * at the given index 357 * @return a copy of the designated elements in this <code>SerialArray</code> 358 * object as an <code>Object</code> in the Java programming language 359 * @throws SerialException if an error occurs; 360 * if {@code free} had previously been called on this object 361 */ 362 public Object getArray(long index, int count) throws SerialException { 363 isValid(); 364 Object dst = new Object[count]; 365 System.arraycopy((Object)elements, (int)index, dst, 0, count); 366 return dst; 367 } 368 369 /** 370 * Returns a new array that is a copy of a slice 371 * of this <code>SerialArray</code> object, starting with the 372 * element at the given index and containing the given number 373 * of consecutive elements. 374 * <P> 375 * This method does custom mapping if the array elements are a UDT 376 * and the given type map has an entry for that UDT. 377 * Custom mapping is recursive, 378 * meaning that if, for instance, an element of an SQL structured type 379 * is an SQL structured type that itself has an element that is an SQL 380 * structured type, each structured type that has a custom mapping will be 381 * mapped according to the given type map. 382 * 383 * @param index the index into this <code>SerialArray</code> object 384 * of the first element to be copied; the index of the 385 * first element in the array is <code>0</code> 386 * @param count the number of consecutive elements to be copied, starting 387 * at the given index 388 * @param map a <code>java.util.Map</code> object in which 389 * each entry consists of 1) a <code>String</code> object 390 * giving the fully qualified name of a UDT and 2) the 391 * <code>Class</code> object for the <code>SQLData</code> implementation 392 * that defines how the UDT is to be mapped 393 * @return a copy of the designated elements in this <code>SerialArray</code> 394 * object as an <code>Object</code> in the Java programming language 395 * @throws SerialException if an error occurs; 396 * if {@code free} had previously been called on this object 397 */ 398 public Object getArray(long index, int count, Map<String,Class<?>> map) 399 throws SerialException 400 { 401 isValid(); 402 Object dst = new Object[count]; 403 System.arraycopy((Object)elements, (int)index, dst, 0, count); 404 return dst; 405 } 406 407 /** 408 * Retrieves the SQL type of the elements in this <code>SerialArray</code> 409 * object. The <code>int</code> returned is one of the constants in the class 410 * <code>java.sql.Types</code>. 411 * 412 * @return one of the constants in <code>java.sql.Types</code>, indicating 413 * the SQL type of the elements in this <code>SerialArray</code> object 414 * @throws SerialException if an error occurs; 415 * if {@code free} had previously been called on this object 416 */ 417 public int getBaseType() throws SerialException { 418 isValid(); 419 return baseType; 420 } 421 422 /** 423 * Retrieves the DBMS-specific type name for the elements in this 424 * <code>SerialArray</code> object. 425 * 426 * @return the SQL type name used by the DBMS for the base type of this 427 * <code>SerialArray</code> object 428 * @throws SerialException if an error occurs; 429 * if {@code free} had previously been called on this object 430 */ 431 public String getBaseTypeName() throws SerialException { 432 isValid(); 433 return baseTypeName; 434 } 435 436 /** 437 * Retrieves a <code>ResultSet</code> object holding the elements of 438 * the subarray that starts at 439 * index <i>index</i> and contains up to <i>count</i> successive elements. 440 * This method uses the connection's type map to map the elements of 441 * the array if the map contains 442 * an entry for the base type. Otherwise, the standard mapping is used. 443 * 444 * @param index the index into this <code>SerialArray</code> object 445 * of the first element to be copied; the index of the 446 * first element in the array is <code>0</code> 447 * @param count the number of consecutive elements to be copied, starting 448 * at the given index 449 * @return a <code>ResultSet</code> object containing the designated 450 * elements in this <code>SerialArray</code> object, with a 451 * separate row for each element 452 * @throws SerialException if called with the cause set to 453 * {@code UnsupportedOperationException} 454 */ 455 public ResultSet getResultSet(long index, int count) throws SerialException { 456 SerialException se = new SerialException(); 457 se.initCause(new UnsupportedOperationException()); 458 throw se; 459 } 460 461 /** 462 * 463 * Retrieves a <code>ResultSet</code> object that contains all of 464 * the elements of the SQL <code>ARRAY</code> 465 * value represented by this <code>SerialArray</code> object. This method uses 466 * the specified map for type map customizations unless the base type of the 467 * array does not match a user-defined type (UDT) in <i>map</i>, in 468 * which case it uses the 469 * standard mapping. This version of the method <code>getResultSet</code> 470 * uses either the given type map or the standard mapping; it never uses the 471 * type map associated with the connection. 472 * 473 * @param map a <code>java.util.Map</code> object in which 474 * each entry consists of 1) a <code>String</code> object 475 * giving the fully qualified name of a UDT and 2) the 476 * <code>Class</code> object for the <code>SQLData</code> implementation 477 * that defines how the UDT is to be mapped 478 * @return a <code>ResultSet</code> object containing all of the 479 * elements in this <code>SerialArray</code> object, with a 480 * separate row for each element 481 * @throws SerialException if called with the cause set to 482 * {@code UnsupportedOperationException} 483 */ 484 public ResultSet getResultSet(Map<String, Class<?>> map) 485 throws SerialException 486 { 487 SerialException se = new SerialException(); 488 se.initCause(new UnsupportedOperationException()); 489 throw se; 490 } 491 492 /** 493 * Retrieves a <code>ResultSet</code> object that contains all of 494 * the elements in the <code>ARRAY</code> value that this 495 * <code>SerialArray</code> object represents. 