1 /* 2 * Copyright (c) 2003, 2010, 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 com.sun.rowset.internal; 27 28 import java.sql.*; 29 import javax.sql.*; 30 import javax.naming.*; 31 import java.io.*; 32 import java.lang.reflect.*; 33 34 import com.sun.rowset.*; 35 import javax.sql.rowset.*; 36 import javax.sql.rowset.spi.*; 37 38 /** 39 * The facility called by the <code>RIOptimisticProvider</code> object 40 * internally to read data into it. The calling <code>RowSet</code> object 41 * must have implemented the <code>RowSetInternal</code> interface 42 * and have the standard <code>CachedRowSetReader</code> object set as its 43 * reader. 44 * <P> 45 * This implementation always reads all rows of the data source, 46 * and it assumes that the <code>command</code> property for the caller 47 * is set with a query that is appropriate for execution by a 48 * <code>PreparedStatement</code> object. 49 * <P> 50 * Typically the <code>SyncFactory</code> manages the <code>RowSetReader</code> and 51 * the <code>RowSetWriter</code> implementations using <code>SyncProvider</code> objects. 52 * Standard JDBC RowSet implementations provide an object instance of this 53 * reader by invoking the <code>SyncProvider.getRowSetReader()</code> method. 54 * 55 * @author Jonathan Bruce 56 * @see javax.sql.rowset.spi.SyncProvider 57 * @see javax.sql.rowset.spi.SyncFactory 58 * @see javax.sql.rowset.spi.SyncFactoryException 59 */ 60 public class CachedRowSetReader implements RowSetReader, Serializable { 61 62 /** 63 * The field that keeps track of whether the writer associated with 64 * this <code>CachedRowSetReader</code> object's rowset has been called since 65 * the rowset was populated. 66 * <P> 67 * When this <code>CachedRowSetReader</code> object reads data into 68 * its rowset, it sets the field <code>writerCalls</code> to 0. 69 * When the writer associated with the rowset is called to write 70 * data back to the underlying data source, its <code>writeData</code> 71 * method calls the method <code>CachedRowSetReader.reset</code>, 72 * which increments <code>writerCalls</code> and returns <code>true</code> 73 * if <code>writerCalls</code> is 1. Thus, <code>writerCalls</code> equals 74 * 1 after the first call to <code>writeData</code> that occurs 75 * after the rowset has had data read into it. 76 * 77 * @serial 78 */ 79 private int writerCalls = 0; 80 81 private boolean userCon = false; 82 83 private int startPosition; 84 85 private JdbcRowSetResourceBundle resBundle; 86 87 public CachedRowSetReader() { 88 try { 89 resBundle = JdbcRowSetResourceBundle.getJdbcRowSetResourceBundle(); 90 } catch(IOException ioe) { 91 throw new RuntimeException(ioe); 92 } 93 } 94 95 96 /** 97 * Reads data from a data source and populates the given 98 * <code>RowSet</code> object with that data. 99 * This method is called by the rowset internally when 100 * the application invokes the method <code>execute</code> 101 * to read a new set of rows. 102 * <P> 103 * After clearing the rowset of its contents, if any, and setting 104 * the number of writer calls to <code>0</code>, this reader calls 105 * its <code>connect</code> method to make 106 * a connection to the rowset's data source. Depending on which 107 * of the rowset's properties have been set, the <code>connect</code> 108 * method will use a <code>DataSource</code> object or the 109 * <code>DriverManager</code> facility to make a connection to the 110 * data source. 111 * <P> 112 * Once the connection to the data source is made, this reader 113 * executes the query in the calling <code>CachedRowSet</code> object's 114 * <code>command</code> property. Then it calls the rowset's 115 * <code>populate</code> method, which reads data from the 116 * <code>ResultSet</code> object produced by executing the rowset's 117 * command. The rowset is then populated with this data. 118 * <P> 119 * This method's final act is to close the connection it made, thus 120 * leaving the rowset disconnected from its data source. 