C3P0 java.lang.Exception: DEBUG -- CLOSE BY CLIENT STACK TRACE

本文介绍 C3P0 数据库连接池中关于 DEBUG--CLOSEBYCLIENTSTACKTRACE 的日志信息含义及其输出条件。该日志主要用于检测连接目标的可连接性，在 log4j 的级别设置为 DEBUG 时会输出此信息。

关于CLOSE BY CLIENT STACK TRACE

url：http://blog.youkuaiyun.com/hallelujah_chen/article/details/6016132

由一个DEBUG说开去

url：http://hi.baidu.com/xhr8334/item/7e5a6f5326aa02d5d48bacca

C3P0 DEBUG -- CLOSE BY CLIENT STACK TRACE

url： http://blog.youkuaiyun.com/greensurfer/article/details/7496283

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.