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 }
--- EOF ---