According to the c3p0 documentation, you can manually specify where logs should go, whether through JDK 1.4 logging, Log4j, or through System.out. I’m running SLF4J, so I’ve included org.slf4j.jul-to-slf4j and call SLF4JBridgeHandler.install() in my application to force all Java util logging to go through SLF4J. Additionally, I’ve included the following property in my c3p0.properties file:
com.mchange.v2.log.MLog = com.mchange.v2.log.jdk14logging.Jdk14MLog
This, according to the documentation, will force c3p0 to log to JDK 1.4 logging, which in turn will log things out to SLF4J. This does work somewhat, but I’m still seeing some logs hit System.err:
Example 1:
17:24:32.648 [main] INFO com.mchange.v2.log.MLog - MLog clients using java 1.4+ standard logging.
Jul 27, 2011 5:24:32 PM com.mchange.v2.log.MLog <clinit>
INFO: MLog clients using java 1.4+ standard logging.
Jul 27, 2011 5:24:32 PM com.mchange.v2.c3p0.C3P0Registry banner
INFO: Initializing c3p0-0.9.1.2 [built 21-May-2007 15:04:56; debug? true; trace: 10]
17:24:32.754 [main] INFO com.mchange.v2.c3p0.C3P0Registry - Initializing c3p0-0.9.1.2 [built 21-May-2007 15:04:56; debug? true; trace: 10]
Lines 1 and 6 above are written to SLF4J, the others are written to System.err.
Example 2:
Jul 27, 2011 5:24:33 PM 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 -> z8kflt8huk1hupkhyfms|13b33a0e, debugUnreturnedConnectionStackTraces -> false, description -> null, driverClass -> org.sqlite.JDBC, factoryClassLocation -> null, forceIgnoreUnresolvedTransactions -> false, identityToken -> z8kflt8huk1hupkhyfms|13b33a0e, idleConnectionTestPeriod -> 0, initialPoolSize -> 3, jdbcUrl -> jdbc:sqlite:/tmp/floodstream.db, maxAdministrativeTaskTime -> 0, maxConnectionAge -> 0, maxIdleTime -> 1800, maxIdleTimeExcessConnections -> 0, maxPoolSize -> 10, 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 ]
17:24:33.603 [main] INFO com.mchange.v2.c3p0.impl.AbstractPoolBackedDataSource - 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 -> z8kflt8huk1hupkhyfms|13b33a0e, debugUnreturnedConnectionStackTraces -> false, description -> null, driverClass -> org.sqlite.JDBC, factoryClassLocation -> null, forceIgnoreUnresolvedTransactions -> false, identityToken -> z8kflt8huk1hupkhyfms|13b33a0e, idleConnectionTestPeriod -> 0, initialPoolSize -> 3, jdbcUrl -> jdbc:sqlite:/tmp/floodstream.db, maxAdministrativeTaskTime -> 0, maxConnectionAge -> 0, maxIdleTime -> 1800, maxIdleTimeExcessConnections -> 0, maxPoolSize -> 10, 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 ]
The first two lines above are logged to System.err, which doesn’t make any sense at all, since it’s also logging to SLF4J as intended.
Is there a way for me to disable logging to System.err from c3p0?
I would suggest giving the log4j binding a try, and configuring c3p0 to use that.
java.util.logging is one of the more confusing things I’ve ever worked with.