jfinal中c3p0断开连接?报错

@红薯 你好，想跟你请教个问题：你好，我在jfinal中写了一个定时器，mysql数据库，请教哈为何总报错啊？Exception in thread "Timer-3" com.jfinal.plugin.activerecord.ActiveRecordException: java.sql.SQLException: com.mchange.v2.c3p0.ComboPooledDataSource [ java.beans.IntrospectionException: java.lang.reflect.InvocationTargetException [numThreadsAwaitingCheckoutDefaultUser] ] has been closed() -- you can no longer use it.
    at com.jfinal.plugin.activerecord.Model.find(Model.java:424)
    at com.jfinal.plugin.activerecord.Model.findFirst(Model.java:462)
    at com.hikvision.sys.config.ParaConfigService.findByKey(ParaConfigService.java:28)
    at com.hikvision.sys.config.ParaConfigService.getValueByKey(ParaConfigService.java:36)
    at com.hikvision.recordTemplate.TimeComputer.getRateFromDb(TimeComputer.java:44)
    at com.hikvision.timer.TaskTimer$1.run(TaskTimer.java:63)
    at java.util.TimerThread.mainLoop(Unknown Source)
    at java.util.TimerThread.run(Unknown Source)
Caused by: java.sql.SQLException: com.mchange.v2.c3p0.ComboPooledDataSource [ java.beans.IntrospectionException: java.lang.reflect.InvocationTargetException [numThreadsAwaitingCheckoutDefaultUser] ] has been closed() -- you can no longer use it.
    at com.mchange.v2.c3p0.impl.AbstractPoolBackedDataSource.assertCpds(AbstractPoolBackedDataSource.java:447)
    at com.mchange.v2.c3p0.impl.AbstractPoolBackedDataSource.getPoolManager(AbstractPoolBackedDataSource.java:459)
    at com.mchange.v2.c3p0.impl.AbstractPoolBackedDataSource.getConnection(AbstractPoolBackedDataSource.java:128)
    at com.jfinal.plugin.activerecord.DbKit.getConnection(DbKit.java:129)
    at com.jfinal.plugin.activerecord.Model.find(Model.java:421)
    ... 7 more