c3p0 不断的输出debug错误信息

在网上查了一些资料，这是c3p0连接管理为检测连接目标是否可连接的测试输出信息，可以忽略掉，把log4j的级别设为DEBUG就会输出，设为INFO以上就不会再输出了。

java.lang.Exception: DEBUG -- CLOSE BY CLIENT STACK TRACE

at com.mchange.v2.c3p0.impl.NewPooledConnection.close(NewPooledConnection.java:566)

at com.mchange.v2.c3p0.impl.NewPooledConnection.close(NewPooledConnection.java:234)

at com.mchange.v2.c3p0.impl.C3P0PooledConnectionPool$1PooledConnectionResourcePoolManager.destroyResource(C3P0PooledConnectionPool.java:470)

at com.mchange.v2.resourcepool.BasicResourcePool$1DestroyResourceTask.run(BasicResourcePool.java:964)

at com.mchange.v2.async.ThreadPoolAsynchronousRunner$PoolThread.run(ThreadPoolAsynchronousRunner.java:547)

08:35:28,668 DEBUG C3P0PooledConnectionPool:476 - Successfully destroyed PooledConnection: com.mchange.v2.c3p0.impl.NewPooledConnection@1f36445

08:35:28,669 DEBUG BasicResourcePool:967 - Successfully destroyed resource: com.mchange.v2.c3p0.impl.NewPooledConnection@1f36445

08:35:28,662 DEBUG NewPooledConnection:566 - com.mchange.v2.c3p0.impl.NewPooledConnection@121484b closed by a client.