阿里巴巴数据源Druid使用时报discard connection异常，为什么

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2014-11-06 22:36:28,537 ERROR [com.alibaba.druid.pool.DruidDataSource] - discard connection
com.mysql.jdbc.CommunicationsException: The last communications with the server was 28816 seconds ago, which is longer than the server configured value of 'wait_timeout'余洞. You should consider either expiring and/吵伏or testing connection validity before use in your application, increasing the server configured values for client timeouts, or using the Connector/J connection property 'autoReconnect=true' to avoid this problem.

配升毁携置了testWhileIdle=true，validationQuery=SELECT 'x'

timeBetweenEvictionRunsMillis=60000

minEvictableIdleTimeMillis=300000

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