| 1 | /* |
| 2 | |
| 3 | Derby - Class org.apache.derby.jdbc.EmbedPooledConnection |
| 4 | |
| 5 | Copyright 2001, 2005 The Apache Software Foundation or its licensors, as applicable. |
| 6 | |
| 7 | Licensed under the Apache License, Version 2.0 (the "License"); |
| 8 | you may not use this file except in compliance with the License. |
| 9 | You may obtain a copy of the License at |
| 10 | |
| 11 | http://www.apache.org/licenses/LICENSE-2.0 |
| 12 | |
| 13 | Unless required by applicable law or agreed to in writing, software |
| 14 | distributed under the License is distributed on an "AS IS" BASIS, |
| 15 | WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| 16 | See the License for the specific language governing permissions and |
| 17 | limitations under the License. |
| 18 | |
| 19 | */ |
| 20 | |
| 21 | package org.apache.derby.jdbc; |
| 22 | |
| 23 | import org.apache.derby.iapi.services.sanity.SanityManager; |
| 24 | import org.apache.derby.iapi.reference.Property; |
| 25 | import org.apache.derby.iapi.error.ExceptionSeverity; |
| 26 | import org.apache.derby.iapi.reference.JDBC30Translation; |
| 27 | |
| 28 | /* import impl class */ |
| 29 | import org.apache.derby.impl.jdbc.Util; |
| 30 | import org.apache.derby.impl.jdbc.EmbedConnection; |
| 31 | import org.apache.derby.iapi.jdbc.BrokeredConnection; |
| 32 | import org.apache.derby.iapi.jdbc.BrokeredConnectionControl; |
| 33 | import org.apache.derby.iapi.jdbc.EngineConnection; |
| 34 | import org.apache.derby.impl.jdbc.EmbedPreparedStatement; |
| 35 | import org.apache.derby.impl.jdbc.EmbedCallableStatement; |
| 36 | |
| 37 | |
| 38 | import java.sql.Connection; |
| 39 | import java.sql.SQLException; |
| 40 | import java.sql.Statement; |
| 41 | import java.sql.PreparedStatement; |
| 42 | import java.sql.CallableStatement; |
| 43 | |
| 44 | import java.util.Vector; |
| 45 | import java.util.Enumeration; |
| 46 | |
| 47 | /* -- New jdbc 20 extension types --- */ |
| 48 | import javax.sql.DataSource; |
| 49 | import javax.sql.PooledConnection; |
| 50 | import javax.sql.ConnectionEventListener; |
| 51 | import javax.sql.ConnectionEvent; |
| 52 | |
| 53 | /** |
| 54 | A PooledConnection object is a connection object that provides hooks for |
| 55 | connection pool management. |
| 56 | |
| 57 | <P>This is Derby's implementation of a PooledConnection for use in |
| 58 | the following environments: |
| 59 | <UL> |
| 60 | <LI> JDBC 3.0 - Java 2 - JDK 1.4, J2SE 5.0 |
| 61 | <LI> JDBC 2.0 - Java 2 - JDK 1.2,1.3 |
| 62 | </UL> |
| 63 | |
| 64 | */ |
| 65 | class EmbedPooledConnection implements javax.sql.PooledConnection, BrokeredConnectionControl |
| 66 | { |
| 67 | |
| 68 | /** Static counter for connection ids */ |
| 69 | private static int idCounter = 0; |
| 70 | |
| 71 | /** The id for this connection. */ |
| 72 | private int connectionId; |
| 73 | |
| 74 | /** the connection string */ |
| 75 | private String connString; |
| 76 | |
| 77 | private Vector eventListener; // who wants to know I am closed or error |
| 78 | |
| 79 | EmbedConnection realConnection; |
| 80 | int defaultIsolationLevel; |
| 81 | private boolean defaultReadOnly; |
| 82 | BrokeredConnection currentConnectionHandle; |
| 83 | |
| 84 | // set up once by the data source |
| 85 | final ReferenceableDataSource dataSource; |
| 86 | private final String username; |
| 87 | private final String password; |
| 88 | /** |
| 89 | True if the password was passed in on the connection request, false if it came from the data source property. |
| 90 | */ |
| 91 | private final boolean requestPassword; |
| 92 | |
| 93 | protected boolean isActive; |
| 94 | |
| 95 | private synchronized int nextId() |
| 96 | { |
| 97 | return idCounter++; |
| 98 | } |
| 99 | |
