获取jdbc连接失败，加载数据库驱动失败， Failed to obtain JDBC Connection; nested exception is java.sql.SQLException:

 Caused by: org.springframework.jdbc.CannotGetJdbcConnectionException: Failed to obtain JDBC Connection; nested exception is java.sql.SQLException: Failed to validate a newly established connection. 

ERROR [ExceptionFilter] [DUBBO] Got unchecked and undeclared exception which called by 10.165.31.88

解决方案：

validationQuery: select 1 from dual

参考文章：

https://segmentfault.com/a/1190000006232823