121 * 122 * @param caller a <code>RowSet</code> object that has implemented 123 * the <code>RowSetInternal</code> interface and had 124 * this <code>CachedRowSetReader</code> object set as 125 * its reader 126 * @throws SQLException if there is a database access error, there is a 127 * problem making the connection, or the command property has not 128 * been set 129 */ 130 public void readData(RowSetInternal caller) throws SQLException 131 { 132 Connection con = null; 133 try { 134 CachedRowSet crs = (CachedRowSet)caller; 135 136 // Get rid of the current contents of the rowset. 137 138 /** 139 * Checking added to verify whether page size has been set or not. 140 * If set then do not close the object as certain parameters need 141 * to be maintained. 142 */ 143 144 if(crs.getPageSize() == 0 && crs.size() >0 ) { 145 // When page size is not set, 146 // crs.size() will show the total no of rows. 147 crs.close(); 148 } 149 150 writerCalls = 0; 151 152 // Get a connection. This reader assumes that the necessary 153 // properties have been set on the caller to let it supply a 154 // connection. 155 userCon = false; 156 157 con = this.connect(caller); 158 159 // Check our assumptions. 160 if (con == null || crs.getCommand() == null) 161 throw new SQLException(resBundle.handleGetObject("crsreader.connecterr").toString()); 162 163 try { 164 con.setTransactionIsolation(crs.getTransactionIsolation()); 165 } catch (Exception ex) { 166 ; 167 } 168 // Use JDBC to read the data. 169 PreparedStatement pstmt = con.prepareStatement(crs.getCommand()); 170 // Pass any input parameters to JDBC. 171 172 decodeParams(caller.getParams(), pstmt); 173 try { 174 pstmt.setMaxRows(crs.getMaxRows()); 175 pstmt.setMaxFieldSize(crs.getMaxFieldSize()); 176 pstmt.setEscapeProcessing(crs.getEscapeProcessing()); 177 pstmt.setQueryTimeout(crs.getQueryTimeout()); 178 } catch (Exception ex) { 179 /* 180 * drivers may not support the above - esp. older 181 * drivers being used by the bridge.. 182 */ 183 throw new SQLException(ex.getMessage()); 184 } 185 186 if(crs.getCommand().toLowerCase().indexOf("select") != -1) { 187 // can be (crs.getCommand()).indexOf("select")) == 0 188 // because we will be getting resultset when 189 // it may be the case that some false select query with 190 // select coming in between instead of first. 191 192 // if ((crs.getCommand()).indexOf("?")) does not return -1 193 // implies a Prepared Statement like query exists. 194 195 ResultSet rs = pstmt.executeQuery(); 196 if(crs.getPageSize() == 0){ 197 crs.populate(rs); 198 } 199 else { 200 /** 201 * If page size has been set then create a ResultSet object that is scrollable using a 202 * PreparedStatement handle.Also call the populate(ResultSet,int) function to populate 203 * a page of data as specified by the page size. 204 */ 205 pstmt = con.prepareStatement(crs.getCommand(),ResultSet.TYPE_SCROLL_INSENSITIVE,ResultSet.CONCUR_UPDATABLE); 206 decodeParams(caller.getParams(), pstmt); 207 try { 208 pstmt.setMaxRows(crs.getMaxRows()); 209 pstmt.setMaxFieldSize(crs.getMaxFieldSize()); 210 pstmt.setEscapeProcessing(crs.getEscapeProcessing()); 211 pstmt.setQueryTimeout(crs.getQueryTimeout()); 212 } catch (Exception ex) { 213 /* 214 * drivers may not support the above - esp. older 215 * drivers being used by the bridge.. 216 */ 217 throw new SQLException(ex.getMessage()); 218 } 219 rs = pstmt.executeQuery(); 220 crs.populate(rs,startPosition); 221 } 222 rs.close(); 223 } else { 224 pstmt.executeUpdate(); 225 } 226 227 // Get the data. 228 pstmt.close(); 229 try { 230 con.commit(); 231 } catch (SQLException ex) { 232 ; 233 } 234 // only close connections we created... 235 if (getCloseConnection() == true) 236 con.close(); 237 } 238 catch (SQLException ex) { 239 // Throw an exception if reading fails for any reason. 240 throw ex; 241 } finally { 242 try { 243 // only close connections we created... 244 if (con != null && getCloseConnection() == true) { 245 try { 246 if (!con.getAutoCommit()) { 247 con.rollback(); 248 } 249 } catch (Exception dummy) { 250 /* 251 * not an error condition, we're closing anyway, but 252 * we'd like to clean up any locks if we can since 253 * it is not clear the connection pool will clean 254 * these connections in a timely manner 255 */ 256 } 257 con.close(); 258 con = null; 259 } 260 } catch (SQLException e) { 261 // will get exception if something already went wrong, but don't 262 // override that exception with this one 263 } 264 } 265 } 266 267 /** 268 * Checks to see if the writer associated with this reader needs 269 * to reset its state. The writer will need to initialize its state 270 * if new contents have been read since the writer was last called. 