| 1 | /* |
| 2 | Copyright (C) 2004 MySQL AB |
| 3 | |
| 4 | This program is free software; you can redistribute it and/or modify |
| 5 | it under the terms of version 2 of the GNU General Public License as |
| 6 | published by the Free Software Foundation. |
| 7 | |
| 8 | There are special exceptions to the terms and conditions of the GPL |
| 9 | as it is applied to this software. View the full text of the |
| 10 | exception in file EXCEPTIONS-CONNECTOR-J in the directory of this |
| 11 | software distribution. |
| 12 | |
| 13 | This program is distributed in the hope that it will be useful, |
| 14 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 15 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 16 | GNU General Public License for more details. |
| 17 | |
| 18 | You should have received a copy of the GNU General Public License |
| 19 | along with this program; if not, write to the Free Software |
| 20 | Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA |
| 21 | */ |
| 22 | package com.mysql.jdbc; |
| 23 | |
| 24 | import java.sql.CallableStatement; |
| 25 | import java.sql.DatabaseMetaData; |
| 26 | import java.sql.PreparedStatement; |
| 27 | import java.sql.SQLException; |
| 28 | import java.sql.SQLWarning; |
| 29 | import java.sql.Savepoint; |
| 30 | import java.sql.Statement; |
| 31 | import java.util.Map; |
| 32 | import java.util.Properties; |
| 33 | |
| 34 | /** |
| 35 | * Connection that opens two connections, one two a replication master, and |
| 36 | * another to one or more slaves, and decides to use master when the connection |
| 37 | * is not read-only, and use slave(s) when the connection is read-only. |
| 38 | * |
| 39 | * @version $Id: ReplicationConnection.java,v 1.1.2.1 2005/05/13 18:58:38 |
| 40 | * mmatthews Exp $ |
| 41 | */ |
| 42 | public class ReplicationConnection implements java.sql.Connection { |
| 43 | private Connection currentConnection; |
| 44 | |
| 45 | private Connection masterConnection; |
| 46 | |
| 47 | private Connection slavesConnection; |
| 48 | |
| 49 | public ReplicationConnection(Properties masterProperties, |
| 50 | Properties slaveProperties) throws SQLException { |
| 51 | Driver driver = new Driver(); |
| 52 | |
| 53 | this.masterConnection = (com.mysql.jdbc.Connection) driver.connect( |
| 54 | "jdbc:mysql:///", masterProperties); |
| 55 | this.slavesConnection = (com.mysql.jdbc.Connection) driver.connect( |
| 56 | "jdbc:mysql:///", slaveProperties); |
| 57 | this.currentConnection = this.masterConnection; |
| 58 | } |
| 59 | |
| 60 | /* |
| 61 | * (non-Javadoc) |
| 62 | * |
| 63 | * @see java.sql.Connection#clearWarnings() |
| 64 | */ |
| 65 | public synchronized void clearWarnings() throws SQLException { |
| 66 | this.currentConnection.clearWarnings(); |
| 67 | } |
| 68 | |
| 69 | /* |
| 70 | * (non-Javadoc) |
| 71 | * |
| 72 | * @see java.sql.Connection#close() |
| 73 | */ |
| 74 | public synchronized void close() throws SQLException { |
| 75 | this.masterConnection.close(); |
| 76 | this.slavesConnection.close(); |
| 77 | } |
| 78 | |
| 79 | /* |
| 80 | * (non-Javadoc) |
| 81 | * |
| 82 | * @see java.sql.Connection#commit() |
| 83 | */ |
| 84 | public synchronized void commit() throws SQLException { |
| 85 | this.currentConnection.commit(); |
| 86 | } |
| 87 | |
| 88 | /* |