| 100 | EmbedPooledConnection(ReferenceableDataSource ds, String u, String p, boolean requestPassword) throws SQLException |
| 101 | { |
| 102 | connectionId = nextId(); |
| 103 | |
| 104 | dataSource = ds; |
| 105 | username = u; |
| 106 | password = p; |
| 107 | this.requestPassword = requestPassword; |
| 108 | isActive = true; |
| 109 | |
| 110 | // open the connection up front in order to do authentication |
| 111 | openRealConnection(); |
| 112 | |
| 113 | } |
| 114 | |
| 115 | String getUsername() |
| 116 | { |
| 117 | if (username == null || username.equals("")) |
| 118 | return Property.DEFAULT_USER_NAME; |
| 119 | else |
| 120 | return username; |
| 121 | } |
| 122 | |
| 123 | String getPassword() |
| 124 | { |
| 125 | if (password == null) |
| 126 | return ""; |
| 127 | else |
| 128 | return password; |
| 129 | } |
| 130 | |
| 131 | |
| 132 | /** |
| 133 | Create an object handle for a database connection. |
| 134 | |
| 135 | @return a Connection object |
| 136 | |
| 137 | @exception SQLException - if a database-access error occurs. |
| 138 | */ |
| 139 | public synchronized Connection getConnection() throws SQLException |
| 140 | { |
| 141 | checkActive(); |
| 142 | |
| 143 | // need to do this in case the connection is forcibly removed without |
| 144 | // first being closed. |
| 145 | closeCurrentConnectionHandle(); |
| 146 | |
| 147 | |
| 148 | // RealConnection is not null if the app server yanks a local |
| 149 | // connection from one client and give it to another. In this case, |
| 150 | // the real connection is ready to be used. Otherwise, set it up |
| 151 | if (realConnection == null) |
| 152 | { |
| 153 | // first time we establish a connection |
| 154 | openRealConnection(); |
| 155 | } |
| 156 | else |
| 157 | { |
| 158 | resetRealConnection(); |
| 159 | } |
| 160 | |
| 161 | // now make a brokered connection wrapper and give this to the user |
| 162 | // we reuse the EmbedConnection(ie realConnection). |
| 163 | Connection c = getNewCurrentConnectionHandle(); |
| 164 | return c; |
| 165 | } |
| 166 | |
| 167 | final void openRealConnection() throws SQLException { |
| 168 | // first time we establish a connection |
| 169 | Connection rc = dataSource.getConnection(username, password, requestPassword); |
| 170 | |
| 171 | this.realConnection = (EmbedConnection) rc; |
| 172 | defaultIsolationLevel = rc.getTransactionIsolation(); |
| 173 | defaultReadOnly = rc.isReadOnly(); |
| 174 | if (currentConnectionHandle != null) |
| 175 | realConnection.setApplicationConnection(currentConnectionHandle); |
| 176 | } |
| 177 | |
| 178 | final Connection getNewCurrentConnectionHandle() { |
| 179 | Connection applicationConnection = currentConnectionHandle = |
| 180 | ((org.apache.derby.jdbc.Driver20) (realConnection.getLocalDriver())).newBrokeredConnection(this); |
| 181 | realConnection.setApplicationConnection(applicationConnection); |
| 182 | return applicationConnection; |
| 183 | |
| 184 | } |
| 185 | |
| 186 | /** |
| 187 | In this case the Listeners are *not* notified. JDBC 3.0 spec section 11.4 |
| 188 | */ |
| 189 | private void closeCurrentConnectionHandle() throws SQLException { |
| 190 | if (currentConnectionHandle != null) |
| 191 | { |
| 192 | Vector tmpEventListener = eventListener; |
| 193 | eventListener = null; |
| 194 | |
| 195 | try { |
| 196 | currentConnectionHandle.close(); |
| 197 | } finally { |
| 198 | eventListener = tmpEventListener; |
| 199 | } |
| 200 | |
| 201 | currentConnectionHandle = null; |
| 202 | } |
| 203 | } |
| 204 | |
| 205 | void resetRealConnection() throws SQLException { |
| 206 | |
| 207 | // ensure any outstanding changes from the previous |
| 208 | // user are rolledback. |
| 209 | realConnection.rollback(); |
| 210 | |
| 211 | // clear any warnings that are left over |