271 * This method is called by the writer that was registered with 272 * this reader when components were being wired together. 273 * 274 * @return <code>true</code> if writer associated with this reader needs 275 * to reset the values of its fields; <code>false</code> otherwise 276 * @throws SQLException if an access error occurs 277 */ 278 public boolean reset() throws SQLException { 279 writerCalls++; 280 return writerCalls == 1; 281 } 282 283 /** 284 * Establishes a connection with the data source for the given 285 * <code>RowSet</code> object. If the rowset's <code>dataSourceName</code> 286 * property has been set, this method uses the JNDI API to retrieve the 287 * <code>DataSource</code> object that it can use to make the connection. 288 * If the url, username, and password properties have been set, this 289 * method uses the <code>DriverManager.getConnection</code> method to 290 * make the connection. 291 * <P> 292 * This method is used internally by the reader and writer associated with 293 * the calling <code>RowSet</code> object; an application never calls it 294 * directly. 295 * 296 * @param caller a <code>RowSet</code> object that has implemented 297 * the <code>RowSetInternal</code> interface and had 298 * this <code>CachedRowSetReader</code> object set as 299 * its reader 300 * @return a <code>Connection</code> object that represents a connection 301 * to the caller's data source 302 * @throws SQLException if an access error occurs 303 */ 304 public Connection connect(RowSetInternal caller) throws SQLException { 305 306 // Get a JDBC connection. 307 if (caller.getConnection() != null) { 308 // A connection was passed to execute(), so use it. 309 // As we are using a connection the user gave us we 310 // won't close it. 311 userCon = true; 312 return caller.getConnection(); 313 } 314 else if (((RowSet)caller).getDataSourceName() != null) { 315 // Connect using JNDI. 316 try { 317 Context ctx = new InitialContext(); 318 DataSource ds = (DataSource)ctx.lookup 319 (((RowSet)caller).getDataSourceName()); 320 321 // Check for username, password, 322 // if it exists try getting a Connection handle through them 323 // else try without these 324 // else throw SQLException 325 326 if(((RowSet)caller).getUsername() != null) { 327 return ds.getConnection(((RowSet)caller).getUsername(), 328 ((RowSet)caller).getPassword()); 329 } else { 330 return ds.getConnection(); 331 } 332 } 333 catch (javax.naming.NamingException ex) { 334 SQLException sqlEx = new SQLException(resBundle.handleGetObject("crsreader.connect").toString()); 335 sqlEx.initCause(ex); 336 throw sqlEx; 337 } 338 } else if (((RowSet)caller).getUrl() != null) { 339 // Connect using the driver manager. 340 return DriverManager.getConnection(((RowSet)caller).getUrl(), 341 ((RowSet)caller).getUsername(), 342 ((RowSet)caller).getPassword()); 343 } 344 else { 345 return null; 346 } 347 } 348 349 /** 350 * Sets the parameter placeholders 351 * in the rowset's command (the given <code>PreparedStatement</code> 352 * object) with the parameters in the given array. 353 * This method, called internally by the method 354 * <code>CachedRowSetReader.readData</code>, reads each parameter, and 355 * based on its type, determines the correct 356 * <code>PreparedStatement.setXXX</code> method to use for setting 357 * that parameter. 358 * 359 * @param params an array of parameters to be used with the given 360 * <code>PreparedStatement</code> object 361 * @param pstmt the <code>PreparedStatement</code> object that is the 362 * command for the calling rowset and into which 363 * the given parameters are to be set 364 * @throws SQLException if an access error occurs 365 */ 366 @SuppressWarnings("deprecation") 367 private void decodeParams(Object[] params, 368 PreparedStatement pstmt) throws SQLException { 369 // There is a corresponding decodeParams in JdbcRowSetImpl 370 // which does the same as this method. This is a design flaw. 371 // Update the JdbcRowSetImpl.decodeParams when you update 372 // this method. 