| 89 | * (non-Javadoc) |
| 90 | * |
| 91 | * @see java.sql.Connection#createStatement() |
| 92 | */ |
| 93 | public Statement createStatement() throws SQLException { |
| 94 | return this.currentConnection.createStatement(); |
| 95 | } |
| 96 | |
| 97 | /* |
| 98 | * (non-Javadoc) |
| 99 | * |
| 100 | * @see java.sql.Connection#createStatement(int, int) |
| 101 | */ |
| 102 | public synchronized Statement createStatement(int resultSetType, |
| 103 | int resultSetConcurrency) throws SQLException { |
| 104 | return this.currentConnection.createStatement(resultSetType, |
| 105 | resultSetConcurrency); |
| 106 | } |
| 107 | |
| 108 | /* |
| 109 | * (non-Javadoc) |
| 110 | * |
| 111 | * @see java.sql.Connection#createStatement(int, int, int) |
| 112 | */ |
| 113 | public synchronized Statement createStatement(int resultSetType, |
| 114 | int resultSetConcurrency, int resultSetHoldability) |
| 115 | throws SQLException { |
| 116 | return this.currentConnection.createStatement(resultSetType, |
| 117 | resultSetConcurrency, resultSetHoldability); |
| 118 | } |
| 119 | |
| 120 | /* |
| 121 | * (non-Javadoc) |
| 122 | * |
| 123 | * @see java.sql.Connection#getAutoCommit() |
| 124 | */ |
| 125 | public synchronized boolean getAutoCommit() throws SQLException { |
| 126 | return this.currentConnection.getAutoCommit(); |
| 127 | } |
| 128 | |
| 129 | /* |
| 130 | * (non-Javadoc) |
| 131 | * |
| 132 | * @see java.sql.Connection#getCatalog() |
| 133 | */ |
| 134 | public synchronized String getCatalog() throws SQLException { |
| 135 | return this.currentConnection.getCatalog(); |
| 136 | } |
| 137 | |
| 138 | public synchronized Connection getCurrentConnection() { |
| 139 | return this.currentConnection; |
| 140 | } |
| 141 | |
| 142 | /* |
| 143 | * (non-Javadoc) |
| 144 | * |
| 145 | * @see java.sql.Connection#getHoldability() |
| 146 | */ |
| 147 | public synchronized int getHoldability() throws SQLException { |
| 148 | return this.currentConnection.getHoldability(); |
| 149 | } |
| 150 | |
| 151 | public synchronized Connection getMasterConnection() { |
| 152 | return this.masterConnection; |
| 153 | } |
| 154 | |
| 155 | /* |
| 156 | * (non-Javadoc) |
| 157 | * |
| 158 | * @see java.sql.Connection#getMetaData() |
| 159 | */ |
| 160 | public synchronized DatabaseMetaData getMetaData() throws SQLException { |
| 161 | return this.currentConnection.getMetaData(); |
| 162 | } |
| 163 | |
| 164 | public synchronized Connection getSlavesConnection() { |
| 165 | return this.slavesConnection; |
| 166 | } |
| 167 | |
| 168 | /* |
| 169 | * (non-Javadoc) |
| 170 | * |
| 171 | * @see java.sql.Connection#getTransactionIsolation() |
| 172 | */ |
| 173 | public synchronized int getTransactionIsolation() throws SQLException { |
| 174 | return this.currentConnection.getTransactionIsolation(); |
| 175 | } |
| 176 | |
| 177 | /* |
| 178 | * (non-Javadoc) |
| 179 | * |
| 180 | * @see java.sql.Connection#getTypeMap() |
| 181 | */ |
| 182 | public synchronized Map getTypeMap() throws SQLException { |
| 183 | return this.currentConnection.getTypeMap(); |
| 184 | } |
| 185 | |
| 186 | /* |
| 187 | * (non-Javadoc) |
| 188 | * |
| 189 | * @see java.sql.Connection#getWarnings() |
| 190 | */ |
| 191 | public synchronized SQLWarning getWarnings() throws SQLException { |
