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 | } |