CentOS release 6.7 (Final)
java version "1.8.0_73"
druid:1.1.10
一段时间后，一个简单的查询，就会报以下堆栈。应用重启后恢复正常

Caused by: java.lang.NoClassDefFoundError: Could not initialize class java.sql.SQLException
at com.alibaba.druid.pool.DruidDataSource.handleConnectionException(DruidDataSource.java:1545)
at com.alibaba.druid.pool.DruidPooledConnection.handleException(DruidPooledConnection.java:133)
at com.alibaba.druid.pool.DruidPooledStatement.checkException(DruidPooledStatement.java:77)
at com.alibaba.druid.pool.DruidPooledPreparedStatement.execute(DruidPooledPreparedStatement.java:502)
at org.apache.ibatis.executor.statement.PreparedStatementHandler.query(PreparedStatementHandler.java:63)
at org.apache.ibatis.executor.statement.RoutingStatementHandler.query(RoutingStatementHandler.java:79)
at org.apache.ibatis.executor.SimpleExecutor.doQuery(SimpleExecutor.java:63)
at org.apache.ibatis.executor.BaseExecutor.queryFromDatabase(BaseExecutor.java:324)
at org.apache.ibatis.executor.BaseExecutor.query(BaseExecutor.java:156)