| 192 | return this.currentConnection.getWarnings(); |
| 193 | } |
| 194 | |
| 195 | /* |
| 196 | * (non-Javadoc) |
| 197 | * |
| 198 | * @see java.sql.Connection#isClosed() |
| 199 | */ |
| 200 | public synchronized boolean isClosed() throws SQLException { |
| 201 | return this.currentConnection.isClosed(); |
| 202 | } |
| 203 | |
| 204 | /* |
| 205 | * (non-Javadoc) |
| 206 | * |
| 207 | * @see java.sql.Connection#isReadOnly() |
| 208 | */ |
| 209 | public synchronized boolean isReadOnly() throws SQLException { |
| 210 | return this.currentConnection == this.slavesConnection; |
| 211 | } |
| 212 | |
| 213 | /* |
| 214 | * (non-Javadoc) |
| 215 | * |
| 216 | * @see java.sql.Connection#nativeSQL(java.lang.String) |
| 217 | */ |
| 218 | public synchronized String nativeSQL(String sql) throws SQLException { |
| 219 | return this.currentConnection.nativeSQL(sql); |
| 220 | } |
| 221 | |
| 222 | /* |
| 223 | * (non-Javadoc) |
| 224 | * |
| 225 | * @see java.sql.Connection#prepareCall(java.lang.String) |
| 226 | */ |
| 227 | public CallableStatement prepareCall(String sql) throws SQLException { |
| 228 | return this.currentConnection.prepareCall(sql); |
| 229 | } |
| 230 | |
| 231 | /* |
| 232 | * (non-Javadoc) |
| 233 | * |
| 234 | * @see java.sql.Connection#prepareCall(java.lang.String, int, int) |
| 235 | */ |
| 236 | public synchronized CallableStatement prepareCall(String sql, |
| 237 | int resultSetType, int resultSetConcurrency) throws SQLException { |
| 238 | return this.currentConnection.prepareCall(sql, resultSetType, |
| 239 | resultSetConcurrency); |
| 240 | } |
| 241 | |
| 242 | /* |
| 243 | * (non-Javadoc) |
| 244 | * |
| 245 | * @see java.sql.Connection#prepareCall(java.lang.String, int, int, int) |
| 246 | */ |
| 247 | public synchronized CallableStatement prepareCall(String sql, |
| 248 | int resultSetType, int resultSetConcurrency, |
| 249 | int resultSetHoldability) throws SQLException { |
| 250 | return this.currentConnection.prepareCall(sql, resultSetType, |
| 251 | resultSetConcurrency, resultSetHoldability); |
| 252 | } |
| 253 | |
| 254 | /* |
| 255 | * (non-Javadoc) |
| 256 | * |
| 257 | * @see java.sql.Connection#prepareStatement(java.lang.String) |
| 258 | */ |
| 259 | public PreparedStatement prepareStatement(String sql) throws SQLException { |
| 260 | return this.currentConnection.prepareStatement(sql); |
| 261 | } |
| 262 | |
| 263 | /* |
| 264 | * (non-Javadoc) |
| 265 | * |
| 266 | * @see java.sql.Connection#prepareStatement(java.lang.String, int) |
| 267 | */ |
| 268 | public synchronized PreparedStatement prepareStatement(String sql, |
| 269 | int autoGeneratedKeys) throws SQLException { |
| 270 | return this.currentConnection.prepareStatement(sql, autoGeneratedKeys); |
| 271 | } |
| 272 | |
| 273 | /* |
| 274 | * (non-Javadoc) |
| 275 | * |
| 276 | * @see java.sql.Connection#prepareStatement(java.lang.String, int, int) |
| 277 | */ |
| 278 | public synchronized PreparedStatement prepareStatement(String sql, |
| 279 | int resultSetType, int resultSetConcurrency) throws SQLException { |
| 280 | return this.currentConnection.prepareStatement(sql, resultSetType, |
| 281 | resultSetConcurrency); |
| 282 | } |
| 283 | |
| 284 | /* |
| 285 | * (non-Javadoc) |
| 286 | * |
| 287 | * @see java.sql.Connection#prepareStatement(java.lang.String, int, int, |