496 * If appropriate, the elements of the array are mapped using the connection's 497 * type map; otherwise, the standard mapping is used. 498 * 499 * @return a <code>ResultSet</code> object containing all of the 500 * elements in this <code>SerialArray</code> object, with a 501 * separate row for each element 502 * @throws SerialException if called with the cause set to 503 * {@code UnsupportedOperationException} 504 */ 505 public ResultSet getResultSet() throws SerialException { 506 SerialException se = new SerialException(); 507 se.initCause(new UnsupportedOperationException()); 508 throw se; 509 } 510 511 512 /** 513 * Retrieves a result set holding the elements of the subarray that starts at 514 * Retrieves a <code>ResultSet</code> object that contains a subarray of the 515 * elements in this <code>SerialArray</code> object, starting at 516 * index <i>index</i> and containing up to <i>count</i> successive 517 * elements. This method uses 518 * the specified map for type map customizations unless the base type of the 519 * array does not match a user-defined type (UDT) in <i>map</i>, in 520 * which case it uses the 521 * standard mapping. This version of the method <code>getResultSet</code> uses 522 * either the given type map or the standard mapping; it never uses the type 523 * map associated with the connection. 524 * 525 * @param index the index into this <code>SerialArray</code> object 526 * of the first element to be copied; the index of the 527 * first element in the array is <code>0</code> 528 * @param count the number of consecutive elements to be copied, starting 529 * at the given index 530 * @param map a <code>java.util.Map</code> object in which 531 * each entry consists of 1) a <code>String</code> object 532 * giving the fully qualified name of a UDT and 2) the 533 * <code>Class</code> object for the <code>SQLData</code> implementation 534 * that defines how the UDT is to be mapped 535 * @return a <code>ResultSet</code> object containing the designated 536 * elements in this <code>SerialArray</code> object, with a 537 * separate row for each element 538 * @throws SerialException if called with the cause set to 539 * {@code UnsupportedOperationException} 540 */ 541 public ResultSet getResultSet(long index, int count, 542 Map<String,Class<?>> map) 543 throws SerialException 544 { 545 SerialException se = new SerialException(); 546 se.initCause(new UnsupportedOperationException()); 547 throw se; 548 } 549 550 551 /** 552 * Compares this SerialArray to the specified object. The result is {@code 553 * true} if and only if the argument is not {@code null} and is a {@code 554 * SerialArray} object whose elements are identical to this object's elements 555 * 556 * @param obj The object to compare this {@code SerialArray} against 557 * 558 * @return {@code true} if the given object represents a {@code SerialArray} 559 * equivalent to this SerialArray, {@code false} otherwise 560 * 561 */ 562 public boolean equals(Object obj) { 563 if (this == obj) { 564 return true; 565 } 566 567 if (obj instanceof SerialArray) { 568 SerialArray sa = (SerialArray)obj; 569 return baseType == sa.baseType && 570 baseTypeName.equals(sa.baseTypeName) && 571 Arrays.equals(elements, sa.elements); 572 } 573 return false; 574 } 575 576 /** 577 * Returns a hash code for this SerialArray. The hash code for a 578 * {@code SerialArray} object is computed using the hash codes 579 * of the elements of the {@code SerialArray} object 580 * 581 * @return a hash code value for this object. 582 */ 583 public int hashCode() { 584 return (((31 + Arrays.hashCode(elements)) * 31 + len) * 31 + 585 baseType) * 31 + baseTypeName.hashCode(); 586 } 587 588 /** 589 * Returns a clone of this {@code SerialArray}. The copy will contain a 590 * reference to a clone of the underlying objects array, not a reference 591 * to the original underlying object array of this {@code SerialArray} object. 592 * 593 * @return a clone of this SerialArray 594 */ 595 public Object clone() { 596 try { 597 SerialArray sa = (SerialArray) super.clone(); 598 sa.elements = (elements != null) ? Arrays.copyOf(elements, len) : null; 599 return sa; 600 } catch (CloneNotSupportedException ex) { 601 // this shouldn't happen, since we are Cloneable 602 throw new InternalError(); 603 } 604 605 } 606 607 /** 608 * readObject is called to restore the state of the {@code SerialArray} from 609 * a stream. 610 */ 611 private void readObject(ObjectInputStream s) 612 throws IOException, ClassNotFoundException { 613 614 ObjectInputStream.GetField fields = s.readFields(); 615 Object[] tmp = (Object[])fields.get("elements", null); 616 if (tmp == null) 617 throw new InvalidObjectException("elements is null and should not be!"); 618 elements = tmp.clone(); 619 len = fields.get("len", 0); 620 if(elements.length != len) 621 throw new InvalidObjectException("elements is not the expected size"); 622 623 baseType = fields.get("baseType", 0); 624 baseTypeName = (String)fields.get("baseTypeName", null); 625 } 626 627 /** 628 * writeObject is called to save the state of the {@code SerialArray} 629 * to a stream. 630 */ 631 private void writeObject(ObjectOutputStream s) 632 throws IOException, ClassNotFoundException { 633 634 ObjectOutputStream.PutField fields = s.putFields(); 635 fields.put("elements", elements); 636 fields.put("len", len); 637 fields.put("baseType", baseType); 638 fields.put("baseTypeName", baseTypeName); 639 s.writeFields(); 640 } 641 642 /** 643 * Check to see if this object had previously had its {@code free} method 644 * called 645 * 646 * @throws SerialException 647 */ 648 private void isValid() throws SerialException { 649 if (elements == null) { 650 throw new SerialException("Error: You cannot call a method on a " 651 + "SerialArray instance once free() has been called."); 652 } 653 } 654 655 /** 656 * The identifier that assists in the serialization of this <code>SerialArray</code> 657 * object. 658 */ 659 static final long serialVersionUID = -8466174297270688520L; 660} 661