1.在配置数据源的时候会报这么一个错误：
Loading class `com.mysql.jdbc.Driver'. This is deprecated. The new driver class is `com.mysql.cj.jdbc.Driver'. The driver is automatically registered via the SPI and manual loading of the driver class is generally unnecessary.
或者
The server time zone value '�й���ʱ��' is unrecognized or represents more than one time zone.
一般这两个错误是相互存在的，原因是：com.mysql.jdbc.Driver 是 mysql-connector-java 5中的，
com.mysql.cj.jdbc.Driver 是 mysql-connector-java 6中的，JDBC连接Mysql6 com.mysql.cj.jdbc.Driver， 需要指定时区serverTimezone：