| 288 | * int) |
| 289 | */ |
| 290 | public synchronized PreparedStatement prepareStatement(String sql, |
| 291 | int resultSetType, int resultSetConcurrency, |
| 292 | int resultSetHoldability) throws SQLException { |
| 293 | return this.currentConnection.prepareStatement(sql, resultSetType, |
| 294 | resultSetConcurrency, resultSetHoldability); |
| 295 | } |
| 296 | |
| 297 | /* |
| 298 | * (non-Javadoc) |
| 299 | * |
| 300 | * @see java.sql.Connection#prepareStatement(java.lang.String, int[]) |
| 301 | */ |
| 302 | public synchronized PreparedStatement prepareStatement(String sql, |
| 303 | int[] columnIndexes) throws SQLException { |
| 304 | return this.currentConnection.prepareStatement(sql, columnIndexes); |
| 305 | } |
| 306 | |
| 307 | /* |
| 308 | * (non-Javadoc) |
| 309 | * |
| 310 | * @see java.sql.Connection#prepareStatement(java.lang.String, |
| 311 | * java.lang.String[]) |
| 312 | */ |
| 313 | public synchronized PreparedStatement prepareStatement(String sql, |
| 314 | String[] columnNames) throws SQLException { |
| 315 | return this.currentConnection.prepareStatement(sql, columnNames); |
| 316 | } |
| 317 | |
| 318 | /* |
| 319 | * (non-Javadoc) |
| 320 | * |
| 321 | * @see java.sql.Connection#releaseSavepoint(java.sql.Savepoint) |
| 322 | */ |
| 323 | public synchronized void releaseSavepoint(Savepoint savepoint) |
| 324 | throws SQLException { |
| 325 | this.currentConnection.releaseSavepoint(savepoint); |
| 326 | } |
| 327 | |
| 328 | /* |
| 329 | * (non-Javadoc) |
| 330 | * |
| 331 | * @see java.sql.Connection#rollback() |
| 332 | */ |
| 333 | public synchronized void rollback() throws SQLException { |
| 334 | this.currentConnection.rollback(); |
| 335 | } |
| 336 | |
| 337 | /* |
| 338 | * (non-Javadoc) |
| 339 | * |
| 340 | * @see java.sql.Connection#rollback(java.sql.Savepoint) |
| 341 | */ |
| 342 | public synchronized void rollback(Savepoint savepoint) throws SQLException { |
| 343 | this.currentConnection.rollback(savepoint); |
| 344 | } |
| 345 | |
| 346 | /* |
| 347 | * (non-Javadoc) |
| 348 | * |
| 349 | * @see java.sql.Connection#setAutoCommit(boolean) |
| 350 | */ |
| 351 | public synchronized void setAutoCommit(boolean autoCommit) |
| 352 | throws SQLException { |
| 353 | this.currentConnection.setAutoCommit(autoCommit); |
| 354 | } |
| 355 | |
| 356 | /* |
| 357 | * (non-Javadoc) |
| 358 | * |
| 359 | * @see java.sql.Connection#setCatalog(java.lang.String) |
| 360 | */ |
| 361 | public synchronized void setCatalog(String catalog) throws SQLException { |
| 362 | this.currentConnection.setCatalog(catalog); |
| 363 | } |
| 364 | |
| 365 | /* |
| 366 | * (non-Javadoc) |
| 367 | * |
| 368 | * @see java.sql.Connection#setHoldability(int) |
| 369 | */ |
| 370 | public synchronized void setHoldability(int holdability) |
| 371 | throws SQLException { |
| 372 | this.currentConnection.setHoldability(holdability); |
| 373 | } |
| 374 | |
| 375 | /* |
| 376 | * (non-Javadoc) |
| 377 | * |
| 378 | * @see java.sql.Connection#setReadOnly(boolean) |
| 379 | */ |
| 380 | public synchronized void setReadOnly(boolean readOnly) throws SQLException { |
| 381 | if (readOnly) { |
| 382 | if (currentConnection != slavesConnection) { |
| 383 | switchToSlavesConnection(); |
| 384 | } |
| 385 | } else { |
