#40 c3p0 does not find drivers on Tomcat

[Mauno Ryytty]

URL=jdbc:mysql://192.168.1.13
11.12.2006 22:30:52 com.mchange.v2.c3p0.impl.AbstractPoolBackedDataSource getPoolManager
INFO: Initializing c3p0 pool... com.mchange.v2.c3p0.ComboPooledDataSource [ acquireIncrement -> 3, acquireRetryAttempts -> 30, acquireRetryDelay -> 1000, autoCommitOnClose -> false, automaticTestTable -> null, breakAfterAcquireFailure -> false, checkoutTimeout -> 0, connectionCustomizerClassName -> null, connectionTesterClassName -> com.mchange.v2.c3p0.impl.DefaultConnectionTester, dataSourceName -> 1hge1b57jvyt2su1ja8bzn|df83e5, debugUnreturnedConnectionStackTraces -> false, description -> null, driverClass -> com.mysql.jdbc.Driver, factoryClassLocation -> null, forceIgnoreUnresolvedTransactions -> false, identityToken -> 1hge1b57jvyt2su1ja8bzn|df83e5, idleConnectionTestPeriod -> 0, initialPoolSize -> 3, jdbcUrl -> jdbc:mysql://192.168.1.13, maxAdministrativeTaskTime -> 0, maxConnectionAge -> 0, maxIdleTime -> 0, maxIdleTimeExcessConnections -> 0, maxPoolSize -> 15, maxStatements -> 0, maxStatementsPerConnection -> 0, minPoolSize -> 3, numHelperThreads -> 3, numThreadsAwaitingCheckoutDefaultUser -> 0, preferredTestQuery -> null, properties -> {user=******, password=******}, propertyCycle -> 0, testConnectionOnCheckin -> false, testConnectionOnCheckout -> false, unreturnedConnectionTimeout -> 0, usesTraditionalReflectiveProxies -> false ]
11.12.2006 22:31:21 com.mchange.v2.resourcepool.BasicResourcePool$AcquireTask run
WARNING: com.mchange.v2.resourcepool.BasicResourcePool$AcquireTask@182c132 -- Acquisition Attempt Failed!!! Clearing pending acquires. While trying to acquire a needed new resource, we failed to succeed more than the maximum number of allowed acquisition attempts (30). Last acquisition attempt exception:
java.sql.SQLException: No suitable driver
at java.sql.DriverManager.getDriver(Unknown Source)
at com.mchange.v2.c3p0.DriverManagerDataSource.driver(DriverManagerDataSource.java:224)
at com.mchange.v2.c3p0.DriverManagerDataSource.getConnection(DriverManagerDataSource.java:135)
at com.mchange.v2.c3p0.WrapperConnectionPoolDataSource.getPooledConnection(WrapperConnectionPoolDataSource.java:182)
at com.mchange.v2.c3p0.WrapperConnectionPoolDataSource.getPooledConnection(WrapperConnectionPoolDataSource.java:171)
at com.mchange.v2.c3p0.impl.C3P0PooledConnectionPool$1PooledConnectionResourcePoolManager.acquireResource(C3P0PooledConnectionPool.java:135)
at com.mchange.v2.resourcepool.BasicResourcePool.doAcquire(BasicResourcePool.java:978)
at com.mchange.v2.resourcepool.BasicResourcePool.access$800(BasicResourcePool.java:32)
at com.mchange.v2.resourcepool.BasicResourcePool$AcquireTask.run(BasicResourcePool.java:1774)
at com.mchange.v2.async.ThreadPoolAsynchronousRunner$PoolThread.run(ThreadPoolAsynchronousRunner.java:547)

[Steve Waldman]

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Hi. So this is a question of where you put the c3p0 library code vs where you put the drivers... Tomcat uses several different classloaders, and it's possible that c3p0 cannot load some code that your web app can load. I expect to add some sort of API that would let apps register classloaders and/or classes to help c3p0 find resources it will be asked to load that may not be visible using the ClassLoader that loaded c3p0, but this will have to wait for c3p0-0.9.2. In the meantime, work around this by making sure that drivers and other classes c3p0 may need are located in the same directory on Tomcat.

Good luck!