| 212 | realConnection.clearWarnings(); |
| 213 | |
| 214 | // need to reset transaction isolation, autocommit, readonly, holdability states |
| 215 | if (realConnection.getTransactionIsolation() != defaultIsolationLevel) { |
| 216 | |
| 217 | realConnection.setTransactionIsolation(defaultIsolationLevel); |
| 218 | } |
| 219 | |
| 220 | if (!realConnection.getAutoCommit()) |
| 221 | realConnection.setAutoCommit(true); |
| 222 | |
| 223 | if (realConnection.isReadOnly() != defaultReadOnly) |
| 224 | realConnection.setReadOnly(defaultReadOnly); |
| 225 | |
| 226 | if (realConnection.getHoldability() != JDBC30Translation.HOLD_CURSORS_OVER_COMMIT) |
| 227 | realConnection.setHoldability(JDBC30Translation.HOLD_CURSORS_OVER_COMMIT); |
| 228 | |
| 229 | // reset any remaining state of the connection |
| 230 | realConnection.resetFromPool(); |
| 231 | } |
| 232 | |
| 233 | /** |
| 234 | Close the Pooled connection. |
| 235 | |
| 236 | @exception SQLException - if a database-access error occurs. |
| 237 | */ |
| 238 | public synchronized void close() throws SQLException |
| 239 | { |
| 240 | if (!isActive) |
| 241 | return; |
| 242 | |
| 243 | closeCurrentConnectionHandle(); |
| 244 | try { |
| 245 | if (realConnection != null) { |
| 246 | if (!realConnection.isClosed()) |
| 247 | realConnection.close(); |
| 248 | } |
| 249 | |
| 250 | } finally { |
| 251 | |
| 252 | realConnection = null; // make sure I am not accessed again. |
| 253 | isActive = false; |
| 254 | eventListener = null; |
| 255 | } |
| 256 | } |
| 257 | |
| 258 | /** |
| 259 | Add an event listener. |
| 260 | */ |
| 261 | public final synchronized void addConnectionEventListener(ConnectionEventListener listener) |
| 262 | { |
| 263 | if (!isActive) |
| 264 | return; |
| 265 | if (listener == null) |
| 266 | return; |
| 267 | if (eventListener == null) |
| 268 | eventListener = new Vector(); |
| 269 | eventListener.addElement(listener); |
| 270 | } |
| 271 | |
| 272 | /** |
| 273 | Remove an event listener. |
| 274 | */ |
| 275 | public final synchronized void removeConnectionEventListener(ConnectionEventListener listener) |
| 276 | { |
| 277 | if (listener == null) |
| 278 | return; |
| 279 | if (eventListener != null) |
| 280 | eventListener.removeElement(listener); |
| 281 | } |
| 282 | |
| 283 | /* |
| 284 | * class specific method |
| 285 | */ |
| 286 | |
| 287 | // called by ConnectionHandle when it needs to forward things to the |
| 288 | // underlying connection |
| 289 | public synchronized EngineConnection getRealConnection() |
| 290 | throws SQLException |
| 291 | { |
| 292 | checkActive(); |
| 293 | |
| 294 | return realConnection; |
| 295 | } |
| 296 | |
| 297 | |
| 298 | // my conneciton handle has caught an error (actually, the real connection |
| 299 | // has already handled the error, we just need to nofity the listener an |
| 300 | // error is about to be thrown to the app). |
| 301 | public synchronized void notifyError(SQLException exception) |
| 302 | { |
| 303 | // only report fatal error to the connection pool manager |
| 304 | if (exception.getErrorCode() < ExceptionSeverity.SESSION_SEVERITY) |
| 305 | return; |
| 306 | |
| 307 | // tell my listeners an exception is about to be thrown |
| 308 | if (eventListener != null && eventListener.size() > 0) |
| 309 | { |
| 310 | ConnectionEvent errorEvent = new ConnectionEvent(this, exception); |
| 311 | |
| 312 | for (Enumeration e = eventListener.elements(); |
| 313 | e.hasMoreElements(); ) |
| 314 | { |
| 315 | ConnectionEventListener l = |
| 316 | (ConnectionEventListener)e.nextElement(); |
| 317 | l.connectionErrorOccurred(errorEvent); |
| 318 | } |
| 319 | } |
| 320 | } |
| 321 | |
| 322 | // my conneciton handle is being closed |