| 386 | if (currentConnection != masterConnection) { |
| 387 | switchToMasterConnection(); |
| 388 | } |
| 389 | } |
| 390 | } |
| 391 | |
| 392 | /* |
| 393 | * (non-Javadoc) |
| 394 | * |
| 395 | * @see java.sql.Connection#setSavepoint() |
| 396 | */ |
| 397 | public synchronized Savepoint setSavepoint() throws SQLException { |
| 398 | return this.currentConnection.setSavepoint(); |
| 399 | } |
| 400 | |
| 401 | /* |
| 402 | * (non-Javadoc) |
| 403 | * |
| 404 | * @see java.sql.Connection#setSavepoint(java.lang.String) |
| 405 | */ |
| 406 | public synchronized Savepoint setSavepoint(String name) throws SQLException { |
| 407 | return this.currentConnection.setSavepoint(name); |
| 408 | } |
| 409 | |
| 410 | /* |
| 411 | * (non-Javadoc) |
| 412 | * |
| 413 | * @see java.sql.Connection#setTransactionIsolation(int) |
| 414 | */ |
| 415 | public synchronized void setTransactionIsolation(int level) |
| 416 | throws SQLException { |
| 417 | this.currentConnection.setTransactionIsolation(level); |
| 418 | } |
| 419 | |
| 420 | // For testing |
| 421 | |
| 422 | /* |
| 423 | * (non-Javadoc) |
| 424 | * |
| 425 | * @see java.sql.Connection#setTypeMap(java.util.Map) |
| 426 | */ |
| 427 | public synchronized void setTypeMap(Map arg0) throws SQLException { |
| 428 | this.currentConnection.setTypeMap(arg0); |
| 429 | } |
| 430 | |
| 431 | private synchronized void switchToMasterConnection() throws SQLException { |
| 432 | swapConnections(this.masterConnection, this.slavesConnection); |
| 433 | } |
| 434 | |
| 435 | private synchronized void switchToSlavesConnection() throws SQLException { |
| 436 | swapConnections(this.slavesConnection, this.masterConnection); |
| 437 | } |
| 438 | |
| 439 | /** |
| 440 | * Swaps current context (catalog, autocommit and txn_isolation) from |
| 441 | * sourceConnection to targetConnection, and makes targetConnection |
| 442 | * the "current" connection that will be used for queries. |
| 443 | * |
| 444 | * @param sourceConnection the connection to swap from |
| 445 | * @param targetConnection the connection to swap to |
| 446 | * |
| 447 | * @throws SQLException if an error occurs |
| 448 | */ |
| 449 | private synchronized void swapConnections(Connection sourceConnection, |
| 450 | Connection targetConnection) throws SQLException { |
| 451 | String targetCatalog = targetConnection.getCatalog(); |
| 452 | String sourceCatalog = sourceConnection.getCatalog(); |
| 453 | |
| 454 | if (sourceCatalog != null && !sourceCatalog.equals(targetCatalog)) { |
| 455 | targetConnection.setCatalog(targetCatalog); |
| 456 | } else if (targetCatalog != null) { |
| 457 | targetConnection.setCatalog(targetCatalog); |
| 458 | } |
| 459 | |
| 460 | boolean sourceAutoCommit = sourceConnection.getAutoCommit(); |
| 461 | |
| 462 | if (targetConnection.getAutoCommit() != sourceAutoCommit) { |
| 463 | targetConnection.setAutoCommit(sourceAutoCommit); |
| 464 | } |
| 465 | |
| 466 | int sourceTransactionIsolation = sourceConnection |
| 467 | .getTransactionIsolation(); |
| 468 | |
| 469 | if (targetConnection.getTransactionIsolation() != sourceTransactionIsolation) { |
| 470 | targetConnection |
| 471 | .setTransactionIsolation(sourceTransactionIsolation); |
| 472 | } |
| 473 | |
| 474 | this.currentConnection = targetConnection; |
| 475 | } |
| 476 | } |