学习c3p0数据库连接池的时候遇到的bug
java.sql.SQLException: An attempt by a client to checkout a Connection has timed out.

Caused by: com.mchange.v2.resourcepool.TimeoutException: A client timed out while waiting to acquire a resource from com.mchange.v2.resourcepool.BasicResourcePool@50675690 – timeout at awaitAvailable()