myBatis连接MySQL报异常：No operations allowed after connection closed.Connection was implicitly closed

### Error querying database. Cause: com.mysql.jdbc.exceptions.jdbc4.MySQLNonTransientConnectionException: No operations allowed after connection closed.

网上查了下，由于使用了默认配置，空闲超过8小时，自动断开该连接

我使用的是mybatis的默认连接池，于是把该配的，都配置上。datasource的属性，可参考mybatis官方文档

        <environment id="env_stg">
            <transactionManager type="JDBC" />
            <dataSource type="POOLED">
                <property name="driver" value="${driver}" />
                <property name="url" value="${url_stg}" />
                <property name="username" value="${username}" />
                <property name="password" value="${password}" />
                <property name="poolMaximumActiveConnections" value="20"/>
                <property name="poolMaximumIdleConnections" value="5"/>
                <!-- MySQLNonTransientConnectionException: No operations allowed after connection closed -->
                <property name="poolPingQuery" value="select 1"/>
                <property name="poolPingEnabled" value="true"/>
                <!-- 对于空闲的连接一个小时检查一次 -->
                <property name="poolPingConnectionsNotUsedFor" value="3600000"/>
            </dataSource>
        </environment>

参考：http://fengbin2005.iteye.com/blog/1906488