| 323 | public synchronized void notifyClose() |
| 324 | { |
| 325 | // tell my listeners I am closed |
| 326 | if (eventListener != null && eventListener.size() > 0) |
| 327 | { |
| 328 | ConnectionEvent closeEvent = new ConnectionEvent(this); |
| 329 | |
| 330 | for (Enumeration e = eventListener.elements(); |
| 331 | e.hasMoreElements(); ) |
| 332 | { |
| 333 | ConnectionEventListener l = |
| 334 | (ConnectionEventListener)e.nextElement(); |
| 335 | l.connectionClosed(closeEvent); |
| 336 | } |
| 337 | } |
| 338 | } |
| 339 | |
| 340 | final void checkActive() throws SQLException { |
| 341 | if (!isActive) |
| 342 | throw Util.noCurrentConnection(); |
| 343 | } |
| 344 | |
| 345 | |
| 346 | /* |
| 347 | ** BrokeredConnectionControl api |
| 348 | */ |
| 349 | |
| 350 | /** |
| 351 | Returns true if isolation level has been set using either JDBC api or SQL |
| 352 | */ |
| 353 | public boolean isIsolationLevelSetUsingSQLorJDBC() throws SQLException { |
| 354 | if (realConnection != null) |
| 355 | return realConnection.getLanguageConnection().isIsolationLevelSetUsingSQLorJDBC(); |
| 356 | else |
| 357 | return false; |
| 358 | } |
| 359 | |
| 360 | /** |
| 361 | Reset the isolation level flag used to keep state in |
| 362 | BrokeredConnection. It will get set to true when isolation level |
| 363 | is set using JDBC/SQL. It will get reset to false at the start |
| 364 | and the end of a global transaction. |
| 365 | */ |
| 366 | public void resetIsolationLevelFlag() throws SQLException { |
| 367 | realConnection.getLanguageConnection().resetIsolationLevelFlagUsedForSQLandJDBC(); |
| 368 | } |
| 369 | |
| 370 | |
| 371 | /** |
| 372 | Notify the control class that a SQLException was thrown |
| 373 | during a call on one of the brokered connection's methods. |
| 374 | */ |
| 375 | public void notifyException(SQLException sqle) { |
| 376 | this.notifyError(sqle); |
| 377 | } |
| 378 | |
| 379 | |
| 380 | /** |
| 381 | Allow control over setting auto commit mode. |
| 382 | */ |
| 383 | public void checkAutoCommit(boolean autoCommit) throws SQLException { |
| 384 | } |
| 385 | |
| 386 | /** |
| 387 | Are held cursors allowed. |
| 388 | */ |
| 389 | public int checkHoldCursors(int holdability, boolean downgrade) |
| 390 | throws SQLException |
| 391 | { |
| 392 | return holdability; |
| 393 | } |
| 394 | |
| 395 | /** |
| 396 | Allow control over creating a Savepoint (JDBC 3.0) |
| 397 | */ |
| 398 | public void checkSavepoint() throws SQLException { |
| 399 | } |
| 400 | |
| 401 | /** |
| 402 | Allow control over calling rollback. |
| 403 | */ |
| 404 | public void checkRollback() throws SQLException { |
| 405 | } |
| 406 | |
| 407 | /** |
| 408 | Allow control over calling commit. |
| 409 | */ |
| 410 | public void checkCommit() throws SQLException { |
| 411 | } |
| 412 | |
| 413 | /** |
| 414 | Close called on BrokeredConnection. If this call |
| 415 | returns true then getRealConnection().close() will be called. |
| 416 | |
| 417 | Don't close the underlying real connection as |
| 418 | it is pooled. |
| 419 | */ |
| 420 | public boolean closingConnection() throws SQLException { |
| 421 | notifyClose(); |
| 422 | currentConnectionHandle = null; |
| 423 | return false; |
| 424 | } |
| 425 | |
| 426 | /** |
| 427 | No need to wrap statements for PooledConnections. |
| 428 | */ |
| 429 | public Statement wrapStatement(Statement s) throws SQLException { |
| 430 | return s; |
| 431 | } |
| 432 | /** |
| 433 | * Call the setBrokeredConnectionControl method inside the |
| 434 | * EmbedPreparedStatement class to set the BrokeredConnectionControl |
| 435 | * variable to this instance of EmbedPooledConnection |
| 436 | * This will then be used to call the onStatementErrorOccurred |
| 437 | * and onStatementClose events when the corresponding events |