373 374 // Adding the same comments to JdbcRowSetImpl.decodeParams. 375 376 int arraySize; 377 Object[] param = null; 378 379 for (int i=0; i < params.length; i++) { 380 if (params[i] instanceof Object[]) { 381 param = (Object[])params[i]; 382 383 if (param.length == 2) { 384 if (param[0] == null) { 385 pstmt.setNull(i + 1, ((Integer)param[1]).intValue()); 386 continue; 387 } 388 389 if (param[0] instanceof java.sql.Date || 390 param[0] instanceof java.sql.Time || 391 param[0] instanceof java.sql.Timestamp) { 392 System.err.println(resBundle.handleGetObject("crsreader.datedetected").toString()); 393 if (param[1] instanceof java.util.Calendar) { 394 System.err.println(resBundle.handleGetObject("crsreader.caldetected").toString()); 395 pstmt.setDate(i + 1, (java.sql.Date)param[0], 396 (java.util.Calendar)param[1]); 397 continue; 398 } 399 else { 400 throw new SQLException(resBundle.handleGetObject("crsreader.paramtype").toString()); 401 } 402 } 403 404 if (param[0] instanceof Reader) { 405 pstmt.setCharacterStream(i + 1, (Reader)param[0], 406 ((Integer)param[1]).intValue()); 407 continue; 408 } 409 410 /* 411 * What's left should be setObject(int, Object, scale) 412 */ 413 if (param[1] instanceof Integer) { 414 pstmt.setObject(i + 1, param[0], ((Integer)param[1]).intValue()); 415 continue; 416 } 417 418 } else if (param.length == 3) { 419 420 if (param[0] == null) { 421 pstmt.setNull(i + 1, ((Integer)param[1]).intValue(), 422 (String)param[2]); 423 continue; 424 } 425 426 if (param[0] instanceof java.io.InputStream) { 427 switch (((Integer)param[2]).intValue()) { 428 case CachedRowSetImpl.UNICODE_STREAM_PARAM: 429 pstmt.setUnicodeStream(i + 1, 430 (java.io.InputStream)param[0], 431 ((Integer)param[1]).intValue()); 432 case CachedRowSetImpl.BINARY_STREAM_PARAM: 433 pstmt.setBinaryStream(i + 1, 434 (java.io.InputStream)param[0], 435 ((Integer)param[1]).intValue()); 436 case CachedRowSetImpl.ASCII_STREAM_PARAM: 437 pstmt.setAsciiStream(i + 1, 438 (java.io.InputStream)param[0], 439 ((Integer)param[1]).intValue()); 440 default: 441 throw new SQLException(resBundle.handleGetObject("crsreader.paramtype").toString()); 442 } 443 } 444 445 /* 446 * no point at looking at the first element now; 447 * what's left must be the setObject() cases. 448 */ 449 if (param[1] instanceof Integer && param[2] instanceof Integer) { 450 pstmt.setObject(i + 1, param[0], ((Integer)param[1]).intValue(), 451 ((Integer)param[2]).intValue()); 452 continue; 453 } 454 455 throw new SQLException(resBundle.handleGetObject("crsreader.paramtype").toString()); 456 457 } else { 458 // common case - this catches all SQL92 types 459 pstmt.setObject(i + 1, params[i]); 460 continue; 461 } 462 } else { 463 // Try to get all the params to be set here 464 pstmt.setObject(i + 1, params[i]); 465 466 } 467 } 468 } 469 470 /** 471 * Assists in determining whether the current connection was created by this 472 * CachedRowSet to ensure incorrect connections are not prematurely terminated. 473 * 474 * @return a boolean giving the status of whether the connection has been closed. 475 */ 476 protected boolean getCloseConnection() { 477 if (userCon == true) 478 return false; 479 480 return true; 481 } 482 483 /** 484 * This sets the start position in the ResultSet from where to begin. This is 485 * called by the Reader in the CachedRowSetImpl to set the position on the page 486 * to begin populating from. 487 * @param pos integer indicating the position in the <code>ResultSet</code> to begin 488 * populating from. 489 */ 490 public void setStartPosition(int pos){ 491 startPosition = pos; 492 } 493 494 private void readObject(ObjectInputStream ois) throws IOException, ClassNotFoundException { 495 // Default state initialization happens here 496 ois.defaultReadObject(); 497 // Initialization of Res Bundle happens here . 498 try { 499 resBundle = JdbcRowSetResourceBundle.getJdbcRowSetResourceBundle(); 500 } catch(IOException ioe) { 501 throw new RuntimeException(ioe); 502 } 503 504 } 505 506 static final long serialVersionUID =5049738185801363801L; 507 }