| 438 | * occur on the PreparedStatement |
| 439 | * |
| 440 | * @param ps PreparedStatment to be wrapped |
| 441 | * @param sql String |
| 442 | * @param generatedKeys Object |
| 443 | * @return returns the wrapped PreparedStatement |
| 444 | * @throws java.sql.SQLException |
| 445 | */ |
| 446 | public PreparedStatement wrapStatement(PreparedStatement ps, String sql, Object generatedKeys) throws SQLException { |
| 447 | /* |
| 448 | |
| 449 | */ |
| 450 | EmbedPreparedStatement ps_ = (EmbedPreparedStatement)ps; |
| 451 | ps_.setBrokeredConnectionControl(this); |
| 452 | return (PreparedStatement)ps_; |
| 453 | } |
| 454 | |
| 455 | /** |
| 456 | * Call the setBrokeredConnectionControl method inside the |
| 457 | * EmbedCallableStatement class to set the BrokeredConnectionControl |
| 458 | * variable to this instance of EmbedPooledConnection |
| 459 | * This will then be used to call the onStatementErrorOccurred |
| 460 | * and onStatementClose events when the corresponding events |
| 461 | * occur on the CallableStatement |
| 462 | * |
| 463 | * @param cs CallableStatment to be wrapped |
| 464 | * @param sql String |
| 465 | * @return returns the wrapped CallableStatement |
| 466 | * @throws java.sql.SQLException |
| 467 | */ |
| 468 | public CallableStatement wrapStatement(CallableStatement cs, String sql) throws SQLException { |
| 469 | EmbedCallableStatement cs_ = (EmbedCallableStatement)cs; |
| 470 | cs_.setBrokeredConnectionControl(this); |
| 471 | return (CallableStatement)cs_; |
| 472 | } |
| 473 | |
| 474 | /** |
| 475 | * Get the string representation of this pooled connection. |
| 476 | * |
| 477 | * A pooled connection is assigned a separate id from a physical |
| 478 | * connection. When a container calls PooledConnection.toString(), |
| 479 | * it gets the string representation of this id. This is useful for |
| 480 | * developers implementing connection pools when they are trying to |
| 481 | * debug pooled connections. |
| 482 | * |
| 483 | * @return a string representation of the uniquie id for this pooled |
| 484 | * connection. |
| 485 | * |
| 486 | */ |
| 487 | public String toString() |
| 488 | { |
| 489 | if ( connString == null ) |
| 490 | { |
| 491 | String physicalConnString = isActive ? |
| 492 | realConnection.toString() : "<none>"; |
| 493 | |
| 494 | connString = |
| 495 | this.getClass().getName() + "@" + this.hashCode() + " " + |
| 496 | "(ID = " + connectionId + "), " + |
| 497 | "Physical Connection = " + physicalConnString; |
| 498 | } |
| 499 | |
| 500 | return connString; |
| 501 | } |
| 502 | |
| 503 | /*-----------------------------------------------------------------*/ |
| 504 | /* |
| 505 | * These methods are from the BrokeredConnectionControl interface. |
| 506 | * These methods are needed to provide StatementEvent support for |
| 507 | * derby. |
| 508 | * They are actually implemented in EmbedPooledConnection40 but have |
| 509 | * a dummy implementation here so that the compilation wont fail when they |
| 510 | * are compiled with jdk1.4 |
| 511 | */ |
| 512 | |
| 513 | /** |
| 514 | * Dummy implementation for the actual methods found in |
| 515 | * org.apache.derby.jdbc.EmbedPooledConnection40 |
| 516 | * @param statement PreparedStatement |
| 517 | */ |
| 518 | public void onStatementClose(PreparedStatement statement) { |
| 519 | |
| 520 | } |
| 521 | |
| 522 | /** |
| 523 | * Dummy implementation for the actual methods found in |
| 524 | * org.apache.derby.jdbc.EmbedPooledConnection40 |
| 525 | * @param statement PreparedStatement |
| 526 | * @param sqle SQLException |
| 527 | */ |
| 528 | public void onStatementErrorOccurred(PreparedStatement statement, |
| 529 | SQLException sqle) { |
| 530 | |
| 531 | } |
| 532 | } |